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 .unlocked_ioctl = ep_ioctl, 709 .read_iter = ep_read_iter, 710 .write_iter = ep_write_iter, 711 }; 712 713 /* ENDPOINT INITIALIZATION 714 * 715 * fd = open ("/dev/gadget/$ENDPOINT", O_RDWR) 716 * status = write (fd, descriptors, sizeof descriptors) 717 * 718 * That write establishes the endpoint configuration, configuring 719 * the controller to process bulk, interrupt, or isochronous transfers 720 * at the right maxpacket size, and so on. 721 * 722 * The descriptors are message type 1, identified by a host order u32 723 * at the beginning of what's written. Descriptor order is: full/low 724 * speed descriptor, then optional high speed descriptor. 725 */ 726 static ssize_t 727 ep_config (struct ep_data *data, const char *buf, size_t len) 728 { 729 struct usb_ep *ep; 730 u32 tag; 731 int value, length = len; 732 733 if (data->state != STATE_EP_READY) { 734 value = -EL2HLT; 735 goto fail; 736 } 737 738 value = len; 739 if (len < USB_DT_ENDPOINT_SIZE + 4) 740 goto fail0; 741 742 /* we might need to change message format someday */ 743 memcpy(&tag, buf, 4); 744 if (tag != 1) { 745 DBG(data->dev, "config %s, bad tag %d\n", data->name, tag); 746 goto fail0; 747 } 748 buf += 4; 749 len -= 4; 750 751 /* NOTE: audio endpoint extensions not accepted here; 752 * just don't include the extra bytes. 753 */ 754 755 /* full/low speed descriptor, then high speed */ 756 memcpy(&data->desc, buf, USB_DT_ENDPOINT_SIZE); 757 if (data->desc.bLength != USB_DT_ENDPOINT_SIZE 758 || data->desc.bDescriptorType != USB_DT_ENDPOINT) 759 goto fail0; 760 if (len != USB_DT_ENDPOINT_SIZE) { 761 if (len != 2 * USB_DT_ENDPOINT_SIZE) 762 goto fail0; 763 memcpy(&data->hs_desc, buf + USB_DT_ENDPOINT_SIZE, 764 USB_DT_ENDPOINT_SIZE); 765 if (data->hs_desc.bLength != USB_DT_ENDPOINT_SIZE 766 || data->hs_desc.bDescriptorType 767 != USB_DT_ENDPOINT) { 768 DBG(data->dev, "config %s, bad hs length or type\n", 769 data->name); 770 goto fail0; 771 } 772 } 773 774 spin_lock_irq (&data->dev->lock); 775 if (data->dev->state == STATE_DEV_UNBOUND) { 776 value = -ENOENT; 777 goto gone; 778 } else { 779 ep = data->ep; 780 if (ep == NULL) { 781 value = -ENODEV; 782 goto gone; 783 } 784 } 785 switch (data->dev->gadget->speed) { 786 case USB_SPEED_LOW: 787 case USB_SPEED_FULL: 788 ep->desc = &data->desc; 789 break; 790 case USB_SPEED_HIGH: 791 /* fails if caller didn't provide that descriptor... */ 792 ep->desc = &data->hs_desc; 793 break; 794 default: 795 DBG(data->dev, "unconnected, %s init abandoned\n", 796 data->name); 797 value = -EINVAL; 798 goto gone; 799 } 800 value = usb_ep_enable(ep); 801 if (value == 0) { 802 data->state = STATE_EP_ENABLED; 803 value = length; 804 } 805 gone: 806 spin_unlock_irq (&data->dev->lock); 807 if (value < 0) { 808 fail: 809 data->desc.bDescriptorType = 0; 810 data->hs_desc.bDescriptorType = 0; 811 } 812 return value; 813 fail0: 814 value = -EINVAL; 815 goto fail; 816 } 817 818 static int 819 ep_open (struct inode *inode, struct file *fd) 820 { 821 struct ep_data *data = inode->i_private; 822 int value = -EBUSY; 823 824 if (mutex_lock_interruptible(&data->lock) != 0) 825 return -EINTR; 826 spin_lock_irq (&data->dev->lock); 827 if (data->dev->state == STATE_DEV_UNBOUND) 828 value = -ENOENT; 829 else if (data->state == STATE_EP_DISABLED) { 830 value = 0; 831 data->state = STATE_EP_READY; 832 get_ep (data); 833 fd->private_data = data; 834 VDEBUG (data->dev, "%s ready\n", data->name); 835 } else 836 DBG (data->dev, "%s state %d\n", 837 data->name, data->state); 838 spin_unlock_irq (&data->dev->lock); 839 mutex_unlock(&data->lock); 840 return value; 841 } 842 843 /*----------------------------------------------------------------------*/ 844 845 /* EP0 IMPLEMENTATION can be partly in userspace. 846 * 847 * Drivers that use this facility receive various events, including 848 * control requests the kernel doesn't handle. Drivers that don't 849 * use this facility may be too simple-minded for real applications. 850 */ 851 852 static inline void ep0_readable (struct dev_data *dev) 853 { 854 wake_up (&dev->wait); 855 kill_fasync (&dev->fasync, SIGIO, POLL_IN); 856 } 857 858 static void clean_req (struct usb_ep *ep, struct usb_request *req) 859 { 860 struct dev_data *dev = ep->driver_data; 861 862 if (req->buf != dev->rbuf) { 863 kfree(req->buf); 864 req->buf = dev->rbuf; 865 } 866 req->complete = epio_complete; 867 dev->setup_out_ready = 0; 868 } 869 870 static void ep0_complete (struct usb_ep *ep, struct usb_request *req) 871 { 872 struct dev_data *dev = ep->driver_data; 873 unsigned long flags; 874 int free = 1; 875 876 /* for control OUT, data must still get to userspace */ 877 spin_lock_irqsave(&dev->lock, flags); 878 if (!dev->setup_in) { 879 dev->setup_out_error = (req->status != 0); 880 if (!dev->setup_out_error) 881 free = 0; 882 dev->setup_out_ready = 1; 883 ep0_readable (dev); 884 } 885 886 /* clean up as appropriate */ 887 if (free && req->buf != &dev->rbuf) 888 clean_req (ep, req); 889 req->complete = epio_complete; 890 spin_unlock_irqrestore(&dev->lock, flags); 891 } 892 893 static int setup_req (struct usb_ep *ep, struct usb_request *req, u16 len) 894 { 895 struct dev_data *dev = ep->driver_data; 896 897 if (dev->setup_out_ready) { 898 DBG (dev, "ep0 request busy!