1 /* 2 * inode.c -- user mode filesystem api for usb gadget controllers 3 * 4 * Copyright (C) 2003-2004 David Brownell 5 * Copyright (C) 2003 Agilent Technologies 6 * 7 * This program is free software; you can redistribute it and/or modify 8 * it under the terms of the GNU General Public License as published by 9 * the Free Software Foundation; either version 2 of the License, or 10 * (at your option) any later version. 11 */ 12 13 14 /* #define VERBOSE_DEBUG */ 15 16 #include <linux/init.h> 17 #include <linux/module.h> 18 #include <linux/fs.h> 19 #include <linux/pagemap.h> 20 #include <linux/uts.h> 21 #include <linux/wait.h> 22 #include <linux/compiler.h> 23 #include <linux/uaccess.h> 24 #include <linux/sched.h> 25 #include <linux/slab.h> 26 #include <linux/poll.h> 27 #include <linux/mmu_context.h> 28 #include <linux/aio.h> 29 #include <linux/uio.h> 30 #include <linux/refcount.h> 31 32 #include <linux/device.h> 33 #include <linux/moduleparam.h> 34 35 #include <linux/usb/gadgetfs.h> 36 #include <linux/usb/gadget.h> 37 38 39 /* 40 * The gadgetfs API maps each endpoint to a file descriptor so that you 41 * can use standard synchronous read/write calls for I/O. There's some 42 * O_NONBLOCK and O_ASYNC/FASYNC style i/o support. Example usermode 43 * drivers show how this works in practice. You can also use AIO to 44 * eliminate I/O gaps between requests, to help when streaming data. 45 * 46 * Key parts that must be USB-specific are protocols defining how the 47 * read/write operations relate to the hardware state machines. There 48 * are two types of files. One type is for the device, implementing ep0. 49 * The other type is for each IN or OUT endpoint. In both cases, the 50 * user mode driver must configure the hardware before using it. 51 * 52 * - First, dev_config() is called when /dev/gadget/$CHIP is configured 53 * (by writing configuration and device descriptors). Afterwards it 54 * may serve as a source of device events, used to handle all control 55 * requests other than basic enumeration. 56 * 57 * - Then, after a SET_CONFIGURATION control request, ep_config() is 58 * called when each /dev/gadget/ep* file is configured (by writing 59 * endpoint descriptors). Afterwards these files are used to write() 60 * IN data or to read() OUT data. To halt the endpoint, a "wrong 61 * direction" request is issued (like reading an IN endpoint). 62 * 63 * Unlike "usbfs" the only ioctl()s are for things that are rare, and maybe 64 * not possible on all hardware. For example, precise fault handling with 65 * respect to data left in endpoint fifos after aborted operations; or 66 * selective clearing of endpoint halts, to implement SET_INTERFACE. 67 */ 68 69 #define DRIVER_DESC "USB Gadget filesystem" 70 #define DRIVER_VERSION "24 Aug 2004" 71 72 static const char driver_desc [] = DRIVER_DESC; 73 static const char shortname [] = "gadgetfs"; 74 75 MODULE_DESCRIPTION (DRIVER_DESC); 76 MODULE_AUTHOR ("David Brownell"); 77 MODULE_LICENSE ("GPL"); 78 79 static int ep_open(struct inode *, struct file *); 80 81 82 /*----------------------------------------------------------------------*/ 83 84 #define GADGETFS_MAGIC 0xaee71ee7 85 86 /* /dev/gadget/$CHIP represents ep0 and the whole device */ 87 enum ep0_state { 88 /* DISABLED is the initial state. */ 89 STATE_DEV_DISABLED = 0, 90 91 /* Only one open() of /dev/gadget/$CHIP; only one file tracks 92 * ep0/device i/o modes and binding to the controller. Driver 93 * must always write descriptors to initialize the device, then 94 * the device becomes UNCONNECTED until enumeration. 95 */ 96 STATE_DEV_OPENED, 97 98 /* From then on, ep0 fd is in either of two basic modes: 99 * - (UN)CONNECTED: read usb_gadgetfs_event(s) from it 100 * - SETUP: read/write will transfer control data and succeed; 101 * or if "wrong direction", performs protocol stall 102 */ 103 STATE_DEV_UNCONNECTED, 104 STATE_DEV_CONNECTED, 105 STATE_DEV_SETUP, 106 107 /* UNBOUND means the driver closed ep0, so the device won't be 108 * accessible again (DEV_DISABLED) until all fds are closed. 109 */ 110 STATE_DEV_UNBOUND, 111 }; 112 113 /* enough for the whole queue: most events invalidate others */ 114 #define N_EVENT 5 115 116 struct dev_data { 117 spinlock_t lock; 118 refcount_t count; 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 [256]; 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 // FALLTHRU 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_event_interruptible (done.wait, done.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_event (done.wait, done.