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 epdata->status = -ENODEV; 366 } 367 } 368 return epdata->status; 369 } 370 return value; 371 } 372 373 static int 374 ep_release (struct inode *inode, struct file *fd) 375 { 376 struct ep_data *data = fd->private_data; 377 int value; 378 379 value = mutex_lock_interruptible(&data->lock); 380 if (value < 0) 381 return value; 382 383 /* clean up if this can be reopened */ 384 if (data->state != STATE_EP_UNBOUND) { 385 data->state = STATE_EP_DISABLED; 386 data->desc.bDescriptorType = 0; 387 data->hs_desc.bDescriptorType = 0; 388 usb_ep_disable(data->ep); 389 } 390 mutex_unlock(&data->lock); 391 put_ep (data); 392 return 0; 393 } 394 395 static long ep_ioctl(struct file *fd, unsigned code, unsigned long value) 396 { 397 struct ep_data *data = fd->private_data; 398 int status; 399 400 if ((status = get_ready_ep (fd->f_flags, data, false)) < 0) 401 return status; 402 403 spin_lock_irq (&data->dev->lock); 404 if (likely (data->ep != NULL)) { 405 switch (code) { 406 case GADGETFS_FIFO_STATUS: 407 status = usb_ep_fifo_status (data->ep); 408 break; 409 case GADGETFS_FIFO_FLUSH: 410 usb_ep_fifo_flush (data->ep); 411 break; 412 case GADGETFS_CLEAR_HALT: 413 status = usb_ep_clear_halt (data->ep); 414 break; 415 default: 416 status = -ENOTTY; 417 } 418 } else 419 status = -ENODEV; 420 spin_unlock_irq (&data->dev->lock); 421 mutex_unlock(&data->lock); 422 return status; 423 } 424 425 /*----------------------------------------------------------------------*/ 426 427 /* ASYNCHRONOUS ENDPOINT I/O OPERATIONS (bulk/intr/iso) */ 428 429 struct kiocb_priv { 430 struct usb_request *req; 431 struct ep_data *epdata; 432 struct kiocb *iocb; 433 struct mm_struct *mm; 434 struct work_struct work; 435 void *buf; 436 struct iov_iter to; 437 const void *to_free; 438 unsigned actual; 439 }; 440 441 static int ep_aio_cancel(struct kiocb *iocb) 442 { 443 struct kiocb_priv *priv = iocb->private; 444 struct ep_data *epdata; 445 int value; 446 447 local_irq_disable(); 448 epdata = priv->epdata; 449 // spin_lock(&epdata->dev->lock); 450 if (likely(epdata && epdata->ep && priv->req)) 451 value = usb_ep_dequeue (epdata->ep, priv->req); 452 else 453 value = -EINVAL; 454 // spin_unlock(&epdata->dev->lock); 455 local_irq_enable(); 456 457 return value; 458 } 459 460 static void ep_user_copy_worker(struct work_struct *work) 461 { 462 struct kiocb_priv *priv = container_of(work, struct kiocb_priv, work); 463 struct mm_struct *mm = priv->mm; 464 struct kiocb *iocb = priv->iocb; 465 size_t ret; 466 467 kthread_use_mm(mm); 468 ret = copy_to_iter(priv->buf, priv->actual, &priv->to); 469 kthread_unuse_mm(mm); 470 if (!ret) 471 ret = -EFAULT; 472 473 /* completing the iocb can drop the ctx and mm, don't touch mm after */ 474 iocb->ki_complete(iocb, ret); 475 476 kfree(priv->buf); 477 kfree(priv->to_free); 478 kfree(priv); 479 } 480 481 static void ep_aio_complete(struct usb_ep *ep, struct usb_request *req) 482 { 483 struct kiocb *iocb = req->context; 484 struct kiocb_priv *priv = iocb->private; 485 struct ep_data *epdata = priv->epdata; 486 487 /* lock against disconnect (and ideally, cancel) */ 488 spin_lock(&epdata->dev->lock); 489 priv->req = NULL; 490 priv->epdata = NULL; 491 492 /* if this was a write or a read returning no data then we 493 * don't need to copy anything to userspace, so we can 494 * complete the aio request immediately. 