inode.c revision 1548b13b75a2ec06f46220004e91c37818be6c18
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 /* FIXME readahead for O_NONBLOCK and poll(); careful with ZLPs */ 402 403 value = -ENOMEM; 404 kbuf = kmalloc (len, GFP_KERNEL); 405 if (unlikely (!kbuf)) 406 goto free1; 407 408 value = ep_io (data, kbuf, len); 409 VDEBUG (data->dev, "%s read %zu OUT, status %d\n", 410 data->name, len, (int) value); 411 if (value >= 0 && copy_to_user (buf, kbuf, value)) 412 value = -EFAULT; 413 414free1: 415 mutex_unlock(&data->lock); 416 kfree (kbuf); 417 return value; 418} 419 420/* handle a synchronous IN bulk/intr/iso transfer */ 421static ssize_t 422ep_write (struct file *fd, const char __user *buf, size_t len, loff_t *ptr) 423{ 424 struct ep_data *data = fd->private_data; 425 void *kbuf; 426 ssize_t value; 427 428 if ((value = get_ready_ep (fd->f_flags, data)) < 0) 429 return value; 430 431 /* halt any endpoint by doing a "wrong direction" i/o call */ 432 if (!usb_endpoint_dir_in(&data->desc)) { 433 if (usb_endpoint_xfer_isoc(&data->desc)) 434 return -EINVAL; 435 DBG (data->dev, "%s halt\n", data->name); 436 spin_lock_irq (&data->dev->lock); 437 if (likely (data->ep != NULL)) 438 usb_ep_set_halt (data->ep); 439 spin_unlock_irq (&data->dev->lock); 440 mutex_unlock(&data->lock); 441 return -EBADMSG; 442 } 443 444 /* FIXME writebehind for O_NONBLOCK and poll(), qlen = 1 */ 445 446 value = -ENOMEM; 447 kbuf = kmalloc (len, GFP_KERNEL); 448 if (!kbuf) 449 goto free1; 450 if (copy_from_user (kbuf, buf, len)) { 451 value = -EFAULT; 452 goto free1; 453 } 454 455 value = ep_io (data, kbuf, len); 456 VDEBUG (data->dev, "%s write %zu IN, status %d\n", 457 data->name, len, (int) value); 458free1: 459 mutex_unlock(&data->lock); 460 kfree (kbuf); 461 return value; 462} 463 464static int 465ep_release (struct inode *inode, struct file *fd) 466{ 467 struct ep_data *data = fd->private_data; 468 int value; 469 470 value = mutex_lock_interruptible(&data->lock); 471 if (value < 0) 472 return value; 473 474 /* clean up if this can be reopened */ 475 if (data->state != STATE_EP_UNBOUND) { 476 data->state = STATE_EP_DISABLED; 477 data->desc.bDescriptorType = 0; 478 data->hs_desc.bDescriptorType = 0; 479 usb_ep_disable(data->ep); 480 } 481 mutex_unlock(&data->lock); 482 put_ep (data); 483 return 0; 484} 485 486static long ep_ioctl(struct file *fd, unsigned code, unsigned long value) 487{ 488 struct ep_data *data = fd->private_data; 489 int status; 490 491 if ((status = get_ready_ep (fd->f_flags, data)) < 0) 492 return status; 493 494 spin_lock_irq (&data->dev->lock); 495 if (likely (data->ep != NULL)) { 496 switch (code) { 497 case GADGETFS_FIFO_STATUS: 498 status = usb_ep_fifo_status (data->ep); 499 break; 500 case GADGETFS_FIFO_FLUSH: 501 usb_ep_fifo_flush (data->ep); 502 break; 503 case GADGETFS_CLEAR_HALT: 504 status = usb_ep_clear_halt (data->ep); 505 break; 506 default: 507 status = -ENOTTY; 508 } 509 } else 510 status = -ENODEV; 511 spin_unlock_irq (&data->dev->lock); 512 mutex_unlock(&data->lock); 513 return status; 514} 515 516/*----------------------------------------------------------------------*/ 517 518/* ASYNCHRONOUS ENDPOINT I/O OPERATIONS (bulk/intr/iso) */ 519 520struct kiocb_priv { 521 struct usb_request *req; 522 struct ep_data *epdata; 523 void *buf; 524 const struct iovec *iv; 525 unsigned long nr_segs; 526 unsigned actual; 527}; 528 529static int ep_aio_cancel(struct kiocb *iocb, struct io_event *e) 530{ 531 struct kiocb_priv *priv = iocb->private; 532 struct ep_data *epdata; 533 int value; 534 535 local_irq_disable(); 536 epdata = priv->epdata; 537 // spin_lock(&epdata->dev->lock); 538 kiocbSetCancelled(iocb); 539 if (likely(epdata && epdata->ep && priv->req)) 540 value = usb_ep_dequeue (epdata->ep, priv->req); 541 else 542 value = -EINVAL; 543 // spin_unlock(&epdata->dev->lock); 544 local_irq_enable(); 545 546 aio_put_req(iocb); 547 return value; 548} 549 550static ssize_t ep_aio_read_retry(struct kiocb *iocb) 551{ 552 struct kiocb_priv *priv = iocb->private; 553 ssize_t len, total; 554 void *to_copy; 555 int i; 556 557 /* we "retry" to get the right mm context for this: */ 558 559 /* copy stuff into user buffers */ 560 total = priv->actual; 561 len = 0; 562 to_copy = priv->buf; 563 for (i=0; i < priv->nr_segs; i++) { 564 ssize_t this = min((ssize_t)(priv->iv[i].iov_len), total); 565 566 if (copy_to_user(priv->iv[i].iov_base, to_copy, this)) { 567 if (len == 0) 568 len = -EFAULT; 569 break; 570 } 571 572 total -= this; 573 len += this; 574 to_copy += this; 575 if (total == 0) 576 break; 577 } 578 kfree(priv->buf); 579 kfree(priv); 580 return len; 581} 582 583static void ep_aio_complete(struct usb_ep *ep, struct usb_request *req) 584{ 585 struct kiocb *iocb = req->context; 586 struct kiocb_priv *priv = iocb->private; 587 struct ep_data *epdata = priv->epdata; 588 589 /* lock against disconnect (and ideally, cancel) */ 590 spin_lock(&epdata->dev->lock); 591 priv->req = NULL; 592 priv->epdata = NULL; 593 594 /* if this was a write or a read returning no data then we 595 * don't need to copy anything to userspace, so we can 596 * complete the aio request immediately. 