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 use_mm(mm); 468 ret = copy_to_iter(priv->buf, priv->actual, &priv->to); 469 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, 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 /* aio_complete() reports bytes-transferred _and_ faults */ 502 503 iocb->ki_complete(iocb, req->actual ? req->actual : req->status, 504 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 spin_unlock(&epdata->dev->lock); 517 518 usb_ep_free_request(ep, req); 519 put_ep(epdata); 520 } 521 522 static 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; 565 566 fail: 567 spin_unlock_irq(&epdata->dev->lock); 568 kfree(priv->to_free); 569 kfree(priv); 570 put_ep(epdata); 571 return value; 572 } 573 574 static ssize_t 575 ep_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 (!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 } 625 fail: 626 kfree(buf); 627 mutex_unlock(&epdata->lock); 628 return value; 629 } 630 631 static ssize_t ep_config(struct ep_data *, const char *, size_t); 632 633 static ssize_t 634 ep_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 } 688 out: 689 kfree(buf); 690 mutex_unlock(&epdata->lock); 691 return value; 692 } 693 694 /*----------------------------------------------------------------------*/ 695 696 /* used after endpoint configuration */ 697 static 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 */ 721 static ssize_t 722 ep_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 } 800 gone: 801 spin_unlock_irq (&data->dev->lock); 802 if (value < 0) { 803 fail: 804 data->desc.bDescriptorType = 0; 805 data->hs_desc.bDescriptorType = 0; 806 } 807 return value; 808 fail0: 809 value = -EINVAL; 810 goto fail; 811 } 812 813 static int 814 ep_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 */ 846 847 static inline void ep0_readable (struct dev_data *dev) 848 { 849 wake_up (&dev->wait); 850 kill_fasync (&dev->fasync, SIGIO, POLL_IN); 851 } 852 853 static 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 } 864 865 static 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 } 887 888 static 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 } 907 908 static ssize_t 909 ep0_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 spin_unlock_irq (&dev->lock); 943 retval = usb_ep_queue (ep, req, GFP_KERNEL); 944 spin_lock_irq (&dev->lock); 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 // FIXME don't call this with the spinlock held ... 987 if (copy_to_user (buf, dev->req->buf, len)) 988 retval = -EFAULT; 989 else 990 retval = len; 991 clean_req (dev->gadget->ep0, dev->req); 992 /* NOTE userspace can't yet choose to stall */ 993 } 994 } 995 goto done; 996 } 997 998 /* else normal: return event data */ 999 if (len < sizeof dev->event [0]) { 1000 retval = -EINVAL; 1001 goto done; 1002 } 1003 len -= len % sizeof (struct usb_gadgetfs_event); 1004 dev->usermode_setup = 1; 1005 1006 scan: 1007 /* return queued events right away */ 1008 if (dev->ev_next != 0) { 1009 unsigned i, n; 1010 1011 n = len / sizeof (struct usb_gadgetfs_event); 1012 if (dev->ev_next < n) 1013 n = dev->ev_next; 1014 1015 /* ep0 i/o has special semantics during STATE_DEV_SETUP */ 1016 for (i = 0; i < n; i++) { 1017 if (dev->event [i].type == GADGETFS_SETUP) { 1018 dev->state = STATE_DEV_SETUP; 1019 n = i + 1; 1020 break; 1021 } 1022 } 1023 spin_unlock_irq (&dev->lock); 1024 len = n * sizeof (struct usb_gadgetfs_event); 1025 if (copy_to_user (buf, &dev->event, len)) 1026 retval = -EFAULT; 1027 else 1028 retval = len; 1029 if (len > 0) { 1030 /* NOTE this doesn't guard against broken drivers; 1031 * concurrent ep0 readers may lose events. 1032 */ 1033 spin_lock_irq (&dev->lock); 1034 if (dev->ev_next > n) { 1035 memmove(&dev->event[0], &dev->event[n], 1036 sizeof (struct usb_gadgetfs_event) 1037 * (dev->ev_next - n)); 1038 } 1039 dev->ev_next -= n; 1040 spin_unlock_irq (&dev->lock); 1041 } 1042 return retval; 1043 } 1044 if (fd->f_flags & O_NONBLOCK) { 1045 retval = -EAGAIN; 1046 goto done; 1047 } 1048 1049 switch (state) { 1050 default: 1051 DBG (dev, "fail %s, state %d\n", __func__, state); 1052 retval = -ESRCH; 1053 break; 1054 case STATE_DEV_UNCONNECTED: 1055 case STATE_DEV_CONNECTED: 1056 spin_unlock_irq (&dev->lock); 1057 DBG (dev, "%s wait\n", __func__); 1058 1059 /* wait for events */ 1060 retval = wait_event_interruptible (dev->wait, 1061 dev->ev_next != 0); 1062 if (retval < 0) 1063 return retval; 1064 spin_lock_irq (&dev->lock); 1065 goto scan; 1066 } 1067 1068 done: 1069 spin_unlock_irq (&dev->lock); 1070 return retval; 1071 } 1072 1073 static struct usb_gadgetfs_event * 1074 next_event (struct dev_data *dev, enum usb_gadgetfs_event_type type) 1075 { 1076 struct usb_gadgetfs_event *event; 1077 