inode.c revision 0864c7a9286b02319d3db2103bada1c2269c1e1e
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 DEBUG /* data to help fault diagnosis */ 24// #define VERBOSE /* extra debug messages (success too) */ 25 26#include <linux/init.h> 27#include <linux/module.h> 28#include <linux/fs.h> 29#include <linux/pagemap.h> 30#include <linux/uts.h> 31#include <linux/wait.h> 32#include <linux/compiler.h> 33#include <asm/uaccess.h> 34#include <linux/slab.h> 35#include <linux/poll.h> 36 37#include <linux/device.h> 38#include <linux/moduleparam.h> 39 40#include <linux/usb_gadgetfs.h> 41#include <linux/usb_gadget.h> 42 43 44/* 45 * The gadgetfs API maps each endpoint to a file descriptor so that you 46 * can use standard synchronous read/write calls for I/O. There's some 47 * O_NONBLOCK and O_ASYNC/FASYNC style i/o support. Example usermode 48 * drivers show how this works in practice. You can also use AIO to 49 * eliminate I/O gaps between requests, to help when streaming data. 50 * 51 * Key parts that must be USB-specific are protocols defining how the 52 * read/write operations relate to the hardware state machines. There 53 * are two types of files. One type is for the device, implementing ep0. 54 * The other type is for each IN or OUT endpoint. In both cases, the 55 * user mode driver must configure the hardware before using it. 56 * 57 * - First, dev_config() is called when /dev/gadget/$CHIP is configured 58 * (by writing configuration and device descriptors). Afterwards it 59 * may serve as a source of device events, used to handle all control 60 * requests other than basic enumeration. 61 * 62 * - Then, after a SET_CONFIGURATION control request, ep_config() is 63 * called when each /dev/gadget/ep* file is configured (by writing 64 * endpoint descriptors). Afterwards these files are used to write() 65 * IN data or to read() OUT data. To halt the endpoint, a "wrong 66 * direction" request is issued (like reading an IN endpoint). 67 * 68 * Unlike "usbfs" the only ioctl()s are for things that are rare, and maybe 69 * not possible on all hardware. For example, precise fault handling with 70 * respect to data left in endpoint fifos after aborted operations; or 71 * selective clearing of endpoint halts, to implement SET_INTERFACE. 72 */ 73 74#define DRIVER_DESC "USB Gadget filesystem" 75#define DRIVER_VERSION "24 Aug 2004" 76 77static const char driver_desc [] = DRIVER_DESC; 78static const char shortname [] = "gadgetfs"; 79 80MODULE_DESCRIPTION (DRIVER_DESC); 81MODULE_AUTHOR ("David Brownell"); 82MODULE_LICENSE ("GPL"); 83 84 85/*----------------------------------------------------------------------*/ 86 87#define GADGETFS_MAGIC 0xaee71ee7 88#define DMA_ADDR_INVALID (~(dma_addr_t)0) 89 90/* /dev/gadget/$CHIP represents ep0 and the whole device */ 91enum ep0_state { 92 /* DISBLED is the initial state. 93 */ 94 STATE_DEV_DISABLED = 0, 95 96 /* Only one open() of /dev/gadget/$CHIP; only one file tracks 97 * ep0/device i/o modes and binding to the controller. Driver 98 * must always write descriptors to initialize the device, then 99 * the device becomes UNCONNECTED until enumeration. 100 */ 101 STATE_DEV_OPENED, 102 103 /* From then on, ep0 fd is in either of two basic modes: 104 * - (UN)CONNECTED: read usb_gadgetfs_event(s) from it 105 * - SETUP: read/write will transfer control data and succeed; 106 * or if "wrong direction", performs protocol stall 107 */ 108 STATE_DEV_UNCONNECTED, 109 STATE_DEV_CONNECTED, 110 STATE_DEV_SETUP, 111 112 /* UNBOUND means the driver closed ep0, so the device won't be 113 * accessible again (DEV_DISABLED) until all fds are closed. 