\n"); 899 return -EBUSY; 900 } 901 if (len > sizeof (dev->rbuf)) 902 req->buf = kmalloc(len, GFP_ATOMIC); 903 if (req->buf == NULL) { 904 req->buf = dev->rbuf; 905 return -ENOMEM; 906 } 907 req->complete = ep0_complete; 908 req->length = len; 909 req->zero = 0; 910 return 0; 911 } 912 913 static ssize_t 914 ep0_read (struct file *fd, char __user *buf, size_t len, loff_t *ptr) 915 { 916 struct dev_data *dev = fd->private_data; 917 ssize_t retval; 918 enum ep0_state state; 919 920 spin_lock_irq (&dev->lock); 921 if (dev->state <= STATE_DEV_OPENED) { 922 retval = -EINVAL; 923 goto done; 924 } 925 926 /* report fd mode change before acting on it */ 927 if (dev->setup_abort) { 928 dev->setup_abort = 0; 929 retval = -EIDRM; 930 goto done; 931 } 932 933 /* control DATA stage */ 934 if ((state = dev->state) == STATE_DEV_SETUP) { 935 936 if (dev->setup_in) { /* stall IN */ 937 VDEBUG(dev, "ep0in stall\n"); 938 (void) usb_ep_set_halt (dev->gadget->ep0); 939 retval = -EL2HLT; 940 dev->state = STATE_DEV_CONNECTED; 941 942 } else if (len == 0) { /* ack SET_CONFIGURATION etc */ 943 struct usb_ep *ep = dev->gadget->ep0; 944 struct usb_request *req = dev->req; 945 946 if ((retval = setup_req (ep, req, 0)) == 0) { 947 ++dev->udc_usage; 948 spin_unlock_irq (&dev->lock); 949 retval = usb_ep_queue (ep, req, GFP_KERNEL); 950 spin_lock_irq (&dev->lock); 951 --dev->udc_usage; 952 } 953 dev->state = STATE_DEV_CONNECTED; 954 955 /* assume that was SET_CONFIGURATION */ 956 if (dev->current_config) { 957 unsigned power; 958 959 if (gadget_is_dualspeed(dev->gadget) 960 && (dev->gadget->speed 961 == USB_SPEED_HIGH)) 962 power = dev->hs_config->bMaxPower; 963 else 964 power = dev->config->bMaxPower; 965 usb_gadget_vbus_draw(dev->gadget, 2 * power); 966 } 967 968 } else { /* collect OUT data */ 969 if ((fd->f_flags & O_NONBLOCK) != 0 970 && !dev->setup_out_ready) { 971 retval = -EAGAIN; 972 goto done; 973 } 974 spin_unlock_irq (&dev->lock); 975 retval = wait_event_interruptible (dev->wait, 976 dev->setup_out_ready != 0); 977 978 /* FIXME state could change from under us */ 979 spin_lock_irq (&dev->lock); 980 if (retval) 981 goto done; 982 983 if (dev->state != STATE_DEV_SETUP) { 984 retval = -ECANCELED; 985 goto done; 986 } 987 dev->state = STATE_DEV_CONNECTED; 988 989 if (dev->setup_out_error) 990 retval = -EIO; 991 else { 992 len = min (len, (size_t)dev->req->actual); 993 ++dev->udc_usage; 994 spin_unlock_irq(&dev->lock); 995 if (copy_to_user (buf, dev->req->buf, len)) 996 retval = -EFAULT; 997 else 998 retval = len; 999 spin_lock_irq(&dev->lock); 1000 --dev->udc_usage; 1001 clean_req (dev->gadget->ep0, dev->req); 1002 /* NOTE userspace can't yet choose to stall */ 1003 } 1004 } 1005 goto done; 1006 } 1007 1008 /* else normal: return event data */ 1009 if (len < sizeof dev->event [0]) { 1010 retval = -EINVAL; 1011 goto done; 1012 } 1013 len -= len % sizeof (struct usb_gadgetfs_event); 1014 dev->usermode_setup = 1; 1015 1016 scan: 1017 /* return queued events right away */ 1018 if (dev->ev_next != 0) { 1019 unsigned i, n; 1020 1021 n = len / sizeof (struct usb_gadgetfs_event); 1022 if (dev->ev_next < n) 1023 n = dev->ev_next; 1024 1025 /* ep0 i/o has special semantics during STATE_DEV_SETUP */ 1026 for (i = 0; i < n; i++) { 1027 if (dev->event [i].type == GADGETFS_SETUP) { 1028 dev->state = STATE_DEV_SETUP; 1029 n = i + 1; 1030 break; 1031 } 1032 } 1033 spin_unlock_irq (&dev->lock); 1034 len = n * sizeof (struct usb_gadgetfs_event); 1035 if (copy_to_user (buf, &dev->event, len)) 1036 retval = -EFAULT; 1037 else 1038 retval = len; 1039 if (len > 0) { 1040 /* NOTE this doesn't guard against broken drivers; 1041 * concurrent ep0 readers may lose events. 1042 */ 1043 spin_lock_irq (&dev->lock); 1044 if (dev->ev_next > n) { 1045 memmove(&dev->event[0], &dev->event[n], 1046 sizeof (struct usb_gadgetfs_event) 1047 * (dev->ev_next - n)); 1048 } 1049 dev->ev_next -= n; 1050 spin_unlock_irq (&dev->lock); 1051 } 1052 return retval; 1053 } 1054 if (fd->f_flags & O_NONBLOCK) { 1055 retval = -EAGAIN; 1056 goto done; 1057 } 1058 1059 switch (state) { 1060 default: 1061 DBG (dev, "fail %s, state %d\n", __func__, state); 1062 retval = -ESRCH; 1063 break; 1064 case STATE_DEV_UNCONNECTED: 1065 case STATE_DEV_CONNECTED: 1066 spin_unlock_irq (&dev->lock); 1067 DBG (dev, "%s wait\n", __func__); 1068 1069 /* wait for events */ 1070 retval = wait_event_interruptible (dev->wait, 1071 dev->ev_next != 0); 1072 if (retval < 0) 1073 return retval; 1074 spin_lock_irq (&dev->lock); 1075 goto scan; 1076 } 1077 1078 done: 1079 spin_unlock_irq (&dev->lock); 1080 return retval; 1081 } 1082 1083 static struct usb_gadgetfs_event * 1084 next_event (struct dev_data *dev, enum