unsigned i; 1078 1079 switch (type) { 1080 /* these events purge the queue */ 1081 case GADGETFS_DISCONNECT: 1082 if (dev->state == STATE_DEV_SETUP) 1083 dev->setup_abort = 1; 1084 // FALL THROUGH 1085 case GADGETFS_CONNECT: 1086 dev->ev_next = 0; 1087 break; 1088 case GADGETFS_SETUP: /* previous request timed out */ 1089 case GADGETFS_SUSPEND: /* same effect */ 1090 /* these events can't be repeated */ 1091 for (i = 0; i != dev->ev_next; i++) { 1092 if (dev->event [i].type != type) 1093 continue; 1094 DBG(dev, "discard old event[%d] %d\n", i, type); 1095 dev->ev_next--; 1096 if (i == dev->ev_next) 1097 break; 1098 /* indices start at zero, for simplicity */ 1099 memmove (&dev->event [i], &dev->event [i + 1], 1100 sizeof (struct usb_gadgetfs_event) 1101 * (dev->ev_next - i)); 1102 } 1103 break; 1104 default: 1105 BUG (); 1106 } 1107 VDEBUG(dev, "event[%d] = %d\n", dev->ev_next, type); 1108 event = &dev->event [dev->ev_next++]; 1109 BUG_ON (dev->ev_next > N_EVENT); 1110 memset (event, 0, sizeof *event); 1111 event->type = type; 1112 return event; 1113 } 1114 1115 static ssize_t 1116 ep0_write (struct file *fd, const char __user *buf, size_t len, loff_t *ptr) 1117 { 1118 struct dev_data *dev = fd->private_data; 1119 ssize_t retval = -ESRCH; 1120 1121 /* report fd mode change before acting on it */ 1122 if (dev->setup_abort) { 1123 dev->setup_abort = 0; 1124 retval = -EIDRM; 1125 1126 /* data and/or status stage for control request */ 1127 } else if (dev->state == STATE_DEV_SETUP) { 1128 1129 len = min_t(size_t, len, dev->setup_wLength); 1130 if (dev->setup_in) { 1131 retval = setup_req (dev->gadget->ep0, dev->req, len); 1132 if (retval == 0) { 1133 dev->state = STATE_DEV_CONNECTED; 1134 spin_unlock_irq (&dev->lock); 1135 if (copy_from_user (dev->req->buf, buf, len)) 1136 retval = -EFAULT; 1137 else { 1138 if (len < dev->setup_wLength) 1139 dev->req->zero = 1; 1140 retval = usb_ep_queue ( 1141 dev->gadget->ep0, dev->req, 1142 GFP_KERNEL); 1143 } 1144 spin_lock_irq(&dev->lock); 1145 if (retval < 0) { 1146 clean_req (dev->gadget->ep0, dev->req); 1147 } else 1148 retval = len; 1149 1150 return retval; 1151 } 1152 1153 /* can stall some OUT transfers */ 1154 } else if (dev->setup_can_stall) { 1155 VDEBUG(dev, "ep0out stall\n"); 1156 (void) usb_ep_set_halt (dev->gadget->ep0); 1157 retval = -EL2HLT; 1158 dev->state = STATE_DEV_CONNECTED; 1159 } else { 1160 DBG(dev, "bogus ep0out stall!\n"); 1161 } 1162 } else 1163 DBG (dev, "fail %s, state %d\n", __func__, dev->state); 1164 1165 return retval; 1166 } 1167 1168 static int 1169 ep0_fasync (int f, struct file *fd, int on) 1170 { 1171 struct dev_data *dev = fd->private_data; 1172 // caller must F_SETOWN before signal delivery happens 1173 VDEBUG (dev, "%s %s\n", __func__, on ? "on" : "off"); 1174 return fasync_helper (f, fd, on, &dev->fasync); 1175 } 1176 1177 static struct usb_gadget_driver gadgetfs_driver; 1178 1179 static int 1180 dev_release (struct inode *inode, struct file *fd) 1181 { 1182 struct dev_data *dev = fd->private_data; 1183 1184 /* closing ep0 === shutdown all */ 1185 1186 if (dev->gadget_registered) 1187 usb_gadget_unregister_driver (&gadgetfs_driver); 1188 1189 /* at this point "good" hardware has disconnected the 1190 * device from USB; the host won't see it any more. 1191 * alternatively, all host requests will time out. 1192 */ 1193 1194 kfree (dev->buf); 1195 dev->buf = NULL; 1196 1197 /* other endpoints were all decoupled from this device */ 1198 spin_lock_irq(&dev->lock); 1199 dev->state = STATE_DEV_DISABLED; 1200 spin_unlock_irq(&dev->lock); 1201 1202 put_dev (dev); 1203 return 0; 1204 } 1205 1206 static unsigned int 1207 ep0_poll (struct file *fd, poll_table *wait) 1208 { 1209 struct dev_data *dev = fd->private_data; 1210 int mask = 0; 1211 1212 if (dev->state <= STATE_DEV_OPENED) 1213 return DEFAULT_POLLMASK; 1214 1215 poll_wait(fd, &dev->wait, wait); 1216 1217 spin_lock_irq (&dev->lock); 1218 1219 /* report fd mode change before acting on it */ 1220 if (dev->setup_abort) { 1221 dev->setup_abort = 0; 1222 mask = POLLHUP; 1223 goto out; 1224 } 1225 1226 if (dev->state == STATE_DEV_SETUP) { 1227 if (dev->setup_in || dev->setup_can_stall) 1228 mask = POLLOUT; 1229 } else { 1230 if (dev->ev_next != 0) 1231 mask = POLLIN; 1232 } 1233 out: 1234 spin_unlock_irq(&dev->lock); 1235 return mask; 1236 } 1237 1238 static long dev_ioctl (struct file *fd, unsigned code, unsigned long value) 1239 { 1240 struct dev_data *dev = fd->private_data; 1241 struct usb_gadget *gadget = dev->gadget; 1242 long ret = -ENOTTY; 1243 1244 if (gadget->ops->ioctl) 1245 ret = gadget->ops->ioctl (gadget, code, value); 1246 1247 return ret; 1248 } 1249 1250 /*----------------------------------------------------------------------*/ 1251 1252 /* The in-kernel gadget driver handles most ep0 issues, in particular 1253 * enumerating the single configuration (as provided from user space). 