597 */ 598 if (priv->iv == NULL || unlikely(req->actual == 0)) { 599 kfree(req->buf); 600 kfree(priv); 601 iocb->private = NULL; 602 /* aio_complete() reports bytes-transferred _and_ faults */ 603 aio_complete(iocb, req->actual ? req->actual : req->status, 604 req->status); 605 } else { 606 /* retry() won't report both; so we hide some faults */ 607 if (unlikely(0 != req->status)) 608 DBG(epdata->dev, "%s fault %d len %d\n", 609 ep->name, req->status, req->actual); 610 611 priv->buf = req->buf; 612 priv->actual = req->actual; 613 kick_iocb(iocb); 614 } 615 spin_unlock(&epdata->dev->lock); 616 617 usb_ep_free_request(ep, req); 618 put_ep(epdata); 619} 620 621static ssize_t 622ep_aio_rwtail( 623 struct kiocb *iocb, 624 char *buf, 625 size_t len, 626 struct ep_data *epdata, 627 const struct iovec *iv, 628 unsigned long nr_segs 629) 630{ 631 struct kiocb_priv *priv; 632 struct usb_request *req; 633 ssize_t value; 634 635 priv = kmalloc(sizeof *priv, GFP_KERNEL); 636 if (!priv) { 637 value = -ENOMEM; 638fail: 639 kfree(buf); 640 return value; 641 } 642 iocb->private = priv; 643 priv->iv = iv; 644 priv->nr_segs = nr_segs; 645 646 value = get_ready_ep(iocb->ki_filp->f_flags, epdata); 647 if (unlikely(value < 0)) { 648 kfree(priv); 649 goto fail; 650 } 651 652 iocb->ki_cancel = ep_aio_cancel; 653 get_ep(epdata); 654 priv->epdata = epdata; 655 priv->actual = 0; 656 657 /* each kiocb is coupled to one usb_request, but we can't 658 * allocate or submit those if the host disconnected. 659 */ 660 spin_lock_irq(&epdata->dev->lock); 661 if (likely(epdata->ep)) { 662 req = usb_ep_alloc_request(epdata->ep, GFP_ATOMIC); 663 if (likely(req)) { 664 priv->req = req; 665 req->buf = buf; 666 req->length = len; 667 req->complete = ep_aio_complete; 668 req->context = iocb; 669 value = usb_ep_queue(epdata->ep, req, GFP_ATOMIC); 670 if (unlikely(0 != value)) 671 usb_ep_free_request(epdata->ep, req); 672 } else 673 value = -EAGAIN; 674 } else 675 value = -ENODEV; 676 spin_unlock_irq(&epdata->dev->lock); 677 678 mutex_unlock(&epdata->lock); 679 680 if (unlikely(value)) { 681 kfree(priv); 682 put_ep(epdata); 683 } else 684 value = (iv ? -EIOCBRETRY : -EIOCBQUEUED); 685 return value; 686} 687 688static ssize_t 689ep_aio_read(struct kiocb *iocb, const struct iovec *iov, 690 unsigned long nr_segs, loff_t o) 691{ 692 struct ep_data *epdata = iocb->ki_filp->private_data; 693 char *buf; 694 695 if (unlikely(usb_endpoint_dir_in(&epdata->desc))) 696 return -EINVAL; 697 698 buf = kmalloc(iocb->ki_left, GFP_KERNEL); 699 if (unlikely(!buf)) 700 return -ENOMEM; 701 702 iocb->ki_retry = ep_aio_read_retry; 703 return ep_aio_rwtail(iocb, buf, iocb->ki_left, epdata, iov, nr_segs); 704} 705 706static ssize_t 707ep_aio_write(struct kiocb *iocb, const struct iovec *iov, 708 unsigned long nr_segs, loff_t o) 709{ 710 struct ep_data *epdata = iocb->ki_filp->private_data; 711 char *buf; 712 size_t len = 0; 713 int i = 0; 714 715 if (unlikely(!usb_endpoint_dir_in(&epdata->desc))) 716 return -EINVAL; 717 718 buf = kmalloc(iocb->ki_left, GFP_KERNEL); 719 if (unlikely(!buf)) 720 return -ENOMEM; 721 722 for (i=0; i < nr_segs; i++) { 723 if (unlikely(copy_from_user(&buf[len], iov[i].iov_base, 724 iov[i].iov_len) != 0)) { 725 kfree(buf); 726 return -EFAULT; 727 } 728 len += iov[i].iov_len; 729 } 730 return ep_aio_rwtail(iocb, buf, len, epdata, NULL, 0); 731} 732 733/*----------------------------------------------------------------------*/ 734 735/* used after endpoint configuration */ 736static const struct file_operations ep_io_operations = { 737 .owner = THIS_MODULE, 738 .llseek = no_llseek, 739 740 .read = ep_read, 741 .write = ep_write, 742 .unlocked_ioctl = ep_ioctl, 743 .release = ep_release, 744 745 .aio_read = ep_aio_read, 746 .aio_write = ep_aio_write, 747}; 748 749/* ENDPOINT INITIALIZATION 750 * 751 * fd = open ("/dev/gadget/$ENDPOINT", O_RDWR) 752 * status = write (fd, descriptors, sizeof descriptors) 753 * 754 * That write establishes the endpoint configuration, configuring 755 * the controller to process bulk, interrupt, or isochronous transfers 756 * at the right maxpacket size, and so on. 757 * 758 * The descriptors are message type 1, identified by a host order u32 759 * at the beginning of what's written. Descriptor order is: full/low 760 * speed descriptor, then optional high speed descriptor. 761 */ 762static ssize_t 763ep_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr) 764{ 765 struct ep_data *data = fd->private_data; 766 struct usb_ep *ep; 767 u32 tag; 768 int value, length = len; 769 770 value = mutex_lock_interruptible(&data->lock); 771 if (value < 0) 772 return value; 773 774 if (data->state != STATE_EP_READY) { 775 value = -EL2HLT; 776 goto fail; 777 } 778 779 value = len; 780 if (len < USB_DT_ENDPOINT_SIZE + 4) 781 goto fail0; 782 783 /* we might need to change message format someday */ 784 if (copy_from_user (&tag, buf, 4)) { 785 goto fail1; 786 } 787 if (tag != 1) { 788 DBG(data->dev, "config %s, bad tag %d\n", data->name, tag); 789 goto fail0; 790 } 791 buf += 4; 792 len -= 4; 793 794 /* NOTE: audio endpoint extensions not accepted here; 795 * just don't include the extra bytes. 796 */ 797 798 /* full/low speed descriptor, then high speed */ 799 if (copy_from_user (&data->desc, buf, USB_DT_ENDPOINT_SIZE)) { 800 goto fail1; 801 } 802 if (data->desc.bLength != USB_DT_ENDPOINT_SIZE 803 || data->desc.bDescriptorType != USB_DT_ENDPOINT) 804 goto fail0; 805 if (len != USB_DT_ENDPOINT_SIZE) { 806 if (len != 2 * USB_DT_ENDPOINT_SIZE) 807 goto fail0; 808 if (copy_from_user (&data->hs_desc, buf + USB_DT_ENDPOINT_SIZE, 809 USB_DT_ENDPOINT_SIZE)) { 810 goto fail1; 811 } 812 if (data->hs_desc.bLength != USB_DT_ENDPOINT_SIZE 813 || data->hs_desc.bDescriptorType 814 != USB_DT_ENDPOINT) { 815 DBG(data->dev, "config %s, bad hs length or type\n", 816 data->name); 817 goto fail0; 818 } 819 } 820 821 spin_lock_irq (&data->dev->lock); 822 if (data->dev->state == STATE_DEV_UNBOUND) { 823 value = -ENOENT; 824 goto gone; 825 } else if ((ep = data->ep) == NULL) { 826 value = -ENODEV; 827 goto gone; 828 } 829 switch (data->dev->gadget->speed) { 830 case USB_SPEED_LOW: 831 case USB_SPEED_FULL: 832 value = usb_ep_enable (ep, &data->desc); 833 if (value == 0) 834 data->state = STATE_EP_ENABLED; 835 break; 836#ifdef CONFIG_USB_GADGET_DUALSPEED 837 case