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 <asm/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 30 #include <linux/device.h> 31 #include <linux/moduleparam.h> 32 33 #include <linux/usb/gadgetfs.h> 34 #include <linux/usb/gadget.h> 35 36 37 /* 38 * The gadgetfs API maps each endpoint to a file descriptor so that you 39 * can use standard synchronous read/write calls for I/O. There's some 40 * O_NONBLOCK and O_ASYNC/FASYNC style i/o support. Example usermode 41 * drivers show how this works in practice. You can also use AIO to 42 * eliminate I/O gaps between requests, to help when streaming data. 43 * 44 * Key parts that must be USB-specific are protocols defining how the 45 * read/write operations relate to the hardware state machines. There 46 * are two types of files. One type is for the device, implementing ep0. 47 * The other type is for each IN or OUT endpoint. In both cases, the 48 * user mode driver must configure the hardware before using it. 49 * 50 * - First, dev_config() is called when /dev/gadget/$CHIP is configured 51 * (by writing configuration and device descriptors). Afterwards it 52 * may serve as a source of device events, used to handle all control 53 * requests other than basic enumeration. 54 * 55 * - Then, after a SET_CONFIGURATION control request, ep_config() is 56 * called when each /dev/gadget/ep* file is configured (by writing 57 * endpoint descriptors). Afterwards these files are used to write() 58 * IN data or to read() OUT data. To halt the endpoint, a "wrong 59 * direction" request is issued (like reading an IN endpoint). 60 * 61 * Unlike "usbfs" the only ioctl()s are for things that are rare, and maybe 62 * not possible on all hardware. For example, precise fault handling with 63 * respect to data left in endpoint fifos after aborted operations; or 64 * selective clearing of endpoint halts, to implement SET_INTERFACE. 65 */ 66 67 #define DRIVER_DESC "USB Gadget filesystem" 68 #define DRIVER_VERSION "24 Aug 2004" 69 70 static const char driver_desc [] = DRIVER_DESC; 71 static const char shortname [] = "gadgetfs"; 72 73 MODULE_DESCRIPTION (DRIVER_DESC); 74 MODULE_AUTHOR ("David Brownell"); 75 MODULE_LICENSE ("GPL"); 76 77 78 /*----------------------------------------------------------------------*/ 79 80 #define GADGETFS_MAGIC 0xaee71ee7 81 82 /* /dev/gadget/$CHIP represents ep0 and the whole device */ 83 enum ep0_state { 84 /* DISBLED is the initial state. 85 */ 86 STATE_DEV_DISABLED = 0, 87 88 /* Only one open() of /dev/gadget/$CHIP; only one file tracks 89 * ep0/device i/o modes and binding to the controller. Driver 90 * must always write descriptors to initialize the device, then 91 * the device becomes UNCONNECTED until enumeration. 92 */ 93 STATE_DEV_OPENED, 94 95 /* From then on, ep0 fd is in either of two basic modes: 96 * - (UN)CONNECTED: read usb_gadgetfs_event(s) from it 97 * - SETUP: read/write will transfer control data and succeed; 98 * or if "wrong direction", performs protocol stall 99 */ 100 STATE_DEV_UNCONNECTED, 101 STATE_DEV_CONNECTED, 102 STATE_DEV_SETUP, 103 104 /* UNBOUND means the driver closed ep0, so the device won't be 105 * accessible again (DEV_DISABLED) until all fds are closed. 106 */ 107 STATE_DEV_UNBOUND, 108 }; 109 110 /* enough for the whole queue: most events invalidate others */ 111 #define N_EVENT 5 112 113 struct dev_data { 114 spinlock_t lock; 115 atomic_t count; 116 enum ep0_state state; /* P: lock */ 117 struct usb_gadgetfs_event event [N_EVENT]; 118 unsigned ev_next; 119 struct fasync_struct *fasync; 120 u8 current_config; 121 122 /* drivers reading ep0 MUST handle control requests (SETUP) 123 * reported that way; else the host will time out. 124 */ 125 unsigned usermode_setup : 1, 126 setup_in : 1, 127 setup_can_stall : 1, 128 setup_out_ready : 1, 129 setup_out_error : 1, 130 setup_abort : 1; 131 unsigned setup_wLength; 132 133 /* the rest is basically write-once */ 134 struct usb_config_descriptor *config, *hs_config; 135 struct usb_device_descriptor *dev; 136 struct usb_request *req; 137 struct usb_gadget *gadget; 138 struct list_head epfiles; 139 void *buf; 140 wait_queue_head_t wait; 141 struct super_block *sb; 142 struct dentry *dentry; 143 144 /* except this scratch i/o buffer for ep0 */ 145 u8 rbuf [256]; 146 }; 147 148 static inline void get_dev (struct dev_data *data) 149 { 150 atomic_inc (&data->count); 151 } 152 153 static void put_dev (struct dev_data *data) 154 { 155 if (likely (!atomic_dec_and_test (&data->count))) 156 return; 157 /* needs no more cleanup */ 158 BUG_ON (waitqueue_active (&data->wait)); 159 kfree (data); 160 } 161 162 static struct dev_data *dev_new (void) 163 { 164 struct dev_data *dev; 165 166 dev = kzalloc(sizeof(*dev), GFP_KERNEL); 167 if (!dev) 168 return NULL; 169 dev->state = STATE_DEV_DISABLED; 170 atomic_set (&dev->count, 1); 171 spin_lock_init (&dev->lock); 172 INIT_LIST_HEAD (&dev->epfiles); 173 init_waitqueue_head (&dev->wait); 174 return dev; 175 } 176 177 /*----------------------------------------------------------------------*/ 178 179 /* other /dev/gadget/$ENDPOINT files represent endpoints */ 180 enum ep_state { 181 STATE_EP_DISABLED = 0, 182 STATE_EP_READY, 183 STATE_EP_ENABLED, 184 STATE_EP_UNBOUND, 185 }; 186 187 struct ep_data { 188 struct mutex lock; 189 enum ep_state state; 190 atomic_t count; 191 struct dev_data *dev; 192 /* must hold dev->lock before accessing ep or req */ 193 struct usb_ep *ep; 194 struct usb_request *req; 195 ssize_t status; 196 char name [16]; 197 struct usb_endpoint_descriptor desc, hs_desc; 198 struct list_head epfiles; 199 wait_queue_head_t wait; 200 struct dentry *dentry; 201 }; 202 203 static inline void get_ep (struct ep_data *data) 204 { 205 atomic_inc (&data->count); 206 } 207 208 static void put_ep (struct ep_data *data) 209 { 210 if (likely (!atomic_dec_and_test (&data->count))) 211 return; 212 put_dev (data->dev); 213 /* needs no more cleanup */ 214 BUG_ON (!list_empty (&data->epfiles)); 215 BUG_ON (waitqueue_active (&data->wait)); 216 kfree (data); 217 } 218 219 /*----------------------------------------------------------------------*/ 220 221 /* most "how to use the hardware" policy choices are in userspace: 222 * mapping endpoint roles (which the driver needs) to the capabilities 223 * which the usb controller has. most of those capabilities are exposed 224 * implicitly, starting with the driver name and then endpoint names. 225 */ 226 227 static const char *CHIP; 228 229 /*----------------------------------------------------------------------*/ 230 231 /* NOTE: don't use dev_printk calls before binding to the gadget 232 * at the end of ep0 configuration, or after unbind. 233 */ 234 235 /* too wordy: dev_printk(level , &(d)->gadget->dev , fmt , ## args) */ 236 #define xprintk(d,level,fmt,args...) \ 237 printk(level "%s: " fmt , shortname , ## args) 238 239 #ifdef DEBUG 240 #define DBG(dev,fmt,args...) \ 241 xprintk(dev , KERN_DEBUG , fmt , ## args) 242 #else 243 #define DBG(dev,fmt,args...) \ 244 do { } while (0) 245 #endif /* DEBUG */ 246 247 #ifdef VERBOSE_DEBUG 248 #define VDEBUG DBG 249 #else 250 #define VDEBUG(dev,fmt,args...) \ 251 do { } while (0) 252 #endif /* DEBUG */ 253 254 #define ERROR(dev,fmt,args...) \ 255 xprintk(dev , KERN_ERR , fmt , ## args) 256 #define INFO(dev,fmt,args...) \ 257 xprintk(dev , KERN_INFO , fmt , ## args) 258 259 260 /*----------------------------------------------------------------------*/ 261 262 /* SYNCHRONOUS ENDPOINT OPERATIONS (bulk/intr/iso) 263 * 264 * After opening, configure non-control endpoints. Then use normal 265 * stream read() and write() requests; and maybe ioctl() to get more 266 * precise FIFO status when recovering from cancellation. 