1254 * 1255 * Unrecognized ep0 requests may be handled in user space. 1256 */ 1257 1258 static void make_qualifier (struct dev_data *dev) 1259 { 1260 struct usb_qualifier_descriptor qual; 1261 struct usb_device_descriptor *desc; 1262 1263 qual.bLength = sizeof qual; 1264 qual.bDescriptorType = USB_DT_DEVICE_QUALIFIER; 1265 qual.bcdUSB = cpu_to_le16 (0x0200); 1266 1267 desc = dev->dev; 1268 qual.bDeviceClass = desc->bDeviceClass; 1269 qual.bDeviceSubClass = desc->bDeviceSubClass; 1270 qual.bDeviceProtocol = desc->bDeviceProtocol; 1271 1272 /* assumes ep0 uses the same value for both speeds ... */ 1273 qual.bMaxPacketSize0 = dev->gadget->ep0->maxpacket; 1274 1275 qual.bNumConfigurations = 1; 1276 qual.bRESERVED = 0; 1277 1278 memcpy (dev->rbuf, &qual, sizeof qual); 1279 } 1280 1281 static int 1282 config_buf (struct dev_data *dev, u8 type, unsigned index) 1283 { 1284 int len; 1285 int hs = 0; 1286 1287 /* only one configuration */ 1288 if (index > 0) 1289 return -EINVAL; 1290 1291 if (gadget_is_dualspeed(dev->gadget)) { 1292 hs = (dev->gadget->speed == USB_SPEED_HIGH); 1293 if (type == USB_DT_OTHER_SPEED_CONFIG) 1294 hs = !hs; 1295 } 1296 if (hs) { 1297 dev->req->buf = dev->hs_config; 1298 len = le16_to_cpu(dev->hs_config->wTotalLength); 1299 } else { 1300 dev->req->buf = dev->config; 1301 len = le16_to_cpu(dev->config->wTotalLength); 1302 } 1303 ((u8 *)dev->req->buf) [1] = type; 1304 return len; 1305 } 1306 1307 static int 1308 gadgetfs_setup (struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl) 1309 { 1310 struct dev_data *dev = get_gadget_data (gadget); 1311 struct usb_request *req = dev->req; 1312 int value = -EOPNOTSUPP; 1313 struct usb_gadgetfs_event *event; 1314 u16 w_value = le16_to_cpu(ctrl->wValue); 1315 u16 w_length = le16_to_cpu(ctrl->wLength); 1316 1317 spin_lock (&dev->lock); 1318 dev->setup_abort = 0; 1319 if (dev->state == STATE_DEV_UNCONNECTED) { 1320 if (gadget_is_dualspeed(gadget) 1321 && gadget->speed == USB_SPEED_HIGH 1322 && dev->hs_config == NULL) { 1323 spin_unlock(&dev->lock); 1324 ERROR (dev, "no high speed config??\n"); 1325 return -EINVAL; 1326 } 1327 1328 dev->state = STATE_DEV_CONNECTED; 1329 1330 INFO (dev, "connected\n"); 1331 event = next_event (dev, GADGETFS_CONNECT); 1332 event->u.speed = gadget->speed; 1333 ep0_readable (dev); 1334 1335 /* host may have given up waiting for response. we can miss control 1336 * requests handled lower down (device/endpoint status and features); 1337 * then ep0_{read,write} will report the wrong status. controller 1338 * driver will have aborted pending i/o. 1339 */ 1340 } else if (dev->state == STATE_DEV_SETUP) 1341 dev->setup_abort = 1; 1342 1343 req->buf = dev->rbuf; 1344 req->context = NULL; 1345 value = -EOPNOTSUPP; 1346 switch (ctrl->bRequest) { 1347 1348 case USB_REQ_GET_DESCRIPTOR: 1349 if (ctrl->bRequestType != USB_DIR_IN) 1350 goto unrecognized; 1351 switch (w_value >> 8) { 1352 1353 case USB_DT_DEVICE: 1354 value = min (w_length, (u16) sizeof *dev->dev); 1355 dev->dev->bMaxPacketSize0 = dev->gadget->ep0->maxpacket; 1356 req->buf = dev->dev; 1357 break; 1358 case USB_DT_DEVICE_QUALIFIER: 1359 if (!dev->hs_config) 1360 break; 1361 value = min (w_length, (u16) 1362 sizeof (struct usb_qualifier_descriptor)); 1363 make_qualifier (dev); 1364 break; 1365 case USB_DT_OTHER_SPEED_CONFIG: 1366 // FALLTHROUGH 1367 case USB_DT_CONFIG: 1368 value = config_buf (dev, 1369 w_value >> 8, 1370 w_value & 0xff); 1371 if (value >= 0) 1372 value = min (w_length, (u16) value); 1373 break; 1374 case USB_DT_STRING: 1375 goto unrecognized; 1376 1377 default: // all others are errors 1378 break; 1379 } 1380 break; 1381 1382 /* currently one config, two speeds */ 1383 case USB_REQ_SET_CONFIGURATION: 1384 if (ctrl->bRequestType != 0) 1385 goto unrecognized; 1386 if (0 == (u8) w_value) { 1387 value = 0; 1388 dev->current_config = 0; 1389 usb_gadget_vbus_draw(gadget, 8 /* mA */ ); 1390 // user mode expected to disable endpoints 1391 } else { 1392 u8 config, power; 1393 1394 if (gadget_is_dualspeed(gadget) 1395 && gadget->speed == USB_SPEED_HIGH) { 1396 config = dev->hs_config->bConfigurationValue; 1397 power = dev->hs_config->bMaxPower; 1398 } else { 1399 config = dev->config->bConfigurationValue; 1400 power = dev->config->bMaxPower; 1401 } 1402 1403 if (config == (u8) w_value) { 1404 value = 0; 1405 dev->current_config = config; 1406 usb_gadget_vbus_draw(gadget, 