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 * This program is distributed in the hope that it will be useful, 13 * but WITHOUT ANY WARRANTY; without even the implied warranty of 14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15 * GNU General Public License for more details. 16 * 17 * You should have received a copy of the GNU General Public License 18 * along with this program; if not, write to the Free Software 19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 20 */ 21 22 23/* #define VERBOSE_DEBUG */ 24 25#include <linux/init.h> 26#include <linux/module.h> 27#include <linux/fs.h> 28#include <linux/pagemap.h> 29#include <linux/uts.h> 30#include <linux/wait.h> 31#include <linux/compiler.h> 32#include <asm/uaccess.h> 33#include <linux/sched.h> 34#include <linux/slab.h> 35#include <linux/poll.h> 36#include <linux/smp_lock.h> 37 38#include <linux/device.h> 39#include <linux/moduleparam.h> 40 41#include <linux/usb/gadgetfs.h> 42#include <linux/usb/gadget.h> 43 44 45/* 46 * The gadgetfs API maps each endpoint to a file descriptor so that you 47 * can use standard synchronous read/write calls for I/O. There's some 48 * O_NONBLOCK and O_ASYNC/FASYNC style i/o support. Example usermode 49 * drivers show how this works in practice. You can also use AIO to 50 * eliminate I/O gaps between requests, to help when streaming data. 51 * 52 * Key parts that must be USB-specific are protocols defining how the 53 * read/write operations relate to the hardware state machines. There 54 * are two types of files. One type is for the device, implementing ep0. 55 * The other type is for each IN or OUT endpoint. In both cases, the 56 * user mode driver must configure the hardware before using it. 57 * 58 * - First, dev_config() is called when /dev/gadget/$CHIP is configured 59 * (by writing configuration and device descriptors). Afterwards it 60 * may serve as a source of device events, used to handle all control 61 * requests other than basic enumeration. 62 * 63 * - Then, after a SET_CONFIGURATION control request, ep_config() is 64 * called when each /dev/gadget/ep* file is configured (by writing 65 * endpoint descriptors). Afterwards these files are used to write() 66 * IN data or to read() OUT data. To halt the endpoint, a "wrong 67 * direction" request is issued (like reading an IN endpoint). 68 * 69 * Unlike "usbfs" the only ioctl()s are for things that are rare, and maybe 70 * not possible on all hardware. For example, precise fault handling with 71 * respect to data left in endpoint fifos after aborted operations; or 72 * selective clearing of endpoint halts, to implement SET_INTERFACE. 73 */ 74 75#define DRIVER_DESC "USB Gadget filesystem" 76#define DRIVER_VERSION "24 Aug 2004" 77 78static const char driver_desc [] = DRIVER_DESC; 79static const char shortname [] = "gadgetfs"; 80 81MODULE_DESCRIPTION (DRIVER_DESC); 82MODULE_AUTHOR ("David Brownell"); 83MODULE_LICENSE ("GPL"); 84 85 86/*----------------------------------------------------------------------*/ 87 88#define GADGETFS_MAGIC 0xaee71ee7 89#define DMA_ADDR_INVALID (~(dma_addr_t)0) 90 91/* /dev/gadget/$CHIP represents ep0 and the whole device */ 92enum ep0_state { 93 /* DISBLED is the initial state. 94 */ 95 STATE_DEV_DISABLED = 0, 96 97 /* Only one open() of /dev/gadget/$CHIP; only one file tracks 98 * ep0/device i/o modes and binding to the controller. Driver 99 * must always write descriptors to initialize the device, then 100 * the device becomes UNCONNECTED until enumeration. 101 */ 102 STATE_DEV_OPENED, 103 104 /* From then on, ep0 fd is in either of two basic modes: 105 * - (UN)CONNECTED: read usb_gadgetfs_event(s) from it 106 * - SETUP: read/write will transfer control data and succeed; 107 * or if "wrong direction", performs protocol stall 108 */ 109 STATE_DEV_UNCONNECTED, 110 STATE_DEV_CONNECTED, 111 STATE_DEV_SETUP, 112 113 /* UNBOUND means the driver closed ep0, so the device won't be 114 * accessible again (DEV_DISABLED) until all fds are closed. 115 */ 116 STATE_DEV_UNBOUND, 117}; 118 119/* enough for the whole queue: most events invalidate others */ 120#define N_EVENT 5 121 122struct dev_data { 123 spinlock_t lock; 124 atomic_t count; 125 enum ep0_state state; /* P: lock */ 126 struct usb_gadgetfs_event event [N_EVENT]; 127 unsigned ev_next; 128 struct fasync_struct *fasync; 129 u8 current_config; 130 131 /* drivers reading ep0 MUST handle control requests (SETUP) 132 * reported that way; else the host will time out. 133 */ 134 unsigned usermode_setup : 1, 135 setup_in : 1, 136 setup_can_stall : 1, 137 setup_out_ready : 1, 138 setup_out_error : 1, 139 setup_abort : 1; 140 unsigned setup_wLength; 141 142 /* the rest is basically write-once */ 143 struct usb_config_descriptor *config, *hs_config; 144 struct usb_device_descriptor *dev; 145 struct usb_request *req; 146 struct usb_gadget *gadget; 147 struct list_head epfiles; 148 void *buf; 149 wait_queue_head_t wait; 150 struct super_block *sb; 151 struct dentry *dentry; 152 153 /* except this scratch i/o buffer for ep0 */ 154 u8 rbuf [256]; 155}; 156 157static inline void get_dev (struct dev_data *data) 158{ 159 atomic_inc (&data->count); 160} 161 162static void put_dev (struct dev_data *data) 163{ 164 if (likely (!atomic_dec_and_test (&data->count))) 165 return; 166 /* needs no more cleanup */ 167 BUG_ON (waitqueue_active (&data->wait)); 168 kfree (data); 169} 170 171static struct dev_data *dev_new (void) 172{ 173 struct dev_data *dev; 174 175 dev = kzalloc(sizeof(*dev), GFP_KERNEL); 176 if (!dev) 177 return NULL; 178 dev->state = STATE_DEV_DISABLED; 179 atomic_set (&dev->count, 1); 180 spin_lock_init (&dev->lock); 181 INIT_LIST_HEAD (&dev->epfiles); 182 init_waitqueue_head (&dev->wait); 183 return dev; 184} 185 186/*----------------------------------------------------------------------*/ 187 188/* other /dev/gadget/$ENDPOINT files represent endpoints */ 189enum ep_state { 190 STATE_EP_DISABLED = 0, 191 STATE_EP_READY, 192 STATE_EP_ENABLED, 193 STATE_EP_UNBOUND, 194}; 195 196struct ep_data { 197 struct mutex lock; 198 enum ep_state state; 199 atomic_t count; 200 struct dev_data *dev; 201 /* must hold dev->lock before accessing ep or req */ 202 struct usb_ep *ep; 203 struct usb_request *req; 204 ssize_t status; 205 char name [16]; 206 struct usb_endpoint_descriptor desc, hs_desc; 207 struct list_head epfiles; 208 wait_queue_head_t wait; 209 struct dentry *dentry; 210 struct inode *inode; 211}; 212 213static inline void get_ep (struct ep_data *data) 214{ 215 atomic_inc (&data->count); 216} 217 218static void put_ep (struct ep_data *data) 219{ 220 if (likely (!atomic_dec_and_test (&data->count))) 221 return; 222 put_dev (data->dev); 223 /* needs no more cleanup */ 224 BUG_ON (!list_empty (&data->epfiles)); 225 BUG_ON (waitqueue_active (&data->wait)); 226 kfree (data); 227} 228 229/*----------------------------------------------------------------------*/ 230 231/* most "how to use the hardware" policy choices are in userspace: 232 * mapping endpoint roles (which the driver needs) to the capabilities 233 * which the usb controller has. most of those capabilities are exposed 234 * implicitly, starting with the driver name and then endpoint names. 