114 */ 115 STATE_DEV_UNBOUND, 116}; 117 118/* enough for the whole queue: most events invalidate others */ 119#define N_EVENT 5 120 121struct dev_data { 122 spinlock_t lock; 123 atomic_t count; 124 enum ep0_state state; /* P: lock */ 125 struct usb_gadgetfs_event event [N_EVENT]; 126 unsigned ev_next; 127 struct fasync_struct *fasync; 128 u8 current_config; 129 130 /* drivers reading ep0 MUST handle control requests (SETUP) 131 * reported that way; else the host will time out. 132 */ 133 unsigned usermode_setup : 1, 134 setup_in : 1, 135 setup_can_stall : 1, 136 setup_out_ready : 1, 137 setup_out_error : 1, 138 setup_abort : 1; 139 unsigned setup_wLength; 140 141 /* the rest is basically write-once */ 142 struct usb_config_descriptor *config, *hs_config; 143 struct usb_device_descriptor *dev; 144 struct usb_request *req; 145 struct usb_gadget *gadget; 146 struct list_head epfiles; 147 void *buf; 148 wait_queue_head_t wait; 149 struct super_block *sb; 150 struct dentry *dentry; 151 152 /* except this scratch i/o buffer for ep0 */ 153 u8 rbuf [256]; 154}; 155 156static inline void get_dev (struct dev_data *data) 157{ 158 atomic_inc (&data->count); 159} 160 161static void put_dev (struct dev_data *data) 162{ 163 if (likely (!atomic_dec_and_test (&data->count))) 164 return; 165 /* needs no more cleanup */ 166 BUG_ON (waitqueue_active (&data->wait)); 167 kfree (data); 168} 169 170static struct dev_data *dev_new (void) 171{ 172 struct dev_data *dev; 173 174 dev = kzalloc(sizeof(*dev), GFP_KERNEL); 175 if (!dev) 176 return NULL; 177 dev->state = STATE_DEV_DISABLED; 178 atomic_set (&dev->count, 1); 179 spin_lock_init (&dev->lock); 180 INIT_LIST_HEAD (&dev->epfiles); 181 init_waitqueue_head (&dev->wait); 182 return dev; 183} 184 185/*----------------------------------------------------------------------*/ 186 187/* other /dev/gadget/$ENDPOINT files represent endpoints */ 188enum ep_state { 189 STATE_EP_DISABLED = 0, 190 STATE_EP_READY, 191 STATE_EP_ENABLED, 192 STATE_EP_UNBOUND, 193}; 194 195struct ep_data { 196 struct semaphore lock; 197 enum ep_state state; 198 atomic_t count; 199 struct dev_data *dev; 200 /* must hold dev->lock before accessing ep or req */ 201 struct usb_ep *ep; 202 struct usb_request *req; 203 ssize_t status; 204 char name [16]; 205 struct usb_endpoint_descriptor desc, hs_desc; 206 struct list_head epfiles; 207 wait_queue_head_t wait; 208 struct dentry *dentry; 209 struct inode *inode; 210}; 211 212static inline void get_ep (struct ep_data *data) 213{ 214 atomic_inc (&data->count); 215} 216 217static void put_ep (struct ep_data *data) 218{ 219 if (likely (!atomic_dec_and_test (&data->count))) 220 return; 221 put_dev (data->dev); 222 /* needs no more cleanup */ 223 BUG_ON (!list_empty (&data->epfiles)); 224 BUG_ON (waitqueue_active (&data->wait)); 225 kfree (data); 226} 227 228/*----------------------------------------------------------------------*/ 229 230/* most "how to use the hardware" policy choices are in userspace: 231 * mapping endpoint roles (which the driver needs) to the capabilities 232 * which the usb controller has. most of those capabilities are exposed 233 * implicitly, starting with the driver name and then endpoint names. 234 */ 235 236static const char *CHIP; 237 238/*----------------------------------------------------------------------*/ 239 240/* NOTE: don't use dev_printk calls before binding to the gadget 241 * at the end of ep0 configuration, or after unbind. 