USB_SPEED_HIGH: 838 /* fails if caller didn't provide that descriptor... */ 839 value = usb_ep_enable (ep, &data->hs_desc); 840 if (value == 0) 841 data->state = STATE_EP_ENABLED; 842 break; 843#endif 844 default: 845 DBG(data->dev, "unconnected, %s init abandoned\n", 846 data->name); 847 value = -EINVAL; 848 } 849 if (value == 0) { 850 fd->f_op = &ep_io_operations; 851 value = length; 852 } 853gone: 854 spin_unlock_irq (&data->dev->lock); 855 if (value < 0) { 856fail: 857 data->desc.bDescriptorType = 0; 858 data->hs_desc.bDescriptorType = 0; 859 } 860 mutex_unlock(&data->lock); 861 return value; 862fail0: 863 value = -EINVAL; 864 goto fail; 865fail1: 866 value = -EFAULT; 867 goto fail; 868} 869 870static int 871ep_open (struct inode *inode, struct file *fd) 872{ 873 struct ep_data *data = inode->i_private; 874 int value = -EBUSY; 875 876 if (mutex_lock_interruptible(&data->lock) != 0) 877 return -EINTR; 878 spin_lock_irq (&data->dev->lock); 879 if (data->dev->state == STATE_DEV_UNBOUND) 880 value = -ENOENT; 881 else if (data->state == STATE_EP_DISABLED) { 882 value = 0; 883 data->state = STATE_EP_READY; 884 get_ep (data); 885 fd->private_data = data; 886 VDEBUG (data->dev, "%s ready\n", data->name); 887 } else 888 DBG (data->dev, "%s state %d\n", 889 data->name, data->state); 890 spin_unlock_irq (&data->dev->lock); 891 mutex_unlock(&data->lock); 892 return value; 893} 894 895/* used before endpoint configuration */ 896static const struct file_operations ep_config_operations = { 897 .owner = THIS_MODULE, 898 .llseek = no_llseek, 899 900 .open = ep_open, 901 .write = ep_config, 902 .release = ep_release, 903}; 904 905/*----------------------------------------------------------------------*/ 906 907/* EP0 IMPLEMENTATION can be partly in userspace. 908 * 909 * Drivers that use this facility receive various events, including 910 * control requests the kernel doesn't handle. Drivers that don't 911 * use this facility may be too simple-minded for real applications. 912 */ 913 914static inline void ep0_readable (struct dev_data *dev) 915{ 916 wake_up (&dev->wait); 917 kill_fasync (&dev->fasync, SIGIO, POLL_IN); 918} 919 920static void clean_req (struct usb_ep *ep, struct usb_request *req) 921{ 922 struct dev_data *dev = ep->driver_data; 923 924 if (req->buf != dev->rbuf) { 925 kfree(req->buf); 926 req->buf = dev->rbuf; 927 req->dma = DMA_ADDR_INVALID; 928 } 929 req->complete = epio_complete; 930 dev->setup_out_ready = 0; 931} 932 933static void ep0_complete (struct usb_ep *ep, struct usb_request *req) 934{ 935 struct dev_data *dev = ep->driver_data; 936 unsigned long flags; 937 int free = 1; 938 939 /* for control OUT, data must still get to userspace */ 940 spin_lock_irqsave(&dev->lock, flags); 941 if (!dev->setup_in) { 942 dev->setup_out_error = (req->status != 0); 943 if (!dev->setup_out_error) 944 free = 0; 945 dev->setup_out_ready = 1; 946 ep0_readable (dev); 947 } 948 949 /* clean up as appropriate */ 950 if (free && req->buf != &dev->rbuf) 951 clean_req (ep, req); 952 req->complete = epio_complete; 953 spin_unlock_irqrestore(&dev->lock, flags); 954} 955 956static int setup_req (struct usb_ep *ep, struct usb_request *req, u16 len) 957{ 958 struct dev_data *dev = ep->driver_data; 959 960 if (dev->setup_out_ready) { 961 DBG (dev, "ep0 request busy!\n"); 962 return -EBUSY; 963 } 964 if (len > sizeof (dev->rbuf)) 965 req->buf = kmalloc(len, GFP_ATOMIC); 966 if (req->buf == NULL) { 967 req->buf = dev->rbuf; 968 return -ENOMEM; 969 } 970 req->complete = ep0_complete; 971 req->length = len; 972 req->zero = 0; 973 return 0; 974} 975 976static ssize_t 977ep0_read (struct file *fd, char __user *buf, size_t len, loff_t *ptr) 978{ 979 struct dev_data *dev = fd->private_data; 980 ssize_t retval; 981 enum ep0_state state; 982 983 spin_lock_irq (&dev->lock); 984 985 /* report fd mode change before acting on it */ 986 if (dev->setup_abort) { 987 dev->setup_abort = 0; 988 retval = -EIDRM; 989 goto done; 990 } 991 992 /* control DATA stage */ 993 if ((state = dev->state) == STATE_DEV_SETUP) { 994 995 if (dev->setup_in) { /* stall IN */ 996 VDEBUG(dev, "ep0in stall\n"); 997 (void) usb_ep_set_halt (dev->gadget->ep0); 998 retval = -EL2HLT; 999 dev->state = STATE_DEV_CONNECTED; 1000 1001 } else if (len == 0) { /* ack SET_CONFIGURATION etc */ 1002 struct usb_ep *ep = dev->gadget->ep0; 1003 struct usb_request *req = dev->req; 1004 1005 if ((retval = setup_req (ep, req, 0)) == 0) 1006 retval = usb_ep_queue (ep, req, GFP_ATOMIC); 1007 dev->state = STATE_DEV_CONNECTED; 1008 1009 /* assume that was SET_CONFIGURATION */ 1010 if (dev->current_config) { 1011 unsigned power; 1012 1013 if (gadget_is_dualspeed(dev->gadget) 1014 && (dev->gadget->speed 1015 == USB_SPEED_HIGH)) 1016 power = dev->hs_config->bMaxPower; 1017 else 1018 power = dev->config->bMaxPower; 1019 usb_gadget_vbus_draw(dev->gadget, 2 * power); 1020 } 1021 1022 } else { /* collect OUT data */ 1023 if ((fd->f_flags & O_NONBLOCK) != 0 1024 && !dev->setup_out_ready) { 1025 retval = -EAGAIN; 1026 goto done; 1027 } 1028 spin_unlock_irq (&dev->lock); 1029 retval = wait_event_interruptible (dev->wait, 1030 dev->setup_out_ready != 0); 1031 1032 /* FIXME state could change from under us */ 1033 spin_lock_irq (&dev->lock); 1034 if (retval) 1035 goto done; 1036 1037 if (dev->state != STATE_DEV_SETUP) { 1038 retval = -ECANCELED; 1039 goto done; 1040 } 1041 dev->state = STATE_DEV_CONNECTED; 1042 1043 if (dev->setup_out_error) 1044 retval = -EIO; 1045 else { 1046 len = min (len, (size_t)dev->req->actual); 1047// FIXME don't call this with the spinlock held ... 