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