242 */ 243 244/* too wordy: dev_printk(level , &(d)->gadget->dev , fmt , ## args) */ 245#define xprintk(d,level,fmt,args...) \ 246 printk(level "%s: " fmt , shortname , ## args) 247 248#ifdef DEBUG 249#define DBG(dev,fmt,args...) \ 250 xprintk(dev , KERN_DEBUG , fmt , ## args) 251#else 252#define DBG(dev,fmt,args...) \ 253 do { } while (0) 254#endif /* DEBUG */ 255 256#ifdef VERBOSE 257#define VDEBUG DBG 258#else 259#define VDEBUG(dev,fmt,args...) \ 260 do { } while (0) 261#endif /* DEBUG */ 262 263#define ERROR(dev,fmt,args...) \ 264 xprintk(dev , KERN_ERR , fmt , ## args) 265#define WARN(dev,fmt,args...) \ 266 xprintk(dev , KERN_WARNING , fmt , ## args) 267#define INFO(dev,fmt,args...) \ 268 xprintk(dev , KERN_INFO , fmt , ## args) 269 270 271/*----------------------------------------------------------------------*/ 272 273/* SYNCHRONOUS ENDPOINT OPERATIONS (bulk/intr/iso) 274 * 275 * After opening, configure non-control endpoints. Then use normal 276 * stream read() and write() requests; and maybe ioctl() to get more 277 * precise FIFO status when recovering from cancellation. 278 */ 279 280static void epio_complete (struct usb_ep *ep, struct usb_request *req) 281{ 282 struct ep_data *epdata = ep->driver_data; 283 284 if (!req->context) 285 return; 286 if (req->status) 287 epdata->status = req->status; 288 else 289 epdata->status = req->actual; 290 complete ((struct completion *)req->context); 291} 292 293/* tasklock endpoint, returning when it's connected. 294 * still need dev->lock to use epdata->ep. 295 */ 296static int 297get_ready_ep (unsigned f_flags, struct ep_data *epdata) 298{ 299 int val; 300 301 if (f_flags & O_NONBLOCK) { 302 if (down_trylock (&epdata->lock) != 0) 303 goto nonblock; 304 if (epdata->state != STATE_EP_ENABLED) { 305 up (&epdata->lock); 306nonblock: 307 val = -EAGAIN; 308 } else 309 val = 0; 310 return val; 311 } 312 313 if ((val = down_interruptible (&epdata->lock)) < 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 up (&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 (data->desc.bEndpointAddress & USB_DIR_IN) { 390 if ((data->desc.bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) 391 == USB_ENDPOINT_XFER_ISOC) 392 return -EINVAL; 393 DBG (data->dev, "%s halt\n", data->name); 394 spin_lock_irq (&data->dev->lock); 395 if (likely (data->ep != NULL)) 396 usb_ep_set_halt (data->ep); 397 spin_unlock_irq (&data->dev->lock); 398 up (&data->lock); 399 return -EBADMSG; 400 } 401 402 /* FIXME readahead for O_NONBLOCK and poll(); careful with ZLPs */ 403 404 value = -ENOMEM; 405 kbuf = kmalloc (len, GFP_KERNEL); 406 if (unlikely (!kbuf)) 407 goto free1; 408 409 value = ep_io (data, kbuf, len); 410 VDEBUG (data->dev, "%s read %zu OUT, status %d\n", 411 data->name, len, (int) value); 412 if (value >= 0 && copy_to_user (buf, kbuf, value)) 413 value = -EFAULT; 414 415free1: 416 up (&data->lock); 417 kfree (kbuf); 418 return value; 419} 420 421/* handle a synchronous IN bulk/intr/iso transfer */ 422static ssize_t 423ep_write (struct file *fd, const char __user *buf, size_t len, loff_t *ptr) 424{ 425 struct ep_data *data = fd->private_data; 426 void *kbuf; 427 ssize_t value; 428 429 if ((value = get_ready_ep (fd->f_flags, data)) < 0) 430 return value; 431 432 /* halt any endpoint by doing a "wrong direction" i/o call */ 433 if (!