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