267 */ 268 269 static void epio_complete (struct usb_ep *ep, struct usb_request *req) 270 { 271 struct ep_data *epdata = ep->driver_data; 272 273 if (!req->context) 274 return; 275 if (req->status) 276 epdata->status = req->status; 277 else 278 epdata->status = req->actual; 279 complete ((struct completion *)req->context); 280 } 281 282 /* tasklock endpoint, returning when it's connected. 283 * still need dev->lock to use epdata->ep. 284 */ 285 static int 286 get_ready_ep (unsigned f_flags, struct ep_data *epdata) 287 { 288 int val; 289 290 if (f_flags & O_NONBLOCK) { 291 if (!mutex_trylock(&epdata->lock)) 292 goto nonblock; 293 if (epdata->state != STATE_EP_ENABLED) { 294 mutex_unlock(&epdata->lock); 295 nonblock: 296 val = -EAGAIN; 297 } else 298 val = 0; 299 return val; 300 } 301 302 val = mutex_lock_interruptible(&epdata->lock); 303 if (val < 0) 304 return val; 305 306 switch (epdata->state) { 307 case STATE_EP_ENABLED: 308 break; 309 // case STATE_EP_DISABLED: /* "can't happen" */ 310 // case STATE_EP_READY: /* "can't happen" */ 311 default: /* error! */ 312 pr_debug ("%s: ep %p not available, state %d\n", 313 shortname, epdata, epdata->state); 314 // FALLTHROUGH 315 case STATE_EP_UNBOUND: /* clean disconnect */ 316 val = -ENODEV; 317 mutex_unlock(&epdata->lock); 318 } 319 return val; 320 } 321 322 static ssize_t 323 ep_io (struct ep_data *epdata, void *buf, unsigned len) 324 { 325 DECLARE_COMPLETION_ONSTACK (done); 326 int value; 327 328 spin_lock_irq (&epdata->dev->lock); 329 if (likely (epdata->ep != NULL)) { 330 struct usb_request *req = epdata->req; 331 332 req->context = &done; 333 req->complete = epio_complete; 334 req->buf = buf; 335 req->length = len; 336 value = usb_ep_queue (epdata->ep, req, GFP_ATOMIC); 337 } else 338 value = -ENODEV; 339 spin_unlock_irq (&epdata->dev->lock); 340 341 if (likely (value == 0)) { 342 value = wait_event_interruptible (done.wait, done.done); 343 if (value != 0) { 344 spin_lock_irq (&epdata->dev->lock); 345 if (likely (epdata->ep != NULL)) { 346 DBG (epdata->dev, "%s i/o interrupted\n", 347 epdata->name); 348 usb_ep_dequeue (epdata->ep, epdata->req); 349 spin_unlock_irq (&epdata->dev->lock); 350 351 wait_event (done.wait, done.done); 352 if (epdata->status == -ECONNRESET) 353 epdata->status = -EINTR; 354 } else { 355 spin_unlock_irq (&epdata->dev->lock); 356 357 DBG (epdata->dev, "endpoint gone\n"); 358 epdata->status = -ENODEV; 359 } 360 } 361 return epdata->status; 362 } 363 return value; 364 } 365 366 367 /* handle a synchronous OUT bulk/intr/iso transfer */ 368 static ssize_t 369 ep_read (struct file *fd, char __user *buf, size_t len, loff_t *ptr) 370 { 371 struct ep_data *data = fd->private_data; 372 void *kbuf; 373 ssize_t value; 374 375 if ((value = get_ready_ep (fd->f_flags, data)) < 0) 376 return value; 377 378 /* halt any endpoint by doing a "wrong direction" i/o call */ 379 if (usb_endpoint_dir_in(&data->desc)) { 380 if (usb_endpoint_xfer_isoc(&data->desc)) { 381 mutex_unlock(&data->lock); 382 return -EINVAL; 383 } 384 DBG (data->dev, "%s halt\n", data->name); 385 spin_lock_irq (&data->dev->lock); 386 if (likely (data->ep != NULL)) 387 usb_ep_set_halt (data->ep); 388 spin_unlock_irq (&data->dev->lock); 389 mutex_unlock(&data->lock); 390 return -EBADMSG; 391 } 392 393 /* FIXME readahead for O_NONBLOCK and poll(); careful with ZLPs */ 394 395 value = -ENOMEM; 396 kbuf = kmalloc (len, GFP_KERNEL); 397 if (unlikely (!kbuf)) 398 goto free1; 399 400 value = ep_io (data, kbuf, len); 401 VDEBUG (data->dev, "%s read %zu OUT, status %d\n", 402 data->name, len, (int) value); 403 if (value >= 0 && copy_to_user (buf, kbuf, value)) 404 value = -EFAULT; 405 406 free1: 407 mutex_unlock(&data->lock); 408 kfree (kbuf); 409 return value; 410 } 411 412 /* handle a synchronous IN bulk/intr/iso transfer */ 413 static ssize_t 414 ep_write (struct file *fd, const char __user *buf, size_t len, loff_t *ptr) 415 { 416 struct ep_data *data = fd->private_data; 417 void *kbuf; 418 ssize_t value; 419 420 if ((value = get_ready_ep (fd->f_flags, data)) < 0) 421 return value; 422 423 /* halt any endpoint by doing a "wrong direction" i/o call */ 424 if (!usb_endpoint_dir_in(&data->desc)) { 425 if (usb_endpoint_xfer_isoc(&data->desc)) { 426 mutex_unlock(&data->lock); 427 return -EINVAL; 428 } 429 DBG (data->dev, "%s halt\n", data->name); 430 spin_lock_irq (&data->dev->lock); 431 if (likely (data->ep != NULL)) 432 usb_ep_set_halt (data->ep); 433 spin_unlock_irq (&data->dev->lock); 434 mutex_unlock(&data->lock); 435 return -EBADMSG; 436 } 437 438 /* FIXME writebehind for O_NONBLOCK and poll(), qlen = 1 */ 439 440 value = -ENOMEM; 441 kbuf = memdup_user(buf, len); 442 if (IS_ERR(kbuf)) { 443 value = PTR_ERR(kbuf); 444 goto free1; 445 } 446 447 value = ep_io (data, kbuf, len); 448 VDEBUG (data->dev, "%s write %zu IN, status %d\n", 449 data->name, len, (int) value); 450 free1: 451 mutex_unlock(&data->lock); 452 return value; 453 } 454 455 static int 456 ep_release (struct inode *inode, struct file *fd) 457 { 458 struct ep_data *data = fd->private_data; 459 int value; 460 461 value = mutex_lock_interruptible(&data->lock); 462 if (value < 0) 463 return value; 464 465 /* clean up if this can be reopened */ 466 if (data->state != STATE_EP_UNBOUND) { 467 data->state = STATE_EP_DISABLED; 468 data->desc.bDescriptorType = 0; 469 data->hs_desc.bDescriptorType = 0; 470 usb_ep_disable(data->ep); 471 } 472 mutex_unlock(&data->lock); 473 put_ep (data); 474 return 0; 475 } 476 477 static long ep_ioctl(struct file *fd, unsigned code, unsigned long value) 478 { 479 struct ep_data *data = fd->private_data; 480 int status; 481 482 if ((status = get_ready_ep (fd->f_flags, data)) < 0) 483 return status; 484 485 spin_lock_irq (&data->dev->lock); 486 if (likely (data->ep != NULL)) { 487 switch (code) { 488 case GADGETFS_FIFO_STATUS: 489 status = usb_ep_fifo_status (data->ep); 490 break; 491 case GADGETFS_FIFO_FLUSH: 492 usb_ep_fifo_flush (data->ep); 493 break; 494 case GADGETFS_CLEAR_HALT: 495 status = usb_ep_clear_halt (data->ep); 496 break; 497 default: 498 status = -ENOTTY; 499 } 500 } else 501 status = -ENODEV; 502 spin_unlock_irq (&data->dev->lock); 503 mutex_unlock(&data->lock); 504 return status; 505 } 506 507 /*----------------------------------------------------------------------*/ 508 509 /* ASYNCHRONOUS ENDPOINT I/O OPERATIONS (bulk/intr/iso) */ 510 511 struct kiocb_priv { 512 struct usb_request *req; 513 struct ep_data *epdata; 514 struct kiocb *iocb; 515 struct mm_struct *mm; 516 struct work_struct work; 517 void *buf; 518 const struct iovec *iv; 519 unsigned long nr_segs; 520 unsigned actual; 521 }; 522 523 static int ep_aio_cancel(struct kiocb *iocb) 524 { 525 struct kiocb_priv *priv = iocb->private; 526 struct ep_data *epdata; 527 int value; 528 529 local_irq_disable(); 530 epdata = priv->epdata; 531 // spin_lock(&epdata->dev->lock); 532 if (likely(epdata && epdata->ep && priv->req)) 533 value = usb_ep_dequeue (epdata->ep, priv->req); 534 else 535 value = -EINVAL; 536 // spin_unlock(&epdata->dev->lock); 537 local_irq_enable(); 538 539 return value; 540 } 541 542 static ssize_t ep_copy_to_user(struct kiocb_priv *priv) 543 { 544 ssize_t len, total; 545 void *to_copy; 546 int i; 547 548 /* copy stuff into user buffers */ 549 total = priv->actual; 550 len = 0; 551 to_copy = priv->buf; 552 for (i=0; i < priv->nr_segs; i++) { 553 ssize_t this = min((ssize_t)(priv->iv[i].iov_len), total); 554 555 if (copy_to_user(priv->iv[i].iov_base, to_copy, this)) { 556 if (len == 0) 557 len = -EFAULT; 558 break; 559 } 560 561 total -= this; 562 len += this; 563 to_copy += this; 564 if (total == 0) 565 break; 566 } 567 568 return len; 569 } 570 571 static void ep_user_copy_worker(struct work_struct *work) 572 { 573 struct kiocb_priv *priv = container_of(work, struct kiocb_priv, work); 574 struct mm_struct *mm = priv->mm; 575 struct kiocb *iocb = priv->iocb; 576 size_t ret; 577 578 use_mm(mm); 579 ret = ep_copy_to_user(priv); 580 unuse_mm(mm); 581 582 /* completing the iocb can drop the ctx and mm, don't touch mm after */ 583 aio_complete(iocb, ret, ret); 584 585 kfree(priv->buf); 586 kfree(priv); 587 } 588 589 static void ep_aio_complete(struct usb_ep *ep, struct usb_request *req) 590 { 591 struct kiocb *iocb = req->context; 592 struct kiocb_priv *priv = iocb->private; 593 struct ep_data *epdata = priv->epdata; 594 595 /* lock against disconnect (and ideally, cancel) */ 596 spin_lock(&epdata->dev->lock); 597 priv->req = NULL; 598 priv->epdata = NULL; 599 600 /* if this was a write or a read returning no data then we 601 * don't need to copy anything to userspace, so we can 602 * complete the aio request immediately. 603 */ 604 if (priv->iv == NULL || unlikely(req->actual == 0)) { 605 kfree(req->buf); 606 kfree(priv); 607 iocb->private = NULL; 608 /* aio_complete() reports bytes-transferred _and_ faults */ 609 aio_complete(iocb, req->actual ? req->actual : req->status, 610 req->status); 611 } else { 612 /* ep_copy_to_user() won't report both; we hide some faults */ 613 if (unlikely(0 != req->status)) 614 DBG(epdata->dev, "%s fault %d len %d\n", 615 ep->name, req->status, req->actual); 616 617 priv->buf = req->buf; 618 priv->actual = req->actual; 619 schedule_work(&priv->work); 620 } 621 spin_unlock(&epdata->dev->lock); 622 623 usb_ep_free_request(ep, req); 624 put_ep(epdata); 625 } 626 627 static ssize_t 628 ep_aio_rwtail( 629 struct kiocb *iocb, 630 char *buf, 631 size_t len, 632 struct ep_data *epdata, 633 const struct iovec *iv, 634 unsigned long nr_segs 635 ) 636 { 637 struct kiocb_priv *priv; 638 struct usb_request *req; 639 ssize_t value; 640 641 priv = kmalloc(sizeof *priv, GFP_KERNEL); 642 if (!priv) { 643 value = -ENOMEM; 644 fail: 645 kfree(buf); 646 return value; 647 } 648 iocb->private = priv; 649 priv->iocb = iocb; 650 priv->iv = iv; 651 priv->nr_segs = nr_segs; 652 INIT_WORK(&priv->work, ep_user_copy_worker); 653 654 value = get_ready_ep(iocb->ki_filp->f_flags, epdata); 655 if (unlikely(value < 0)) { 656 kfree(priv); 657 goto fail; 658 } 659 660 kiocb_set_cancel_fn(iocb, ep_aio_cancel); 661 get_ep(epdata); 662 priv->epdata = epdata; 663 priv->actual = 0; 664 priv->mm = current->mm; /* mm teardown waits for iocbs in exit_aio() */ 665 666 /* each kiocb is coupled to one usb_request, but we can't 667 * allocate or submit those if the host disconnected. 668 */ 669 spin_lock_irq(&epdata->dev->lock); 670 if (likely(epdata->ep)) { 671 req = usb_ep_alloc_request(epdata->ep, GFP_ATOMIC); 672 if (likely(req)) { 673 priv->req = req; 674 req->buf = buf; 675 req->length = len; 676 req->complete = ep_aio_complete; 677 req->context = iocb; 678 value = usb_ep_queue(epdata->ep, req, GFP_ATOMIC); 679 if (unlikely(0 != value)) 680 usb_ep_free_request(epdata->ep, req); 681 } else 682 value = -EAGAIN; 683 } else 684 value = -ENODEV; 685 spin_unlock_irq(&epdata->dev->lock); 686 687 mutex_unlock(&epdata->lock); 688 689 if (unlikely(value)) { 690 kfree(priv); 691 put_ep(epdata); 692 } else 693 value = -EIOCBQUEUED; 694 return value; 695 } 696 697 static ssize_t 698 ep_aio_read(struct kiocb *iocb, const struct iovec *iov, 699 unsigned long nr_segs, loff_t o) 700 { 701 struct ep_data *epdata = iocb->ki_filp->private_data; 702 char *buf; 703 704 if (unlikely(usb_endpoint_dir_in(&epdata->desc))) 705 return -EINVAL; 706 707 buf = kmalloc(iocb->ki_nbytes, GFP_KERNEL); 708 if (unlikely(!buf)) 709 return -ENOMEM; 710 711 return ep_aio_rwtail(iocb, buf, iocb->ki_nbytes, epdata, iov, nr_segs); 712 } 713 714 static ssize_t 715 ep_aio_write(struct kiocb *iocb, const struct iovec *iov, 716 unsigned long nr_segs, loff_t o) 717 { 718 struct ep_data *epdata = iocb->ki_filp->private_data; 719 char *buf; 720 size_t len = 0; 721 int i = 0; 722 723 if (unlikely(!usb_endpoint_dir_in(&epdata->desc))) 724 return -EINVAL; 725 726 buf = kmalloc(iocb->ki_nbytes, GFP_KERNEL); 727 if (unlikely(!buf)) 728 return -ENOMEM; 729 730 for (i=0; i < nr_segs; i++) { 731 if (unlikely(copy_from_user(&buf[len], iov[i].iov_base, 732 iov[i].iov_len) != 0)) { 733 kfree(buf); 734 return -EFAULT; 735 } 736 len += iov[i].iov_len; 737 } 738 return ep_aio_rwtail(iocb, buf, len, epdata, NULL, 0); 739 } 740 741 /*----------------------------------------------------------------------*/ 742 743 /* used after endpoint configuration */ 744 static const struct file_operations ep_io_operations = { 745 .owner = THIS_MODULE, 746 .llseek = no_llseek, 747 748 .read = ep_read, 749 .write = ep_write, 750 .unlocked_ioctl = ep_ioctl, 751 .release = ep_release, 752 753 .aio_read = ep_aio_read, 754 .aio_write = ep_aio_write, 755 }; 756 757 /* ENDPOINT INITIALIZATION 758 * 759 * fd = open ("/dev/gadget/$ENDPOINT", O_RDWR) 760 * status = write (fd, descriptors, sizeof descriptors) 761 * 762 * That write establishes the endpoint configuration, configuring 763 * the controller to process bulk, interrupt, or isochronous transfers 764 * at the right maxpacket size, and so on. 765 * 766 * The descriptors are message type 1, identified by a host order u32 767 * at the beginning of what's written. Descriptor order is: full/low 768 * speed descriptor, then optional high speed descriptor. 769 */ 770 static ssize_t 771 ep_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr) 772 { 773 struct ep_data *data = fd->private_data; 774 struct usb_ep *ep; 775 u32 tag; 776 int value, length = len; 777 778 value = mutex_lock_interruptible(&data->lock); 779 if (value < 0) 780 return value; 781 782 if (data->state != STATE_EP_READY) { 783 value = -EL2HLT; 784 goto fail; 785 } 786 787 value = len; 788 if (len < USB_DT_ENDPOINT_SIZE + 4) 789 goto fail0; 790 791 /* we might need to change message format someday */ 792 if (copy_from_user (&tag, buf, 4)) { 793 goto fail1; 794 } 795 if (tag != 1) { 796 DBG(data->dev, "config %s, bad tag %d\n", data->name, tag); 797 goto fail0; 798 } 799 buf += 4; 800 len -= 4; 801 802 /* NOTE: audio endpoint extensions not accepted here; 803 * just don't include the extra bytes. 