(data->desc.bEndpointAddress & USB_DIR_IN)) { 434 if ((data->desc.bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) 435 == USB_ENDPOINT_XFER_ISOC) 436 return -EINVAL; 437 DBG (data->dev, "%s halt\n", data->name); 438 spin_lock_irq (&data->dev->lock); 439 if (likely (data->ep != NULL)) 440 usb_ep_set_halt (data->ep); 441 spin_unlock_irq (&data->dev->lock); 442 up (&data->lock); 443 return -EBADMSG; 444 } 445 446 /* FIXME writebehind for O_NONBLOCK and poll(), qlen = 1 */ 447 448 value = -ENOMEM; 449 kbuf = kmalloc (len, GFP_KERNEL); 450 if (!kbuf) 451 goto free1; 452 if (copy_from_user (kbuf, buf, len)) { 453 value = -EFAULT; 454 goto free1; 455 } 456 457 value = ep_io (data, kbuf, len); 458 VDEBUG (data->dev, "%s write %zu IN, status %d\n", 459 data->name, len, (int) value); 460free1: 461 up (&data->lock); 462 kfree (kbuf); 463 return value; 464} 465 466static int 467ep_release (struct inode *inode, struct file *fd) 468{ 469 struct ep_data *data = fd->private_data; 470 int value; 471 472 if ((value = down_interruptible(&data->lock)) < 0) 473 return value; 474 475 /* clean up if this can be reopened */ 476 if (data->state != STATE_EP_UNBOUND) { 477 data->state = STATE_EP_DISABLED; 478 data->desc.bDescriptorType = 0; 479 data->hs_desc.bDescriptorType = 0; 480 usb_ep_disable(data->ep); 481 } 482 up (&data->lock); 483 put_ep (data); 484 return 0; 485} 486 487static int ep_ioctl (struct inode *inode, struct file *fd, 488 unsigned code, unsigned long value) 489{ 490 struct ep_data *data = fd->private_data; 491 int status; 492 493 if ((status = get_ready_ep (fd->f_flags, data)) < 0) 494 return status; 495 496 spin_lock_irq (&data->dev->lock); 497 if (likely (data->ep != NULL)) { 498 switch (code) { 499 case GADGETFS_FIFO_STATUS: 500 status = usb_ep_fifo_status (data->ep); 501 break; 502 case GADGETFS_FIFO_FLUSH: 503 usb_ep_fifo_flush (data->ep); 504 break; 505 case GADGETFS_CLEAR_HALT: 506 status = usb_ep_clear_halt (data->ep); 507 break; 508 default: 509 status = -ENOTTY; 510 } 511 } else 512 status = -ENODEV; 513 spin_unlock_irq (&data->dev->lock); 514 up (&data->lock); 515 return status; 516} 517 518/*----------------------------------------------------------------------*/ 519 520/* ASYNCHRONOUS ENDPOINT I/O OPERATIONS (bulk/intr/iso) */ 521 522struct kiocb_priv { 523 struct usb_request *req; 524 struct ep_data *epdata; 525 void *buf; 526 const struct iovec *iv; 527 unsigned long nr_segs; 528 unsigned actual; 529}; 530 531static int ep_aio_cancel(struct kiocb *iocb, struct io_event *e) 532{ 533 struct kiocb_priv *priv = iocb->private; 534 struct ep_data *epdata; 535 int value; 536 537 local_irq_disable(); 538 epdata = priv->epdata; 539 // spin_lock(&epdata->dev->lock); 540 kiocbSetCancelled(iocb); 541 if (likely(epdata && epdata->ep && priv->req)) 542 value = usb_ep_dequeue (epdata->ep, priv->req); 543 else 544 value = -EINVAL; 545 // spin_unlock(&epdata->dev->lock); 546 local_irq_enable(); 547 548 aio_put_req(iocb); 549 return value; 550} 551 552static ssize_t ep_aio_read_retry(struct kiocb *iocb) 553{ 554 struct kiocb_priv *priv = iocb->private; 555 ssize_t len, total; 556 int i; 557 558 /* we "retry" to get the right mm context for this: */ 559 560 /* copy stuff into user buffers */ 561 total = priv->actual; 562 len = 0; 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, priv->buf, this)) { 567 if (len == 0) 568 len = -EFAULT; 569 break; 570 } 571 572 total -= this; 573 len += this; 574 if (total == 0) 575 break; 576 } 577 kfree(priv->buf); 578 kfree(priv); 579 aio_put_req(iocb); 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 if (priv->iv == NULL 594 || unlikely(req->actual == 0) 595 || unlikely(kiocbIsCancelled(iocb))) { 596 kfree(req->buf); 597 kfree(priv); 598 iocb->private = NULL; 599 /* aio_complete() reports bytes-transferred _and_ faults */ 600 if (unlikely(kiocbIsCancelled(iocb))) 601 aio_put_req(iocb); 602 else 603 aio_complete(iocb, 604 req->actual ? req->actual : req->status, 605 req->status); 606 } else { 607 /* retry() won't report both; so we hide some faults */ 608 if (unlikely(0 != req->status)) 609 DBG(epdata->dev, "%s fault %d len %d\n", 610 ep->name, req->status, req->actual); 611 612 priv->buf = req->buf; 613 priv->actual = req->actual; 614 kick_iocb(iocb); 615 } 616 spin_unlock(&epdata->dev->lock); 617 618 usb_ep_free_request(ep, req); 619 put_ep(epdata); 620} 621 622static ssize_t 623ep_aio_rwtail( 624 struct kiocb *iocb, 625 char *buf, 626 size_t len, 627 struct ep_data *epdata, 628 const struct iovec *iv, 629 unsigned long nr_segs 630) 631{ 632 struct kiocb_priv *priv; 633 struct usb_request *req; 634 ssize_t value; 635 636 priv = kmalloc(sizeof *priv, GFP_KERNEL); 637 if (!priv) { 638 value = -ENOMEM; 639fail: 640 kfree(buf); 641 return value; 642 } 643 iocb->private = priv; 644 priv->iv = iv; 645 priv->nr_segs = nr_segs; 646 647 value = get_ready_ep(iocb->ki_filp->f_flags, epdata); 648 if (unlikely(value < 0)) { 649 kfree(priv); 650 goto fail; 651 } 652 653 iocb->ki_cancel = ep_aio_cancel; 654 get_ep(epdata); 655 priv->epdata = epdata; 656 priv->actual = 0; 657 658 /* each kiocb is coupled to one usb_request, but we can't 659 * allocate or submit those if the host disconnected. 660 */ 661 spin_lock_irq(&epdata->dev->lock); 662 if (likely(epdata->ep)) { 663 req = usb_ep_alloc_request(epdata->ep, GFP_ATOMIC); 664 if (likely(req)) { 665 priv->req = req; 666 req->buf = buf; 667 req->length = len; 668 req->complete = ep_aio_complete; 669 req->context = iocb; 670 value = usb_ep_queue(epdata->ep, req, GFP_ATOMIC); 671 if (unlikely(0 != value)) 672 usb_ep_free_request(epdata->ep, req); 673 } else 674 value = -EAGAIN; 675 } else 676 value = -ENODEV; 677 spin_unlock_irq(&epdata->dev->lock); 678 679 up(&epdata->lock); 680 681 if (unlikely(value)) { 682 kfree(priv); 683 put_ep(epdata); 684 } else 685 value = (iv ? -EIOCBRETRY : -EIOCBQUEUED); 686 return value; 687} 688 689static ssize_t 690ep_aio_read(struct kiocb *iocb, const struct iovec *iov, 691 unsigned long nr_segs, loff_t o) 692{ 693 struct ep_data *epdata = iocb->ki_filp->private_data; 694 char *buf; 695 696 if (unlikely(epdata->desc.bEndpointAddress & USB_DIR_IN)) 697 return -EINVAL; 698 699 buf = kmalloc(iocb->ki_left, GFP_KERNEL); 700 if (unlikely(!buf)) 701 return -ENOMEM; 702 703 iocb->ki_retry = ep_aio_read_retry; 704 return ep_aio_rwtail(iocb, buf, iocb->ki_left, epdata, iov, nr_segs); 705} 706 707static ssize_t 708ep_aio_write(struct kiocb *iocb, const struct iovec *iov, 709 unsigned long nr_segs, loff_t o) 710{ 711 struct ep_data *epdata = iocb->ki_filp->private_data; 712 char *buf; 713 size_t len = 0; 714 int i = 0; 715 716 if (unlikely(!(epdata->desc.bEndpointAddress & USB_DIR_IN))) 717 return -EINVAL; 718 719 buf = kmalloc(iocb->ki_left, GFP_KERNEL); 720 if (unlikely(!buf)) 721 return -ENOMEM; 722 723 for (i=0; i < nr_segs; i++) { 724 if (unlikely(copy_from_user(&buf[len], iov[i].iov_base, 725 iov[i].iov_len) != 0)) { 726 kfree(buf); 727 return -EFAULT; 728 } 729 len += iov[i].iov_len; 730 } 731 return ep_aio_rwtail(iocb, buf, len, epdata, NULL, 0); 732} 733 734/*----------------------------------------------------------------------*/ 735 736/* used after endpoint configuration */ 737static const struct file_operations ep_io_operations = { 738 .owner = THIS_MODULE, 739 .llseek = no_llseek, 740 741 .read = ep_read, 742 .write = ep_write, 743 .ioctl = ep_ioctl, 744 .release = ep_release, 745 746 .aio_read = ep_aio_read, 747 .aio_write = ep_aio_write, 748}; 749 750/* ENDPOINT INITIALIZATION 751 * 752 * fd = open ("/dev/gadget/$ENDPOINT", O_RDWR) 753 * status = write (fd, descriptors, sizeof descriptors) 754 * 755 * That write establishes the endpoint configuration, configuring 756 * the controller to process bulk, interrupt, or isochronous transfers 757 * at the right maxpacket size, and so on. 758 * 759 * The descriptors are message type 1, identified by a host order u32 760 * at the beginning of what's written. Descriptor order is: full/low 761 * speed descriptor, then optional high speed descriptor. 762 */ 763static ssize_t 764ep_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr) 765{ 766 struct ep_data *data = fd->private_data; 767 struct usb_ep *ep; 768 u32 tag; 769 int value, length = len; 770 771 if ((value = down_interruptible (&data->lock)) < 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 up (&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 (down_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 up (&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 usb_ep_free_buffer (ep, req->buf, req->dma, req->length); 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 int free = 1; 937 938 /* for control OUT, data must still get to userspace */ 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 } else { 946 unsigned long flags; 947 948 spin_lock_irqsave(&dev->lock, flags); 949 if (dev->state == STATE_DEV_SETUP) 950 dev->state = STATE_DEV_CONNECTED; 951 spin_unlock_irqrestore(&dev->lock, flags); 952 } 953 954 /* clean up as appropriate */ 955 if (free && req->buf != &dev->rbuf) 956 clean_req (ep, req); 957 req->complete = epio_complete; 958} 959 960static int setup_req (struct usb_ep *ep, struct usb_request *req, u16 len) 961{ 962 struct dev_data *dev = ep->driver_data; 963 964 if (dev->setup_out_ready) { 965 DBG (dev, "ep0 request busy!\n"); 966 return -EBUSY; 967 } 968 if (len > sizeof (dev->rbuf)) 969 req->buf = usb_ep_alloc_buffer (ep, len, &req->dma, GFP_ATOMIC); 970 if (req->buf == 0) { 971 req->buf = dev->rbuf; 972 return -ENOMEM; 973 } 974 req->complete = ep0_complete; 975 req->length = len; 976 req->zero = 0; 977 return 0; 978} 979 980static ssize_t 981ep0_read (struct file *fd, char __user *buf, size_t len, loff_t *ptr) 982{ 983 struct dev_data *dev = fd->private_data; 984 ssize_t retval; 985 enum ep0_state state; 986 987 spin_lock_irq (&dev->lock); 988 989 /* report fd mode change before acting on it */ 990 if (dev->setup_abort) { 991 dev->setup_abort = 0; 992 retval = -EIDRM; 993 goto done; 994 } 995 996 /* control DATA stage */ 997 if ((state = dev->state) == STATE_DEV_SETUP) { 998 999 if (dev->setup_in) { /* stall IN */ 1000 VDEBUG(dev, "ep0in stall\n"); 1001 (void) usb_ep_set_halt (dev->gadget->ep0); 1002 retval = -EL2HLT; 1003 dev->state = STATE_DEV_CONNECTED; 1004 1005 } else if (len == 0) { /* ack SET_CONFIGURATION etc */ 1006 struct usb_ep *ep = dev->gadget->ep0; 1007 struct usb_request *req = dev->req; 1008 1009 if ((retval = setup_req (ep, req, 0)) == 0) 1010 retval = usb_ep_queue (ep, req, GFP_ATOMIC); 1011 dev->state = STATE_DEV_CONNECTED; 1012 1013 /* assume that was SET_CONFIGURATION */ 1014 if (dev->current_config) { 1015 unsigned power; 1016#ifdef CONFIG_USB_GADGET_DUALSPEED 1017 if (dev->gadget->speed == USB_SPEED_HIGH) 1018 power = dev->hs_config->bMaxPower; 1019 else 1020#endif 1021 power = dev->config->bMaxPower; 1022 usb_gadget_vbus_draw(dev->gadget, 