2 * power); 1407 } 1408 } 1409 1410 /* report SET_CONFIGURATION like any other control request, 1411 * except that usermode may not stall this. the next 1412 * request mustn't be allowed start until this finishes: 1413 * endpoints and threads set up, etc. 1414 * 1415 * NOTE: older PXA hardware (before PXA 255: without UDCCFR) 1416 * has bad/racey automagic that prevents synchronizing here. 1417 * even kernel mode drivers often miss them. 1418 */ 1419 if (value == 0) { 1420 INFO (dev, "configuration #%d\n", dev->current_config); 1421 usb_gadget_set_state(gadget, USB_STATE_CONFIGURED); 1422 if (dev->usermode_setup) { 1423 dev->setup_can_stall = 0; 1424 goto delegate; 1425 } 1426 } 1427 break; 1428 1429 #ifndef CONFIG_USB_PXA25X 1430 /* PXA automagically handles this request too */ 1431 case USB_REQ_GET_CONFIGURATION: 1432 if (ctrl->bRequestType != 0x80) 1433 goto unrecognized; 1434 *(u8 *)req->buf = dev->current_config; 1435 value = min (w_length, (u16) 1); 1436 break; 1437 #endif 1438 1439 default: 1440 unrecognized: 1441 VDEBUG (dev, "%s req%02x.%02x v%04x i%04x l%d\n", 1442 dev->usermode_setup ? "delegate" : "fail", 1443 ctrl->bRequestType, ctrl->bRequest, 1444 w_value, le16_to_cpu(ctrl->wIndex), w_length); 1445 1446 /* if there's an ep0 reader, don't stall */ 1447 if (dev->usermode_setup) { 1448 dev->setup_can_stall = 1; 1449 delegate: 1450 dev->setup_in = (ctrl->bRequestType & USB_DIR_IN) 1451 ? 1 : 0; 1452 dev->setup_wLength = w_length; 1453 dev->setup_out_ready = 0; 1454 dev->setup_out_error = 0; 1455 value = 0; 1456 1457 /* read DATA stage for OUT right away */ 1458 if (unlikely (!dev->setup_in && w_length)) { 1459 value = setup_req (gadget->ep0, dev->req, 1460 w_length); 1461 if (value < 0) 1462 break; 1463 1464 spin_unlock (&dev->lock); 1465 value = usb_ep_queue (gadget->ep0, dev->req, 1466 GFP_KERNEL); 1467 spin_lock (&dev->lock); 1468 if (value < 0) { 1469 clean_req (gadget->ep0, dev->req); 1470 break; 1471 } 1472 1473 /* we can't currently stall these */ 1474 dev->setup_can_stall = 0; 1475 } 1476 1477 /* state changes when reader collects event */ 1478 event = next_event (dev, GADGETFS_SETUP); 1479 event->u.setup = *ctrl; 1480 ep0_readable (dev); 1481 spin_unlock (&dev->lock); 1482 return 0; 1483 } 1484 } 1485 1486 /* proceed with data transfer and status phases? */ 1487 if (value >= 0 && dev->state != STATE_DEV_SETUP) { 1488 req->length = value; 1489 req->zero = value < w_length; 1490 1491 spin_unlock (&dev->lock); 1492 value = usb_ep_queue (gadget->ep0, req, GFP_KERNEL); 1493 if (value < 0) { 1494 DBG (dev, "ep_queue --> %d\n", value); 1495 req->status = 0; 1496 } 1497 return value; 1498 } 1499 1500 /* device stalls when value < 0 */ 1501 spin_unlock (&dev->lock); 1502 return value; 1503 } 1504 1505 static void destroy_ep_files (struct dev_data *dev) 1506 { 1507 DBG (dev, "%s %d\n", __func__, dev->state); 1508 1509 /* dev->state must prevent interference */ 1510 spin_lock_irq (&dev->lock); 1511 while (!list_empty(&dev->epfiles)) { 1512 struct ep_data *ep; 1513 struct inode *parent; 1514 struct dentry *dentry; 1515 1516 /* break link to FS */ 1517 ep = list_first_entry (&dev->epfiles, struct ep_data, epfiles); 1518 list_del_init (&ep->epfiles); 1519 dentry = ep->dentry; 1520 ep->dentry = NULL; 1521 parent = d_inode(dentry->d_parent); 1522 1523 /* break link to controller */ 1524 if (ep->state == STATE_EP_ENABLED) 1525 (void) usb_ep_disable (ep->ep); 1526 ep->state = STATE_EP_UNBOUND; 1527 usb_ep_free_request (ep->ep, ep->req); 1528 ep->ep = NULL; 1529 wake_up (&ep->wait); 1530 put_ep (ep); 1531 1532 spin_unlock_irq (&dev->lock); 1533 1534 /* break link to dcache */ 1535 inode_lock(parent); 1536 d_delete (dentry); 1537 dput (dentry); 1538 inode_unlock(parent); 1539 1540 spin_lock_irq (&dev->lock); 1541 } 1542 spin_unlock_irq (&dev->lock); 1543 } 1544 1545 1546 static struct dentry * 1547 gadgetfs_create_file (struct super_block *sb, char const *name, 1548 void *data, const struct file_operations *fops); 1549 1550 static int activate_ep_files (struct dev_data *dev) 1551 { 1552 struct usb_ep *ep; 1553 struct ep_data *data; 1554 1555 gadget_for_each_ep (ep, dev->gadget) { 1556 1557 data = kzalloc(sizeof(*data), GFP_KERNEL); 1558 if (!data) 1559 goto enomem0; 1560 data->state = STATE_EP_DISABLED; 1561 mutex_init(&data->lock); 1562 init_waitqueue_head (&data->wait); 1563 1564 strncpy (data->name, ep->name, sizeof (data->name) - 1); 1565 refcount_set (&data->count, 1); 1566 data->dev = dev; 1567 get_dev (dev); 1568 1569 data->ep = ep; 1570 ep->driver_data = data; 1571 1572 data->req = usb_ep_alloc_request (ep, GFP_KERNEL); 1573 if (!data->req) 1574 