495 */ 496 if (priv->to_free == NULL || unlikely(req->actual == 0)) { 497 kfree(req->buf); 498 kfree(priv->to_free); 499 kfree(priv); 500 iocb->private = NULL; 501 iocb->ki_complete(iocb, 502 req->actual ? req->actual : (long)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 gadget_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 if (w_length > RBUF_SIZE) { 1337 if (ctrl->bRequestType & USB_DIR_IN) { 1338 /* Cast away the const, we are going to overwrite on purpose. */ 1339 __le16 *temp = (__le16 *)&ctrl->wLength; 1340 1341 *temp = cpu_to_le16(RBUF_SIZE); 1342 w_length = RBUF_SIZE; 1343 } else { 1344 return value; 1345 } 1346 } 1347 1348 spin_lock (&dev->lock); 1349 dev->setup_abort = 0; 1350 if (dev->state == STATE_DEV_UNCONNECTED) { 1351 if (gadget_is_dualspeed(gadget) 1352 && gadget->speed == USB_SPEED_HIGH 1353 && dev->hs_config == NULL) { 1354 spin_unlock(&dev->lock); 1355 ERROR (dev, "no high speed config??\n"); 1356 return -EINVAL; 1357 } 1358 1359 dev->state = STATE_DEV_CONNECTED; 1360 1361 INFO (dev, "connected\n"); 1362 event = next_event (dev, GADGETFS_CONNECT); 1363 event->u.speed = gadget->speed; 1364 ep0_readable (dev); 1365 1366 /* host may have given up waiting for response. we can miss control 1367 * requests handled lower down (device/endpoint status and features); 1368 * then ep0_{read,write} will report the wrong status. controller 1369 * driver will have aborted pending i/o. 1370 */ 1371 } else if (dev->state == STATE_DEV_SETUP) 1372 dev->setup_abort = 1; 1373 1374 req->buf = dev->rbuf; 1375 req->context = NULL; 1376 switch (ctrl->bRequest) { 1377 1378 case USB_REQ_GET_DESCRIPTOR: 1379 if (ctrl->bRequestType != USB_DIR_IN) 1380 goto unrecognized; 1381 switch (w_value >> 8) { 1382 1383 case USB_DT_DEVICE: 1384 value = min (w_length, (u16) sizeof *dev->dev); 1385 dev->dev->bMaxPacketSize0 = dev->gadget->ep0->maxpacket; 1386 req->buf = dev->dev; 1387 break; 1388 case USB_DT_DEVICE_QUALIFIER: 1389 if (!dev->hs_config) 1390 break; 1391 value = min (w_length, (u16) 1392 sizeof (struct usb_qualifier_descriptor)); 1393 make_qualifier (dev); 1394 break; 1395 case USB_DT_OTHER_SPEED_CONFIG: 1396 case USB_DT_CONFIG: 1397 value = config_buf (dev, 1398 w_value >> 8, 1399 w_value & 0xff); 1400 if (value >= 0) 1401 value = min (w_length, (u16) value); 1402 break; 1403 case USB_DT_STRING: 1404 goto unrecognized; 1405 1406 default: // all others are errors 1407 break; 1408 } 1409 break; 1410 1411 /* currently one config, two speeds */ 1412 case USB_REQ_SET_CONFIGURATION: 1413 if (ctrl->bRequestType != 0) 1414 goto unrecognized; 1415 if (0 == (u8) w_value) { 1416 value = 0; 1417 dev->current_config = 0; 1418 usb_gadget_vbus_draw(gadget, 8 /* mA */ ); 1419 // user mode expected to disable endpoints 1420 } else { 1421 u8 config, power; 1422 1423 if (gadget_is_dualspeed(gadget) 1424 && gadget->speed == USB_SPEED_HIGH) { 1425 config = dev->hs_config->bConfigurationValue; 1426 power = dev->hs_config->bMaxPower; 1427 } else { 1428 config = dev->config->bConfigurationValue; 1429 power = dev->config->bMaxPower; 1430 } 1431 1432 