usb_gadgetfs_event_type type) 1085 { 1086 struct usb_gadgetfs_event *event; 1087 unsigned i; 1088 1089 switch (type) { 1090 /* these events purge the queue */ 1091 case GADGETFS_DISCONNECT: 1092 if (dev->state == STATE_DEV_SETUP) 1093 dev->setup_abort = 1; 1094 fallthrough; 1095 case GADGETFS_CONNECT: 1096 dev->ev_next = 0; 1097 break; 1098 case GADGETFS_SETUP: /* previous request timed out */ 1099 case GADGETFS_SUSPEND: /* same effect */ 1100 /* these events can't be repeated */ 1101 for (i = 0; i != dev->ev_next; i++) { 1102 if (dev->event [i].type != type) 1103 continue; 1104 DBG(dev, "discard old event[%d] %d\n", i, type); 1105 dev->ev_next--; 1106 if (i == dev->ev_next) 1107 break; 1108 /* indices start at zero, for simplicity */ 1109 memmove (&dev->event [i], &dev->event [i + 1], 1110 sizeof (struct usb_gadgetfs_event) 1111 * (dev->ev_next - i)); 1112 } 1113 break; 1114 default: 1115 BUG (); 1116 } 1117 VDEBUG(dev, "event[%d] = %d\n", dev->ev_next, type); 1118 event = &dev->event [dev->ev_next++]; 1119 BUG_ON (dev->ev_next > N_EVENT); 1120 memset (event, 0, sizeof *event); 1121 event->type = type; 1122 return event; 1123 } 1124 1125 static ssize_t 1126 ep0_write (struct file *fd, const char __user *buf, size_t len, loff_t *ptr) 1127 { 1128 struct dev_data *dev = fd->private_data; 1129 ssize_t retval = -ESRCH; 1130 1131 /* report fd mode change before acting on it */ 1132 if (dev->setup_abort) { 1133 dev->setup_abort = 0; 1134 retval = -EIDRM; 1135 1136 /* data and/or status stage for control request */ 1137 } else if (dev->state == STATE_DEV_SETUP) { 1138 1139 len = min_t(size_t, len, dev->setup_wLength); 1140 if (dev->setup_in) { 1141 retval = setup_req (dev->gadget->ep0, dev->req, len); 1142 if (retval == 0) { 1143 dev->state = STATE_DEV_CONNECTED; 1144 ++dev->udc_usage; 1145 spin_unlock_irq (&dev->lock); 1146 if (copy_from_user (dev->req->buf, buf, len)) 1147 retval = -EFAULT; 1148 else { 1149 if (len < dev->setup_wLength) 1150 dev->req->zero = 1; 1151 retval = usb_ep_queue ( 1152 dev->gadget->ep0, dev->req, 1153 GFP_KERNEL); 1154 } 1155 spin_lock_irq(&dev->lock); 1156 --dev->udc_usage; 1157 if (retval < 0) { 1158 clean_req (dev->gadget->ep0, dev->req); 1159 } else 1160 retval = len; 1161 1162 return retval; 1163 } 1164 1165 /* can stall some OUT transfers */ 1166 } else if (dev->setup_can_stall) { 1167 VDEBUG(dev, "ep0out stall\n"); 1168 (void) usb_ep_set_halt (dev->gadget->ep0); 1169 retval = -EL2HLT; 1170 dev->state = STATE_DEV_CONNECTED; 1171 } else { 1172 DBG(dev, "bogus ep0out stall!\n"); 1173 } 1174 } else 1175 DBG (dev, "fail %s, state %d\n", __func__, dev->state); 1176 1177 return retval; 1178 } 1179 1180 static int 1181 ep0_fasync (int f, struct file *fd, int on) 1182 { 1183 struct dev_data *dev = fd->private_data; 1184 // caller must F_SETOWN before signal delivery happens 1185 VDEBUG (dev, "%s %s\n", __func__, on ? "on" : "off"); 1186 return fasync_helper (f, fd, on, &dev->fasync); 1187 } 1188 1189 static struct usb_gadget_driver gadgetfs_driver; 1190 1191 static int 1192 dev_release (struct inode *inode, struct file *fd) 1193 { 1194 struct dev_data *dev = fd->private_data; 1195 1196 /* closing ep0 === shutdown all */ 1197 1198 if (dev->gadget_registered) { 1199 usb_gadget_unregister_driver (&gadgetfs_driver); 1200 dev->gadget_registered = false; 1201 } 1202 1203 /* at this point "good" hardware has disconnected the 1204 * device from USB; the host won't see it any more. 1205 * alternatively, all host requests will time out. 1206 */ 1207 1208 kfree (dev->buf); 1209 dev->buf = NULL; 1210 1211 /* other endpoints were all decoupled from this device */ 1212 spin_lock_irq(&dev->lock); 1213 dev->state = STATE_DEV_DISABLED; 1214 spin_unlock_irq(&dev->lock); 1215 1216 put_dev (dev); 1217 return 0; 1218 } 1219 1220 static __poll_t 1221 ep0_poll (struct file *fd, poll_table *wait) 1222 { 1223 struct dev_data *dev = fd->private_data; 1224 __poll_t mask = 0; 1225 1226 if (dev->state <= STATE_DEV_OPENED) 1227 return DEFAULT_POLLMASK; 1228 1229 poll_wait(fd, &dev->wait, wait); 1230 1231 spin_lock_irq(&dev->lock); 1232 1233 /* report fd mode change before acting on it */ 1234 if (dev->setup_abort) { 1235 dev->setup_abort = 0; 1236 mask = EPOLLHUP; 1237 goto out; 1238 } 1239 1240 if (dev->state == STATE_DEV_SETUP) { 1241 if (dev->setup_in || dev->setup_can_stall) 1242 mask = EPOLLOUT; 1243 } else { 1244 if (dev->ev_next != 0) 1245 mask = EPOLLIN; 1246 } 1247 out: 1248 spin_unlock_irq(&dev->lock); 1249 return mask; 1250 } 1251 1252 static long gadget_dev_ioctl (struct file *fd, unsigned code, unsigned long value) 1253 { 1254 struct dev_data *dev = fd->private_data; 1255 struct usb_gadget *gadget = dev->gadget; 1256 long ret = -ENOTTY; 1257 1258 spin_lock_irq(&dev->lock); 1259 if (dev->state == STATE_DEV_OPENED || 1260 dev->state == STATE_DEV_UNBOUND) { 1261 /* Not bound to a UDC */ 1262 } else if (gadget->ops->ioctl) { 1263 ++dev->udc_usage; 1264 spin_unlock_irq(&dev->lock); 1265 1266 ret = gadget->ops->ioctl (gadget, code, value); 1267 1268 spin_lock_irq(&dev->lock); 1269 --dev->udc_usage; 1270 } 1271 spin_unlock_irq(&dev->lock); 1272 1273 return ret; 1274 } 1275 1276 /*----------------------------------------------------------------------*/ 1277 1278 /* The in-kernel gadget driver handles most ep0 issues, in particular 1279 * enumerating the single configuration (as provided from user space). 