235 */ 236 237static const char *CHIP; 238 239/*----------------------------------------------------------------------*/ 240 241/* NOTE: don't use dev_printk calls before binding to the gadget 242 * at the end of ep0 configuration, or after unbind. 243 */ 244 245/* too wordy: dev_printk(level , &(d)->gadget->dev , fmt , ## args) */ 246#define xprintk(d,level,fmt,args...) \ 247 printk(level "%s: " fmt , shortname , ## args) 248 249#ifdef DEBUG 250#define DBG(dev,fmt,args...) \ 251 xprintk(dev , KERN_DEBUG , fmt , ## args) 252#else 253#define DBG(dev,fmt,args...) \ 254 do { } while (0) 255#endif /* DEBUG */ 256 257#ifdef VERBOSE_DEBUG 258#define VDEBUG DBG 259#else 260#define VDEBUG(dev,fmt,args...) \ 261 do { } while (0) 262#endif /* DEBUG */ 263 264#define ERROR(dev,fmt,args...) \ 265 xprintk(dev , KERN_ERR , fmt , ## args) 266#define INFO(dev,fmt,args...) \ 267 xprintk(dev , KERN_INFO , fmt , ## args) 268 269 270/*----------------------------------------------------------------------*/ 271 272/* SYNCHRONOUS ENDPOINT OPERATIONS (bulk/intr/iso) 273 * 274 * After opening, configure non-control endpoints. Then use normal 275 * stream read() and write() requests; and maybe ioctl() to get more 276 * precise FIFO status when recovering from cancellation. 277 */ 278 279static void epio_complete (struct usb_ep *ep, struct usb_request *req) 280{ 281 struct ep_data *epdata = ep->driver_data; 282 283 if (!req->context) 284 return; 285 if (req->status) 286 epdata->status = req->status; 287 else 288 epdata->status = req->actual; 289 complete ((struct completion *)req->context); 290} 291 292/* tasklock endpoint, returning when it's connected. 293 * still need dev->lock to use epdata->ep. 294 */ 295static int 296get_ready_ep (unsigned f_flags, struct ep_data *epdata) 297{ 298 int val; 299 300 if (f_flags & O_NONBLOCK) { 301 if (!mutex_trylock(&epdata->lock)) 302 goto nonblock; 303 if (epdata->state != STATE_EP_ENABLED) { 304 mutex_unlock(&epdata->lock); 305nonblock: 306 val = -EAGAIN; 307 } else 308 val = 0; 309 return val; 310 } 311 312 val = mutex_lock_interruptible(&epdata->lock); 313 if (val < 0) 314 return val; 315 316 switch (epdata->state) { 317 case STATE_EP_ENABLED: 318 break; 319 // case STATE_EP_DISABLED: /* "can't happen" */ 320 // case STATE_EP_READY: /* "can't happen" */ 321 default: /* error! */ 322 pr_debug ("%s: ep %p not available, state %d\n", 323 shortname, epdata, epdata->state); 324 // FALLTHROUGH 325 case STATE_EP_UNBOUND: /* clean disconnect */ 326 val = -ENODEV; 327 mutex_unlock(&epdata->lock); 328 } 329 return val; 330} 331 332static ssize_t 333ep_io (struct ep_data *epdata, void *buf, unsigned len) 334{ 335 DECLARE_COMPLETION_ONSTACK (done); 336 int value; 337 338 spin_lock_irq (&epdata->dev->lock); 339 if (likely (epdata->ep != NULL)) { 340 struct usb_request *req = epdata->req; 341 342 req->context = &done; 343 req->complete = epio_complete; 344 req->buf = buf; 345 req->length = len; 346 value = usb_ep_queue (epdata->ep, req, GFP_ATOMIC); 347 } else 348 value = -ENODEV; 349 spin_unlock_irq (&epdata->dev->lock); 350 351 if (likely (value == 0)) { 352 value = wait_event_interruptible (done.wait, done.done); 353 if (value != 0) { 354 spin_lock_irq (&epdata->dev->lock); 355 if (likely (epdata->ep != NULL)) { 356 DBG (epdata->dev, "%s i/o interrupted\n", 357 epdata->name); 358 usb_ep_dequeue (epdata->ep, epdata->req); 359 spin_unlock_irq (&epdata->dev->lock); 360 361 wait_event (done.wait, done.done); 362 if (epdata->status == -ECONNRESET) 363 epdata->status = -EINTR; 364 } else { 365 spin_unlock_irq (&epdata->dev->lock); 366 367 DBG (epdata->dev, "endpoint gone\n"); 368 epdata->status = -ENODEV; 369 } 370 } 371 return epdata->status; 372 } 373 return value; 374} 375 376 377/* handle a synchronous OUT bulk/intr/iso transfer */ 378static ssize_t 379ep_read (struct file *fd, char __user *buf, size_t len, loff_t *ptr) 380{ 381 struct ep_data *data = fd->private_data; 382 void *kbuf; 383 ssize_t value; 384 385 if ((value = get_ready_ep (fd->f_flags, data)) < 0) 386 return value; 387 388 /* halt any endpoint by doing a "wrong direction" i/o call */ 389 if (usb_endpoint_dir_in(&data->desc)) { 390 if (usb_endpoint_xfer_isoc(&data->desc)) 391 return -EINVAL; 392 DBG (data->dev, "%s halt\n", data->name); 393 spin_lock_irq (&data->dev->lock); 394 if (likely (data->ep != NULL)) 395 usb_ep_set_halt (data->ep); 396 spin_unlock_irq (&data->dev->lock); 397 mutex_unlock(&data->lock); 398 return -EBADMSG; 399 } 400 401 402 value = -ENOMEM; 403 kbuf = kmalloc (len, GFP_KERNEL); 404 if (unlikely (!kbuf)) 405 goto free1; 406 407 value = ep_io (data, kbuf, len); 408 VDEBUG (data->dev, "%s read %zu OUT, status %d\n", 409 data->name, len, (int) value); 410 if (value >= 0 && copy_to_user (buf, kbuf, value)) 411 value = -EFAULT; 412 413free1: 414 mutex_unlock(&data->lock); 415 kfree (kbuf); 416 return value; 417} 418 419/* handle a synchronous IN bulk/intr/iso transfer */ 420static ssize_t 421ep_write (struct file *fd, const char __user *buf, size_t len, loff_t *ptr) 422{ 423 struct ep_data *data = fd->private_data; 424 void *kbuf; 425 ssize_t value; 426 427 if ((value = get_ready_ep (fd->f_flags, data)) < 0) 428 return value; 429 430 /* halt any endpoint by doing a "wrong direction" i/o call */ 431 if (!usb_endpoint_dir_in(&data->desc)) { 432 if (usb_endpoint_xfer_isoc(&data->desc)) 433 return -EINVAL; 434 DBG (data->dev, "%s halt\n", data->name); 435 spin_lock_irq (&data->dev->lock); 436 if (likely (data->ep != NULL)) 437 usb_ep_set_halt (data->ep); 438 spin_unlock_irq (&data->dev->lock); 439 mutex_unlock(&data->lock); 440 return -EBADMSG; 441 } 442 443 444 value = -ENOMEM; 445 kbuf = kmalloc (len, GFP_KERNEL); 446 if (!kbuf) 447 goto free1; 448 if (copy_from_user (kbuf, buf, len)) { 449 value = -EFAULT; 450 goto free1; 451 } 452 453 value = ep_io (data, kbuf, len); 454 VDEBUG (data->dev, "%s write %zu IN, status %d\n", 455 data->name, len, (int) value); 456free1: 457 mutex_unlock(&data->lock); 458 kfree (kbuf); 459 return value; 460} 461 462static int 463ep_release (struct inode *inode, struct file *fd) 464{ 465 struct ep_data *data = fd->private_data; 466 int value; 467 468 value = mutex_lock_interruptible(&data->lock); 469 if (value < 0) 470 return value; 471 472 /* clean up if this can be reopened */ 473 if (data->state != STATE_EP_UNBOUND) { 474 data->state = STATE_EP_DISABLED; 475 data->desc.bDescriptorType = 0; 476 data->hs_desc.bDescriptorType = 0; 477 usb_ep_disable(data->ep); 478 } 479 mutex_unlock(&data->lock); 480 put_ep (data); 481 return 0; 482} 483 484static long ep_ioctl(struct file *fd, unsigned code, unsigned long value) 485{ 486 struct ep_data *data = fd->private_data; 487 int status; 488 489 if ((status = get_ready_ep (fd->f_flags, data)) < 0) 490 return status; 491 492 spin_lock_irq (&data->dev->lock); 493 if (likely (data->ep != NULL)) { 494 switch (code) { 495 case GADGETFS_FIFO_STATUS: 496 status = usb_ep_fifo_status (data->ep); 497 break; 498 case GADGETFS_FIFO_FLUSH: 499 usb_ep_fifo_flush (data->ep); 