if (config == (u8) w_value) { 1433 value = 0; 1434 dev->current_config = config; 1435 usb_gadget_vbus_draw(gadget, 2 * power); 1436 } 1437 } 1438 1439 /* report SET_CONFIGURATION like any other control request, 1440 * except that usermode may not stall this. the next 1441 * request mustn't be allowed start until this finishes: 1442 * endpoints and threads set up, etc. 1443 * 1444 * NOTE: older PXA hardware (before PXA 255: without UDCCFR) 1445 * has bad/racey automagic that prevents synchronizing here. 1446 * even kernel mode drivers often miss them. 1447 */ 1448 if (value == 0) { 1449 INFO (dev, "configuration #%d\n", dev->current_config); 1450 usb_gadget_set_state(gadget, USB_STATE_CONFIGURED); 1451 if (dev->usermode_setup) { 1452 dev->setup_can_stall = 0; 1453 goto delegate; 1454 } 1455 } 1456 break; 1457 1458 #ifndef CONFIG_USB_PXA25X 1459 /* PXA automagically handles this request too */ 1460 case USB_REQ_GET_CONFIGURATION: 1461 if (ctrl->bRequestType != 0x80) 1462 goto unrecognized; 1463 *(u8 *)req->buf = dev->current_config; 1464 value = min (w_length, (u16) 1); 1465 break; 1466 #endif 1467 1468 default: 1469 unrecognized: 1470 VDEBUG (dev, "%s req%02x.%02x v%04x i%04x l%d\n", 1471 dev->usermode_setup ? "delegate" : "fail", 1472 ctrl->bRequestType, ctrl->bRequest, 1473 w_value, le16_to_cpu(ctrl->wIndex), w_length); 1474 1475 /* if there's an ep0 reader, don't stall */ 1476 if (dev->usermode_setup) { 1477 dev->setup_can_stall = 1; 1478 delegate: 1479 dev->setup_in = (ctrl->bRequestType & USB_DIR_IN) 1480 ? 1 : 0; 1481 dev->setup_wLength = w_length; 1482 dev->setup_out_ready = 0; 1483 dev->setup_out_error = 0; 1484 1485 /* read DATA stage for OUT right away */ 1486 if (unlikely (!dev->setup_in && w_length)) { 1487 value = setup_req (gadget->ep0, dev->req, 1488 w_length); 1489 if (value < 0) 1490 break; 1491 1492 ++dev->udc_usage; 1493 spin_unlock (&dev->lock); 1494 value = usb_ep_queue (gadget->ep0, dev->req, 1495 GFP_KERNEL); 1496 spin_lock (&dev->lock); 1497 --dev->udc_usage; 1498 if (value < 0) { 1499 clean_req (gadget->ep0, dev->req); 1500 break; 1501 } 1502 1503 /* we can't currently stall these */ 1504 dev->setup_can_stall = 0; 1505 } 1506 1507 /* state changes when reader collects event */ 1508 event = next_event (dev, GADGETFS_SETUP); 1509 event->u.setup = *ctrl; 1510 ep0_readable (dev); 1511 spin_unlock (&dev->lock); 1512 return 0; 1513 } 1514 } 1515 1516 /* proceed with data transfer and status phases? */ 1517 if (value >= 0 && dev->state != STATE_DEV_SETUP) { 1518 req->length = value; 1519 req->zero = value < w_length; 1520 1521 ++dev->udc_usage; 1522 spin_unlock (&dev->lock); 1523 value = usb_ep_queue (gadget->ep0, req, GFP_KERNEL); 1524 spin_lock(&dev->lock); 1525 --dev->udc_usage; 1526 spin_unlock(&dev->lock); 1527 if (value < 0) { 1528 DBG (dev, "ep_queue --> %d\n", value); 1529 req->status = 0; 1530 } 1531 return value; 1532 } 1533 1534 /* device stalls when value < 0 */ 1535 spin_unlock (&dev->lock); 1536 return value; 1537 } 1538 1539 static void destroy_ep_files (struct dev_data *dev) 1540 { 1541 DBG (dev, "%s %d\n", __func__, dev->state); 1542 1543 /* dev->state must prevent interference */ 1544 spin_lock_irq (&dev->lock); 1545 while (!list_empty(&dev->epfiles)) { 