1048 if (copy_to_user (buf, dev->req->buf, len)) 1049 retval = -EFAULT; 1050 clean_req (dev->gadget->ep0, dev->req); 1051 /* NOTE userspace can't yet choose to stall */ 1052 } 1053 } 1054 goto done; 1055 } 1056 1057 /* else normal: return event data */ 1058 if (len < sizeof dev->event [0]) { 1059 retval = -EINVAL; 1060 goto done; 1061 } 1062 len -= len % sizeof (struct usb_gadgetfs_event); 1063 dev->usermode_setup = 1; 1064 1065scan: 1066 /* return queued events right away */ 1067 if (dev->ev_next != 0) { 1068 unsigned i, n; 1069 1070 n = len / sizeof (struct usb_gadgetfs_event); 1071 if (dev->ev_next < n) 1072 n = dev->ev_next; 1073 1074 /* ep0 i/o has special semantics during STATE_DEV_SETUP */ 1075 for (i = 0; i < n; i++) { 1076 if (dev->event [i].type == GADGETFS_SETUP) { 1077 dev->state = STATE_DEV_SETUP; 1078 n = i + 1; 1079 break; 1080 } 1081 } 1082 spin_unlock_irq (&dev->lock); 1083 len = n * sizeof (struct usb_gadgetfs_event); 1084 if (copy_to_user (buf, &dev->event, len)) 1085 retval = -EFAULT; 1086 else 1087 retval = len; 1088 if (len > 0) { 1089 /* NOTE this doesn't guard against broken drivers; 1090 * concurrent ep0 readers may lose events. 1091 */ 1092 spin_lock_irq (&dev->lock); 1093 if (dev->ev_next > n) { 1094 memmove(&dev->event[0], &dev->event[n], 1095 sizeof (struct usb_gadgetfs_event) 1096 * (dev->ev_next - n)); 1097 } 1098 dev->ev_next -= n; 1099 spin_unlock_irq (&dev->lock); 1100 } 1101 return retval; 1102 } 1103 if (fd->f_flags & O_NONBLOCK) { 1104 retval = -EAGAIN; 1105 goto done; 1106 } 1107 1108 switch (state) { 1109 default: 1110 DBG (dev, "fail %s, state %d\n", __func__, state); 1111 retval = -ESRCH; 1112 break; 1113 case STATE_DEV_UNCONNECTED: 1114 case STATE_DEV_CONNECTED: 1115 spin_unlock_irq (&dev->lock); 1116 DBG (dev, "%s wait\n", __func__); 1117 1118 /* wait for events */ 1119 retval = wait_event_interruptible (dev->wait, 1120 dev->ev_next != 0); 1121 if (retval < 0) 1122 return retval; 1123 spin_lock_irq (&dev->lock); 1124 goto scan; 1125 } 1126 1127done: 1128 spin_unlock_irq (&dev->lock); 1129 return retval; 1130} 1131 1132static struct usb_gadgetfs_event * 1133next_event (struct dev_data *dev, enum usb_gadgetfs_event_type type) 1134{ 1135 struct usb_gadgetfs_event *event; 1136 unsigned i; 1137 1138 switch (type) { 1139 /* these events purge the queue */ 1140 case GADGETFS_DISCONNECT: 1141 if (dev->state == STATE_DEV_SETUP) 1142 dev->setup_abort = 1; 1143 // FALL THROUGH 1144 case GADGETFS_CONNECT: 1145 dev->ev_next = 0; 1146 break; 1147 case GADGETFS_SETUP: /* previous request timed out */ 1148 case GADGETFS_SUSPEND: /* same effect */ 1149 /* these events can't be repeated */ 1150 for (i = 0; i != dev->ev_next; i++) { 1151 if (dev->event [i].type != type) 1152 continue; 1153 DBG(dev, "discard old event[%d] %d\n", i, type); 1154 dev->ev_next--; 1155 if (i == dev->ev_next) 1156 break; 1157 /* indices start at zero, for simplicity */ 1158 memmove (&dev->event [i], &dev->event [i + 1], 1159 sizeof (struct usb_gadgetfs_event) 1160 * (dev->ev_next - i)); 1161 } 1162 break; 1163 default: 1164 BUG (); 1165 } 1166 VDEBUG(dev, "event[%d] = %d\n", dev->ev_next, type); 1167 event = &dev->event [dev->ev_next++]; 1168 BUG_ON (dev->ev_next > N_EVENT); 1169 memset (event, 0, sizeof *event); 1170 event->type = type; 1171 return event; 1172} 1173 1174static ssize_t 1175ep0_write (struct file *fd, const char __user *buf, size_t len, loff_t *ptr) 1176{ 1177 struct dev_data *dev = fd->private_data; 1178 ssize_t retval = -ESRCH; 1179 1180 spin_lock_irq (&dev->lock); 1181 1182 /* report fd mode change before acting on it */ 1183 if (dev->setup_abort) { 1184 dev->setup_abort = 0; 1185 retval = -EIDRM; 1186 1187 /* data and/or status stage for control request */ 1188 } else if (dev->state == STATE_DEV_SETUP) { 1189 1190 /* IN DATA+STATUS caller makes len <= wLength */ 1191 if (dev->setup_in) { 1192 retval = setup_req (dev->gadget->ep0, dev->req, len); 1193 if (retval == 0) { 1194 dev->state = STATE_DEV_CONNECTED; 1195 spin_unlock_irq (&dev->lock); 1196 if (copy_from_user (dev->req->buf, buf, len)) 1197 retval = -EFAULT; 1198 else { 1199 if (len < dev->setup_wLength) 1200 dev->req->zero = 1; 1201 retval = usb_ep_queue ( 1202 dev->gadget->ep0, dev->req, 1203 GFP_KERNEL); 1204 } 1205 if (retval < 0) { 1206 spin_lock_irq (&dev->lock); 1207 clean_req (dev->gadget->ep0, dev->req); 1208 spin_unlock_irq (&dev->lock); 1209 } else 1210 retval = len; 1211 1212 return retval; 1213 } 1214 1215 /* can stall some OUT transfers */ 1216 } else if (dev->setup_can_stall) { 1217 VDEBUG(dev, "ep0out stall\n"); 1218 (void) usb_ep_set_halt (dev->gadget->ep0); 1219 retval = -EL2HLT; 1220 dev->state = STATE_DEV_CONNECTED; 1221 } else { 1222 DBG(dev, "bogus ep0out stall!\n"); 1223 } 1224 } else 1225 DBG (dev, "fail %s, state %d\n", __func__, dev->state); 1226 1227 spin_unlock_irq (&dev->lock); 1228 return retval; 1229} 1230 1231static int 1232ep0_fasync (int f, struct file *fd, int on) 1233{ 1234 struct dev_data *dev = fd->private_data; 1235 // caller must F_SETOWN before signal delivery happens 1236 VDEBUG (dev, "%s %s\n", __func__, on ? "on" : "off"); 1237 return fasync_helper (f, fd, on, &dev->fasync); 1238} 1239 1240static struct usb_gadget_driver gadgetfs_driver; 1241 1242static int 1243dev_release (struct inode *inode, struct file *fd) 1244{ 1245 struct dev_data *dev = fd->private_data; 1246 1247 /* closing ep0 === shutdown all */ 1248 1249 usb_gadget_unregister_driver (&gadgetfs_driver); 1250 1251 /* at this point "good" hardware has disconnected the 1252 * device from USB; the host won't see it any more. 1253 * alternatively, all host requests will time out. 1254 */ 1255 1256 kfree (dev->buf); 1257 dev->buf = NULL; 1258 put_dev (dev); 1259 1260 /* other endpoints were all decoupled from this device */ 1261 spin_lock_irq(&dev->lock); 1262 dev->state = STATE_DEV_DISABLED; 1263 spin_unlock_irq(&dev->lock); 