500 break; 501 case GADGETFS_CLEAR_HALT: 502 status = usb_ep_clear_halt (data->ep); 503 break; 504 default: 505 status = -ENOTTY; 506 } 507 } else 508 status = -ENODEV; 509 spin_unlock_irq (&data->dev->lock); 510 mutex_unlock(&data->lock); 511 return status; 512} 513 514/*----------------------------------------------------------------------*/ 515 516/* ASYNCHRONOUS ENDPOINT I/O OPERATIONS (bulk/intr/iso) */ 517 518struct kiocb_priv { 519 struct usb_request *req; 520 struct ep_data *epdata; 521 void *buf; 522 const struct iovec *iv; 523 unsigned long nr_segs; 524 unsigned actual; 525}; 526 527static int ep_aio_cancel(struct kiocb *iocb, struct io_event *e) 528{ 529 struct kiocb_priv *priv = iocb->private; 530 struct ep_data *epdata; 531 int value; 532 533 local_irq_disable(); 534 epdata = priv->epdata; 535 // spin_lock(&epdata->dev->lock); 536 kiocbSetCancelled(iocb); 537 if (likely(epdata && epdata->ep && priv->req)) 538 value = usb_ep_dequeue (epdata->ep, priv->req); 539 else 540 value = -EINVAL; 541 // spin_unlock(&epdata->dev->lock); 542 local_irq_enable(); 543 544 aio_put_req(iocb); 545 return value; 546} 547 548static ssize_t ep_aio_read_retry(struct kiocb *iocb) 549{ 550 struct kiocb_priv *priv = iocb->private; 551 ssize_t len, total; 552 void *to_copy; 553 int i; 554 555 /* we "retry" to get the right mm context for this: */ 556 557 /* copy stuff into user buffers */ 558 total = priv->actual; 559 len = 0; 560 to_copy = priv->buf; 561 for (i=0; i < priv->nr_segs; i++) { 562 ssize_t this = min((ssize_t)(priv->iv[i].iov_len), total); 563 564 if (copy_to_user(priv->iv[i].iov_base, to_copy, this)) { 565 if (len == 0) 566 len = -EFAULT; 567 break; 568 } 569 570 total -= this; 571 len += this; 572 to_copy += this; 573 if (total == 0) 574 break; 575 } 576 kfree(priv->buf); 577 kfree(priv); 578 return len; 579} 580 581static void ep_aio_complete(struct usb_ep *ep, struct usb_request *req) 582{ 583 struct kiocb *iocb = req->context; 584 struct kiocb_priv *priv = iocb->private; 585 struct ep_data *epdata = priv->epdata; 586 587 /* lock against disconnect (and ideally, cancel) */ 588 spin_lock(&epdata->dev->lock); 589 priv->req = NULL; 590 priv->epdata = NULL; 591 592 /* if this was a write or a read returning no data then we 593 * don't need to copy anything to userspace, so we can 594 * complete the aio request immediately. 595 */ 596 if (priv->iv == NULL || unlikely(req->actual == 0)) { 597 kfree(req->buf); 598 kfree(priv); 599 iocb->private = NULL; 600 /* aio_complete() reports bytes-transferred _and_ faults */ 601 aio_complete(iocb, req->actual ? req->actual : req->status, 602 req->status); 603 } else { 604 /* retry() won't report both; so we hide some faults */ 605 if (unlikely(0 != req->status)) 606 DBG(epdata->dev, "%s fault %d len %d\n", 607 ep->name, req->status, req->actual); 608 609 priv->buf = req->buf; 610 priv->actual = req->actual; 611 kick_iocb(iocb); 612 } 613 spin_unlock(&epdata->dev->lock); 614 615 usb_ep_free_request(ep, req); 616 put_ep(epdata); 617} 618 619static ssize_t 620ep_aio_rwtail( 621 struct kiocb *iocb, 622 char *buf, 623 size_t len, 624 struct ep_data *epdata, 625 const struct iovec *iv, 626 unsigned long nr_segs 627) 628{ 629 struct kiocb_priv *priv; 630 struct usb_request *req; 631 ssize_t value; 632 633 priv = kmalloc(sizeof *priv, GFP_KERNEL); 634 if (!priv) { 635 value = -ENOMEM; 636fail: 637 kfree(buf); 638 return value; 639 } 640 iocb->private = priv; 641 priv->iv = iv; 642 priv->nr_segs = nr_segs; 643 644 value = get_ready_ep(iocb->ki_filp->f_flags, epdata); 645 if (unlikely(value < 0)) { 646 kfree(priv); 647 goto fail; 648 } 649 650 iocb->ki_cancel = ep_aio_cancel; 651 get_ep(epdata); 652 priv->epdata = epdata; 653 priv->actual = 0; 654 655 /* each kiocb is coupled to one usb_request, but we can't 656 * allocate or submit those if the host disconnected. 657 */ 658 spin_lock_irq(&epdata->dev->lock); 659 if (likely(epdata->ep)) { 660 req = usb_ep_alloc_request(epdata->ep, GFP_ATOMIC); 661 if (likely(req)) { 662 priv->req = req; 663 req->buf = buf; 664 req->length = len; 665 req->complete = ep_aio_complete; 666 req->context = iocb; 667 value = usb_ep_queue(epdata->ep, req, GFP_ATOMIC); 668 if (unlikely(0 != value)) 669 usb_ep_free_request(epdata->ep, req); 670 } else 671 value = -EAGAIN; 672 } else 673 value = -ENODEV; 674 spin_unlock_irq(&epdata->dev->lock); 675 676 mutex_unlock(&epdata->lock); 677 678 if (unlikely(value)) { 679 kfree(priv); 680 put_ep(epdata); 681 } else 682 value = (iv ? -EIOCBRETRY : -EIOCBQUEUED); 683 return value; 684} 685 686static ssize_t 687ep_aio_read(struct kiocb *iocb, const struct iovec *iov, 688 unsigned long nr_segs, loff_t o) 689{ 690 struct ep_data *epdata = iocb->ki_filp->private_data; 691 char *buf; 692 693 if (unlikely(usb_endpoint_dir_in(&epdata->desc))) 694 return -EINVAL; 695 696 buf = kmalloc(iocb->ki_left, GFP_KERNEL); 697 if (unlikely(!buf)) 698 return -ENOMEM; 699 700 iocb->ki_retry = ep_aio_read_retry; 701 return ep_aio_rwtail(iocb, buf, iocb->ki_left, epdata, iov, nr_segs); 702} 703 704static ssize_t 705ep_aio_write(struct kiocb *iocb, const struct iovec *iov, 706 unsigned long nr_segs, loff_t o) 707{ 708 struct ep_data *epdata = iocb->ki_filp->private_data; 709 char *buf; 710 size_t len = 0; 711 int i = 0; 712 713 if (unlikely(!usb_endpoint_dir_in(&epdata->desc))) 714 return -EINVAL; 715 716 buf = kmalloc(iocb->ki_left, GFP_KERNEL); 717 if (unlikely(!buf)) 718 return -ENOMEM; 719 720 for (i=0; i < nr_segs; i++) { 721 if (unlikely(copy_from_user(&buf[len], iov[i].iov_base, 722 iov[i].iov_len) != 0)) { 723 kfree(buf); 724 return -EFAULT; 725 } 726 len += iov[i].iov_len; 727 } 728 return ep_aio_rwtail(iocb, buf, len, epdata, NULL, 0); 729} 730 731/*----------------------------------------------------------------------*/ 732 733/* used after endpoint configuration */ 734static const struct file_operations ep_io_operations = { 735 .owner = THIS_MODULE, 736 .llseek = no_llseek, 737 738 .read = ep_read, 739 .write = ep_write, 740 .unlocked_ioctl = ep_ioctl, 741 .release = ep_release, 742 743 .aio_read = ep_aio_read, 744 .aio_write = ep_aio_write, 745}; 746 747/* ENDPOINT INITIALIZATION 748 * 749 * fd = open ("/dev/gadget/$ENDPOINT", O_RDWR) 750 * status = write (fd, descriptors, sizeof descriptors) 751 * 752 * That write establishes the endpoint configuration, configuring 753 * the controller to process bulk, interrupt, or isochronous transfers 754 * at the right maxpacket size, and so on. 755 * 756 * The descriptors are message type 1, identified by a host order u32 757 * at the beginning of what's written. Descriptor order is: full/low 758 * speed descriptor, then optional high speed descriptor. 759 */ 760static ssize_t 761ep_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr) 762{ 763 struct ep_data *data = fd->private_data; 764 struct usb_ep *ep; 765 u32 tag; 766 int value, length = len; 767 768 value = mutex_lock_interruptible(&data->lock); 769 if (value < 0) 770 return value; 771 772 if (data->state != STATE_EP_READY) { 773 value = -EL2HLT; 774 goto fail; 775 } 776 777 value = len; 778 if (len < USB_DT_ENDPOINT_SIZE + 4) 779 goto fail0; 780 781 /* we might need to change message format someday */ 782 if (copy_from_user (&tag, buf, 4)) { 783 goto fail1; 784 } 785 if (tag != 1) { 786 DBG(data->dev, "config %s, bad tag %d\n", data->name, tag); 787 goto fail0; 788 } 789 buf += 4; 790 len -= 4; 791 792 /* NOTE: audio endpoint extensions not accepted here; 793 * just don't include the extra bytes. 