1546 struct ep_data *ep; 1547 struct inode *parent; 1548 struct dentry *dentry; 1549 1550 /* break link to FS */ 1551 ep = list_first_entry (&dev->epfiles, struct ep_data, epfiles); 1552 list_del_init (&ep->epfiles); 1553 spin_unlock_irq (&dev->lock); 1554 1555 dentry = ep->dentry; 1556 ep->dentry = NULL; 1557 parent = d_inode(dentry->d_parent); 1558 1559 /* break link to controller */ 1560 mutex_lock(&ep->lock); 1561 if (ep->state == STATE_EP_ENABLED) 1562 (void) usb_ep_disable (ep->ep); 1563 ep->state = STATE_EP_UNBOUND; 1564 usb_ep_free_request (ep->ep, ep->req); 1565 ep->ep = NULL; 1566 mutex_unlock(&ep->lock); 1567 1568 wake_up (&ep->wait); 1569 put_ep (ep); 1570 1571 /* break link to dcache */ 1572 inode_lock(parent); 1573 d_delete (dentry); 1574 dput (dentry); 1575 inode_unlock(parent); 1576 1577 spin_lock_irq (&dev->lock); 1578 } 1579 spin_unlock_irq (&dev->lock); 1580 } 1581 1582 1583 static struct dentry * 1584 gadgetfs_create_file (struct super_block *sb, char const *name, 1585 void *data, const struct file_operations *fops); 1586 1587 static int activate_ep_files (struct dev_data *dev) 1588 { 1589 struct usb_ep *ep; 1590 struct ep_data *data; 1591 1592 gadget_for_each_ep (ep, dev->gadget) { 1593 1594 data = kzalloc(sizeof(*data), GFP_KERNEL); 1595 if (!data) 1596 goto enomem0; 1597 data->state = STATE_EP_DISABLED; 1598 mutex_init(&data->lock); 1599 init_waitqueue_head (&data->wait); 1600 1601 strncpy (data->name, ep->name, sizeof (data->name) - 1); 1602 refcount_set (&data->count, 1); 1603 data->dev = dev; 1604 get_dev (dev); 1605 1606 data->ep = ep; 1607 ep->driver_data = data; 1608 1609 data->req = usb_ep_alloc_request (ep, GFP_KERNEL); 1610 if (!data->req) 1611 goto enomem1; 1612 1613 data->dentry = gadgetfs_create_file (dev->sb, data->name, 1614 data, &ep_io_operations); 1615 if (!data->dentry) 1616 goto enomem2; 1617 list_add_tail (&data->epfiles, &dev->epfiles); 1618 } 1619 return 0; 1620 1621 enomem2: 1622 usb_ep_free_request (ep, data->req); 1623 enomem1: 1624 put_dev (dev); 1625 kfree (data); 1626 enomem0: 1627 DBG (dev, "%s enomem\n", __func__); 1628 destroy_ep_files (dev); 1629 return -ENOMEM; 1630 } 1631 1632 static void 1633 gadgetfs_unbind (struct usb_gadget *gadget) 1634 { 1635 struct dev_data *dev = get_gadget_data (gadget); 1636 1637 DBG (dev, "%s\n", __func__); 1638 1639 spin_lock_irq (&dev->lock); 1640 dev->state = STATE_DEV_UNBOUND; 1641 while (dev->udc_usage > 0) { 1642 spin_unlock_irq(&dev->lock); 1643 usleep_range(1000, 2000); 1644 spin_lock_irq(&dev->lock); 1645 } 1646 spin_unlock_irq (&dev->lock); 1647 1648 destroy_ep_files (dev); 1649 gadget->ep0->driver_data = NULL; 1650 set_gadget_data (gadget, NULL); 1651 1652 /* we've already been disconnected ... no i/o is active */ 1653 if (dev->req) 1654 usb_ep_free_request (gadget->ep0, dev->req); 1655 DBG (dev, "%s done\n", __func__); 1656 put_dev (dev); 1657 } 1658 1659 static struct dev_data *the_device; 1660 1661 static int gadgetfs_bind(struct usb_gadget *gadget, 1662 struct usb_gadget_driver *driver) 1663 { 1664 struct dev_data *dev = the_device; 1665 1666 if (!dev) 1667 return -ESRCH; 1668 if (0 != strcmp (CHIP, gadget->name)) { 1669 pr_err("%s expected %s controller not %s\n", 1670 shortname, CHIP, gadget->name); 