804 */ 805 806 /* full/low speed descriptor, then high speed */ 807 if (copy_from_user (&data->desc, buf, USB_DT_ENDPOINT_SIZE)) { 808 goto fail1; 809 } 810 if (data->desc.bLength != USB_DT_ENDPOINT_SIZE 811 || data->desc.bDescriptorType != USB_DT_ENDPOINT) 812 goto fail0; 813 if (len != USB_DT_ENDPOINT_SIZE) { 814 if (len != 2 * USB_DT_ENDPOINT_SIZE) 815 goto fail0; 816 if (copy_from_user (&data->hs_desc, buf + USB_DT_ENDPOINT_SIZE, 817 USB_DT_ENDPOINT_SIZE)) { 818 goto fail1; 819 } 820 if (data->hs_desc.bLength != USB_DT_ENDPOINT_SIZE 821 || data->hs_desc.bDescriptorType 822 != USB_DT_ENDPOINT) { 823 DBG(data->dev, "config %s, bad hs length or type\n", 824 data->name); 825 goto fail0; 826 } 827 } 828 829 spin_lock_irq (&data->dev->lock); 830 if (data->dev->state == STATE_DEV_UNBOUND) { 831 value = -ENOENT; 832 goto gone; 833 } else if ((ep = data->ep) == NULL) { 834 value = -ENODEV; 835 goto gone; 836 } 837 switch (data->dev->gadget->speed) { 838 case USB_SPEED_LOW: 839 case USB_SPEED_FULL: 840 ep->desc = &data->desc; 841 value = usb_ep_enable(ep); 842 if (value == 0) 843 data->state = STATE_EP_ENABLED; 844 break; 845 case USB_SPEED_HIGH: 846 /* fails if caller didn't provide that descriptor... */ 847 ep->desc = &data->hs_desc; 848 value = usb_ep_enable(ep); 849 if (value == 0) 850 data->state = STATE_EP_ENABLED; 851 break; 852 default: 853 DBG(data->dev, "unconnected, %s init abandoned\n", 854 data->name); 855 value = -EINVAL; 856 } 857 if (value == 0) { 858 fd->f_op = &ep_io_operations; 859 value = length; 860 } 861 gone: 862 spin_unlock_irq (&data->dev->lock); 863 if (value < 0) { 864 fail: 865 data->desc.bDescriptorType = 0; 866 data->hs_desc.bDescriptorType = 0; 867 } 868 mutex_unlock(&data->lock); 869 return value; 870 fail0: 871 value = -EINVAL; 872 goto fail; 873 fail1: 874 value = -EFAULT; 875 goto fail; 876 } 877 878 static int 879 ep_open (struct inode *inode, struct file *fd) 880 { 881 struct ep_data *data = inode->i_private; 882 int value = -EBUSY; 883 884 if (mutex_lock_interruptible(&data->lock) != 0) 885 return -EINTR; 886 spin_lock_irq (&data->dev->lock); 887 if (data->dev->state == STATE_DEV_UNBOUND) 888 value = -ENOENT; 889 else if (data->state == STATE_EP_DISABLED) { 890 value = 0; 891 data->state = STATE_EP_READY; 892 get_ep (data); 893 fd->private_data = data; 894 VDEBUG (data->dev, "%s ready\n", data->name); 895 } else 896 DBG (data->dev, "%s state %d\n", 897 data->name, data->state); 898 spin_unlock_irq (&data->dev->lock); 899 mutex_unlock(&data->lock); 900 return value; 901 } 902 903 /* used before endpoint configuration */ 904 static const struct file_operations ep_config_operations = { 905 .llseek = no_llseek, 906 907 .open = ep_open, 908 .write = ep_config, 909 .release = ep_release, 910 }; 911 912 /*----------------------------------------------------------------------*/ 913 914 /* EP0 IMPLEMENTATION can be partly in userspace. 915 * 916 * Drivers that use this facility receive various events, including 917 * control requests the kernel doesn't handle. Drivers that don't 918 * use this facility may be too simple-minded for real applications. 919 */ 920 921 static inline void ep0_readable (struct dev_data *dev) 922 { 923 wake_up (&dev->wait); 924 kill_fasync (&dev->fasync, SIGIO, POLL_IN); 925 } 926 927 static void clean_req (struct usb_ep *ep, struct usb_request *req) 928 { 929 struct dev_data *dev = ep->driver_data; 930 931 if (req->buf != dev->rbuf) { 932 kfree(req->buf); 933 req->buf = dev->rbuf; 934 } 935 req->complete = epio_complete; 936 dev->setup_out_ready = 0; 937 } 938 939 static void ep0_complete (struct usb_ep *ep, struct usb_request *req) 940 { 941 struct dev_data *dev = ep->driver_data; 942 unsigned long flags; 943 int free = 1; 944 945 /* for control OUT, data must still get to userspace */ 946 spin_lock_irqsave(&dev->lock, flags); 947 if (!dev->setup_in) { 948 dev->setup_out_error = (req->status != 0); 949 if (!dev->setup_out_error) 950 free = 0; 951 dev->setup_out_ready = 1; 952 ep0_readable (dev); 953 } 954 955 /* clean up as appropriate */ 956 if (free && req->buf != &dev->rbuf) 957 clean_req (ep, req); 958 req->complete = epio_complete; 959 spin_unlock_irqrestore(&dev->lock, flags); 960 } 961 962 static int setup_req (struct usb_ep *ep, struct usb_request *req, u16 len) 963 { 964 struct dev_data *dev = ep->driver_data; 965 966 if (dev->setup_out_ready) { 967 DBG (dev, "ep0 request busy!\n"); 968 return -EBUSY; 969 } 970 if (len > sizeof (dev->rbuf)) 971 req->buf = kmalloc(len, GFP_ATOMIC); 972 if (req->buf == NULL) { 973 req->buf = dev->rbuf; 974 return -ENOMEM; 975 } 976 req->complete = ep0_complete; 977 req->length = len; 978 req->zero = 0; 979 return 0; 980 } 981 982 static ssize_t 983 ep0_read (struct file *fd, char __user *buf, size_t len, loff_t *ptr) 984 { 985 struct dev_data *dev = fd->private_data; 986 ssize_t retval; 987 enum ep0_state state; 988 989 spin_lock_irq (&dev->lock); 990 991 /* report fd mode change before acting on it */ 992 if (dev->setup_abort) { 993 dev->setup_abort = 0; 994 retval = -EIDRM; 995 goto done; 996 } 997 998 /* control DATA stage */ 999 if ((state = dev->state) == STATE_DEV_SETUP) { 1000 1001 if (dev->setup_in) { /* stall IN */ 1002 VDEBUG(dev, "ep0in stall\n"); 1003 (void) usb_ep_set_halt (dev->gadget->ep0); 1004 retval = -EL2HLT; 1005 dev->state = STATE_DEV_CONNECTED; 1006 1007 } else if (len == 0) { /* ack SET_CONFIGURATION etc */ 1008 struct usb_ep *ep = dev->gadget->ep0; 1009 struct usb_request *req = dev->req; 1010 1011 if ((retval = setup_req (ep, req, 0)) == 0) 1012 retval = usb_ep_queue (ep, req, GFP_ATOMIC); 1013 dev->state = STATE_DEV_CONNECTED; 1014 1015 /* assume that was SET_CONFIGURATION */ 1016 if (dev->current_config) { 1017 unsigned power; 1018 1019 if (gadget_is_dualspeed(dev->gadget) 1020 && (dev->gadget->speed 1021 == USB_SPEED_HIGH)) 1022 power = dev->hs_config->bMaxPower; 1023 else 1024 power = dev->config->bMaxPower; 1025 usb_gadget_vbus_draw(dev->gadget, 2 * power); 1026 } 1027 1028 } else { /* collect OUT data */ 1029 if ((fd->f_flags & O_NONBLOCK) != 0 1030 && !dev->setup_out_ready) { 1031 retval = -EAGAIN; 1032 goto done; 1033 } 1034 spin_unlock_irq (&dev->lock); 1035 retval = wait_event_interruptible (dev->wait, 1036 dev->setup_out_ready != 0); 1037 1038 /* FIXME state could change from under us */ 1039 spin_lock_irq (&dev->lock); 1040 if (retval) 1041 goto done; 1042 1043 if (dev->state != STATE_DEV_SETUP) { 1044 retval = -ECANCELED; 1045 goto done; 1046 } 1047 dev->state = STATE_DEV_CONNECTED; 1048 1049 if (dev->setup_out_error) 1050 retval = -EIO; 1051 else { 1052 len = min (len, (size_t)dev->req->actual); 1053 // FIXME don't call this with the spinlock held ... 1054 if (copy_to_user (buf, dev->req->buf, len)) 1055 retval = -EFAULT; 1056 else 1057 retval = len; 1058 clean_req (dev->gadget->ep0, dev->req); 1059 /* NOTE userspace can't yet choose to stall */ 1060 } 1061 } 1062 goto done; 1063 } 1064 1065 /* else normal: return event data */ 1066 if (len < sizeof dev->event [0]) { 1067 retval = -EINVAL; 1068 goto done; 1069 } 1070 len -= len % sizeof (struct usb_gadgetfs_event); 1071 dev->usermode_setup = 1; 1072 1073 scan: 1074 /* return queued events right away */ 1075 if (dev->ev_next != 0) { 1076 unsigned i, n; 1077 1078 n = len / sizeof (struct usb_gadgetfs_event); 1079 if (dev->ev_next < n) 1080 n = dev->ev_next; 1081 1082 /* ep0 i/o has special semantics during STATE_DEV_SETUP */ 1083 for (i = 0; i < n; i++) { 1084 if (dev->event [i].type == GADGETFS_SETUP) { 1085 dev->state = STATE_DEV_SETUP; 1086 n = i + 1; 1087 break; 1088 } 1089 } 1090 spin_unlock_irq (&dev->lock); 1091 len = n * sizeof (struct usb_gadgetfs_event); 1092 if (copy_to_user (buf, &dev->event, len)) 1093 retval = -EFAULT; 1094 else 1095 retval = len; 1096 if (len > 0) { 1097 /* NOTE this doesn't guard against broken drivers; 1098 * concurrent ep0 readers may lose events. 