goto enomem1; 1575 1576 data->dentry = gadgetfs_create_file (dev->sb, data->name, 1577 data, &ep_io_operations); 1578 if (!data->dentry) 1579 goto enomem2; 1580 list_add_tail (&data->epfiles, &dev->epfiles); 1581 } 1582 return 0; 1583 1584 enomem2: 1585 usb_ep_free_request (ep, data->req); 1586 enomem1: 1587 put_dev (dev); 1588 kfree (data); 1589 enomem0: 1590 DBG (dev, "%s enomem\n", __func__); 1591 destroy_ep_files (dev); 1592 return -ENOMEM; 1593 } 1594 1595 static void 1596 gadgetfs_unbind (struct usb_gadget *gadget) 1597 { 1598 struct dev_data *dev = get_gadget_data (gadget); 1599 1600 DBG (dev, "%s\n", __func__); 1601 1602 spin_lock_irq (&dev->lock); 1603 dev->state = STATE_DEV_UNBOUND; 1604 spin_unlock_irq (&dev->lock); 1605 1606 destroy_ep_files (dev); 1607 gadget->ep0->driver_data = NULL; 1608 set_gadget_data (gadget, NULL); 1609 1610 /* we've already been disconnected ... no i/o is active */ 1611 if (dev->req) 1612 usb_ep_free_request (gadget->ep0, dev->req); 1613 DBG (dev, "%s done\n", __func__); 1614 put_dev (dev); 1615 } 1616 1617 static struct dev_data *the_device; 1618 1619 static int gadgetfs_bind(struct usb_gadget *gadget, 1620 struct usb_gadget_driver *driver) 1621 { 1622 struct dev_data *dev = the_device; 1623 1624 if (!dev) 1625 return -ESRCH; 1626 if (0 != strcmp (CHIP, gadget->name)) { 1627 pr_err("%s expected %s controller not %s\n", 1628 shortname, CHIP, gadget->name); 1629 return -ENODEV; 1630 } 1631 1632 set_gadget_data (gadget, dev); 1633 dev->gadget = gadget; 1634 gadget->ep0->driver_data = dev; 1635 1636 /* preallocate control response and buffer */ 1637 dev->req = usb_ep_alloc_request (gadget->ep0, GFP_KERNEL); 1638 if (!dev->req) 1639 goto enomem; 1640 dev->req->context = NULL; 1641 dev->req->complete = epio_complete; 1642 1643 if (activate_ep_files (dev) < 0) 1644 goto enomem; 1645 1646 INFO (dev, "bound to %s driver\n", gadget->name); 1647 spin_lock_irq(&dev->lock); 1648 dev->state = STATE_DEV_UNCONNECTED; 1649 spin_unlock_irq(&dev->lock); 1650 get_dev (dev); 1651 return 0; 1652 1653 enomem: 1654 gadgetfs_unbind (gadget); 1655 return -ENOMEM; 1656 } 1657 1658 static void 1659 gadgetfs_disconnect (struct usb_gadget *gadget) 1660 { 1661 struct dev_data *dev = get_gadget_data (gadget); 1662 unsigned long flags; 1663 1664 spin_lock_irqsave (&dev->lock, flags); 1665 if (dev->state == STATE_DEV_UNCONNECTED) 1666 goto exit; 1667 dev->state = STATE_DEV_UNCONNECTED; 1668 1669 INFO (dev, "disconnected\n"); 1670 next_event (dev, GADGETFS_DISCONNECT); 1671 ep0_readable (dev); 1672 exit: 1673 spin_unlock_irqrestore (&dev->lock, flags); 1674 } 1675 1676 static void 1677 gadgetfs_suspend (struct usb_gadget *gadget) 1678 { 1679 struct dev_data *dev = get_gadget_data (gadget); 1680 1681 INFO (dev, "suspended from state %d\n", dev->state); 1682 spin_lock (&dev->lock); 1683 switch (dev->state) { 1684 case STATE_DEV_SETUP: // VERY odd... host died?? 1685 case STATE_DEV_CONNECTED: 1686 case STATE_DEV_UNCONNECTED: 1687 next_event (dev, GADGETFS_SUSPEND); 1688 ep0_readable (dev); 1689 /* FALLTHROUGH */ 1690 default: 1691 break; 1692 } 1693 spin_unlock (&dev->lock); 1694 } 1695 1696 static struct usb_gadget_driver gadgetfs_driver = { 1697 .function = (char *) driver_desc, 1698 .bind = gadgetfs_bind, 1699 .unbind = gadgetfs_unbind, 1700 .setup = gadgetfs_setup, 1701 .reset = gadgetfs_disconnect, 1702 .disconnect = gadgetfs_disconnect, 1703 .suspend = gadgetfs_suspend, 1704 1705 .driver = { 1706 .name = (char *) shortname, 1707 }, 1708 }; 1709 1710 /*----------------------------------------------------------------------*/ 1711 /* DEVICE INITIALIZATION 1712 * 1713 * fd = open ("/dev/gadget/$CHIP", O_RDWR) 1714 * status = write (fd, descriptors, sizeof descriptors) 1715 * 1716 * That write establishes the device configuration, so the kernel can 1717 * bind to the controller ... guaranteeing it can handle enumeration 1718 * at all necessary speeds. Descriptor order is: 1719 * 1720 * . message tag (u32, host order) ... for now, must be zero; it 1721 * would change to support features like multi-config devices 1722 * . full/low speed config ... all wTotalLength bytes (with interface, 1723 * class, altsetting, endpoint, and other descriptors) 1724 * . high speed config ... all descriptors, for high speed operation; 1725 * this one's optional except for high-speed hardware 1726 * . device descriptor 1727 * 1728 * Endpoints are not yet enabled. Drivers must wait until device 1729 * configuration and interface altsetting changes create 1730 * the need to configure (or unconfigure) them. 1731 * 1732 * After initialization, the device stays active for as long as that 1733 * $CHIP file is open. Events must then be read from that descriptor, 1734 * such as configuration notifications. 