1671 return -ENODEV; 1672 } 1673 1674 set_gadget_data (gadget, dev); 1675 dev->gadget = gadget; 1676 gadget->ep0->driver_data = dev; 1677 1678 /* preallocate control response and buffer */ 1679 dev->req = usb_ep_alloc_request (gadget->ep0, GFP_KERNEL); 1680 if (!dev->req) 1681 goto enomem; 1682 dev->req->context = NULL; 1683 dev->req->complete = epio_complete; 1684 1685 if (activate_ep_files (dev) < 0) 1686 goto enomem; 1687 1688 INFO (dev, "bound to %s driver\n", gadget->name); 1689 spin_lock_irq(&dev->lock); 1690 dev->state = STATE_DEV_UNCONNECTED; 1691 spin_unlock_irq(&dev->lock); 1692 get_dev (dev); 1693 return 0; 1694 1695 enomem: 1696 gadgetfs_unbind (gadget); 1697 return -ENOMEM; 1698 } 1699 1700 static void 1701 gadgetfs_disconnect (struct usb_gadget *gadget) 1702 { 1703 struct dev_data *dev = get_gadget_data (gadget); 1704 unsigned long flags; 1705 1706 spin_lock_irqsave (&dev->lock, flags); 1707 if (dev->state == STATE_DEV_UNCONNECTED) 1708 goto exit; 1709 dev->state = STATE_DEV_UNCONNECTED; 1710 1711 INFO (dev, "disconnected\n"); 1712 next_event (dev, GADGETFS_DISCONNECT); 1713 ep0_readable (dev); 1714 exit: 1715 spin_unlock_irqrestore (&dev->lock, flags); 1716 } 1717 1718 static void 1719 gadgetfs_suspend (struct usb_gadget *gadget) 1720 { 1721 struct dev_data *dev = get_gadget_data (gadget); 1722 unsigned long flags; 1723 1724 INFO (dev, "suspended from state %d\n", dev->state); 1725 spin_lock_irqsave(&dev->lock, flags); 1726 switch (dev->state) { 1727 case STATE_DEV_SETUP: // VERY odd... host died?? 1728 case STATE_DEV_CONNECTED: 1729 case STATE_DEV_UNCONNECTED: 1730 next_event (dev, GADGETFS_SUSPEND); 1731 ep0_readable (dev); 1732 fallthrough; 1733 default: 1734 break; 1735 } 1736 spin_unlock_irqrestore(&dev->lock, flags); 1737 } 1738 1739 static struct usb_gadget_driver gadgetfs_driver = { 1740 .function = (char *) driver_desc, 1741 .bind = gadgetfs_bind, 1742 .unbind = gadgetfs_unbind, 1743 .setup = gadgetfs_setup, 1744 .reset = gadgetfs_disconnect, 1745 .disconnect = gadgetfs_disconnect, 1746 .suspend = gadgetfs_suspend, 1747 1748 .driver = { 1749 .name = shortname, 1750 }, 1751 }; 1752 1753 /*----------------------------------------------------------------------*/ 1754 /* DEVICE INITIALIZATION 1755 * 1756 * fd = open ("/dev/gadget/$CHIP", O_RDWR) 1757 * status = write (fd, descriptors, sizeof descriptors) 1758 * 1759 * That write establishes the device configuration, so the kernel can 1760 * bind to the controller ... guaranteeing it can handle enumeration 1761 * at all necessary speeds. Descriptor order is: 1762 * 1763 * . message tag (u32, host order) ... for now, must be zero; it 1764 * would change to support features like multi-config devices 1765 * . full/low speed config ... all wTotalLength bytes (with interface, 1766 * class, altsetting, endpoint, and other descriptors) 1767 * . high speed config ... all descriptors, for high speed operation; 1768 * this one's optional except for high-speed hardware 1769 * . device descriptor 1770 * 1771 * Endpoints are not yet enabled. Drivers must wait until device 1772 * configuration and interface altsetting changes create 1773 * the need to configure (or unconfigure) them. 1774 * 1775 * After initialization, the device stays active for as long as that 1776 * $CHIP file is open. Events must then be read from that descriptor, 1777 * such as configuration notifications. 