794 */ 795 796 /* full/low speed descriptor, then high speed */ 797 if (copy_from_user (&data->desc, buf, USB_DT_ENDPOINT_SIZE)) { 798 goto fail1; 799 } 800 if (data->desc.bLength != USB_DT_ENDPOINT_SIZE 801 || data->desc.bDescriptorType != USB_DT_ENDPOINT) 802 goto fail0; 803 if (len != USB_DT_ENDPOINT_SIZE) { 804 if (len != 2 * USB_DT_ENDPOINT_SIZE) 805 goto fail0; 806 if (copy_from_user (&data->hs_desc, buf + USB_DT_ENDPOINT_SIZE, 807 USB_DT_ENDPOINT_SIZE)) { 808 goto fail1; 809 } 810 if (data->hs_desc.bLength != USB_DT_ENDPOINT_SIZE 811 || data->hs_desc.bDescriptorType 812 != USB_DT_ENDPOINT) { 813 DBG(data->dev, "config %s, bad hs length or type\n", 814 data->name); 815 goto fail0; 816 } 817 } 818 819 spin_lock_irq (&data->dev->lock); 820 if (data->dev->state == STATE_DEV_UNBOUND) { 821 value = -ENOENT; 822 goto gone; 823 } else if ((ep = data->ep) == NULL) { 824 value = -ENODEV; 825 goto gone; 826 } 827 switch (data->dev->gadget->speed) { 828 case USB_SPEED_LOW: 829 case USB_SPEED_FULL: 830 value = usb_ep_enable (ep, &data->desc); 831 if (value == 0) 832 data->state = STATE_EP_ENABLED; 833 break; 834#ifdef CONFIG_USB_GADGET_DUALSPEED 835 case USB_SPEED_HIGH: 836 /* fails if caller didn't provide that descriptor... */ 837 value = usb_ep_enable (ep, &data->hs_desc); 838 if (value == 0) 839 data->state = STATE_EP_ENABLED; 840 break; 841#endif 842 default: 843 DBG(data->dev, "unconnected, %s init abandoned\n", 844 data->name); 845 value = -EINVAL; 846 } 847 if (value == 0) { 848 fd->f_op = &ep_io_operations; 849 value = length; 850 } 851gone: 852 spin_unlock_irq (&data->dev->lock); 853 if (value < 0) { 854fail: 855 data->desc.bDescriptorType = 0; 856 data->hs_desc.bDescriptorType = 0; 857 } 858 mutex_unlock(&data->lock); 859 return value; 860fail0: 861 value = -EINVAL; 862 goto fail; 863fail1: 864 value = -EFAULT; 865 goto fail; 866} 867 868static int 869ep_open (struct inode *inode, struct file *fd) 870{ 871 struct ep_data *data = inode->i_private; 872 int value = -EBUSY; 873 874 if (mutex_lock_interruptible(&data->lock) != 0) 875 return -EINTR; 876 spin_lock_irq (&data->dev->lock); 877 if (data->dev->state == STATE_DEV_UNBOUND) 878 value = -ENOENT; 879 else if (data->state == STATE_EP_DISABLED) { 880 value = 0; 881 data->state = STATE_EP_READY; 882 get_ep (data); 883 fd->private_data = data; 884 VDEBUG (data->dev, "%s ready\n", data->name); 885 } else 886 DBG (data->dev, "%s state %d\n", 887 data->name, data->state); 888 spin_unlock_irq (&data->dev->lock); 889 mutex_unlock(&data->lock); 890 return value; 891} 892 893/* used before endpoint configuration */ 894static const struct file_operations ep_config_operations = { 895 .owner = THIS_MODULE, 896 .llseek = no_llseek, 897 898 .open = ep_open, 899 .write = ep_config, 900 .release = ep_release, 901}; 902 903/*----------------------------------------------------------------------*/ 904 905/* EP0 IMPLEMENTATION can be partly in userspace. 906 * 907 * Drivers that use this facility receive various events, including 908 * control requests the kernel doesn't handle. Drivers that don't 909 * use this facility may be too simple-minded for real applications. 910 */ 911 912static inline void ep0_readable (struct dev_data *dev) 913{ 914 wake_up (&dev->wait); 915 kill_fasync (&dev->fasync, SIGIO, POLL_IN); 916} 917 918static void clean_req (struct usb_ep *ep, struct usb_request *req) 919{ 920 struct dev_data *dev = ep->driver_data; 921 922 if (req->buf != dev->rbuf) { 923 kfree(req->buf); 924 req->buf = dev->rbuf; 925 req->dma = DMA_ADDR_INVALID; 926 } 927 req->complete = epio_complete; 928 dev->setup_out_ready = 0; 929} 930 931static void ep0_complete (struct usb_ep *ep, struct usb_request *req) 932{ 933 struct dev_data *dev = ep->driver_data; 934 unsigned long flags; 935 int free = 1; 936 937 /* for control OUT, data must still get to userspace */ 938 spin_lock_irqsave(&dev->lock, flags); 939 if (!dev->setup_in) { 940 dev->setup_out_error = (req->status != 0); 941 if (!dev->setup_out_error) 942 free = 0; 943 dev->setup_out_ready = 1; 944 ep0_readable (dev); 945 } 946 947 /* clean up as appropriate */ 948 if (free && req->buf != &dev->rbuf) 949 clean_req (ep, req); 950 req->complete = epio_complete; 951 spin_unlock_irqrestore(&dev->lock, flags); 952} 953 954static int setup_req (struct usb_ep *ep, struct usb_request *req, u16 len) 955{ 956 struct dev_data *dev = ep->driver_data; 957 958 if (dev->setup_out_ready) { 959 DBG (dev, "ep0 request busy!\n"); 960 return -EBUSY; 961 } 962 if (len > sizeof (dev->rbuf)) 963 req->buf = kmalloc(len, GFP_ATOMIC); 964 if (req->buf == NULL) { 965 req->buf = dev->rbuf; 966 return -ENOMEM; 967 } 968 req->complete = ep0_complete; 969 req->length = len; 970 req->zero = 0; 971 return 0; 972} 973 974static ssize_t 975ep0_read (struct file *fd, char __user *buf, size_t len, loff_t *ptr) 976{ 977 struct dev_data *dev = fd->private_data; 978 ssize_t retval; 979 enum ep0_state state; 980 981 spin_lock_irq (&dev->lock); 982 983 /* report fd mode change before acting on it */ 984 if (dev->setup_abort) { 985 dev->setup_abort = 0; 986 retval = -EIDRM; 987 goto done; 988 } 989 990 /* control DATA stage */ 991 if ((state = dev->state) == STATE_DEV_SETUP) { 992 993 if (dev->setup_in) { /* stall IN */ 994 VDEBUG(dev, "ep0in stall\n"); 995 (void) usb_ep_set_halt (dev->gadget->ep0); 996 retval = -EL2HLT; 997 dev->state = STATE_DEV_CONNECTED; 998 999 } else if (len == 0) { /* ack SET_CONFIGURATION etc */ 1000 struct usb_ep *ep = dev->gadget->ep0; 1001 struct usb_request *req = dev->req; 1002 1003 if ((retval = setup_req (ep, req, 0)) == 0) 1004 retval = usb_ep_queue (ep, req, GFP_ATOMIC); 1005 dev->state = STATE_DEV_CONNECTED; 1006 1007 /* assume that was SET_CONFIGURATION */ 1008 if (dev->current_config) { 1009 unsigned power; 1010 1011 if (gadget_is_dualspeed(dev->gadget) 1012 && (dev->gadget->speed 1013 == USB_SPEED_HIGH)) 1014 power = dev->hs_config->bMaxPower; 1015 else 1016 power = dev->config->bMaxPower; 1017 usb_gadget_vbus_draw(dev->gadget, 2 * power); 1018 } 1019 1020 } else { /* collect OUT data */ 1021 if ((fd->f_flags & O_NONBLOCK) != 0 1022 && !dev->setup_out_ready) { 1023 retval = -EAGAIN; 1024 goto done; 1025 } 1026 spin_unlock_irq (&dev->lock); 1027 retval = wait_event_interruptible (dev->wait, 1028 dev->setup_out_ready != 0); 1029 1030 spin_lock_irq (&dev->lock); 1031 if (retval) 1032 goto done; 1033 1034 if (dev->state != STATE_DEV_SETUP) { 1035 retval = -ECANCELED; 1036 goto done; 1037 } 1038 dev->state = STATE_DEV_CONNECTED; 1039 1040 if (dev->setup_out_error) 1041 retval = -EIO; 1042 else { 1043 len = min (len, (size_t)dev->req->actual); 1044 if (copy_to_user (buf, dev->req->buf, len)) 1045 retval = -EFAULT; 1046 clean_req (dev->gadget->ep0, dev->req); 1047 /* NOTE userspace can't yet choose to stall */ 1048 } 1049 } 1050 goto done; 1051 } 1052 1053 /* else normal: return event data */ 1054 if (len < sizeof dev->event [0]) { 1055 retval = -EINVAL; 1056 goto done; 1057 } 1058 len -= len % sizeof (struct usb_gadgetfs_event); 1059 dev->usermode_setup = 1; 1060 1061scan: 1062 /* return queued events right away */ 1063 if (dev->ev_next != 0) { 1064 unsigned i, n; 1065 1066 n = len / sizeof (struct usb_gadgetfs_event); 1067 if (dev->ev_next < n) 1068 n = dev->ev_next; 1069 1070 /* ep0 i/o has special semantics during STATE_DEV_SETUP */ 1071 for (i = 0; i < n; i++) { 1072 if (dev->event [i].type == GADGETFS_SETUP) { 1073 dev->state = STATE_DEV_SETUP; 1074 n = i + 1; 1075 break; 1076 } 1077 } 1078 spin_unlock_irq (&dev->lock); 1079 len = n * sizeof (struct usb_gadgetfs_event); 1080 if (copy_to_user (buf, &dev->event, len)) 1081 retval = -EFAULT; 1082 else 1083 retval = len; 1084 if (len > 0) { 1085 /* NOTE this doesn't guard against broken drivers; 1086 * concurrent ep0 readers may lose events. 1087 */ 1088 spin_lock_irq (&dev->lock); 1089 if (dev->ev_next > n) { 1090 memmove(&dev->event[0], &dev->event[n], 1091 sizeof (struct usb_gadgetfs_event) 1092 * (dev->ev_next - n)); 1093 } 1094 dev->ev_next -= n; 1095 spin_unlock_irq (&dev->lock); 1096 } 1097 return retval; 1098 } 1099 if (fd->f_flags & O_NONBLOCK) { 1100 retval = -EAGAIN; 1101 goto done; 1102 } 1103 1104 switch (state) { 1105 default: 1106 DBG (dev, "fail %s, state %d\n", __func__, state); 1107 retval = -ESRCH; 1108 break; 1109 case STATE_DEV_UNCONNECTED: 1110 case STATE_DEV_CONNECTED: 1111 spin_unlock_irq (&dev->lock); 1112 DBG (dev, "%s wait\n", __func__); 1113 1114 /* wait for events */ 1115 retval = wait_event_interruptible (dev->wait, 1116 dev->ev_next != 0); 1117 if (retval < 0) 1118 return retval; 1119 spin_lock_irq (&dev->lock); 1120 goto scan; 1121 } 1122 1123done: 1124 spin_unlock_irq (&dev->lock); 1125 return retval; 1126} 1127 1128static struct usb_gadgetfs_event * 1129next_event (struct dev_data *dev, enum usb_gadgetfs_event_type type) 1130{ 1131 struct usb_gadgetfs_event *event; 1132 unsigned i; 1133 1134 switch (type) { 1135 /* these events purge the queue */ 1136 case GADGETFS_DISCONNECT: 1137 if (dev->state == STATE_DEV_SETUP) 1138 dev->setup_abort = 1; 1139 // FALL THROUGH 1140 case GADGETFS_CONNECT: 1141 dev->ev_next = 0; 1142 break; 1143 case GADGETFS_SETUP: /* previous request timed out */ 1144 case GADGETFS_SUSPEND: /* same effect */ 1145 /* these events can't be repeated */ 1146 for (i = 0; i != dev->ev_next; i++) { 1147 if (dev->event [i].type != type) 1148 continue; 1149 DBG(dev, "discard old event[%d] %d\n", i, type); 1150 dev->ev_next--; 1151 if (i == dev->ev_next) 1152 break; 1153 /* indices start at zero, for simplicity */ 1154 memmove (&dev->event [i], &dev->event [i + 1], 1155 sizeof (struct usb_gadgetfs_event) 1156 * (dev->ev_next - i)); 1157 } 1158 break; 1159 default: 1160 BUG (); 1161 } 1162 VDEBUG(dev, "event[%d] = %d\n", dev->ev_next, type); 1163 event = &dev->event [dev->ev_next++]; 1164 BUG_ON (dev->ev_next > N_EVENT); 1165 memset (event, 0, sizeof *event); 1166 event->type = type; 1167 return event; 1168} 1169 1170static ssize_t 1171ep0_write (struct file *fd, const char __user *buf, size_t len, loff_t *ptr) 1172{ 1173 struct dev_data *dev = fd->private_data; 1174 ssize_t retval = -ESRCH; 1175 1176 spin_lock_irq (&dev->lock); 1177 1178 /* report fd mode change before acting on it */ 1179 if (dev->setup_abort) { 1180 dev->setup_abort = 0; 1181 retval = -EIDRM; 1182 1183 /* data and/or status stage for control request */ 1184 } else if (dev->state == STATE_DEV_SETUP) { 1185 1186 /* IN DATA+STATUS caller makes len <= wLength */ 1187 if (dev->setup_in) { 1188 retval = setup_req (dev->gadget->ep0, dev->req, len); 1189 if (retval == 0) { 1190 dev->state = STATE_DEV_CONNECTED; 1191 spin_unlock_irq (&dev->lock); 1192 if (copy_from_user (dev->req->buf, buf, len)) 1193 retval = -EFAULT; 1194 else { 1195 if (len < dev->setup_wLength) 1196 dev->req->zero = 1; 1197 retval = usb_ep_queue ( 1198 dev->gadget->ep0, dev->req, 1199 GFP_KERNEL); 1200 } 1201 if (retval < 0) { 1202 spin_lock_irq (&dev->lock); 1203 clean_req (dev->gadget->ep0, dev->req); 1204 spin_unlock_irq (&dev->lock); 1205 } else 1206 retval = len; 1207 1208 return retval; 1209 } 1210 1211 /* can stall some OUT transfers */ 1212 } else if (dev->setup_can_stall) { 1213 VDEBUG(dev, "ep0out stall\n"); 1214 (void) usb_ep_set_halt (dev->gadget->ep0); 1215 retval = -EL2HLT; 1216 dev->state = STATE_DEV_CONNECTED; 1217 } else { 1218 DBG(dev, "bogus ep0out stall!\n"); 1219 } 1220 } else 1221 DBG (dev, "fail %s, state %d\n", __func__, dev->state); 1222 1223 spin_unlock_irq (&dev->lock); 1224 return retval; 1225} 1226 1227static int 1228ep0_fasync (int f, struct file *fd, int on) 1229{ 1230 struct dev_data *dev = fd->private_data; 1231 // caller must F_SETOWN before signal delivery happens 1232 VDEBUG (dev, "%s %s\n", __func__, on ? "on" : "off"); 1233 return fasync_helper (f, fd, on, &dev->fasync); 1234} 1235 1236static struct usb_gadget_driver gadgetfs_driver; 1237 1238static int 1239dev_release (struct inode *inode, struct file *fd) 1240{ 1241 struct dev_data *dev = fd->private_data; 1242 1243 /* closing ep0 === shutdown all */ 1244 1245 usb_gadget_unregister_driver (&gadgetfs_driver); 1246 1247 /* at this point "good" hardware has disconnected the 1248 * device from USB; the host won't see it any more. 1249 * alternatively, all host requests will time out. 1250 */ 1251 1252 kfree (dev->buf); 1253 dev->buf = NULL; 1254 put_dev (dev); 1255 1256 /* other endpoints were all decoupled from this device */ 1257 spin_lock_irq(&dev->lock); 1258 dev->state = STATE_DEV_DISABLED; 1259 spin_unlock_irq(&dev->lock); 1260 return 0; 1261} 1262 1263static unsigned int 1264ep0_poll (struct file *fd, poll_table *wait) 1265{ 1266 struct dev_data *dev = fd->private_data; 1267 int mask = 0; 1268 1269 poll_wait(fd, &dev->wait, wait); 1270 1271 spin_lock_irq (&dev->lock); 1272 1273 /* report fd mode change before acting on it */ 1274 if (dev->setup_abort) { 1275 dev->setup_abort = 0; 1276 mask = POLLHUP; 1277 goto out; 1278 } 1279 1280 if (dev->state == STATE_DEV_SETUP) { 1281 if (dev->setup_in || dev->setup_can_stall) 1282 mask = POLLOUT; 1283 } else { 1284 if (dev->ev_next != 0) 1285 mask = POLLIN; 1286 } 1287out: 1288 spin_unlock_irq(&dev->lock); 1289 return mask; 1290} 1291 1292static long dev_ioctl (struct file *fd, unsigned code, unsigned long value) 1293{ 1294 struct dev_data *dev = fd->private_data; 1295 struct usb_gadget *gadget = dev->gadget; 1296 long ret = -ENOTTY; 1297 1298 if (gadget->ops->ioctl) 1299 ret = gadget->ops->ioctl (gadget, code, value); 1300 1301 return ret; 1302} 1303 1304/* used after device configuration */ 1305static const struct file_operations ep0_io_operations = { 1306 .owner = THIS_MODULE, 1307 .llseek = no_llseek, 1308 1309 .read = ep0_read, 1310 .write = ep0_write, 1311 .fasync = ep0_fasync, 1312 .poll = ep0_poll, 1313 .unlocked_ioctl = dev_ioctl, 1314 .release = dev_release, 1315}; 1316 1317/*----------------------------------------------------------------------*/ 1318 1319/* The in-kernel gadget driver handles most ep0 issues, in particular 1320 * enumerating the single configuration (as provided from user space). 