1099 */ 1100 spin_lock_irq (&dev->lock); 1101 if (dev->ev_next > n) { 1102 memmove(&dev->event[0], &dev->event[n], 1103 sizeof (struct usb_gadgetfs_event) 1104 * (dev->ev_next - n)); 1105 } 1106 dev->ev_next -= n; 1107 spin_unlock_irq (&dev->lock); 1108 } 1109 return retval; 1110 } 1111 if (fd->f_flags & O_NONBLOCK) { 1112 retval = -EAGAIN; 1113 goto done; 1114 } 1115 1116 switch (state) { 1117 default: 1118 DBG (dev, "fail %s, state %d\n", __func__, state); 1119 retval = -ESRCH; 1120 break; 1121 case STATE_DEV_UNCONNECTED: 1122 case STATE_DEV_CONNECTED: 1123 spin_unlock_irq (&dev->lock); 1124 DBG (dev, "%s wait\n", __func__); 1125 1126 /* wait for events */ 1127 retval = wait_event_interruptible (dev->wait, 1128 dev->ev_next != 0); 1129 if (retval < 0) 1130 return retval; 1131 spin_lock_irq (&dev->lock); 1132 goto scan; 1133 } 1134 1135 done: 1136 spin_unlock_irq (&dev->lock); 1137 return retval; 1138 } 1139 1140 static struct usb_gadgetfs_event * 1141 next_event (struct dev_data *dev, enum usb_gadgetfs_event_type type) 1142 { 1143 struct usb_gadgetfs_event *event; 1144 unsigned i; 1145 1146 switch (type) { 1147 /* these events purge the queue */ 1148 case GADGETFS_DISCONNECT: 1149 if (dev->state == STATE_DEV_SETUP) 1150 dev->setup_abort = 1; 1151 // FALL THROUGH 1152 case GADGETFS_CONNECT: 1153 dev->ev_next = 0; 1154 break; 1155 case GADGETFS_SETUP: /* previous request timed out */ 1156 case GADGETFS_SUSPEND: /* same effect */ 1157 /* these events can't be repeated */ 1158 for (i = 0; i != dev->ev_next; i++) { 1159 if (dev->event [i].type != type) 1160 continue; 1161 DBG(dev, "discard old event[%d] %d\n", i, type); 1162 dev->ev_next--; 1163 if (i == dev->ev_next) 1164 break; 1165 /* indices start at zero, for simplicity */ 1166 memmove (&dev->event [i], &dev->event [i + 1], 1167 sizeof (struct usb_gadgetfs_event) 1168 * (dev->ev_next - i)); 1169 } 1170 break; 1171 default: 1172 BUG (); 1173 } 1174 VDEBUG(dev, "event[%d] = %d\n", dev->ev_next, type); 1175 event = &dev->event [dev->ev_next++]; 1176 BUG_ON (dev->ev_next > N_EVENT); 1177 memset (event, 0, sizeof *event); 1178 event->type = type; 1179 return event; 1180 } 1181 1182 static ssize_t 1183 ep0_write (struct file *fd, const char __user *buf, size_t len, loff_t *ptr) 1184 { 1185 struct dev_data *dev = fd->private_data; 1186 ssize_t retval = -ESRCH; 1187 1188 spin_lock_irq (&dev->lock); 1189 1190 /* report fd mode change before acting on it */ 1191 if (dev->setup_abort) { 1192 dev->setup_abort = 0; 1193 retval = -EIDRM; 1194 1195 /* data and/or status stage for control request */ 1196 } else if (dev->state == STATE_DEV_SETUP) { 1197 1198 /* IN DATA+STATUS caller makes len <= wLength */ 1199 if (dev->setup_in) { 1200 retval = setup_req (dev->gadget->ep0, dev->req, len); 1201 if (retval == 0) { 1202 dev->state = STATE_DEV_CONNECTED; 1203 spin_unlock_irq (&dev->lock); 1204 if (copy_from_user (dev->req->buf, buf, len)) 1205 retval = -EFAULT; 1206 else { 1207 if (len < dev->setup_wLength) 1208 dev->req->zero = 1; 1209 retval = usb_ep_queue ( 1210 dev->gadget->ep0, dev->req, 1211 GFP_KERNEL); 1212 } 1213 if (retval < 0) { 1214 spin_lock_irq (&dev->lock); 1215 clean_req (dev->gadget->ep0, dev->req); 1216 spin_unlock_irq (&dev->lock); 1217 } else 1218 retval = len; 1219 1220 return retval; 1221 } 1222 1223 /* can stall some OUT transfers */ 1224 } else if (dev->setup_can_stall) { 1225 VDEBUG(dev, "ep0out stall\n"); 1226 (void) usb_ep_set_halt (dev->gadget->ep0); 1227 retval = -EL2HLT; 1228 dev->state = STATE_DEV_CONNECTED; 1229 } else { 1230 DBG(dev, "bogus ep0out stall!\n"); 1231 } 1232 } else 1233 DBG (dev, "fail %s, state %d\n", __func__, dev->state); 1234 1235 spin_unlock_irq (&dev->lock); 1236 return retval; 1237 } 1238 1239 static int 1240 ep0_fasync (int f, struct file *fd, int on) 1241 { 1242 struct dev_data *dev = fd->private_data; 1243 // caller must F_SETOWN before signal delivery happens 1244 VDEBUG (dev, "%s %s\n", __func__, on ? "on" : "off"); 1245 return fasync_helper (f, fd, on, &dev->fasync); 1246 } 1247 1248 static struct usb_gadget_driver gadgetfs_driver; 1249 1250 static int 1251 dev_release (struct inode *inode, struct file *fd) 1252 { 1253 struct dev_data *dev = fd->private_data; 1254 1255 /* closing ep0 === shutdown all */ 1256 1257 usb_gadget_unregister_driver (&gadgetfs_driver); 1258 1259 /* at this point "good" hardware has disconnected the 1260 * device from USB; the host won't see it any more. 1261 * alternatively, all host requests will time out. 1262 */ 1263 1264 kfree (dev->buf); 1265 dev->buf = NULL; 1266 1267 /* other endpoints were all decoupled from this device */ 1268 spin_lock_irq(&dev->lock); 1269 dev->state = STATE_DEV_DISABLED; 1270 spin_unlock_irq(&dev->lock); 1271 1272 put_dev (dev); 1273 return 0; 1274 } 1275 1276 static unsigned int 1277 ep0_poll (struct file *fd, poll_table *wait) 1278 { 1279 struct dev_data *dev = fd->private_data; 1280 int mask = 0; 1281 1282 poll_wait(fd, &dev->wait, wait); 1283 1284 spin_lock_irq (&dev->lock); 1285 1286 /* report fd mode change before acting on it */ 1287 if (dev->setup_abort) { 1288 dev->setup_abort = 0; 1289 mask = POLLHUP; 1290 goto out; 1291 } 1292 1293 if (dev->state == STATE_DEV_SETUP) { 1294 if (dev->setup_in || dev->setup_can_stall) 1295 mask = POLLOUT; 1296 } else { 1297 if (dev->ev_next != 0) 1298 mask = POLLIN; 1299 } 1300 out: 1301 spin_unlock_irq(&dev->lock); 1302 return mask; 1303 } 1304 1305 static long dev_ioctl (struct file *fd, unsigned code, unsigned long value) 1306 { 1307 struct dev_data *dev = fd->private_data; 1308 struct usb_gadget *gadget = dev->gadget; 1309 long ret = -ENOTTY; 1310 1311 if (gadget->ops->ioctl) 1312 ret = gadget->ops->ioctl (gadget, code, value); 1313 1314 return ret; 1315 } 1316 1317 /* used after device configuration */ 1318 static const struct file_operations ep0_io_operations = { 1319 .owner = THIS_MODULE, 1320 .llseek = no_llseek, 1321 1322 .read = ep0_read, 1323 .write = ep0_write, 1324 .fasync = ep0_fasync, 1325 .poll = ep0_poll, 1326 .unlocked_ioctl = dev_ioctl, 1327 .release = dev_release, 1328 }; 1329 1330 /*----------------------------------------------------------------------*/ 1331 1332 /* The in-kernel gadget driver handles most ep0 issues, in particular 1333 * enumerating the single configuration (as provided from user space). 1334 * 1335 * Unrecognized ep0 requests may be handled in user space. 