1778 */ 1779 1780 static int is_valid_config(struct usb_config_descriptor *config, 1781 unsigned int total) 1782 { 1783 return config->bDescriptorType == USB_DT_CONFIG 1784 && config->bLength == USB_DT_CONFIG_SIZE 1785 && total >= USB_DT_CONFIG_SIZE 1786 && config->bConfigurationValue != 0 1787 && (config->bmAttributes & USB_CONFIG_ATT_ONE) != 0 1788 && (config->bmAttributes & USB_CONFIG_ATT_WAKEUP) == 0; 1789 /* FIXME if gadget->is_otg, _must_ include an otg descriptor */ 1790 /* FIXME check lengths: walk to end */ 1791 } 1792 1793 static ssize_t 1794 dev_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr) 1795 { 1796 struct dev_data *dev = fd->private_data; 1797 ssize_t value, length = len; 1798 unsigned total; 1799 u32 tag; 1800 char *kbuf; 1801 1802 spin_lock_irq(&dev->lock); 1803 if (dev->state > STATE_DEV_OPENED) { 1804 value = ep0_write(fd, buf, len, ptr); 1805 spin_unlock_irq(&dev->lock); 1806 return value; 1807 } 1808 spin_unlock_irq(&dev->lock); 1809 1810 if ((len < (USB_DT_CONFIG_SIZE + USB_DT_DEVICE_SIZE + 4)) || 1811 (len > PAGE_SIZE * 4)) 1812 return -EINVAL; 1813 1814 /* we might need to change message format someday */ 1815 if (copy_from_user (&tag, buf, 4)) 1816 return -EFAULT; 1817 if (tag != 0) 1818 return -EINVAL; 1819 buf += 4; 1820 length -= 4; 1821 1822 kbuf = memdup_user(buf, length); 1823 if (IS_ERR(kbuf)) 1824 return PTR_ERR(kbuf); 1825 1826 spin_lock_irq (&dev->lock); 1827 value = -EINVAL; 1828 if (dev->buf) { 1829 spin_unlock_irq(&dev->lock); 1830 kfree(kbuf); 1831 return value; 1832 } 1833 dev->buf = kbuf; 1834 1835 /* full or low speed config */ 1836 dev->config = (void *) kbuf; 1837 total = le16_to_cpu(dev->config->wTotalLength); 1838 if (!is_valid_config(dev->config, total) || 1839 total > length - USB_DT_DEVICE_SIZE) 1840 goto fail; 1841 kbuf += total; 1842 length -= total; 1843 1844 /* optional high speed config */ 1845 if (kbuf [1] == USB_DT_CONFIG) { 1846 dev->hs_config = (void *) kbuf; 1847 total = le16_to_cpu(dev->hs_config->wTotalLength); 1848 if (!is_valid_config(dev->hs_config, total) || 1849 total > length - USB_DT_DEVICE_SIZE) 1850 goto fail; 1851 kbuf += total; 1852 length -= total; 1853 } else { 1854 dev->hs_config = NULL; 1855 } 1856 1857 /* could support multiple configs, using another encoding! */ 1858 1859 /* device descriptor (tweaked for paranoia) */ 1860 if (length != USB_DT_DEVICE_SIZE) 1861 goto fail; 1862 dev->dev = (void *)kbuf; 1863 if (dev->dev->bLength != USB_DT_DEVICE_SIZE 1864 || dev->dev->bDescriptorType != USB_DT_DEVICE 1865 || dev->dev->bNumConfigurations != 1) 1866 goto fail; 1867 dev->dev->bcdUSB = cpu_to_le16 (0x0200); 1868 1869 /* triggers gadgetfs_bind(); then we can enumerate. */ 1870 spin_unlock_irq (&dev->lock); 1871 if (dev->hs_config) 1872 gadgetfs_driver.max_speed = USB_SPEED_HIGH; 1873 else 1874 gadgetfs_driver.max_speed = USB_SPEED_FULL; 1875 1876 value = usb_gadget_probe_driver(&gadgetfs_driver); 1877 if (value != 0) { 1878 spin_lock_irq(&dev->lock); 1879 goto fail; 1880 } else { 1881 /* at this point "good" hardware has for the first time 1882 * let the USB the host see us. alternatively, if users 1883 * unplug/replug that will clear all the error state. 