1280 * 1281 * Unrecognized ep0 requests may be handled in user space. 1282 */ 1283 1284 static void make_qualifier (struct dev_data *dev) 1285 { 1286 struct usb_qualifier_descriptor qual; 1287 struct usb_device_descriptor *desc; 1288 1289 qual.bLength = sizeof qual; 1290 qual.bDescriptorType = USB_DT_DEVICE_QUALIFIER; 1291 qual.bcdUSB = cpu_to_le16 (0x0200); 1292 1293 desc = dev->dev; 1294 qual.bDeviceClass = desc->bDeviceClass; 1295 qual.bDeviceSubClass = desc->bDeviceSubClass; 1296 qual.bDeviceProtocol = desc->bDeviceProtocol; 1297 1298 /* assumes ep0 uses the same value for both speeds ... */ 1299 qual.bMaxPacketSize0 = dev->gadget->ep0->maxpacket; 1300 1301 qual.bNumConfigurations = 1; 1302 qual.bRESERVED = 0; 1303 1304 memcpy (dev->rbuf, &qual, sizeof qual); 1305 } 1306 1307 static int 1308 config_buf (struct dev_data *dev, u8 type, unsigned index) 1309 { 1310 int len; 1311 int hs = 0; 1312 1313 /* only one configuration */ 1314 if (index > 0) 1315 return -EINVAL; 1316 1317 if (gadget_is_dualspeed(dev->gadget)) { 1318 hs = (dev->gadget->speed == USB_SPEED_HIGH); 1319 if (type == USB_DT_OTHER_SPEED_CONFIG) 1320 hs = !hs; 1321 } 1322 if (hs) { 1323 dev->req->buf = dev->hs_config; 1324 len = le16_to_cpu(dev->hs_config->wTotalLength); 1325 } else { 1326 dev->req->buf = dev->config; 1327 len = le16_to_cpu(dev->config->wTotalLength); 1328 } 1329 ((u8 *)dev->req->buf) [1] = type; 1330 return len; 1331 } 1332 1333 static int 1334 gadgetfs_setup (struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl) 1335 { 1336 struct dev_data *dev = get_gadget_data (gadget); 1337 struct usb_request *req = dev->req; 1338 int value = -EOPNOTSUPP; 1339 struct usb_gadgetfs_event *event; 1340 u16 w_value = le16_to_cpu(ctrl->wValue); 1341 u16 w_length = le16_to_cpu(ctrl->wLength); 1342 1343 if (w_length > RBUF_SIZE) { 1344 if (ctrl->bRequestType & USB_DIR_IN) { 1345 /* Cast away the const, we are going to overwrite on purpose. */ 1346 __le16 *temp = (__le16 *)&ctrl->wLength; 1347 1348 *temp = cpu_to_le16(RBUF_SIZE); 1349 w_length = RBUF_SIZE; 1350 } else { 1351 return value; 1352 } 1353 } 1354 1355 spin_lock (&dev->lock); 1356 dev->setup_abort = 0; 1357 if (dev->state == STATE_DEV_UNCONNECTED) { 1358 if (gadget_is_dualspeed(gadget) 1359 && gadget->speed == USB_SPEED_HIGH 1360 && dev->hs_config == NULL) { 1361 spin_unlock(&dev->lock); 1362 ERROR (dev, "no high speed config??\n"); 1363 return -EINVAL; 1364 } 1365 1366 dev->state = STATE_DEV_CONNECTED; 1367 1368 INFO (dev, "connected\n"); 1369 event = next_event (dev, GADGETFS_CONNECT); 1370 event->u.speed = gadget->speed; 1371 ep0_readable (dev); 1372 1373 /* host may have given up waiting for response. we can miss control 1374 * requests handled lower down (device/endpoint status and features); 1375 * then ep0_{read,write} will report the wrong status. controller 1376 * driver will have aborted pending i/o. 1377 */ 1378 } else if (dev->state == STATE_DEV_SETUP) 1379 dev->setup_abort = 1; 1380 1381 req->buf = dev->rbuf; 1382 req->context = NULL; 1383 switch (ctrl->bRequest) { 1384 1385 case USB_REQ_GET_DESCRIPTOR: 1386 if (ctrl->bRequestType != USB_DIR_IN) 1387 goto unrecognized; 1388 switch (w_value >> 8) { 1389 1390 case USB_DT_DEVICE: 1391 value = min (w_length, (u16) sizeof *dev->dev); 1392 dev->dev->bMaxPacketSize0 = dev->gadget->ep0->maxpacket; 1393 req->buf = dev->dev; 1394 break; 1395 case USB_DT_DEVICE_QUALIFIER: 1396 if (!dev->hs_config) 1397 break; 1398 value = min (w_length, (u16) 1399 sizeof (struct usb_qualifier_descriptor)); 1400 make_qualifier (dev); 1401 break; 1402 case USB_DT_OTHER_SPEED_CONFIG: 1403 case USB_DT_CONFIG: 1404 value = config_buf (dev, 1405 w_value >> 8, 1406 w_value & 0xff); 1407 if (value >= 0) 1408 value = min (w_length, (u16) value); 1409 break; 1410 case USB_DT_STRING: 1411 goto unrecognized; 1412 1413 default: // all others are errors 1414 break; 1415 } 1416 break; 1417 1418 /* currently one config, two speeds */ 1419 case USB_REQ_SET_CONFIGURATION: 1420 if (ctrl->bRequestType != 0) 1421 goto unrecognized; 1422 if (0 == (u8) w_value) { 1423 value = 0; 1424 dev->current_config = 0; 1425 usb_gadget_vbus_draw(gadget, 8 /* mA */ ); 1426 // user mode expected to disable endpoints 1427 } else { 1428 u8 config, power; 1429 1430 if (gadget_is_dualspeed(gadget) 1431 && gadget->speed == USB_SPEED_HIGH) { 1432 config = dev->hs_config->bConfigurationValue; 1433 power = dev->hs_config->bMaxPower; 1434 } else { 1435 config = dev->config->bConfigurationValue; 1436 power = dev->config->bMaxPower; 1437 } 1438 1439 if (config == (u8) w_value) { 1440 