1336 */ 1337 1338 static void make_qualifier (struct dev_data *dev) 1339 { 1340 struct usb_qualifier_descriptor qual; 1341 struct usb_device_descriptor *desc; 1342 1343 qual.bLength = sizeof qual; 1344 qual.bDescriptorType = USB_DT_DEVICE_QUALIFIER; 1345 qual.bcdUSB = cpu_to_le16 (0x0200); 1346 1347 desc = dev->dev; 1348 qual.bDeviceClass = desc->bDeviceClass; 1349 qual.bDeviceSubClass = desc->bDeviceSubClass; 1350 qual.bDeviceProtocol = desc->bDeviceProtocol; 1351 1352 /* assumes ep0 uses the same value for both speeds ... */ 1353 qual.bMaxPacketSize0 = dev->gadget->ep0->maxpacket; 1354 1355 qual.bNumConfigurations = 1; 1356 qual.bRESERVED = 0; 1357 1358 memcpy (dev->rbuf, &qual, sizeof qual); 1359 } 1360 1361 static int 1362 config_buf (struct dev_data *dev, u8 type, unsigned index) 1363 { 1364 int len; 1365 int hs = 0; 1366 1367 /* only one configuration */ 1368 if (index > 0) 1369 return -EINVAL; 1370 1371 if (gadget_is_dualspeed(dev->gadget)) { 1372 hs = (dev->gadget->speed == USB_SPEED_HIGH); 1373 if (type == USB_DT_OTHER_SPEED_CONFIG) 1374 hs = !hs; 1375 } 1376 if (hs) { 1377 dev->req->buf = dev->hs_config; 1378 len = le16_to_cpu(dev->hs_config->wTotalLength); 1379 } else { 1380 dev->req->buf = dev->config; 1381 len = le16_to_cpu(dev->config->wTotalLength); 1382 } 1383 ((u8 *)dev->req->buf) [1] = type; 1384 return len; 1385 } 1386 1387 static int 1388 gadgetfs_setup (struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl) 1389 { 1390 struct dev_data *dev = get_gadget_data (gadget); 1391 struct usb_request *req = dev->req; 1392 int value = -EOPNOTSUPP; 1393 struct usb_gadgetfs_event *event; 1394 u16 w_value = le16_to_cpu(ctrl->wValue); 1395 u16 w_length = le16_to_cpu(ctrl->wLength); 1396 1397 spin_lock (&dev->lock); 1398 dev->setup_abort = 0; 1399 if (dev->state == STATE_DEV_UNCONNECTED) { 1400 if (gadget_is_dualspeed(gadget) 1401 && gadget->speed == USB_SPEED_HIGH 1402 && dev->hs_config == NULL) { 1403 spin_unlock(&dev->lock); 1404 ERROR (dev, "no high speed config??\n"); 1405 return -EINVAL; 1406 } 1407 1408 dev->state = STATE_DEV_CONNECTED; 1409 1410 INFO (dev, "connected\n"); 1411 event = next_event (dev, GADGETFS_CONNECT); 1412 event->u.speed = gadget->speed; 1413 ep0_readable (dev); 1414 1415 /* host may have given up waiting for response. we can miss control 1416 * requests handled lower down (device/endpoint status and features); 1417 * then ep0_{read,write} will report the wrong status. controller 1418 * driver will have aborted pending i/o. 1419 */ 1420 } else if (dev->state == STATE_DEV_SETUP) 1421 dev->setup_abort = 1; 1422 1423 req->buf = dev->rbuf; 1424 req->context = NULL; 1425 value = -EOPNOTSUPP; 1426 switch (ctrl->bRequest) { 1427 1428 case USB_REQ_GET_DESCRIPTOR: 1429 if (ctrl->bRequestType != USB_DIR_IN) 1430 goto unrecognized; 1431 switch (w_value >> 8) { 1432 1433 case USB_DT_DEVICE: 1434 value = min (w_length, (u16) sizeof *dev->dev); 1435 dev->dev->bMaxPacketSize0 = dev->gadget->ep0->maxpacket; 1436 req->buf = dev->dev; 1437 break; 1438 case USB_DT_DEVICE_QUALIFIER: 1439 if (!dev->hs_config) 1440 break; 1441 value = min (w_length, (u16) 1442 sizeof (struct usb_qualifier_descriptor)); 1443 make_qualifier (dev); 1444 break; 1445 case USB_DT_OTHER_SPEED_CONFIG: 1446 // FALLTHROUGH 1447 case USB_DT_CONFIG: 1448 value = config_buf (dev, 1449 w_value >> 8, 1450 w_value & 0xff); 1451 if (value >= 0) 1452 value = min (w_length, (u16) value); 1453 break; 1454 case USB_DT_STRING: 1455 goto unrecognized; 1456 1457 default: // all others are errors 1458 break; 1459 } 1460 break; 1461 1462 /* currently one config, two speeds */ 1463 case USB_REQ_SET_CONFIGURATION: 1464 if (ctrl->bRequestType != 0) 1465 goto unrecognized; 1466 if (0 == (u8) w_value) { 1467 value = 0; 1468 dev->current_config = 0; 1469 usb_gadget_vbus_draw(gadget, 8 /* mA */ ); 1470 // user mode expected to disable endpoints 1471 } else { 1472 u8 config, power; 1473 1474 if (gadget_is_dualspeed(gadget) 1475 && gadget->speed == USB_SPEED_HIGH) { 1476 config = dev->hs_config->bConfigurationValue; 1477 power = dev->hs_config->bMaxPower; 1478 } else { 1479 config = dev->config->bConfigurationValue; 1480 power = dev->config->bMaxPower; 1481 } 1482 1483 if (config == (u8) w_value) { 1484 value = 0; 1485 dev->current_config = config; 1486 usb_gadget_vbus_draw(gadget, 2 * power); 1487 } 1488 } 1489 1490 /* report SET_CONFIGURATION like any other control request, 1491 * except that usermode may not stall this. the next 1492 * request mustn't be allowed start until this finishes: 1493 * endpoints and threads set up, etc. 1494 * 1495 * NOTE: older PXA hardware (before PXA 255: without UDCCFR) 1496 * has bad/racey automagic that prevents synchronizing here. 1497 * even kernel mode drivers often miss them. 1498 */ 1499 if (value == 0) { 1500 INFO (dev, "configuration #%d\n", dev->current_config); 1501 usb_gadget_set_state(gadget, USB_STATE_CONFIGURED); 1502 if (dev->usermode_setup) { 1503 dev->setup_can_stall = 0; 1504 goto delegate; 1505 } 1506 } 1507 break; 1508 1509 #ifndef CONFIG_USB_PXA25X 1510 /* PXA automagically handles this request too */ 1511 case USB_REQ_GET_CONFIGURATION: 1512 if (ctrl->bRequestType != 0x80) 1513 goto unrecognized; 1514 *(u8 *)req->buf = dev->current_config; 1515 value = min (w_length, (u16) 1); 1516 break; 1517 #endif 1518 1519 default: 1520 unrecognized: 1521 VDEBUG (dev, "%s req%02x.%02x v%04x i%04x l%d\n", 1522 dev->usermode_setup ? "delegate" : "fail", 1523 ctrl->bRequestType, ctrl->bRequest, 1524 w_value, le16_to_cpu(ctrl->wIndex), w_length); 1525 1526 /* if there's an ep0 reader, don't stall */ 1527 if (dev->usermode_setup) { 1528 dev->setup_can_stall = 1; 1529 delegate: 1530 dev->setup_in = (ctrl->bRequestType & USB_DIR_IN) 1531 ? 1 : 0; 1532 dev->setup_wLength = w_length; 1533 dev->setup_out_ready = 0; 1534 dev->setup_out_error = 0; 1535 value = 0; 1536 1537 /* read DATA stage for OUT right away */ 1538 if (unlikely (!dev->setup_in && w_length)) { 1539 value = setup_req (gadget->ep0, dev->req, 1540 w_length); 1541 if (value < 0) 1542 break; 1543 value = usb_ep_queue (gadget->ep0, dev->req, 1544 GFP_ATOMIC); 1545 if (value < 0) { 1546 clean_req (gadget->ep0, dev->req); 1547 break; 1548 } 1549 1550 /* we can't currently stall these */ 1551 dev->setup_can_stall = 0; 1552 } 1553 1554 /* state changes when reader collects event */ 1555 event = next_event (dev, GADGETFS_SETUP); 1556 event->u.setup = *ctrl; 1557 ep0_readable (dev); 1558 spin_unlock (&dev->lock); 1559 return 0; 1560 } 1561 } 1562 1563 /* proceed with data transfer and status phases? */ 1564 if (value >= 0 && dev->state != STATE_DEV_SETUP) { 1565 req->length = value; 1566 req->zero = value < w_length; 1567 value = usb_ep_queue (gadget->ep0, req, GFP_ATOMIC); 1568 if (value < 0) { 1569 DBG (dev, "ep_queue --> %d\n", value); 1570 req->status = 0; 1571 } 1572 } 1573 1574 /* device stalls when value < 0 */ 1575 spin_unlock (&dev->lock); 1576 return value; 1577 } 1578 1579 static void destroy_ep_files (struct dev_data *dev) 1580 { 1581 DBG (dev, "%s %d\n", __func__, dev->state); 1582 1583 /* dev->state must prevent interference */ 1584 spin_lock_irq (&dev->lock); 1585 while (!list_empty(&dev->epfiles)) { 1586 struct ep_data *ep; 1587 struct inode *parent; 1588 struct dentry *dentry; 1589 1590 /* break link to FS */ 1591 ep = list_first_entry (&dev->epfiles, struct ep_data, epfiles); 1592 list_del_init (&ep->epfiles); 1593 dentry = ep->dentry; 1594 ep->dentry = NULL; 1595 parent = dentry->d_parent->d_inode; 1596 1597 /* break link to controller */ 1598 if (ep->state == STATE_EP_ENABLED) 1599 (void) usb_ep_disable (ep->ep); 1600 ep->state = STATE_EP_UNBOUND; 1601 usb_ep_free_request (ep->ep, ep->req); 1602 ep->ep = NULL; 1603 wake_up (&ep->wait); 1604 put_ep (ep); 1605 1606 spin_unlock_irq (&dev->lock); 1607 1608 /* break link to dcache */ 1609 mutex_lock (&parent->i_mutex); 1610 d_delete (dentry); 1611 dput (dentry); 1612 mutex_unlock (&parent->i_mutex); 1613 1614 spin_lock_irq (&dev->lock); 1615 } 1616 spin_unlock_irq (&dev->lock); 1617 } 1618 1619 1620 static struct dentry * 1621 gadgetfs_create_file (struct super_block *sb, char const *name, 1622 void *data, const struct