1264 return 0; 1265} 1266 1267static unsigned int 1268ep0_poll (struct file *fd, poll_table *wait) 1269{ 1270 struct dev_data *dev = fd->private_data; 1271 int mask = 0; 1272 1273 poll_wait(fd, &dev->wait, wait); 1274 1275 spin_lock_irq (&dev->lock); 1276 1277 /* report fd mode change before acting on it */ 1278 if (dev->setup_abort) { 1279 dev->setup_abort = 0; 1280 mask = POLLHUP; 1281 goto out; 1282 } 1283 1284 if (dev->state == STATE_DEV_SETUP) { 1285 if (dev->setup_in || dev->setup_can_stall) 1286 mask = POLLOUT; 1287 } else { 1288 if (dev->ev_next != 0) 1289 mask = POLLIN; 1290 } 1291out: 1292 spin_unlock_irq(&dev->lock); 1293 return mask; 1294} 1295 1296static long dev_ioctl (struct file *fd, unsigned code, unsigned long value) 1297{ 1298 struct dev_data *dev = fd->private_data; 1299 struct usb_gadget *gadget = dev->gadget; 1300 long ret = -ENOTTY; 1301 1302 if (gadget->ops->ioctl) 1303 ret = gadget->ops->ioctl (gadget, code, value); 1304 1305 return ret; 1306} 1307 1308/* used after device configuration */ 1309static const struct file_operations ep0_io_operations = { 1310 .owner = THIS_MODULE, 1311 .llseek = no_llseek, 1312 1313 .read = ep0_read, 1314 .write = ep0_write, 1315 .fasync = ep0_fasync, 1316 .poll = ep0_poll, 1317 .unlocked_ioctl = dev_ioctl, 1318 .release = dev_release, 1319}; 1320 1321/*----------------------------------------------------------------------*/ 1322 1323/* The in-kernel gadget driver handles most ep0 issues, in particular 1324 * enumerating the single configuration (as provided from user space). 1325 * 1326 * Unrecognized ep0 requests may be handled in user space. 1327 */ 1328 1329#ifdef CONFIG_USB_GADGET_DUALSPEED 1330static void make_qualifier (struct dev_data *dev) 1331{ 1332 struct usb_qualifier_descriptor qual; 1333 struct usb_device_descriptor *desc; 1334 1335 qual.bLength = sizeof qual; 1336 qual.bDescriptorType = USB_DT_DEVICE_QUALIFIER; 1337 qual.bcdUSB = cpu_to_le16 (0x0200); 1338 1339 desc = dev->dev; 1340 qual.bDeviceClass = desc->bDeviceClass; 1341 qual.bDeviceSubClass = desc->bDeviceSubClass; 1342 qual.bDeviceProtocol = desc->bDeviceProtocol; 1343 1344 /* assumes ep0 uses the same value for both speeds ... */ 1345 qual.bMaxPacketSize0 = desc->bMaxPacketSize0; 1346 1347 qual.bNumConfigurations = 1; 1348 qual.bRESERVED = 0; 1349 1350 memcpy (dev->rbuf, &qual, sizeof qual); 1351} 1352#endif 1353 1354static int 1355config_buf (struct dev_data *dev, u8 type, unsigned index) 1356{ 1357 int len; 1358 int hs = 0; 1359 1360 /* only one configuration */ 1361 if (index > 0) 1362 return -EINVAL; 1363 1364 if (gadget_is_dualspeed(dev->gadget)) { 1365 hs = (dev->gadget->speed == USB_SPEED_HIGH); 1366 if (type == USB_DT_OTHER_SPEED_CONFIG) 1367 hs = !hs; 1368 } 1369 if (hs) { 1370 dev->req->buf = dev->hs_config; 1371 len = le16_to_cpu(dev->hs_config->wTotalLength); 1372 } else { 1373 dev->req->buf = dev->config; 1374 len = le16_to_cpu(dev->config->wTotalLength); 1375 } 1376 ((u8 *)dev->req->buf) [1] = type; 1377 return len; 1378} 1379 1380static int 1381gadgetfs_setup (struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl) 1382{ 1383 struct dev_data *dev = get_gadget_data (gadget); 1384 struct usb_request *req = dev->req; 1385 int value = -EOPNOTSUPP; 1386 struct usb_gadgetfs_event *event; 1387 u16 w_value = le16_to_cpu(ctrl->wValue); 1388 u16 w_length = le16_to_cpu(ctrl->wLength); 1389 1390 spin_lock (&dev->lock); 1391 dev->setup_abort = 0; 1392 if (dev->state == STATE_DEV_UNCONNECTED) { 1393 if (gadget_is_dualspeed(gadget) 1394 && gadget->speed == USB_SPEED_HIGH 1395 && dev->hs_config == NULL) { 1396 spin_unlock(&dev->lock); 1397 ERROR (dev, "no high speed config??\n"); 1398 return -EINVAL; 1399 } 1400 1401 dev->state = STATE_DEV_CONNECTED; 1402 dev->dev->bMaxPacketSize0 = gadget->ep0->maxpacket; 1403 1404 INFO (dev, "connected\n"); 1405 event = next_event (dev, GADGETFS_CONNECT); 1406 event->u.speed = gadget->speed; 1407 ep0_readable (dev); 1408 1409 /* host may have given up waiting for response. we can miss control 1410 * requests handled lower down (device/endpoint status and features); 1411 * then ep0_{read,write} will report the wrong status. controller 1412 * driver will have aborted pending i/o. 1413 */ 1414 } else if (dev->state == STATE_DEV_SETUP) 1415 dev->setup_abort = 1; 1416 1417 req->buf = dev->rbuf; 1418 req->dma = DMA_ADDR_INVALID; 1419 req->context = NULL; 1420 value = -EOPNOTSUPP; 1421 switch (ctrl->bRequest) { 1422 1423 case USB_REQ_GET_DESCRIPTOR: 1424 if (ctrl->bRequestType != USB_DIR_IN) 1425 goto unrecognized; 1426 switch (w_value >> 8) { 1427 1428 case USB_DT_DEVICE: 1429 value = min (w_length, (u16) sizeof *dev->dev); 1430 req->buf = dev->dev; 1431 break; 1432#ifdef CONFIG_USB_GADGET_DUALSPEED 1433 case USB_DT_DEVICE_QUALIFIER: 1434 if (!dev->hs_config) 1435 break; 1436 value = min (w_length, (u16) 1437 sizeof (struct usb_qualifier_descriptor)); 1438 make_qualifier (dev); 1439 break; 1440 case USB_DT_OTHER_SPEED_CONFIG: 1441 // FALLTHROUGH 1442#endif 1443 case USB_DT_CONFIG: 1444 value = config_buf (dev, 1445 w_value >> 8, 1446 w_value & 0xff); 1447 if (value >= 0) 1448 value = min (w_length, (u16) value); 1449 break; 1450 case USB_DT_STRING: 1451 goto unrecognized; 1452 1453 default: // all others are errors 1454 break; 1455 } 1456 break; 1457 1458 /* currently one config, two speeds */ 1459 case USB_REQ_SET_CONFIGURATION: 1460 if (ctrl->bRequestType != 0) 1461 goto unrecognized; 1462 if (0 == (u8) w_value) { 1463 value = 0; 1464 dev->current_config = 0; 1465 usb_gadget_vbus_draw(gadget, 8 /* mA */ ); 1466 // user mode expected to disable endpoints 1467 } else { 1468 u8 config, power; 1469 1470 if (gadget_is_dualspeed(gadget) 1471 && gadget->speed == USB_SPEED_HIGH) { 