value = 0; 1441 dev->current_config = config; 1442 usb_gadget_vbus_draw(gadget, 2 * power); 1443 } 1444 } 1445 1446 /* report SET_CONFIGURATION like any other control request, 1447 * except that usermode may not stall this. the next 1448 * request mustn't be allowed start until this finishes: 1449 * endpoints and threads set up, etc. 1450 * 1451 * NOTE: older PXA hardware (before PXA 255: without UDCCFR) 1452 * has bad/racey automagic that prevents synchronizing here. 1453 * even kernel mode drivers often miss them. 1454 */ 1455 if (value == 0) { 1456 INFO (dev, "configuration #%d\n", dev->current_config); 1457 usb_gadget_set_state(gadget, USB_STATE_CONFIGURED); 1458 if (dev->usermode_setup) { 1459 dev->setup_can_stall = 0; 1460 goto delegate; 1461 } 1462 } 1463 break; 1464 1465 #ifndef CONFIG_USB_PXA25X 1466 /* PXA automagically handles this request too */ 1467 case USB_REQ_GET_CONFIGURATION: 1468 if (ctrl->bRequestType != 0x80) 1469 goto unrecognized; 1470 *(u8 *)req->buf = dev->current_config; 1471 value = min (w_length, (u16) 1); 1472 break; 1473 #endif 1474 1475 default: 1476 unrecognized: 1477 VDEBUG (dev, "%s req%02x.%02x v%04x i%04x l%d\n", 1478 dev->usermode_setup ? "delegate" : "fail", 1479 ctrl->bRequestType, ctrl->bRequest, 1480 w_value, le16_to_cpu(ctrl->wIndex), w_length); 1481 1482 /* if there's an ep0 reader, don't stall */ 1483 if (dev->usermode_setup) { 1484 dev->setup_can_stall = 1; 1485 delegate: 1486 dev->setup_in = (ctrl->bRequestType & USB_DIR_IN) 1487 ? 1 : 0; 1488 dev->setup_wLength = w_length; 1489 dev->setup_out_ready = 0; 1490 dev->setup_out_error = 0; 1491 1492 /* read DATA stage for OUT right away */ 1493 if (unlikely (!dev->setup_in && w_length)) { 1494 value = setup_req (gadget->ep0, dev->req, 1495 w_length); 1496 if (value < 0) 1497 break; 1498 1499 ++dev->udc_usage; 1500 spin_unlock (&dev->lock); 1501 value = usb_ep_queue (gadget->ep0, dev->req, 1502 GFP_KERNEL); 1503 spin_lock (&dev->lock); 1504 --dev->udc_usage; 1505 if (value < 0) { 1506 clean_req (gadget->ep0, dev->req); 1507 break; 1508 } 1509 1510 /* we can't currently stall these */ 1511 dev->setup_can_stall = 0; 1512 } 1513 1514 /* state changes when reader collects event */ 1515 event = next_event (dev, GADGETFS_SETUP); 1516 event->u.setup = *ctrl; 1517 ep0_readable (dev); 1518 spin_unlock (&dev->lock); 1519 /* 1520 * Return USB_GADGET_DELAYED_STATUS as a workaround to 1521 * stop some UDC drivers (e.g. dwc3) from automatically 1522 * proceeding with the status stage for 0-length 1523 * transfers. 1524 * Should be removed once all UDC drivers are fixed to 1525 * always delay the status stage until a response is 1526 * queued to EP0. 1527 */ 1528 return w_length == 0 ? USB_GADGET_DELAYED_STATUS : 0; 1529 } 1530 } 1531 1532 /* proceed with data transfer and status phases? */ 1533 if (value >= 0 && dev->state != STATE_DEV_SETUP) { 1534 req->length = value; 1535 req->zero = value < w_length; 1536 1537 ++dev->udc_usage; 1538 spin_unlock (&dev->lock); 1539 value = usb_ep_queue (gadget->ep0, req, GFP_KERNEL); 1540 spin_lock(&dev->lock); 1541 --dev->udc_usage; 1542 spin_unlock(&dev->lock); 1543 if (value < 0) { 1544 DBG (dev, "ep_queue --> %d\n", value); 1545 req->status = 0; 1546 } 1547 return value; 1548 } 1549 1550 /* device stalls when value < 0 */ 1551 spin_unlock (&dev->lock); 1552 return value; 1553 } 1554 1555 static void destroy_ep_files (struct dev_data *dev) 1556 { 1557 DBG (dev, "%s %d\n", __func__, dev->state); 1558 1559 /* dev->state must prevent interference */ 1560 spin_lock_irq (&dev->lock); 1561 while (!list_empty(&dev->epfiles)) { 1562 struct ep_data *ep; 1563 struct inode *parent; 1564 struct dentry *dentry; 1565 1566 /* break link to FS */ 1567 ep = list_first_entry (&dev->epfiles, struct ep_data, epfiles); 1568 list_del_init (&ep->epfiles); 1569 spin_unlock_irq (&dev->lock); 1570 1571 dentry = ep->dentry; 1572 ep->dentry = NULL; 1573 parent = d_inode(dentry->d_parent); 1574 1575 /* break link to controller */ 1576 mutex_lock(&ep->lock); 1577 if (ep->state == STATE_EP_ENABLED) 1578 (void) usb_ep_disable (ep->ep); 1579 ep->state = STATE_EP_UNBOUND; 1580 usb_ep_free_request (ep->ep, ep->req); 1581 ep->ep = NULL; 1582 mutex_unlock(&ep->lock); 1583 1584 wake_up (&ep->wait); 1585 put_ep (ep); 1586 1587 /* break link to dcache */ 1588 inode_lock(parent); 1589 d_delete (dentry); 1590 dput (dentry); 1591 inode_unlock(parent); 1592 1593 spin_lock_irq (&dev->lock); 1594 } 1595 spin_unlock_irq (&dev->lock); 1596 } 1597 1598 1599 static struct dentry * 1600 gadgetfs_create_file (struct super_block *sb, char const *name, 1601 void *data, const struct file_operations *fops); 1602 1603 static int activate_ep_files (struct dev_data *dev) 1604 { 1605 struct usb_ep *ep; 1606 struct ep_data *data; 1607 1608 gadget_for_each_ep (ep, dev->gadget) { 1609 1610 data = kzalloc(sizeof(*data), GFP_KERNEL); 1611 if (!data) 1612 goto enomem0; 1613 data->state = STATE_EP_DISABLED; 1614 mutex_init(&data->lock); 1615 init_waitqueue_head (&data->wait); 1616 1617 strncpy (data->name, ep->name, sizeof (data->name) - 1); 1618 refcount_set (&data->count, 1); 1619 data->dev = dev; 1620 get_dev (dev); 1621 1622 data->ep = ep; 1623 ep->driver_data = data; 1624 1625 data->req = usb_ep_alloc_request (ep, GFP_KERNEL); 1626 if (!data->req) 1627 goto enomem1; 1628 1629 data->dentry = gadgetfs_create_file (dev->sb, data->name, 1630 data, &ep_io_operations); 1631 if (!data->dentry) 1632 goto enomem2; 1633 list_add_tail (&data->epfiles, &dev->epfiles); 1634 } 1635 return 0; 1636 1637 enomem2: 1638 usb_ep_free_request (ep, data->req); 1639 enomem1: 1640 put_dev (dev); 1641 kfree (data); 1642 enomem0: 1643 DBG (dev, "%s enomem\n", __func__); 1644 destroy_ep_files (dev); 1645 return -ENOMEM; 1646 } 1647 1648 static void 1649 gadgetfs_unbind (struct usb_gadget *gadget) 1650 { 1651 struct dev_data *dev = get_gadget_data (gadget); 1652 1653 DBG (dev, "%s\n", __func__); 1654 1655 spin_lock_irq (&dev->lock); 1656 dev->state = STATE_DEV_UNBOUND; 1657 while (dev->udc_usage > 0) { 1658 spin_unlock_irq(&dev->lock); 1659 usleep_range(1000, 2000); 1660 spin_lock_irq(&dev->lock); 1661 } 1662 spin_unlock_irq (&dev->lock); 1663 1664 destroy_ep_files (dev); 1665 gadget->ep0->driver_data = NULL; 1666 set_gadget_data (gadget, NULL); 1667 1668 /* we've already been disconnected ... no i/o is active */ 1669 if (dev->req) 1670 usb_ep_free_request (gadget->ep0, dev->req); 1671 DBG (dev, "%s done\n", __func__); 1672 put_dev (dev); 1673 } 1674 1675 static struct dev_data *the_device; 1676 1677 static int gadgetfs_bind(struct usb_gadget *gadget, 1678 struct usb_gadget_driver *driver) 1679 { 1680 struct dev_data *dev = the_device; 1681 1682 if (!dev) 1683 return -ESRCH; 1684 if (0 != strcmp (CHIP, gadget->name)) { 1685 pr_err("%s expected %s controller not %s\n", 1686 shortname, CHIP, gadget->name); 1687 return -ENODEV; 1688 } 1689 1690 set_gadget_data (gadget, dev); 1691 dev->gadget = gadget; 1692 gadget->ep0->driver_data = dev; 1693 1694 /* preallocate control response and buffer */ 1695 dev->req = usb_ep_alloc_request (gadget->ep0, GFP_KERNEL); 1696 if (!dev->req) 1697 goto enomem; 1698 dev->req->context = NULL; 1699 dev->req->complete = epio_complete; 1700 1701 if (activate_ep_files (dev) < 0) 1702 goto enomem; 1703 1704 INFO (dev, "bound to %s driver\n", gadget->name); 1705 spin_lock_irq(&dev->lock); 1706 dev->state = STATE_DEV_UNCONNECTED; 1707 spin_unlock_irq(&dev->lock); 1708 get_dev (dev); 1709 return 0; 1710 1711 enomem: 1712 gadgetfs_unbind (gadget); 1713 return -ENOMEM; 1714 } 1715 1716 static void 1717 gadgetfs_disconnect (struct usb_gadget *gadget) 1718 { 1719 struct dev_data *dev = get_gadget_data (gadget); 1720 unsigned long flags; 1721 1722 spin_lock_irqsave (&dev->lock, flags); 1723 if (dev->state == STATE_DEV_UNCONNECTED) 1724 goto exit; 1725 dev->state = STATE_DEV_UNCONNECTED; 1726 1727 INFO (dev, "disconnected\n"); 1728 next_event (dev, GADGETFS_DISCONNECT); 1729 ep0_readable (dev); 1730 exit: 1731 spin_unlock_irqrestore (&dev->lock, flags); 1732 } 1733 1734 static void 1735 gadgetfs_suspend (struct usb_gadget *gadget) 1736 { 1737 struct dev_data *dev = get_gadget_data (gadget); 1738 unsigned long flags; 1739 1740 INFO (dev, "suspended from state %d\n", dev->state); 1741 spin_lock_irqsave(&dev->lock, flags); 1742 switch (dev->state) { 1743 case STATE_DEV_SETUP: // VERY odd... host died?? 1744 case STATE_DEV_CONNECTED: 1745 case STATE_DEV_UNCONNECTED: 1746 next_event (dev, GADGETFS_SUSPEND); 1747 ep0_readable (dev); 1748 fallthrough; 1749 default: 1750 break; 1751 } 1752 spin_unlock_irqrestore(&dev->lock, flags); 1753 } 1754 1755 static struct usb_gadget_driver gadgetfs_driver = { 1756 .function = (char *) driver_desc, 1757 .bind = gadgetfs_bind, 1758 .unbind = gadgetfs_unbind, 1759 .setup = gadgetfs_setup, 1760 .reset = gadgetfs_disconnect, 1761 .disconnect = gadgetfs_disconnect, 1762 .suspend = gadgetfs_suspend, 1763 1764 .driver = { 1765 .name = shortname, 1766 }, 1767 }; 1768 1769 /*----------------------------------------------------------------------*/ 1770 /* DEVICE INITIALIZATION 1771 * 1772 * fd = open ("/dev/gadget/$CHIP", O_RDWR) 1773 * status = write (fd, descriptors, sizeof descriptors) 1774 * 1775 * That write establishes the device configuration, so the kernel can 1776 * bind to the controller ... guaranteeing it can handle enumeration 1777 * at all necessary speeds. Descriptor order is: 1778 * 1779 * . message tag (u32, host order) ... for now, must be zero; it 1780 * would change to support features like multi-config devices 1781 * . full/low speed config ... all wTotalLength bytes (with interface, 1782 * class, altsetting, endpoint, and other descriptors) 1783 * . high speed config ... all descriptors, for high speed operation; 1784 * this one's optional except for high-speed hardware 1785 * . device descriptor 1786 * 1787 * Endpoints are not yet enabled. Drivers must wait until device 1788 * configuration and interface altsetting changes create 1789 * the need to configure (or unconfigure) them. 1790 * 1791 * After initialization, the device stays active for as long as that 1792 * $CHIP file is open. Events must then be read from that descriptor, 1793 * such as configuration notifications. 