file_operations *fops); 1623 1624 static int activate_ep_files (struct dev_data *dev) 1625 { 1626 struct usb_ep *ep; 1627 struct ep_data *data; 1628 1629 gadget_for_each_ep (ep, dev->gadget) { 1630 1631 data = kzalloc(sizeof(*data), GFP_KERNEL); 1632 if (!data) 1633 goto enomem0; 1634 data->state = STATE_EP_DISABLED; 1635 mutex_init(&data->lock); 1636 init_waitqueue_head (&data->wait); 1637 1638 strncpy (data->name, ep->name, sizeof (data->name) - 1); 1639 atomic_set (&data->count, 1); 1640 data->dev = dev; 1641 get_dev (dev); 1642 1643 data->ep = ep; 1644 ep->driver_data = data; 1645 1646 data->req = usb_ep_alloc_request (ep, GFP_KERNEL); 1647 if (!data->req) 1648 goto enomem1; 1649 1650 data->dentry = gadgetfs_create_file (dev->sb, data->name, 1651 data, &ep_config_operations); 1652 if (!data->dentry) 1653 goto enomem2; 1654 list_add_tail (&data->epfiles, &dev->epfiles); 1655 } 1656 return 0; 1657 1658 enomem2: 1659 usb_ep_free_request (ep, data->req); 1660 enomem1: 1661 put_dev (dev); 1662 kfree (data); 1663 enomem0: 1664 DBG (dev, "%s enomem\n", __func__); 1665 destroy_ep_files (dev); 1666 return -ENOMEM; 1667 } 1668 1669 static void 1670 gadgetfs_unbind (struct usb_gadget *gadget) 1671 { 1672 struct dev_data *dev = get_gadget_data (gadget); 1673 1674 DBG (dev, "%s\n", __func__); 1675 1676 spin_lock_irq (&dev->lock); 1677 dev->state = STATE_DEV_UNBOUND; 1678 spin_unlock_irq (&dev->lock); 1679 1680 destroy_ep_files (dev); 1681 gadget->ep0->driver_data = NULL; 1682 set_gadget_data (gadget, NULL); 1683 1684 /* we've already been disconnected ... no i/o is active */ 1685 if (dev->req) 1686 usb_ep_free_request (gadget->ep0, dev->req); 1687 DBG (dev, "%s done\n", __func__); 1688 put_dev (dev); 1689 } 1690 1691 static struct dev_data *the_device; 1692 1693 static int gadgetfs_bind(struct usb_gadget *gadget, 1694 struct usb_gadget_driver *driver) 1695 { 1696 struct dev_data *dev = the_device; 1697 1698 if (!dev) 1699 return -ESRCH; 1700 if (0 != strcmp (CHIP, gadget->name)) { 1701 pr_err("%s expected %s controller not %s\n", 1702 shortname, CHIP, gadget->name); 1703 return -ENODEV; 1704 } 1705 1706 set_gadget_data (gadget, dev); 1707 dev->gadget = gadget; 1708 gadget->ep0->driver_data = dev; 1709 1710 /* preallocate control response and buffer */ 1711 dev->req = usb_ep_alloc_request (gadget->ep0, GFP_KERNEL); 1712 if (!dev->req) 1713 goto enomem; 1714 dev->req->context = NULL; 1715 dev->req->complete = epio_complete; 1716 1717 if (activate_ep_files (dev) < 0) 1718 goto enomem; 1719 1720 INFO (dev, "bound to %s driver\n", gadget->name); 1721 spin_lock_irq(&dev->lock); 1722 dev->state = STATE_DEV_UNCONNECTED; 1723 spin_unlock_irq(&dev->lock); 1724 get_dev (dev); 1725 return 0; 1726 1727 enomem: 1728 gadgetfs_unbind (gadget); 1729 return -ENOMEM; 1730 } 1731 1732 static void 1733 gadgetfs_disconnect (struct usb_gadget *gadget) 1734 { 1735 struct dev_data *dev = get_gadget_data (gadget); 1736 unsigned long flags; 1737 1738 spin_lock_irqsave (&dev->lock, flags); 1739 if (dev->state == STATE_DEV_UNCONNECTED) 1740 goto exit; 1741 dev->state = STATE_DEV_UNCONNECTED; 1742 1743 INFO (dev, "disconnected\n"); 1744 next_event (dev, GADGETFS_DISCONNECT); 1745 ep0_readable (dev); 1746 exit: 1747 spin_unlock_irqrestore (&dev->lock, flags); 1748 } 1749 1750 static void 1751 gadgetfs_suspend (struct usb_gadget *gadget) 1752 { 1753 struct dev_data *dev = get_gadget_data (gadget); 1754 1755 INFO (dev, "suspended from state %d\n", dev->state); 1756 spin_lock (&dev->lock); 1757 switch (dev->state) { 1758 case STATE_DEV_SETUP: // VERY odd... host died?? 1759 case STATE_DEV_CONNECTED: 1760 case STATE_DEV_UNCONNECTED: 1761 next_event (dev, GADGETFS_SUSPEND); 1762 ep0_readable (dev); 1763 /* FALLTHROUGH */ 1764 default: 1765 break; 1766 } 1767 spin_unlock (&dev->lock); 1768 } 1769 1770 static struct usb_gadget_driver gadgetfs_driver = { 1771 .function = (char *) driver_desc, 1772 .bind = gadgetfs_bind, 1773 .unbind = gadgetfs_unbind, 1774 .setup = gadgetfs_setup, 1775 .reset = gadgetfs_disconnect, 1776 .disconnect = gadgetfs_disconnect, 1777 .suspend = gadgetfs_suspend, 1778 1779 .driver = { 1780 .name = (char *) shortname, 1781 }, 1782 }; 1783 1784 /*----------------------------------------------------------------------*/ 1785 1786 static void gadgetfs_nop(struct usb_gadget *arg) { } 1787 1788 static int gadgetfs_probe(struct usb_gadget *gadget, 1789 struct usb_gadget_driver *driver) 1790 { 1791 CHIP = gadget->name; 1792 return -EISNAM; 1793 } 1794 1795 static struct usb_gadget_driver probe_driver = { 1796 .max_speed = USB_SPEED_HIGH, 1797 .bind = gadgetfs_probe, 1798 .unbind = gadgetfs_nop, 1799 .setup = (void *)gadgetfs_nop, 1800 .disconnect = gadgetfs_nop, 1801 .driver = { 1802 .name = "nop", 1803 }, 1804 }; 1805 1806 1807 /* DEVICE INITIALIZATION 1808 * 1809 * fd = open ("/dev/gadget/$CHIP", O_RDWR) 1810 * status = write (fd, descriptors, sizeof descriptors) 1811 * 1812 * That write establishes the device configuration, so the kernel can 1813 * bind to the controller ... guaranteeing it can handle enumeration 1814 * at all necessary speeds. Descriptor order is: 1815 * 1816 * . message tag (u32, host order) ... for now, must be zero; it 1817 * would change to support features like multi-config devices 1818 * . full/low speed config ... all wTotalLength bytes (with interface, 1819 * class, altsetting, endpoint, and other descriptors) 1820 * . high speed config ... all descriptors, for high speed operation; 1821 * this one's optional except for high-speed hardware 1822 * . device descriptor 1823 * 1824 * Endpoints are not yet enabled. Drivers must wait until device 1825 * configuration and interface altsetting changes create 1826 * the need to configure (or unconfigure) them. 1827 * 1828 * After initialization, the device stays active for as long as that 1829 * $CHIP file is open. Events must then be read from that descriptor, 1830 * such as configuration notifications. 1831 */ 1832 1833 static int is_valid_config (struct usb_config_descriptor *config) 1834 { 1835 return config->bDescriptorType == USB_DT_CONFIG 1836 && config->bLength == USB_DT_CONFIG_SIZE 1837 && config->bConfigurationValue != 0 1838 && (config->bmAttributes & USB_CONFIG_ATT_ONE) != 0 1839 && (config->bmAttributes & USB_CONFIG_ATT_WAKEUP) == 0; 1840 /* FIXME if gadget->is_otg, _must_ include an otg descriptor */ 1841 /* FIXME check lengths: walk to end */ 1842 } 1843 1844 static ssize_t 1845 dev_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr) 1846 { 1847 struct dev_data *dev = fd->private_data; 1848 ssize_t value = len, length = len; 1849 unsigned total; 1850 u32 tag; 1851 char *kbuf; 1852 1853 if (len < (USB_DT_CONFIG_SIZE + USB_DT_DEVICE_SIZE + 4)) 1854 return -EINVAL; 1855 1856 /* we might need to change message format someday */ 1857 if (copy_from_user (&tag, buf, 4)) 1858 return -EFAULT; 1859 if (tag != 0) 1860 return -EINVAL; 1861 buf += 4; 1862 length -= 4; 1863 1864 kbuf = memdup_user(buf, length); 1865 if (IS_ERR(kbuf)) 1866 return PTR_ERR(kbuf); 1867 1868 spin_lock_irq (&dev->lock); 1869 value = -EINVAL; 1870 if (dev->buf) 1871 goto fail; 1872 dev->buf = kbuf; 1873 1874 /* full or low speed config */ 1875 dev->config = (void *) kbuf; 1876 total = le16_to_cpu(dev->config->wTotalLength); 1877 if (!is_valid_config (dev->config) || total >= length) 1878 goto fail; 