1884 * 1885 * note: everything running before here was guaranteed 1886 * to choke driver model style diagnostics. from here 1887 * on, they can work ... except in cleanup paths that 1888 * kick in after the ep0 descriptor is closed. 1889 */ 1890 value = len; 1891 dev->gadget_registered = true; 1892 } 1893 return value; 1894 1895 fail: 1896 dev->config = NULL; 1897 dev->hs_config = NULL; 1898 dev->dev = NULL; 1899 spin_unlock_irq (&dev->lock); 1900 pr_debug ("%s: %s fail %zd, %p\n", shortname, __func__, value, dev); 1901 kfree (dev->buf); 1902 dev->buf = NULL; 1903 return value; 1904 } 1905 1906 static int 1907 gadget_dev_open (struct inode *inode, struct file *fd) 1908 { 1909 struct dev_data *dev = inode->i_private; 1910 int value = -EBUSY; 1911 1912 spin_lock_irq(&dev->lock); 1913 if (dev->state == STATE_DEV_DISABLED) { 1914 dev->ev_next = 0; 1915 dev->state = STATE_DEV_OPENED; 1916 fd->private_data = dev; 1917 get_dev (dev); 1918 value = 0; 1919 } 1920 spin_unlock_irq(&dev->lock); 1921 return value; 1922 } 1923 1924 static const struct file_operations ep0_operations = { 1925 .llseek = no_llseek, 1926 1927 .open = gadget_dev_open, 1928 .read = ep0_read, 1929 .write = dev_config, 1930 .fasync = ep0_fasync, 1931 .poll = ep0_poll, 1932 .unlocked_ioctl = gadget_dev_ioctl, 1933 .release = dev_release, 1934 }; 1935 1936 /*----------------------------------------------------------------------*/ 1937 1938 /* FILESYSTEM AND SUPERBLOCK OPERATIONS 1939 * 1940 * Mounting the filesystem creates a controller file, used first for 1941 * device configuration then later for event monitoring. 1942 */ 1943 1944 1945 /* FIXME PAM etc could set this security policy without mount options 1946 * if epfiles inherited ownership and permissons from ep0 ... 1947 */ 1948 1949 static unsigned default_uid; 1950 static unsigned default_gid; 1951 static unsigned default_perm = S_IRUSR | S_IWUSR; 1952 1953 module_param (default_uid, uint, 0644); 1954 module_param (default_gid, uint, 0644); 1955 module_param (default_perm, uint, 0644); 1956 1957 1958 static struct inode * 1959 gadgetfs_make_inode (struct super_block *sb, 1960 void *data, const struct file_operations *fops, 1961 int mode) 1962 { 1963 struct inode *inode = new_inode (sb); 1964 1965 if (inode) { 1966 inode->i_ino = get_next_ino(); 1967 inode->i_mode = mode; 1968 inode->i_uid = make_kuid(&init_user_ns, default_uid); 1969 inode->i_gid = make_kgid(&init_user_ns, default_gid); 1970 inode->i_atime = inode->i_mtime = inode->i_ctime 1971 = current_time(inode); 1972 inode->i_private = data; 1973 inode->i_fop = fops; 1974 } 1975 return inode; 1976 } 1977 1978 /* creates in fs root directory, so non-renamable and non-linkable. 1979 * so inode and dentry are paired, until device reconfig. 