1794 */ 1795 1796 static int is_valid_config(struct usb_config_descriptor *config, 1797 unsigned int total) 1798 { 1799 return config->bDescriptorType == USB_DT_CONFIG 1800 && config->bLength == USB_DT_CONFIG_SIZE 1801 && total >= USB_DT_CONFIG_SIZE 1802 && config->bConfigurationValue != 0 1803 && (config->bmAttributes & USB_CONFIG_ATT_ONE) != 0 1804 && (config->bmAttributes & USB_CONFIG_ATT_WAKEUP) == 0; 1805 /* FIXME if gadget->is_otg, _must_ include an otg descriptor */ 1806 /* FIXME check lengths: walk to end */ 1807 } 1808 1809 static ssize_t 1810 dev_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr) 1811 { 1812 struct dev_data *dev = fd->private_data; 1813 ssize_t value, length = len; 1814 unsigned total; 1815 u32 tag; 1816 char *kbuf; 1817 1818 spin_lock_irq(&dev->lock); 1819 if (dev->state > STATE_DEV_OPENED) { 1820 value = ep0_write(fd, buf, len, ptr); 1821 spin_unlock_irq(&dev->lock); 1822 return value; 1823 } 1824 spin_unlock_irq(&dev->lock); 1825 1826 if ((len < (USB_DT_CONFIG_SIZE + USB_DT_DEVICE_SIZE + 4)) || 1827 (len > PAGE_SIZE * 4)) 1828 return -EINVAL; 1829 1830 /* we might need to change message format someday */ 1831 if (copy_from_user (&tag, buf, 4)) 1832 return -EFAULT; 1833 if (tag != 0) 1834 return -EINVAL; 1835 buf += 4; 1836 length -= 4; 1837 1838 kbuf = memdup_user(buf, length); 1839 if (IS_ERR(kbuf)) 1840 return PTR_ERR(kbuf); 1841 1842 spin_lock_irq (&dev->lock); 1843 value = -EINVAL; 1844 if (dev->buf) { 1845 spin_unlock_irq(&dev->lock); 1846 kfree(kbuf); 1847 return value; 1848 } 1849 dev->buf = kbuf; 1850 1851 /* full or low speed config */ 1852 dev->config = (void *) kbuf; 1853 total = le16_to_cpu(dev->config->wTotalLength); 1854 if (!is_valid_config(dev->config, total) || 1855 total > length - USB_DT_DEVICE_SIZE) 1856 goto fail; 1857 kbuf += total; 1858 length -= total; 1859 1860 /* optional high speed config */ 1861 if (kbuf [1] == USB_DT_CONFIG) { 1862 dev->hs_config = (void *) kbuf; 1863 total = le16_to_cpu(dev->hs_config->wTotalLength); 1864 if (!is_valid_config(dev->hs_config, total) || 1865 total > length - USB_DT_DEVICE_SIZE) 1866 goto fail; 1867 kbuf += total; 1868 length -= total; 1869 } else { 1870 dev->hs_config = NULL; 1871 } 1872 1873 /* could support multiple configs, using another encoding! */ 1874 1875 /* device descriptor (tweaked for paranoia) */ 1876 if (length != USB_DT_DEVICE_SIZE) 1877 goto fail; 1878 dev->dev = (void *)kbuf; 1879 if (dev->dev->bLength != USB_DT_DEVICE_SIZE 1880 || dev->dev->bDescriptorType != USB_DT_DEVICE 1881 || dev->dev->bNumConfigurations != 1) 1882 goto fail; 1883 dev->dev->bcdUSB = cpu_to_le16 (0x0200); 1884 1885 /* triggers gadgetfs_bind(); then we can enumerate. */ 1886 spin_unlock_irq (&dev->lock); 1887 if (dev->hs_config) 1888 gadgetfs_driver.max_speed = USB_SPEED_HIGH; 1889 else 1890 gadgetfs_driver.max_speed = USB_SPEED_FULL; 1891 1892 value = usb_gadget_register_driver(&gadgetfs_driver); 1893 if (value != 0) { 1894 spin_lock_irq(&dev->lock); 1895 goto fail; 1896 } else { 1897 /* at this point "good" hardware has for the first time 1898 * let the USB the host see us. alternatively, if users 1899 * unplug/replug that will clear all the error state. 1900 * 1901 * note: everything running before here was guaranteed 1902 * to choke driver model style diagnostics. from here 1903 * on, they can work ... except in cleanup paths that 1904 * kick in after the ep0 descriptor is closed. 1905 */ 1906 value = len; 1907 dev->gadget_registered = true; 1908 } 1909 return value; 1910 1911 fail: 1912 dev->config = NULL; 1913 dev->hs_config = NULL; 1914 dev->dev = NULL; 1915 spin_unlock_irq (&dev->lock); 1916 pr_debug ("%s: %s fail %zd, %p\n", shortname, __func__, value, dev); 1917 kfree (dev->buf); 1918 dev->buf = NULL; 1919 return value; 1920 } 1921 1922 static int 1923 gadget_dev_open (struct inode *inode, struct file *fd) 1924 { 1925 struct dev_data *dev = inode->i_private; 1926 int value = -EBUSY; 1927 1928 spin_lock_irq(&dev->lock); 1929 if (dev->state == STATE_DEV_DISABLED) { 1930 dev->ev_next = 0; 1931 dev->state = STATE_DEV_OPENED; 1932 fd->private_data = dev; 1933 get_dev (dev); 1934 value = 0; 1935 } 1936 spin_unlock_irq(&dev->lock); 1937 return value; 1938 } 1939 1940 static const struct file_operations ep0_operations = { 1941 1942 .open = gadget_dev_open, 1943 .read = ep0_read, 1944 .write = dev_config, 1945 .fasync = ep0_fasync, 1946 .poll = ep0_poll, 1947 .unlocked_ioctl = gadget_dev_ioctl, 1948 .release = dev_release, 1949 }; 1950 1951 /*----------------------------------------------------------------------*/ 1952 1953 /* FILESYSTEM AND SUPERBLOCK OPERATIONS 1954 * 1955 * Mounting the filesystem creates a controller file, used first for 1956 * device configuration then later for event monitoring. 