1472 config = dev->hs_config->bConfigurationValue; 1473 power = dev->hs_config->bMaxPower; 1474 } else { 1475 config = dev->config->bConfigurationValue; 1476 power = dev->config->bMaxPower; 1477 } 1478 1479 if (config == (u8) w_value) { 1480 value = 0; 1481 dev->current_config = config; 1482 usb_gadget_vbus_draw(gadget, 2 * power); 1483 } 1484 } 1485 1486 /* report SET_CONFIGURATION like any other control request, 1487 * except that usermode may not stall this. the next 1488 * request mustn't be allowed start until this finishes: 1489 * endpoints and threads set up, etc. 1490 * 1491 * NOTE: older PXA hardware (before PXA 255: without UDCCFR) 1492 * has bad/racey automagic that prevents synchronizing here. 1493 * even kernel mode drivers often miss them. 1494 */ 1495 if (value == 0) { 1496 INFO (dev, "configuration #%d\n", dev->current_config); 1497 if (dev->usermode_setup) { 1498 dev->setup_can_stall = 0; 1499 goto delegate; 1500 } 1501 } 1502 break; 1503 1504#ifndef CONFIG_USB_GADGET_PXA25X 1505 /* PXA automagically handles this request too */ 1506 case USB_REQ_GET_CONFIGURATION: 1507 if (ctrl->bRequestType != 0x80) 1508 goto unrecognized; 1509 *(u8 *)req->buf = dev->current_config; 1510 value = min (w_length, (u16) 1); 1511 break; 1512#endif 1513 1514 default: 1515unrecognized: 1516 VDEBUG (dev, "%s req%02x.%02x v%04x i%04x l%d\n", 1517 dev->usermode_setup ? "delegate" : "fail", 1518 ctrl->bRequestType, ctrl->bRequest, 1519 w_value, le16_to_cpu(ctrl->wIndex), w_length); 1520 1521 /* if there's an ep0 reader, don't stall */ 1522 if (dev->usermode_setup) { 1523 dev->setup_can_stall = 1; 1524delegate: 1525 dev->setup_in = (ctrl->bRequestType & USB_DIR_IN) 1526 ? 1 : 0; 1527 dev->setup_wLength = w_length; 1528 dev->setup_out_ready = 0; 1529 dev->setup_out_error = 0; 1530 value = 0; 1531 1532 /* read DATA stage for OUT right away */ 1533 if (unlikely (!dev->setup_in && w_length)) { 1534 value = setup_req (gadget->ep0, dev->req, 1535 w_length); 1536 if (value < 0) 1537 break; 1538 value = usb_ep_queue (gadget->ep0, dev->req, 1539 GFP_ATOMIC); 1540 if (value < 0) { 1541 clean_req (gadget->ep0, dev->req); 1542 break; 1543 } 1544 1545 /* we can't currently stall these */ 1546 dev->setup_can_stall = 0; 1547 } 1548 1549 /* state changes when reader collects event */ 1550 event = next_event (dev, GADGETFS_SETUP); 1551 event->u.setup = *ctrl; 1552 ep0_readable (dev); 1553 spin_unlock (&dev->lock); 1554 return 0; 1555 } 1556 } 1557 1558 /* proceed with data transfer and status phases? */ 1559 if (value >= 0 && dev->state != STATE_DEV_SETUP) { 1560 req->length = value; 1561 req->zero = value < w_length; 1562 value = usb_ep_queue (gadget->ep0, req, GFP_ATOMIC); 1563 if (value < 0) { 1564 DBG (dev, "ep_queue --> %d\n", value); 1565 req->status = 0; 1566 } 1567 } 1568 1569 /* device stalls when value < 0 */ 1570 spin_unlock (&dev->lock); 1571 return value; 1572} 1573 1574static void destroy_ep_files (struct dev_data *dev) 1575{ 1576 struct list_head *entry, *tmp; 1577 1578 DBG (dev, "%s %d\n", __func__, dev->state); 1579 1580 /* dev->state must prevent interference */ 1581restart: 1582 spin_lock_irq (&dev->lock); 1583 list_for_each_safe (entry, tmp, &dev->epfiles) { 1584 struct ep_data *ep; 1585 struct inode *parent; 1586 struct dentry *dentry; 1587 1588 /* break link to FS */ 1589 ep = list_entry (entry, struct ep_data, epfiles); 1590 list_del_init (&ep->epfiles); 1591 dentry = ep->dentry; 1592 ep->dentry = NULL; 1593 parent = dentry->d_parent->d_inode; 1594 1595 /* break link to controller */ 1596 if (ep->state == STATE_EP_ENABLED) 1597 (void) usb_ep_disable (ep->ep); 1598 ep->state = STATE_EP_UNBOUND; 1599 usb_ep_free_request (ep->ep, ep->req); 1600 ep->ep = NULL; 1601 wake_up (&ep->wait); 1602 put_ep (ep); 1603 1604 spin_unlock_irq (&dev->lock); 1605 1606 /* break link to dcache */ 1607 mutex_lock (&parent->i_mutex); 1608 d_delete (dentry); 1609 dput (dentry); 1610 mutex_unlock (&parent->i_mutex); 1611 1612 /* fds may still be open */ 1613 goto restart; 1614 } 1615 spin_unlock_irq (&dev->lock); 1616} 1617 1618 1619static struct inode * 1620gadgetfs_create_file (struct super_block *sb, char const *name, 1621 void *data, const struct file_operations *fops, 1622 struct dentry **dentry_p); 1623 1624static 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->inode = gadgetfs_create_file (dev->sb, data->name, 1651 data, &ep_config_operations, 1652 &data->dentry); 1653 if (!data->inode) 1654 goto enomem2; 1655 list_add_tail (&data->epfiles, &dev->epfiles); 1656 } 1657 return 0; 1658 1659enomem2: 1660 usb_ep_free_request (ep, data->req); 1661enomem1: 1662 put_dev (dev); 1663 kfree (data); 1664enomem0: 1665 DBG (dev, "%s enomem\n", __func__); 1666 destroy_ep_files (dev); 1667 return -ENOMEM; 1668} 1669 1670static void 1671gadgetfs_unbind (struct usb_gadget *gadget) 1672{ 1673 struct dev_data *dev = get_gadget_data (gadget); 1674 1675 DBG (dev, "%s\n", __func__); 1676 1677 spin_lock_irq (&dev->lock); 1678 dev->state = STATE_DEV_UNBOUND; 1679 spin_unlock_irq (&dev->lock); 1680 1681 destroy_ep_files (dev); 1682 gadget->ep0->driver_data = NULL; 1683 set_gadget_data (gadget, NULL); 1684 1685 /* we've already been disconnected ... no i/o is active */ 1686 if (dev->req) 1687 usb_ep_free_request (gadget->ep0, dev->req); 1688 DBG (dev, "%s done\n", __func__); 1689 put_dev (dev); 1690} 1691 1692static struct dev_data *the_device; 1693 1694static int 1695gadgetfs_bind (struct usb_gadget *gadget) 1696{ 1697 struct dev_data *dev = the_device; 1698 1699 if (!dev) 1700 return -ESRCH; 1701 if (0 != strcmp (CHIP, gadget->name)) { 1702 pr_err("%s expected %s controller not %s\n", 1703 shortname, CHIP, gadget->name); 1704 return -ENODEV; 1705 } 1706 1707 set_gadget_data (gadget, dev); 1708 dev->gadget = gadget; 1709 gadget->ep0->driver_data = dev; 1710 dev->dev->bMaxPacketSize0 = gadget->ep0->maxpacket; 1711 1712 /* preallocate control response and buffer */ 1713 dev->req = usb_ep_alloc_request (gadget->ep0, GFP_KERNEL); 1714 if (!dev->req) 1715 goto enomem; 1716 dev->req->context = NULL; 1717 dev->req->complete = epio_complete; 1718 1719 if (activate_ep_files (dev) < 0) 1720 goto enomem; 1721 1722 INFO (dev, "bound to %s driver\n", gadget->name); 1723 spin_lock_irq(&dev->lock); 1724 dev->state = STATE_DEV_UNCONNECTED; 1725 spin_unlock_irq(&dev->lock); 1726 get_dev (dev); 1727 return 0; 1728 1729enomem: 1730 gadgetfs_unbind (gadget); 1731 return -ENOMEM; 1732} 1733 1734static void 1735gadgetfs_disconnect (struct usb_gadget *gadget) 1736{ 1737 struct dev_data *dev = get_gadget_data (gadget); 1738 1739 spin_lock (&dev->lock); 1740 if (dev->state == STATE_DEV_UNCONNECTED) 1741 goto exit; 1742 dev->state = STATE_DEV_UNCONNECTED; 1743 1744 INFO (dev, "disconnected\n"); 1745 next_event (dev, GADGETFS_DISCONNECT); 1746 ep0_readable (dev); 1747exit: 1748 spin_unlock (&dev->lock); 1749} 1750 1751static void 1752gadgetfs_suspend (struct usb_gadget *gadget) 1753{ 1754 struct dev_data *dev = get_gadget_data (gadget); 1755 1756 INFO (dev, "suspended from state %d\n", dev->state); 1757 spin_lock (&dev->lock); 1758 switch (dev->state) { 1759 case STATE_DEV_SETUP: // VERY odd... host died?? 1760 case STATE_DEV_CONNECTED: 1761 case STATE_DEV_UNCONNECTED: 1762 next_event (dev, GADGETFS_SUSPEND); 1763 ep0_readable (dev); 1764 /* FALLTHROUGH */ 1765 default: 1766 break; 1767 } 1768 spin_unlock (&dev->lock); 1769} 1770 1771static struct usb_gadget_driver gadgetfs_driver = { 1772#ifdef CONFIG_USB_GADGET_DUALSPEED 1773 .speed = USB_SPEED_HIGH, 1774#else 1775 .speed = USB_SPEED_FULL, 1776#endif 1777 .function = (char *) driver_desc, 1778 .bind = gadgetfs_bind, 1779 .unbind = gadgetfs_unbind, 1780 .setup = gadgetfs_setup, 1781 .disconnect = gadgetfs_disconnect, 1782 .suspend = gadgetfs_suspend, 1783 1784 .driver = { 1785 .name = (char *) shortname, 1786 }, 1787}; 1788 1789/*----------------------------------------------------------------------*/ 1790 1791static void gadgetfs_nop(struct usb_gadget *arg) { } 1792 1793static int gadgetfs_probe (struct usb_gadget *gadget) 1794{ 1795 CHIP = gadget->name; 1796 return -EISNAM; 1797} 1798 1799static struct usb_gadget_driver probe_driver = { 1800 .speed = USB_SPEED_HIGH, 1801 .bind = gadgetfs_probe, 1802 .unbind = gadgetfs_nop, 1803 .setup = (void *)gadgetfs_nop, 1804 .disconnect = gadgetfs_nop, 1805 .driver = { 1806 .name = "nop", 1807 }, 1808}; 1809 1810 1811/* DEVICE INITIALIZATION 1812 * 1813 * fd = open ("/dev/gadget/$CHIP", O_RDWR) 1814 * status = write (fd, descriptors, sizeof descriptors) 1815 * 1816 * That write establishes the device configuration, so the kernel can 1817 * bind to the controller ... guaranteeing it can handle enumeration 1818 * at all necessary speeds. Descriptor order is: 1819 * 1820 * . message tag (u32, host order) ... for now, must be zero; it 1821 * would change to support features like multi-config devices 1822 * . full/low speed config ... all wTotalLength bytes (with interface, 1823 * class, altsetting, endpoint, and other descriptors) 1824 * . high speed config ... all descriptors, for high speed operation; 1825 * this one's optional except for high-speed hardware 1826 * . device descriptor 1827 * 1828 * Endpoints are not yet enabled. Drivers must wait until device 1829 * configuration and interface altsetting changes create 1830 * the need to configure (or unconfigure) them. 1831 * 1832 * After initialization, the device stays active for as long as that 1833 * $CHIP file is open. Events must then be read from that descriptor, 1834 * such as configuration notifications. 1835 */ 1836 1837static int is_valid_config (struct usb_config_descriptor *config) 1838{ 1839 return config->bDescriptorType == USB_DT_CONFIG 1840 && config->bLength == USB_DT_CONFIG_SIZE 1841 && config->bConfigurationValue != 0 1842 && (config->bmAttributes & USB_CONFIG_ATT_ONE) != 0 1843 && (config->bmAttributes & USB_CONFIG_ATT_WAKEUP) == 0; 1844 /* FIXME if gadget->is_otg, _must_ include an otg descriptor */ 1845 /* FIXME check lengths: walk to end */ 1846} 1847 1848static ssize_t 1849dev_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr) 1850{ 1851 struct dev_data *dev = fd->private_data; 1852 ssize_t value = len, length = len; 1853 unsigned total; 1854 u32 tag; 1855 char *kbuf; 1856 1857 if (len < (USB_DT_CONFIG_SIZE + USB_DT_DEVICE_SIZE + 4)) 1858 return -EINVAL; 1859 1860 /* we might need to change message format someday */ 1861 if (copy_from_user (&tag, buf, 4)) 1862 return -EFAULT; 1863 if (tag != 0) 1864 return -EINVAL; 1865 buf += 4; 1866 length -= 4; 1867 1868 kbuf = memdup_user(buf, length); 1869 if (IS_ERR(kbuf)) 1870 return PTR_ERR(kbuf); 1871 1872 spin_lock_irq (&dev->lock); 1873 value = -EINVAL; 1874 if (dev->buf) 1875 goto fail; 1876 dev->buf = kbuf; 1877 1878 /* full or low speed config */ 1879 dev->config = (void *) kbuf; 1880 total = le16_to_cpu(dev->config->wTotalLength); 1881 if (!is_valid_config (dev->config) || total >= length) 1882 goto fail; 1883 kbuf += total; 1884 length -= total; 1885 1886 /* optional high speed config */ 1887 if (kbuf [1] == USB_DT_CONFIG) { 1888 dev->hs_config = (void *) kbuf; 1889 total = le16_to_cpu(dev->hs_config->wTotalLength); 1890 if (!is_valid_config (dev->hs_config) || total >= length) 1891 goto fail; 1892 kbuf += total; 1893 length -= total; 1894 } 1895 1896 /* could support multiple configs, using another encoding! */ 1897 1898 /* device descriptor (tweaked for paranoia) */ 1899 if (length != USB_DT_DEVICE_SIZE) 1900 goto fail; 1901 dev->dev = (void *)kbuf; 1902 if (dev->dev->bLength != USB_DT_DEVICE_SIZE 1903 || dev->dev->bDescriptorType != USB_DT_DEVICE 1904 || dev->dev->bNumConfigurations != 1) 1905 goto fail; 1906 dev->dev->bNumConfigurations = 1; 1907 dev->dev->bcdUSB = cpu_to_le16 (0x0200); 1908 1909 /* triggers gadgetfs_bind(); then we can enumerate. */ 1910 spin_unlock_irq (&dev->lock); 1911 value = usb_gadget_register_driver (&gadgetfs_driver); 1912 if (value != 0) { 1913 kfree (dev->buf); 1914 dev->buf = NULL; 1915 } else { 1916 /* at this point "good" hardware has for the first time 1917 * let the USB the host see us. alternatively, if users 1918 * unplug/replug that will clear all the error state. 