1879 kbuf += total; 1880 length -= total; 1881 1882 /* optional high speed config */ 1883 if (kbuf [1] == USB_DT_CONFIG) { 1884 dev->hs_config = (void *) kbuf; 1885 total = le16_to_cpu(dev->hs_config->wTotalLength); 1886 if (!is_valid_config (dev->hs_config) || total >= length) 1887 goto fail; 1888 kbuf += total; 1889 length -= total; 1890 } 1891 1892 /* could support multiple configs, using another encoding! */ 1893 1894 /* device descriptor (tweaked for paranoia) */ 1895 if (length != USB_DT_DEVICE_SIZE) 1896 goto fail; 1897 dev->dev = (void *)kbuf; 1898 if (dev->dev->bLength != USB_DT_DEVICE_SIZE 1899 || dev->dev->bDescriptorType != USB_DT_DEVICE 1900 || dev->dev->bNumConfigurations != 1) 1901 goto fail; 1902 dev->dev->bNumConfigurations = 1; 1903 dev->dev->bcdUSB = cpu_to_le16 (0x0200); 1904 1905 /* triggers gadgetfs_bind(); then we can enumerate. */ 1906 spin_unlock_irq (&dev->lock); 1907 if (dev->hs_config) 1908 gadgetfs_driver.max_speed = USB_SPEED_HIGH; 1909 else 1910 gadgetfs_driver.max_speed = USB_SPEED_FULL; 1911 1912 value = usb_gadget_probe_driver(&gadgetfs_driver); 1913 if (value != 0) { 1914 kfree (dev->buf); 1915 dev->buf = NULL; 1916 } else { 1917 /* at this point "good" hardware has for the first time 1918 * let the USB the host see us. alternatively, if users 1919 * unplug/replug that will clear all the error state. 1920 * 1921 * note: everything running before here was guaranteed 1922 * to choke driver model style diagnostics. from here 1923 * on, they can work ... except in cleanup paths that 1924 * kick in after the ep0 descriptor is closed. 1925 */ 1926 fd->f_op = &ep0_io_operations; 1927 value = len; 1928 } 1929 return value; 1930 1931 fail: 1932 spin_unlock_irq (&dev->lock); 1933 pr_debug ("%s: %s fail %Zd, %p\n", shortname, __func__, value, dev); 1934 kfree (dev->buf); 1935 dev->buf = NULL; 1936 return value; 1937 } 1938 1939 static int 1940 dev_open (struct inode *inode, struct file *fd) 1941 { 1942 struct dev_data *dev = inode->i_private; 1943 int value = -EBUSY; 1944 1945 spin_lock_irq(&dev->lock); 1946 if (dev->state == STATE_DEV_DISABLED) { 1947 dev->ev_next = 0; 1948 dev->state = STATE_DEV_OPENED; 1949 fd->private_data = dev; 1950 get_dev (dev); 1951 value = 0; 1952 } 1953 spin_unlock_irq(&dev->lock); 1954 return value; 1955 } 1956 1957 static const struct file_operations dev_init_operations = { 1958 .llseek = no_llseek, 1959 1960 .open = dev_open, 1961 .write = dev_config, 1962 .fasync = ep0_fasync, 1963 .unlocked_ioctl = dev_ioctl, 1964 .release = dev_release, 1965 }; 1966 1967 /*----------------------------------------------------------------------*/ 1968 1969 /* FILESYSTEM AND SUPERBLOCK OPERATIONS 1970 * 1971 * Mounting the filesystem creates a controller file, used first for 1972 * device configuration then later for event monitoring. 1973 */ 1974 1975 1976 /* FIXME PAM etc could set this security policy without mount options 1977 * if epfiles inherited ownership and permissons from ep0 ... 1978 */ 1979 1980 static unsigned default_uid; 1981 static unsigned default_gid; 1982 static unsigned default_perm = S_IRUSR | S_IWUSR; 1983 1984 module_param (default_uid, uint, 0644); 1985 module_param (default_gid, uint, 0644); 1986 module_param (default_perm, uint, 0644); 1987 1988 1989 static struct inode * 1990 gadgetfs_make_inode (struct super_block *sb, 1991 void *data, const struct file_operations *fops, 1992 int mode) 1993 { 1994 struct inode *inode = new_inode (sb); 1995 1996 if (inode) { 1997 inode->i_ino = get_next_ino(); 1998 inode->i_mode = mode; 1999 inode->i_uid = make_kuid(&init_user_ns, default_uid); 2000 inode->i_gid = make_kgid(&init_user_ns, default_gid); 2001 inode->i_atime = inode->i_mtime = inode->i_ctime 2002 = CURRENT_TIME; 2003 inode->i_private = data; 2004 inode->i_fop = fops; 2005 } 2006 return inode; 2007 } 2008 2009 /* creates in fs root directory, so non-renamable and non-linkable. 2010 * so inode and dentry are paired, until device reconfig. 2011 */ 2012 static struct dentry * 2013 gadgetfs_create_file (struct super_block *sb, char const *name, 2014 void *data, const struct file_operations *fops) 2015 { 2016 struct dentry *dentry; 2017 struct inode *inode; 2018 2019 dentry = d_alloc_name(sb->s_root, name); 2020 if (!dentry) 2021 return NULL; 2022 2023 inode = gadgetfs_make_inode (sb, data, fops, 2024 S_IFREG | (default_perm & S_IRWXUGO)); 2025 if (!inode) { 2026 dput(dentry); 2027 return NULL; 2028 } 2029 d_add (dentry, inode); 2030 return dentry; 2031 } 2032 2033 static const struct super_operations gadget_fs_operations = { 2034 .statfs = simple_statfs, 2035 .drop_inode = generic_delete_inode, 2036 }; 2037 2038 static int 2039 gadgetfs_fill_super (struct super_block *sb, void *opts, int silent) 2040 { 2041 struct inode *inode; 2042 struct dev_data *dev; 2043 2044 if (the_device) 2045 return -ESRCH; 2046 2047 /* fake probe to determine $CHIP */ 2048 CHIP = NULL; 2049 usb_gadget_probe_driver(&probe_driver); 2050 if (!CHIP) 2051 return -ENODEV; 2052 2053 /* superblock */ 2054 sb->s_blocksize = PAGE_CACHE_SIZE; 2055 sb->s_blocksize_bits = PAGE_CACHE_SHIFT; 2056 sb->s_magic = GADGETFS_MAGIC; 2057 sb->s_op = &gadget_fs_operations; 2058 sb->s_time_gran = 1; 2059 2060 /* root inode */ 2061 inode = gadgetfs_make_inode (sb, 2062 NULL, &simple_dir_operations, 2063 S_IFDIR | S_IRUGO | S_IXUGO); 2064 if (!inode) 2065 goto Enomem; 2066 inode->i_op = &simple_dir_inode_operations; 2067 if (!(sb->s_root = d_make_root (inode))) 2068 goto Enomem; 2069 2070 /* the ep0 file is named after the controller we expect; 2071 * user mode code can use it for sanity checks, like we do. 2072 */ 2073 dev = dev_new (); 2074 if (!dev) 2075 goto Enomem; 2076 2077 dev->sb = sb; 2078 dev->dentry = gadgetfs_create_file(sb, CHIP, dev, &dev_init_operations); 2079 if (!dev->dentry) { 2080 put_dev(dev); 2081 goto Enomem; 2082 } 2083 2084 /* other endpoint files are available after hardware setup, 2085 * from binding to a controller. 2086 */ 2087 the_device = dev; 2088 return 0; 2089 2090 Enomem: 2091 return -ENOMEM; 2092 } 2093 2094 /* "mount -t gadgetfs path /dev/gadget" ends up here */ 2095 static struct dentry * 2096 gadgetfs_mount (struct file_system_type *t, int flags, 2097 const char *path, void *opts) 2098 { 2099 return mount_single (t, flags, opts, gadgetfs_fill_super); 2100 } 2101 2102 static void 2103 gadgetfs_kill_sb (struct super_block *sb) 2104 { 2105 kill_litter_super (sb); 2106 if (the_device) { 2107 put_dev (the_device); 2108 the_device = NULL; 2109 } 2110 } 2111 2112 /*----------------------------------------------------------------------*/ 2113 2114 static struct file_system_type gadgetfs_type = { 2115 .owner = THIS_MODULE, 2116 .name = shortname, 2117 .mount = gadgetfs_mount, 2118 .kill_sb = gadgetfs_kill_sb, 2119 }; 2120 MODULE_ALIAS_FS("gadgetfs"); 2121 2122 /*----------------------------------------------------------------------*/ 2123 2124 static int __init init (void) 2125 { 2126 int status; 2127 2128 status = register_filesystem (&gadgetfs_type); 2129 if (status == 0) 2130 pr_info ("%s: %s, version " DRIVER_VERSION "\n", 2131 shortname, driver_desc); 2132 return status; 2133 } 2134 module_init (init); 2135 2136 static void __exit cleanup (void) 2137 { 2138 pr_debug ("unregister %s\n", shortname); 2139 unregister_filesystem (&gadgetfs_type); 2140 } 2141 module_exit (cleanup); 2142 2143