1321 * 1322 * Unrecognized ep0 requests may be handled in user space. 1323 */ 1324 1325#ifdef CONFIG_USB_GADGET_DUALSPEED 1326static void make_qualifier (struct dev_data *dev) 1327{ 1328 struct usb_qualifier_descriptor qual; 1329 struct usb_device_descriptor *desc; 1330 1331 qual.bLength = sizeof qual; 1332 qual.bDescriptorType = USB_DT_DEVICE_QUALIFIER; 1333 qual.bcdUSB = cpu_to_le16 (0x0200); 1334 1335 desc = dev->dev; 1336 qual.bDeviceClass = desc->bDeviceClass; 1337 qual.bDeviceSubClass = desc->bDeviceSubClass; 1338 qual.bDeviceProtocol = desc->bDeviceProtocol; 1339 1340 /* assumes ep0 uses the same value for both speeds ... */ 1341 qual.bMaxPacketSize0 = desc->bMaxPacketSize0; 1342 1343 qual.bNumConfigurations = 1; 1344 qual.bRESERVED = 0; 1345 1346 memcpy (dev->rbuf, &qual, sizeof qual); 1347} 1348#endif 1349 1350static int 1351config_buf (struct dev_data *dev, u8 type, unsigned index) 1352{ 1353 int len; 1354 int hs = 0; 1355 1356 /* only one configuration */ 1357 if (index > 0) 1358 return -EINVAL; 1359 1360 if (gadget_is_dualspeed(dev->gadget)) { 1361 hs = (dev->gadget->speed == USB_SPEED_HIGH); 1362 if (type == USB_DT_OTHER_SPEED_CONFIG) 1363 hs = !hs; 1364 } 1365 if (hs) { 1366 dev->req->buf = dev->hs_config; 1367 len = le16_to_cpu(dev->hs_config->wTotalLength); 1368 } else { 1369 dev->req->buf = dev->config; 1370 len = le16_to_cpu(dev->config->wTotalLength); 1371 } 1372 ((u8 *)dev->req->buf) [1] = type; 1373 return len; 1374} 1375 1376static int 1377gadgetfs_setup (struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl) 1378{ 1379 struct dev_data *dev = get_gadget_data (gadget); 1380 struct usb_request *req = dev->req; 1381 int value = -EOPNOTSUPP; 1382 struct usb_gadgetfs_event *event; 1383 u16 w_value = le16_to_cpu(ctrl->wValue); 1384 u16 w_length = le16_to_cpu(ctrl->wLength); 1385 1386 spin_lock (&dev->lock); 1387 dev->setup_abort = 0; 1388 if (dev->state == STATE_DEV_UNCONNECTED) { 1389 if (gadget_is_dualspeed(gadget) 1390 && gadget->speed == USB_SPEED_HIGH 1391 && dev->hs_config == NULL) { 1392 spin_unlock(&dev->lock); 1393 ERROR (dev, "no high speed config??\n"); 1394 return -EINVAL; 1395 } 1396 1397 dev->state = STATE_DEV_CONNECTED; 1398 dev->dev->bMaxPacketSize0 = gadget->ep0->maxpacket; 1399 1400 INFO (dev, "connected\n"); 1401 event = next_event (dev, GADGETFS_CONNECT); 1402 event->u.speed = gadget->speed; 1403 ep0_readable (dev); 1404 1405 /* host may have given up waiting for response. we can miss control 1406 * requests handled lower down (device/endpoint status and features); 1407 * then ep0_{read,write} will report the wrong status. controller 1408 * driver will have aborted pending i/o. 1409 */ 1410 } else if (dev->state == STATE_DEV_SETUP) 1411 dev->setup_abort = 1; 1412 1413 req->buf = dev->rbuf; 1414 req->dma = DMA_ADDR_INVALID; 1415 req->context = NULL; 1416 value = -EOPNOTSUPP; 1417 switch (ctrl->bRequest) { 1418 1419 case USB_REQ_GET_DESCRIPTOR: 1420 if (ctrl->bRequestType != USB_DIR_IN) 1421 goto unrecognized; 1422 switch (w_value >> 8) { 1423 1424 case USB_DT_DEVICE: 1425 value = min (w_length, (u16) sizeof *dev->dev); 1426 req->buf = dev->dev; 1427 break; 1428#ifdef CONFIG_USB_GADGET_DUALSPEED 1429 case USB_DT_DEVICE_QUALIFIER: 1430 if (!dev->hs_config) 1431 break; 1432 value = min (w_length, (u16) 1433 sizeof (struct usb_qualifier_descriptor)); 1434 make_qualifier (dev); 1435 break; 1436 case USB_DT_OTHER_SPEED_CONFIG: 1437 // FALLTHROUGH 1438#endif 1439 case USB_DT_CONFIG: 1440 value = config_buf (dev, 1441 w_value >> 8, 1442 w_value & 0xff); 1443 if (value >= 0) 1444 value = min (w_length, (u16) value); 1445 break; 1446 case USB_DT_STRING: 1447 goto unrecognized; 1448 1449 default: // all others are errors 1450 break; 1451 } 1452 break; 1453 1454 /* currently one config, two speeds */ 1455 case USB_REQ_SET_CONFIGURATION: 1456 if (ctrl->bRequestType != 0) 1457 goto unrecognized; 1458 if (0 == (u8) w_value) { 1459 value = 0; 1460 dev->current_config = 0; 1461 usb_gadget_vbus_draw(gadget, 8 /* mA */ ); 1462 // user mode expected to disable endpoints 1463 } else { 1464 u8 config, power; 1465 1466 if (gadget_is_dualspeed(gadget) 1467 && gadget->speed == USB_SPEED_HIGH) { 1468 config = dev->hs_config->bConfigurationValue; 1469 power = dev->hs_config->bMaxPower; 1470 } else { 1471 config = dev->config->bConfigurationValue; 1472 power = dev->config->bMaxPower; 1473 } 1474 1475 if (config == (u8) w_value) { 1476 value = 0; 1477 dev->current_config = config; 1478 usb_gadget_vbus_draw(gadget, 2 * power); 1479 } 1480 } 1481 1482 /* report SET_CONFIGURATION like any other control request, 1483 * except that usermode may not stall this. the next 1484 * request mustn't be allowed start until this finishes: 1485 * endpoints and threads set up, etc. 1486 * 1487 * NOTE: older PXA hardware (before PXA 255: without UDCCFR) 1488 * has bad/racey automagic that prevents synchronizing here. 1489 * even kernel mode drivers often miss them. 1490 */ 1491 if (value == 0) { 1492 INFO (dev, "configuration #%d\n", dev->current_config); 1493 if (dev->usermode_setup) { 1494 dev->setup_can_stall = 0; 1495 goto delegate; 1496 } 1497 } 1498 break; 1499 1500#ifndef CONFIG_USB_GADGET_PXA25X 1501 /* PXA automagically handles this request too */ 1502 case USB_REQ_GET_CONFIGURATION: 1503 if (ctrl->bRequestType != 0x80) 1504 goto unrecognized; 1505 *(u8 *)req->buf = dev->current_config; 1506 value = min (w_length, (u16) 1); 1507 break; 1508#endif 1509 1510 default: 1511unrecognized: 1512 VDEBUG (dev, "%s req%02x.%02x v%04x i%04x l%d\n", 1513 dev->usermode_setup ? "delegate" : "fail", 1514 ctrl->bRequestType, ctrl->bRequest, 1515 w_value, le16_to_cpu(ctrl->wIndex), w_length); 1516 1517 /* if there's an ep0 reader, don't stall */ 1518 if (dev->usermode_setup) { 1519 dev->setup_can_stall = 1; 1520delegate: 1521 dev->setup_in = (ctrl->bRequestType & USB_DIR_IN) 1522 ? 