1919 * 1920 * note: everything running before here was guaranteed 1921 * to choke driver model style diagnostics. from here 1922 * on, they can work ... except in cleanup paths that 1923 * kick in after the ep0 descriptor is closed. 1924 */ 1925 fd->f_op = &ep0_io_operations; 1926 value = len; 1927 } 1928 return value; 1929 1930fail: 1931 spin_unlock_irq (&dev->lock); 1932 pr_debug ("%s: %s fail %Zd, %p\n", shortname, __func__, value, dev); 1933 kfree (dev->buf); 1934 dev->buf = NULL; 1935 return value; 1936} 1937 1938static int 1939dev_open (struct inode *inode, struct file *fd) 1940{ 1941 struct dev_data *dev = inode->i_private; 1942 int value = -EBUSY; 1943 1944 spin_lock_irq(&dev->lock); 1945 if (dev->state == STATE_DEV_DISABLED) { 1946 dev->ev_next = 0; 1947 dev->state = STATE_DEV_OPENED; 1948 fd->private_data = dev; 1949 get_dev (dev); 1950 value = 0; 1951 } 1952 spin_unlock_irq(&dev->lock); 1953 return value; 1954} 1955 1956static const struct file_operations dev_init_operations = { 1957 .owner = THIS_MODULE, 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 1980static unsigned default_uid; 1981static unsigned default_gid; 1982static unsigned default_perm = S_IRUSR | S_IWUSR; 1983 1984module_param (default_uid, uint, 0644); 1985module_param (default_gid, uint, 0644); 1986module_param (default_perm, uint, 0644); 1987 1988 1989static struct inode * 1990gadgetfs_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_mode = mode; 1998 inode->i_uid = default_uid; 1999 inode->i_gid = default_gid; 2000 inode->i_atime = inode->i_mtime = inode->i_ctime 2001 = CURRENT_TIME; 2002 inode->i_private = data; 2003 inode->i_fop = fops; 2004 } 2005 return inode; 2006} 2007 2008/* creates in fs root directory, so non-renamable and non-linkable. 2009 * so inode and dentry are paired, until device reconfig. 2010 */ 2011static struct inode * 2012gadgetfs_create_file (struct super_block *sb, char const *name, 2013 void *data, const struct file_operations *fops, 2014 struct dentry **dentry_p) 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 *dentry_p = dentry; 2031 return inode; 2032} 2033 2034static const struct super_operations gadget_fs_operations = { 2035 .statfs = simple_statfs, 2036 .drop_inode = generic_delete_inode, 2037}; 2038 2039static int 2040gadgetfs_fill_super (struct super_block *sb, void *opts, int silent) 2041{ 2042 struct inode *inode; 2043 struct dentry *d; 2044 struct dev_data *dev; 2045 2046 if (the_device) 2047 return -ESRCH; 2048 2049 /* fake probe to determine $CHIP */ 2050 (void) usb_gadget_register_driver (&probe_driver); 2051 if (!CHIP) 2052 return -ENODEV; 2053 2054 /* superblock */ 2055 sb->s_blocksize = PAGE_CACHE_SIZE; 2056 sb->s_blocksize_bits = PAGE_CACHE_SHIFT; 2057 sb->s_magic = GADGETFS_MAGIC; 2058 sb->s_op = &gadget_fs_operations; 2059 sb->s_time_gran = 1; 2060 2061 /* root inode */ 2062 inode = gadgetfs_make_inode (sb, 2063 NULL, &simple_dir_operations, 2064 S_IFDIR | S_IRUGO | S_IXUGO); 2065 if (!inode) 2066 goto enomem0; 2067 inode->i_op = &simple_dir_inode_operations; 2068 if (!(d = d_alloc_root (inode))) 2069 goto enomem1; 2070 sb->s_root = d; 2071 2072 /* the ep0 file is named after the controller we expect; 2073 * user mode code can use it for sanity checks, like we do. 2074 */ 2075 dev = dev_new (); 2076 if (!dev) 2077 goto enomem2; 2078 2079 dev->sb = sb; 2080 if (!gadgetfs_create_file (sb, CHIP, 2081 dev, &dev_init_operations, 2082 &dev->dentry)) 2083 goto enomem3; 2084 2085 /* other endpoint files are available after hardware setup, 2086 * from binding to a controller. 2087 */ 2088 the_device = dev; 2089 return 0; 2090 2091enomem3: 2092 put_dev (dev); 2093enomem2: 2094 dput (d); 2095enomem1: 2096 iput (inode); 2097enomem0: 2098 return -ENOMEM; 2099} 2100 2101/* "mount -t gadgetfs path /dev/gadget" ends up here */ 2102static int 2103gadgetfs_get_sb (struct file_system_type *t, int flags, 2104 const char *path, void *opts, struct vfsmount *mnt) 2105{ 2106 return get_sb_single (t, flags, opts, gadgetfs_fill_super, mnt); 2107} 2108 2109static void 2110gadgetfs_kill_sb (struct super_block *sb) 2111{ 2112 kill_litter_super (sb); 2113 if (the_device) { 2114 put_dev (the_device); 2115 the_device = NULL; 2116 } 2117} 2118 2119/*----------------------------------------------------------------------*/ 2120 2121static struct file_system_type gadgetfs_type = { 2122 .owner = THIS_MODULE, 2123 .name = shortname, 2124 .get_sb = gadgetfs_get_sb, 2125 .kill_sb = gadgetfs_kill_sb, 2126}; 2127 2128/*----------------------------------------------------------------------*/ 2129 2130static int __init init (void) 2131{ 2132 int status; 2133 2134 status = register_filesystem (&gadgetfs_type); 2135 if (status == 0) 2136 pr_info ("%s: %s, version " DRIVER_VERSION "\n", 2137 shortname, driver_desc); 2138 return status; 2139} 2140module_init (init); 2141 2142static void __exit cleanup (void) 2143{ 2144 pr_debug ("unregister %s\n", shortname); 2145 unregister_filesystem (&gadgetfs_type); 2146} 2147module_exit (cleanup); 2148 2149