1980 */ 1981 static struct dentry * 1982 gadgetfs_create_file (struct super_block *sb, char const *name, 1983 void *data, const struct file_operations *fops) 1984 { 1985 struct dentry *dentry; 1986 struct inode *inode; 1987 1988 dentry = d_alloc_name(sb->s_root, name); 1989 if (!dentry) 1990 return NULL; 1991 1992 inode = gadgetfs_make_inode (sb, data, fops, 1993 S_IFREG | (default_perm & S_IRWXUGO)); 1994 if (!inode) { 1995 dput(dentry); 1996 return NULL; 1997 } 1998 d_add (dentry, inode); 1999 return dentry; 2000 } 2001 2002 static const struct super_operations gadget_fs_operations = { 2003 .statfs = simple_statfs, 2004 .drop_inode = generic_delete_inode, 2005 }; 2006 2007 static int 2008 gadgetfs_fill_super (struct super_block *sb, struct fs_context *fc) 2009 { 2010 struct inode *inode; 2011 struct dev_data *dev; 2012 2013 if (the_device) 2014 return -ESRCH; 2015 2016 CHIP = usb_get_gadget_udc_name(); 2017 if (!CHIP) 2018 return -ENODEV; 2019 2020 /* superblock */ 2021 sb->s_blocksize = PAGE_SIZE; 2022 sb->s_blocksize_bits = PAGE_SHIFT; 2023 sb->s_magic = GADGETFS_MAGIC; 2024 sb->s_op = &gadget_fs_operations; 2025 sb->s_time_gran = 1; 2026 2027 /* root inode */ 2028 inode = gadgetfs_make_inode (sb, 2029 NULL, &simple_dir_operations, 2030 S_IFDIR | S_IRUGO | S_IXUGO); 2031 if (!inode) 2032 goto Enomem; 2033 inode->i_op = &simple_dir_inode_operations; 2034 if (!(sb->s_root = d_make_root (inode))) 2035 goto Enomem; 2036 2037 /* the ep0 file is named after the controller we expect; 2038 * user mode code can use it for sanity checks, like we do. 2039 */ 2040 dev = dev_new (); 2041 if (!dev) 2042 goto Enomem; 2043 2044 dev->sb = sb; 2045 dev->dentry = gadgetfs_create_file(sb, CHIP, dev, &ep0_operations); 2046 if (!dev->dentry) { 2047 put_dev(dev); 2048 goto Enomem; 2049 } 2050 2051 /* other endpoint files are available after hardware setup, 2052 * from binding to a controller. 2053 */ 2054 the_device = dev; 2055 return 0; 2056 2057 Enomem: 2058 kfree(CHIP); 2059 CHIP = NULL; 2060 2061 return -ENOMEM; 2062 } 2063 2064 /* "mount -t gadgetfs path /dev/gadget" ends up here */ 2065 static int gadgetfs_get_tree(struct fs_context *fc) 2066 { 2067 return get_tree_single(fc, gadgetfs_fill_super); 2068 } 2069 2070 static const struct fs_context_operations gadgetfs_context_ops = { 2071 .get_tree = gadgetfs_get_tree, 2072 }; 2073 2074 static int gadgetfs_init_fs_context(struct fs_context *fc) 2075 { 2076 fc->ops = &gadgetfs_context_ops; 2077 return 0; 2078 } 2079 2080 static void 2081 gadgetfs_kill_sb (struct super_block *sb) 2082 { 2083 kill_litter_super (sb); 2084 if (the_device) { 2085 put_dev (the_device); 2086 the_device = NULL; 2087 } 2088 kfree(CHIP); 2089 CHIP = NULL; 2090 } 2091 2092 /*----------------------------------------------------------------------*/ 2093 2094 static struct file_system_type gadgetfs_type = { 2095 .owner = THIS_MODULE, 2096 .name = shortname, 2097 .init_fs_context = gadgetfs_init_fs_context, 2098 .kill_sb = gadgetfs_kill_sb, 2099 }; 2100 MODULE_ALIAS_FS("gadgetfs"); 2101 2102 /*----------------------------------------------------------------------*/ 2103 2104 static int __init gadgetfs_init (void) 2105 { 2106 int status; 2107 2108 status = register_filesystem (&gadgetfs_type); 2109 if (status == 0) 2110 pr_info ("%s: %s, version " DRIVER_VERSION "\n", 2111 shortname, driver_desc); 2112 return status; 2113 } 2114 module_init (gadgetfs_init); 2115 2116 static void __exit gadgetfs_cleanup (void) 2117 { 2118 pr_debug ("unregister %s\n", shortname); 2119 unregister_filesystem (&gadgetfs_type); 2120 } 2121 module_exit (gadgetfs_cleanup); 2122 2123