1 : 0; 1523 dev->setup_wLength = w_length; 1524 dev->setup_out_ready = 0; 1525 dev->setup_out_error = 0; 1526 value = 0; 1527 1528 /* read DATA stage for OUT right away */ 1529 if (unlikely (!dev->setup_in && w_length)) { 1530 value = setup_req (gadget->ep0, dev->req, 1531 w_length); 1532 if (value < 0) 1533 break; 1534 value = usb_ep_queue (gadget->ep0, dev->req, 1535 GFP_ATOMIC); 1536 if (value < 0) { 1537 clean_req (gadget->ep0, dev->req); 1538 break; 1539 } 1540 1541 /* we can't currently stall these */ 1542 dev->setup_can_stall = 0; 1543 } 1544 1545 /* state changes when reader collects event */ 1546 event = next_event (dev, GADGETFS_SETUP); 1547 event->u.setup = *ctrl; 1548 ep0_readable (dev); 1549 spin_unlock (&dev->lock); 1550 return 0; 1551 } 1552 } 1553 1554 /* proceed with data transfer and status phases? */ 1555 if (value >= 0 && dev->state != STATE_DEV_SETUP) { 1556 req->length = value; 1557 req->zero = value < w_length; 1558 value = usb_ep_queue (gadget->ep0, req, GFP_ATOMIC); 1559 if (value < 0) { 1560 DBG (dev, "ep_queue --> %d\n", value); 1561 req->status = 0; 1562 } 1563 } 1564 1565 /* device stalls when value < 0 */ 1566 spin_unlock (&dev->lock); 1567 return value; 1568} 1569 1570static void destroy_ep_files (struct dev_data *dev) 1571{ 1572 struct list_head *entry, *tmp; 1573 1574 DBG (dev, "%s %d\n", __func__, dev->state); 1575 1576 /* dev->state must prevent interference */ 1577restart: 1578 spin_lock_irq (&dev->lock); 1579 list_for_each_safe (entry, tmp, &dev->epfiles) { 1580 struct ep_data *ep; 1581 struct inode *parent; 1582 struct dentry *dentry; 1583 1584 /* break link to FS */ 1585 ep = list_entry (entry, struct ep_data, epfiles); 1586 list_del_init (&ep->epfiles); 1587 dentry = ep->dentry; 1588 ep->dentry = NULL; 1589 parent = dentry->d_parent->d_inode; 1590 1591 /* break link to controller */ 1592 if (ep->state == STATE_EP_ENABLED) 1593 (void) usb_ep_disable (ep->ep); 1594 ep->state = STATE_EP_UNBOUND; 1595 usb_ep_free_request (ep->ep, ep->req); 1596 ep->ep = NULL; 1597 wake_up (&ep->wait); 1598 put_ep (ep); 1599 1600 spin_unlock_irq (&dev->lock); 1601 1602 /* break link to dcache */ 1603 mutex_lock (&parent->i_mutex); 1604 d_delete (dentry); 1605 dput (dentry); 1606 mutex_unlock (&parent->i_mutex); 1607 1608 /* fds may still be open */ 1609 goto restart; 1610 } 1611 spin_unlock_irq (&dev->lock); 1612} 1613 1614 1615static struct inode * 1616gadgetfs_create_file (struct super_block *sb, char const *name, 1617 void *data, const struct file_operations *fops, 1618 struct dentry **dentry_p); 1619 1620static int activate_ep_files (struct dev_data *dev) 1621{ 1622 struct usb_ep *ep; 1623 struct ep_data *data; 1624 1625 gadget_for_each_ep (ep, dev->gadget) { 1626 1627 data = kzalloc(sizeof(*data), GFP_KERNEL); 1628 if (!data) 1629 goto enomem0; 1630 data->state = STATE_EP_DISABLED; 1631 mutex_init(&data->lock); 1632 init_waitqueue_head (&data->wait); 1633 1634 strncpy (data->name, ep->name, sizeof (data->name) - 1); 1635 atomic_set (&data->count, 1); 1636 data->dev = dev; 1637 get_dev (dev); 1638 1639 data->ep = ep; 1640 ep->driver_data = data; 1641 1642 data->req = usb_ep_alloc_request (ep, GFP_KERNEL); 1643 if (!data->req) 1644 goto enomem1; 1645 1646 data->inode = gadgetfs_create_file (dev->sb, data->name, 1647 data, &ep_config_operations, 1648 &data->dentry); 1649 if (!data->inode) 1650 goto enomem2; 1651 list_add_tail (&data->epfiles, &dev->epfiles); 1652 } 1653 return 0; 1654 1655enomem2: 1656 usb_ep_free_request (ep, data->req); 1657enomem1: 1658 put_dev (dev); 1659 kfree (data); 1660enomem0: 1661 DBG (dev, "%s enomem\n", __func__); 1662 destroy_ep_files (dev); 1663 return -ENOMEM; 1664} 1665 1666static void 1667gadgetfs_unbind (struct usb_gadget *gadget) 1668{ 1669 struct dev_data *dev = get_gadget_data (gadget); 1670 1671 DBG (dev, "%s\n", __func__); 1672 1673 spin_lock_irq (&dev->lock); 1674 dev->state = STATE_DEV_UNBOUND; 1675 spin_unlock_irq (&dev->lock); 1676 1677 destroy_ep_files (dev); 1678 gadget->ep0->driver_data = NULL; 1679 set_gadget_data (gadget, NULL); 1680 1681 /* we've already been disconnected ... no i/o is active */ 1682 if (dev->req) 1683 usb_ep_free_request (gadget->ep0, dev->req); 1684 DBG (dev, "%s done\n", __func__); 1685 put_dev (dev); 1686} 1687 1688static struct dev_data *the_device; 1689 1690static int 1691gadgetfs_bind (struct usb_gadget *gadget) 1692{ 1693 struct dev_data *dev = the_device; 1694 1695 if (!dev) 1696 return -ESRCH; 1697 if (0 != strcmp (CHIP, gadget->name)) { 1698 pr_err("%s expected %s controller not %s\n", 1699 shortname, CHIP, gadget->name); 1700 return -ENODEV; 1701 } 1702 1703 set_gadget_data (gadget, dev); 1704 dev->gadget = gadget; 1705 gadget->ep0->driver_data = dev; 1706 dev->dev->bMaxPacketSize0 = gadget->ep0->maxpacket; 1707 1708 /* preallocate control response and buffer */ 1709 dev->req = usb_ep_alloc_request (gadget->ep0, GFP_KERNEL); 1710 if (!dev->req) 1711 goto enomem; 1712 dev->req->context = NULL; 1713 dev->req->complete = epio_complete; 1714 1715 if (activate_ep_files (dev) < 0) 1716 goto enomem; 1717 1718 INFO (dev, "bound to %s driver\n", gadget->name); 1719 spin_lock_irq(&dev->lock); 1720 dev->state = STATE_DEV_UNCONNECTED; 1721 spin_unlock_irq(&dev->lock); 1722 get_dev (dev); 1723 return 0; 1724 1725enomem: 1726 gadgetfs_unbind (gadget); 1727 return -ENOMEM; 1728} 1729 1730static void 1731gadgetfs_disconnect (struct usb_gadget *gadget) 1732{ 1733 struct dev_data *dev = get_gadget_data (gadget); 1734 1735 spin_lock (&dev->lock); 1736 if (dev->state == STATE_DEV_UNCONNECTED) 1737 goto exit; 1738 dev->state = STATE_DEV_UNCONNECTED; 1739 1740 INFO (dev, "disconnected\n"); 1741 next_event (dev, GADGETFS_DISCONNECT); 1742 ep0_readable (dev); 1743exit: 1744 spin_unlock (&dev->lock); 1745} 1746 1747static void 1748gadgetfs_suspend (struct usb_gadget *gadget) 1749{ 1750 struct dev_data *dev = get_gadget_data (gadget); 1751 1752 INFO (dev, "suspended from state %d\n", dev->state); 1753 spin_lock (&dev->lock); 1754 switch (dev->state) { 1755 case STATE_DEV_SETUP: // VERY odd... host died?? 1756 case STATE_DEV_CONNECTED: 1757 case STATE_DEV_UNCONNECTED: 1758 next_event (dev, GADGETFS_SUSPEND); 1759 ep0_readable (dev); 1760 /* FALLTHROUGH */ 1761 default: 1762 break; 1763 } 1764 spin_unlock (&dev->lock); 1765} 1766 1767static struct usb_gadget_driver gadgetfs_driver = { 1768#ifdef CONFIG_USB_GADGET_DUALSPEED 1769 .speed = USB_SPEED_HIGH, 1770#else 1771 .speed = USB_SPEED_FULL, 1772#endif 1773 .function = (char *) driver_desc, 1774 .bind = gadgetfs_bind, 1775 .unbind = gadgetfs_unbind, 1776 .setup = gadgetfs_setup, 1777 .disconnect = gadgetfs_disconnect, 1778 .suspend = gadgetfs_suspend, 1779 1780 .driver = { 1781 .name = (char *) shortname, 1782 }, 1783}; 1784 1785/*----------------------------------------------------------------------*/ 1786 1787static void gadgetfs_nop(struct usb_gadget *arg) { } 1788 1789static int gadgetfs_probe (struct usb_gadget *gadget) 1790{ 1791 CHIP = gadget->name; 1792 return -EISNAM; 1793} 1794 1795static struct usb_gadget_driver probe_driver = { 1796 .