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