1735 */ 1736 1737 static int is_valid_config(struct usb_config_descriptor *config, 1738 unsigned int total) 1739 { 1740 return config->bDescriptorType == USB_DT_CONFIG 1741 && config->bLength == USB_DT_CONFIG_SIZE 1742 && total >= USB_DT_CONFIG_SIZE 1743 && config->bConfigurationValue != 0 1744 && (config->bmAttributes & USB_CONFIG_ATT_ONE) != 0 1745 && (config->bmAttributes & USB_CONFIG_ATT_WAKEUP) == 0; 1746 /* FIXME if gadget->is_otg, _must_ include an otg descriptor */ 1747 /* FIXME check lengths: walk to end */ 1748 } 1749 1750 static ssize_t 1751 dev_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr) 1752 { 1753 struct dev_data *dev = fd->private_data; 1754 ssize_t value = len, length = len; 1755 unsigned total; 1756 u32 tag; 1757 char *kbuf; 1758 1759 spin_lock_irq(&dev->lock); 1760 if (dev->state > STATE_DEV_OPENED) { 1761 value = ep0_write(fd, buf, len, ptr); 1762 spin_unlock_irq(&dev->lock); 1763 return value; 1764 } 1765 spin_unlock_irq(&dev->lock); 1766 1767 if ((len < (USB_DT_CONFIG_SIZE + USB_DT_DEVICE_SIZE + 4)) || 1768 (len > PAGE_SIZE * 4)) 1769 return -EINVAL; 1770 1771 /* we might need to change message format someday */ 1772 if (copy_from_user (&tag, buf, 4)) 1773 return -EFAULT; 1774 if (tag != 0) 1775 return -EINVAL; 1776 buf += 4; 1777 length -= 4; 1778 1779 kbuf = memdup_user(buf, length); 1780 if (IS_ERR(kbuf)) 1781 return PTR_ERR(kbuf); 1782 1783 spin_lock_irq (&dev->lock); 1784 value = -EINVAL; 1785 if (dev->buf) { 1786 kfree(kbuf); 1787 goto fail; 1788 } 1789 dev->buf = kbuf; 1790 1791 /* full or low speed config */ 1792 dev->config = (void *) kbuf; 1793 total = le16_to_cpu(dev->config->wTotalLength); 1794 if (!is_valid_config(dev->config, total) || 1795 total > length - USB_DT_DEVICE_SIZE) 1796 goto fail; 1797 kbuf += total; 1798 length -= total; 1799 1800 /* optional high speed config */ 1801 if (kbuf [1] == USB_DT_CONFIG) { 1802 dev->hs_config = (void *) kbuf; 1803 total = le16_to_cpu(dev->hs_config->wTotalLength); 1804 if (!is_valid_config(dev->hs_config, total) || 1805 total > length - USB_DT_DEVICE_SIZE) 1806 goto fail; 1807 kbuf += total; 1808 length -= total; 1809 } else { 1810 dev->hs_config = NULL; 1811 } 1812 1813 /* could support multiple configs, using another encoding! */ 1814 1815 /* device descriptor (tweaked for paranoia) */ 1816 if (length != USB_DT_DEVICE_SIZE) 1817 goto fail; 1818 dev->dev = (void *)kbuf; 1819 if (dev->dev->bLength != USB_DT_DEVICE_SIZE 1820 || dev->dev->bDescriptorType != USB_DT_DEVICE 1821 || dev->dev->bNumConfigurations != 1) 1822 goto fail; 1823 dev->dev->bcdUSB = cpu_to_le16 (0x0200); 1824 1825 /* triggers gadgetfs_bind(); then we can enumerate. */ 1826 spin_unlock_irq (&dev->lock); 1827 if (dev->hs_config) 1828 gadgetfs_driver.max_speed = USB_SPEED_HIGH; 1829 else 1830 gadgetfs_driver.max_speed = USB_SPEED_FULL; 1831 1832 value = usb_gadget_probe_driver(&gadgetfs_driver); 1833 if (value != 0) { 1834 kfree (dev->buf); 1835 dev->buf = NULL; 1836 } else { 1837 /* at this point "good" hardware has for the first time 1838 * let the USB the host see us. alternatively, if users 1839 * unplug/replug that will clear all the error state. 1840 * 1841 * note: everything running before here was guaranteed 1842 * to choke driver model style diagnostics. from here 1843 * on, they can work ... except in cleanup paths that 1844 * kick in after the ep0 descriptor is closed. 1845 */ 1846 value = len; 1847 dev->gadget_registered = true; 1848 } 1849 return value; 1850 1851 fail: 1852 spin_unlock_irq (&dev->lock); 1853 pr_debug ("%s: %s fail %zd, %p\n", shortname, __func__, value, dev); 1854 kfree (dev->buf); 1855 dev->buf = NULL; 1856 return value; 1857 } 1858 1859 static int 1860 dev_open (struct inode *inode, struct file *fd) 1861 { 1862 struct dev_data *dev = inode->i_private; 1863 int value = -EBUSY; 1864 1865 spin_lock_irq(&dev->lock); 1866 if (dev->state == STATE_DEV_DISABLED) { 1867 dev->ev_next = 0; 1868 dev->state = STATE_DEV_OPENED; 1869 fd->private_data = dev; 1870 get_dev (dev); 1871 value = 0; 1872 } 1873 spin_unlock_irq(&dev->lock); 1874 return value; 1875 } 1876 1877 static const struct file_operations ep0_operations = { 1878 .llseek = no_llseek, 1879 1880 .open = dev_open, 1881 .read = ep0_read, 1882 .write = dev_config, 1883 .fasync = ep0_fasync, 1884 .poll = ep0_poll, 1885 .unlocked_ioctl = dev_ioctl, 1886 .release = dev_release, 1887 }; 1888 1889 /*----------------------------------------------------------------------*/ 1890 1891 /* FILESYSTEM AND SUPERBLOCK OPERATIONS 1892 * 1893 * Mounting the filesystem creates a controller file, used first for 1894 * device configuration then later for event monitoring. 