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 1833static 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} 1841 1842static ssize_t 1843dev_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr) 1844{ 1845 struct dev_data *dev = fd->private_data; 1846 ssize_t value = len, length = len; 1847 unsigned total; 1848 u32 tag; 1849 char *kbuf; 1850 1851 if (len < (USB_DT_CONFIG_SIZE + USB_DT_DEVICE_SIZE + 4)) 1852 return -EINVAL; 1853 1854 /* we might need to change message format someday */ 1855 if (copy_from_user (&tag, buf, 4)) 1856 return -EFAULT; 1857 if (tag != 0) 1858 return -EINVAL; 1859 buf += 4; 1860 length -= 4; 1861 1862 kbuf = memdup_user(buf, length); 1863 if (IS_ERR(kbuf)) 1864 return PTR_ERR(kbuf); 1865 1866 spin_lock_irq (&dev->lock); 1867 value = -EINVAL; 1868 if (dev->buf) 1869 goto fail; 1870 dev->buf = kbuf; 1871 1872 /* full or low speed config */ 1873 dev->config = (void *) kbuf; 1874 total = le16_to_cpu(dev->config->wTotalLength); 1875 if (!is_valid_config (dev->config) || total >= length) 1876 goto fail; 1877 kbuf += total; 1878 length -= total; 1879 1880 /* optional high speed config */ 1881 if (kbuf [1] == USB_DT_CONFIG) { 1882 dev->hs_config = (void *) kbuf; 1883 total = le16_to_cpu(dev->hs_config->wTotalLength); 1884 if (!is_valid_config (dev->hs_config) || total >= length) 1885 goto fail; 1886 kbuf += total; 1887 length -= total; 1888 } 1889 1890 /* could support multiple configs, using another encoding! */ 1891 1892 /* device descriptor (tweaked for paranoia) */ 1893 if (length != USB_DT_DEVICE_SIZE) 1894 goto fail; 1895 dev->dev = (void *)kbuf; 1896 if (dev->dev->bLength != USB_DT_DEVICE_SIZE 1897 || dev->dev->bDescriptorType != USB_DT_DEVICE 1898 || dev->dev->bNumConfigurations != 1) 1899 goto fail; 1900 dev->dev->bNumConfigurations = 1; 1901 dev->dev->bcdUSB = cpu_to_le16 (0x0200); 1902 1903 /* triggers gadgetfs_bind(); then we can enumerate. */ 1904 spin_unlock_irq (&dev->lock); 1905 value = usb_gadget_register_driver (&gadgetfs_driver); 1906 if (value != 0) { 1907 kfree (dev->buf); 1908 dev->buf = NULL; 1909 } else { 1910 /* at this point "good" hardware has for the first time 1911 * let the USB the host see us. alternatively, if users 1912 * unplug/replug that will clear all the error state. 1913 * 1914 * note: everything running before here was guaranteed 1915 * to choke driver model style diagnostics. from here 1916 * on, they can work ... except in cleanup paths that 1917 * kick in after the ep0 descriptor is closed. 1918 */ 1919 fd->f_op = &ep0_io_operations; 1920 value = len; 1921 } 1922 return value; 1923 1924fail: 1925 spin_unlock_irq (&dev->lock); 1926 pr_debug ("%s: %s fail %Zd, %p\n", shortname, __func__, value, dev); 1927 kfree (dev->buf); 1928 dev->buf = NULL; 1929 return value; 1930} 1931 1932static int 1933dev_open (struct inode *inode, struct file *fd) 1934{ 1935 struct dev_data *dev = inode->i_private; 1936 int value = -EBUSY; 1937 1938 spin_lock_irq(&dev->lock); 1939 if (dev->state == STATE_DEV_DISABLED) { 1940 dev->ev_next = 0; 1941 dev->state = STATE_DEV_OPENED; 1942 fd->private_data = dev; 1943 get_dev (dev); 1944 value = 0; 1945 } 1946 spin_unlock_irq(&dev->lock); 1947 return value; 1948} 1949 1950static const struct file_operations dev_init_operations = { 1951 .owner = THIS_MODULE, 1952 .llseek = no_llseek, 1953 1954 .open = dev_open, 1955 .write = dev_config, 1956 .fasync = ep0_fasync, 1957 .unlocked_ioctl = dev_ioctl, 1958 .release = dev_release, 1959}; 1960 1961/*----------------------------------------------------------------------*/ 1962 1963/* FILESYSTEM AND SUPERBLOCK OPERATIONS 1964 * 1965 * Mounting the filesystem creates a controller file, used first for 1966 * device configuration then later for event monitoring. 1967 */ 1968 1969 1970 1971static unsigned default_uid; 1972static unsigned default_gid; 1973static unsigned default_perm = S_IRUSR | S_IWUSR; 1974 1975module_param (default_uid, uint, 0644); 1976module_param (default_gid, uint, 0644); 1977module_param (default_perm, uint, 0644); 1978 1979 1980static struct inode * 1981gadgetfs_make_inode (struct super_block *sb, 1982 void *data, const struct file_operations *fops, 1983 int mode) 1984{ 1985 struct inode *inode = new_inode (sb); 1986 1987 if (inode) { 1988 inode->i_mode = mode; 1989 inode->i_uid = default_uid; 1990 inode->i_gid = default_gid; 1991 inode->i_atime = inode->i_mtime = inode->i_ctime 1992 = CURRENT_TIME; 1993 inode->i_private = data; 1994 inode->i_fop = fops; 1995 } 1996 return inode; 1997} 1998 1999/* creates in fs root directory, so non-renamable and non-linkable. 2000 * so inode and dentry are paired, until device reconfig. 2001 */ 2002static struct inode * 2003gadgetfs_create_file (struct super_block *sb, char const *name, 2004 void *data, const struct file_operations *fops, 2005 struct dentry **dentry_p) 2006{ 2007 struct dentry *dentry; 2008 struct inode *inode; 2009 2010 dentry = d_alloc_name(sb->s_root, name); 2011 if (!dentry) 2012 return NULL; 2013 2014 inode = gadgetfs_make_inode (sb, data, fops, 2015 S_IFREG | (default_perm & S_IRWXUGO)); 2016 if (!inode) { 2017 dput(dentry); 2018 return NULL; 2019 } 2020 d_add (dentry, inode); 2021 *dentry_p = dentry; 2022 return inode; 2023} 2024 2025static const struct super_operations gadget_fs_operations = { 2026 .statfs = simple_statfs, 2027 .drop_inode = generic_delete_inode, 2028}; 2029 2030static int 2031gadgetfs_fill_super (struct super_block *sb, void *opts, int silent) 2032{ 2033 struct inode *inode; 2034 struct dentry *d; 2035 struct dev_data *dev; 2036 2037 if (the_device) 2038 return -ESRCH; 2039 2040 /* fake probe to determine $CHIP */ 2041 (void) usb_gadget_register_driver (&probe_driver); 2042 if (!CHIP) 2043 return -ENODEV; 2044 2045 /* superblock */ 2046 sb->s_blocksize = PAGE_CACHE_SIZE; 2047 sb->s_blocksize_bits = PAGE_CACHE_SHIFT; 2048 sb->s_magic = GADGETFS_MAGIC; 2049 sb->s_op = &gadget_fs_operations; 2050 sb->s_time_gran = 1; 2051 2052 /* root inode */ 2053 inode = gadgetfs_make_inode (sb, 2054 NULL, &simple_dir_operations, 2055 S_IFDIR | S_IRUGO | S_IXUGO); 2056 if (!inode) 2057 goto enomem0; 2058 inode->i_op = &simple_dir_inode_operations; 2059 if (!(d = d_alloc_root (inode))) 2060 goto enomem1; 2061 sb->s_root = d; 2062 2063 /* the ep0 file is named after the controller we expect; 2064 * user mode code can use it for sanity checks, like we do. 2065 */ 2066 dev = dev_new (); 2067 if (!dev) 2068 goto enomem2; 2069 2070 dev->sb = sb; 2071 if (!gadgetfs_create_file (sb, CHIP, 2072 dev, &dev_init_operations, 2073 &dev->dentry)) 2074 goto enomem3; 2075 2076 /* other endpoint files are available after hardware setup, 2077 * from binding to a controller. 2078 */ 2079 the_device = dev; 2080 return 0; 2081 2082enomem3: 2083 put_dev (dev); 2084enomem2: 2085 dput (d); 2086enomem1: 2087 iput (inode); 2088enomem0: 2089 return -ENOMEM; 2090} 2091 2092/* "mount -t gadgetfs path /dev/gadget" ends up here */ 2093static int 2094gadgetfs_get_sb (struct file_system_type *t, int flags, 2095 const char *path, void *opts, struct vfsmount *mnt) 2096{ 2097 return get_sb_single (t, flags, opts, gadgetfs_fill_super, mnt); 2098} 2099 2100static void 2101gadgetfs_kill_sb (struct super_block *sb) 2102{ 2103 kill_litter_super (sb); 2104 if (the_device) { 2105 put_dev (the_device); 2106 the_device = NULL; 2107 } 2108} 2109 2110/*----------------------------------------------------------------------*/ 2111 2112static struct file_system_type gadgetfs_type = { 2113 .owner = THIS_MODULE, 2114 .name = shortname, 2115 .get_sb = gadgetfs_get_sb, 2116 .kill_sb = gadgetfs_kill_sb, 2117}; 2118 2119/*----------------------------------------------------------------------*/ 2120 2121static int __init init (void) 2122{ 2123 int status; 2124 2125 status = register_filesystem (&gadgetfs_type); 2126 if (status == 0) 2127 pr_info ("%s: %s, version " DRIVER_VERSION "\n", 2128 shortname, driver_desc); 2129 return status; 2130} 2131module_init (init); 2132 2133static void __exit cleanup (void) 2134{ 2135 pr_debug ("unregister %s\n", shortname); 2136 unregister_filesystem (&gadgetfs_type); 2137} 2138module_exit (cleanup); 2139