1957 */ 1958 1959 1960 /* FIXME PAM etc could set this security policy without mount options 1961 * if epfiles inherited ownership and permissons from ep0 ... 1962 */ 1963 1964 static unsigned default_uid; 1965 static unsigned default_gid; 1966 static unsigned default_perm = S_IRUSR | S_IWUSR; 1967 1968 module_param (default_uid, uint, 0644); 1969 module_param (default_gid, uint, 0644); 1970 module_param (default_perm, uint, 0644); 1971 1972 1973 static struct inode * 1974 gadgetfs_make_inode (struct super_block *sb, 1975 void *data, const struct file_operations *fops, 1976 int mode) 1977 { 1978 struct inode *inode = new_inode (sb); 1979 1980 if (inode) { 1981 inode->i_ino = get_next_ino(); 1982 inode->i_mode = mode; 1983 inode->i_uid = make_kuid(&init_user_ns, default_uid); 1984 inode->i_gid = make_kgid(&init_user_ns, default_gid); 1985 simple_inode_init_ts(inode); 1986 inode->i_private = data; 1987 inode->i_fop = fops; 1988 } 1989 return inode; 1990 } 1991 1992 /* creates in fs root directory, so non-renamable and non-linkable. 1993 * so inode and dentry are paired, until device reconfig. 1994 */ 1995 static struct dentry * 1996 gadgetfs_create_file (struct super_block *sb, char const *name, 1997 void *data, const struct file_operations *fops) 1998 { 1999 struct dentry *dentry; 2000 struct inode *inode; 2001 2002 dentry = d_alloc_name(sb->s_root, name); 2003 if (!dentry) 2004 return NULL; 2005 2006 inode = gadgetfs_make_inode (sb, data, fops, 2007 S_IFREG | (default_perm & S_IRWXUGO)); 2008 if (!inode) { 2009 dput(dentry); 2010 return NULL; 2011 } 2012 d_add (dentry, inode); 2013 return dentry; 2014 } 2015 2016 static const struct super_operations gadget_fs_operations = { 2017 .statfs = simple_statfs, 2018 .drop_inode = generic_delete_inode, 2019 }; 2020 2021 static int 2022 gadgetfs_fill_super (struct super_block *sb, struct fs_context *fc) 2023 { 2024 struct inode *inode; 2025 struct dev_data *dev; 2026 int rc; 2027 2028 mutex_lock(&sb_mutex); 2029 2030 if (the_device) { 2031 rc = -ESRCH; 2032 goto Done; 2033 } 2034 2035 CHIP = usb_get_gadget_udc_name(); 2036 if (!CHIP) { 2037 rc = -ENODEV; 2038 goto Done; 2039 } 2040 2041 /* superblock */ 2042 sb->s_blocksize = PAGE_SIZE; 2043 sb->s_blocksize_bits = PAGE_SHIFT; 2044 sb->s_magic = GADGETFS_MAGIC; 2045 sb->s_op = &gadget_fs_operations; 2046 sb->s_time_gran = 1; 2047 2048 /* root inode */ 2049 inode = gadgetfs_make_inode (sb, 2050 NULL, &simple_dir_operations, 2051 S_IFDIR | S_IRUGO | S_IXUGO); 2052 if (!inode) 2053 goto Enomem; 2054 inode->i_op = &simple_dir_inode_operations; 2055 if (!(sb->s_root = d_make_root (inode))) 2056 goto Enomem; 2057 2058 /* the ep0 file is named after the controller we expect; 2059 * user mode code can use it for sanity checks, like we do. 2060 */ 2061 dev = dev_new (); 2062 if (!dev) 2063 goto Enomem; 2064 2065 dev->sb = sb; 2066 dev->dentry = gadgetfs_create_file(sb, CHIP, dev, &ep0_operations); 2067 if (!dev->dentry) { 2068 put_dev(dev); 2069 goto Enomem; 2070 } 2071 2072 /* other endpoint files are available after hardware setup, 2073 * from binding to a controller. 2074 */ 2075 the_device = dev; 2076 rc = 0; 2077 goto Done; 2078 2079 Enomem: 2080 kfree(CHIP); 2081 CHIP = NULL; 2082 rc = -ENOMEM; 2083 2084 Done: 2085 mutex_unlock(&sb_mutex); 2086 return rc; 2087 } 2088 2089 /* "mount -t gadgetfs path /dev/gadget" ends up here */ 2090 static int gadgetfs_get_tree(struct fs_context *fc) 2091 { 2092 return get_tree_single(fc, gadgetfs_fill_super); 2093 } 2094 2095 static const struct fs_context_operations gadgetfs_context_ops = { 2096 .get_tree = gadgetfs_get_tree, 2097 }; 2098 2099 static int gadgetfs_init_fs_context(struct fs_context *fc) 2100 { 2101 fc->ops = &gadgetfs_context_ops; 2102 return 0; 2103 } 2104 2105 static void 2106 gadgetfs_kill_sb (struct super_block *sb) 2107 { 2108 mutex_lock(&sb_mutex); 2109 kill_litter_super (sb); 2110 if (the_device) { 2111 put_dev (the_device); 2112 the_device = NULL; 2113 } 2114 kfree(CHIP); 2115 CHIP = NULL; 2116 mutex_unlock(&sb_mutex); 2117 } 2118 2119 /*----------------------------------------------------------------------*/ 2120 2121 static struct file_system_type gadgetfs_type = { 2122 .owner = THIS_MODULE, 2123 .name = shortname, 2124 .init_fs_context = gadgetfs_init_fs_context, 2125 .kill_sb = gadgetfs_kill_sb, 2126 }; 2127 MODULE_ALIAS_FS("gadgetfs"); 2128 2129 /*----------------------------------------------------------------------*/ 2130 2131 static int __init gadgetfs_init (void) 2132 { 2133 int status; 2134 2135 status = register_filesystem (&gadgetfs_type); 2136 if (status == 0) 2137 pr_info ("%s: %s, version " DRIVER_VERSION "\n", 2138 shortname, driver_desc); 2139 return status; 2140 } 2141 module_init (gadgetfs_init); 2142 2143 static void __exit gadgetfs_cleanup (void) 2144 { 2145 pr_debug ("unregister %s\n", shortname); 2146 unregister_filesystem (&gadgetfs_type); 2147 } 2148 module_exit (gadgetfs_cleanup); 2149 2150