1895 */ 1896 1897 1898 /* FIXME PAM etc could set this security policy without mount options 1899 * if epfiles inherited ownership and permissons from ep0 ... 1900 */ 1901 1902 static unsigned default_uid; 1903 static unsigned default_gid; 1904 static unsigned default_perm = S_IRUSR | S_IWUSR; 1905 1906 module_param (default_uid, uint, 0644); 1907 module_param (default_gid, uint, 0644); 1908 module_param (default_perm, uint, 0644); 1909 1910 1911 static struct inode * 1912 gadgetfs_make_inode (struct super_block *sb, 1913 void *data, const struct file_operations *fops, 1914 int mode) 1915 { 1916 struct inode *inode = new_inode (sb); 1917 1918 if (inode) { 1919 inode->i_ino = get_next_ino(); 1920 inode->i_mode = mode; 1921 inode->i_uid = make_kuid(&init_user_ns, default_uid); 1922 inode->i_gid = make_kgid(&init_user_ns, default_gid); 1923 inode->i_atime = inode->i_mtime = inode->i_ctime 1924 = current_time(inode); 1925 inode->i_private = data; 1926 inode->i_fop = fops; 1927 } 1928 return inode; 1929 } 1930 1931 /* creates in fs root directory, so non-renamable and non-linkable. 1932 * so inode and dentry are paired, until device reconfig. 1933 */ 1934 static struct dentry * 1935 gadgetfs_create_file (struct super_block *sb, char const *name, 1936 void *data, const struct file_operations *fops) 1937 { 1938 struct dentry *dentry; 1939 struct inode *inode; 1940 1941 dentry = d_alloc_name(sb->s_root, name); 1942 if (!dentry) 1943 return NULL; 1944 1945 inode = gadgetfs_make_inode (sb, data, fops, 1946 S_IFREG | (default_perm & S_IRWXUGO)); 1947 if (!inode) { 1948 dput(dentry); 1949 return NULL; 1950 } 1951 d_add (dentry, inode); 1952 return dentry; 1953 } 1954 1955 static const struct super_operations gadget_fs_operations = { 1956 .statfs = simple_statfs, 1957 .drop_inode = generic_delete_inode, 1958 }; 1959 1960 static int 1961 gadgetfs_fill_super (struct super_block *sb, void *opts, int silent) 1962 { 1963 struct inode *inode; 1964 struct dev_data *dev; 1965 1966 if (the_device) 1967 return -ESRCH; 1968 1969 CHIP = usb_get_gadget_udc_name(); 1970 if (!CHIP) 1971 return -ENODEV; 1972 1973 /* superblock */ 1974 sb->s_blocksize = PAGE_SIZE; 1975 sb->s_blocksize_bits = PAGE_SHIFT; 1976 sb->s_magic = GADGETFS_MAGIC; 1977 sb->s_op = &gadget_fs_operations; 1978 sb->s_time_gran = 1; 1979 1980 /* root inode */ 1981 inode = gadgetfs_make_inode (sb, 1982 NULL, &simple_dir_operations, 1983 S_IFDIR | S_IRUGO | S_IXUGO); 1984 if (!inode) 1985 goto Enomem; 1986 inode->i_op = &simple_dir_inode_operations; 1987 if (!(sb->s_root = d_make_root (inode))) 1988 goto Enomem; 1989 1990 /* the ep0 file is named after the controller we expect; 1991 * user mode code can use it for sanity checks, like we do. 1992 */ 1993 dev = dev_new (); 1994 if (!dev) 1995 goto Enomem; 1996 1997 dev->sb = sb; 1998 dev->dentry = gadgetfs_create_file(sb, CHIP, dev, &ep0_operations); 1999 if (!dev->dentry) { 2000 put_dev(dev); 2001 goto Enomem; 2002 } 2003 2004 /* other endpoint files are available after hardware setup, 2005 * from binding to a controller. 2006 */ 2007 the_device = dev; 2008 return 0; 2009 2010 Enomem: 2011 return -ENOMEM; 2012 } 2013 2014 /* "mount -t gadgetfs path /dev/gadget" ends up here */ 2015 static struct dentry * 2016 gadgetfs_mount (struct file_system_type *t, int flags, 2017 const char *path, void *opts) 2018 { 2019 return mount_single (t, flags, opts, gadgetfs_fill_super); 2020 } 2021 2022 static void 2023 gadgetfs_kill_sb (struct super_block *sb) 2024 { 2025 kill_litter_super (sb); 2026 if (the_device) { 2027 put_dev (the_device); 2028 the_device = NULL; 2029 } 2030 kfree(CHIP); 2031 CHIP = NULL; 2032 } 2033 2034 /*----------------------------------------------------------------------*/ 2035 2036 static struct file_system_type gadgetfs_type = { 2037 .owner = THIS_MODULE, 2038 .name = shortname, 2039 .mount = gadgetfs_mount, 2040 .kill_sb = gadgetfs_kill_sb, 2041 }; 2042 MODULE_ALIAS_FS("gadgetfs"); 2043 2044 /*----------------------------------------------------------------------*/ 2045 2046 static int __init init (void) 2047 { 2048 int status; 2049 2050 status = register_filesystem (&gadgetfs_type); 2051 if (status == 0) 2052 pr_info ("%s: %s, version " DRIVER_VERSION "\n", 2053 shortname, driver_desc); 2054 return status; 2055 } 2056 module_init (init); 2057 2058 static void __exit cleanup (void) 2059 { 2060 pr_debug ("unregister %s\n", shortname); 2061 unregister_filesystem (&gadgetfs_type); 2062 } 2063 module_exit (cleanup); 2064 2065