2 * power); 1023 } 1024 1025 } else { /* collect OUT data */ 1026 if ((fd->f_flags & O_NONBLOCK) != 0 1027 && !dev->setup_out_ready) { 1028 retval = -EAGAIN; 1029 goto done; 1030 } 1031 spin_unlock_irq (&dev->lock); 1032 retval = wait_event_interruptible (dev->wait, 1033 dev->setup_out_ready != 0); 1034 1035 /* FIXME state could change from under us */ 1036 spin_lock_irq (&dev->lock); 1037 if (retval) 1038 goto done; 1039 if (dev->setup_out_error) 1040 retval = -EIO; 1041 else { 1042 len = min (len, (size_t)dev->req->actual); 1043// FIXME don't call this with the spinlock held ... 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", __FUNCTION__, 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", __FUNCTION__); 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 spin_unlock_irq (&dev->lock); 1191 if (copy_from_user (dev->req->buf, buf, len)) 1192 retval = -EFAULT; 1193 else { 1194 if (len < dev->setup_wLength) 1195 dev->req->zero = 1; 1196 retval = usb_ep_queue ( 1197 dev->gadget->ep0, dev->req, 1198 GFP_KERNEL); 1199 } 1200 if (retval < 0) { 1201 spin_lock_irq (&dev->lock); 1202 clean_req (dev->gadget->ep0, dev->req); 1203 spin_unlock_irq (&dev->lock); 1204 } else 1205 retval = len; 1206 1207 return retval; 1208 } 1209 1210 /* can stall some OUT transfers */ 1211 } else if (dev->setup_can_stall) { 1212 VDEBUG(dev, "ep0out stall\n"); 1213 (void) usb_ep_set_halt (dev->gadget->ep0); 1214 retval = -EL2HLT; 1215 dev->state = STATE_DEV_CONNECTED; 1216 } else { 1217 DBG(dev, "bogus ep0out stall!\n"); 1218 } 1219 } else 1220 DBG (dev, "fail %s, state %d\n", __FUNCTION__, dev->state); 1221 1222 spin_unlock_irq (&dev->lock); 1223 return retval; 1224} 1225 1226static int 1227ep0_fasync (int f, struct file *fd, int on) 1228{ 1229 struct dev_data *dev = fd->private_data; 1230 // caller must F_SETOWN before signal delivery happens 1231 VDEBUG (dev, "%s %s\n", __FUNCTION__, on ? "on" : "off"); 1232 return fasync_helper (f, fd, on, &dev->fasync); 1233} 1234 1235static struct usb_gadget_driver gadgetfs_driver; 1236 1237static int 1238dev_release (struct inode *inode, struct file *fd) 1239{ 1240 struct dev_data *dev = fd->private_data; 1241 1242 /* closing ep0 === shutdown all */ 1243 1244 usb_gadget_unregister_driver (&gadgetfs_driver); 1245 1246 /* at this point "good" hardware has disconnected the 1247 * device from USB; the host won't see it any more. 1248 * alternatively, all host requests will time out. 1249 */ 1250 1251 fasync_helper (-1, fd, 0, &dev->fasync); 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 int dev_ioctl (struct inode *inode, struct file *fd, 1293 unsigned code, unsigned long value) 1294{ 1295 struct dev_data *dev = fd->private_data; 1296 struct usb_gadget *gadget = dev->gadget; 1297 1298 if (gadget->ops->ioctl) 1299 return gadget->ops->ioctl (gadget, code, value); 1300 return -ENOTTY; 1301} 1302 1303/* used after device configuration */ 1304static const struct file_operations ep0_io_operations = { 1305 .owner = THIS_MODULE, 1306 .llseek = no_llseek, 1307 1308 .read = ep0_read, 1309 .write = ep0_write, 1310 .fasync = ep0_fasync, 1311 .poll = ep0_poll, 1312 .ioctl = dev_ioctl, 1313 .release = dev_release, 1314}; 1315 1316/*----------------------------------------------------------------------*/ 1317 1318/* The in-kernel gadget driver handles most ep0 issues, in particular 1319 * enumerating the single configuration (as provided from user space). 1320 * 1321 * Unrecognized ep0 requests may be handled in user space. 1322 */ 1323 1324#ifdef CONFIG_USB_GADGET_DUALSPEED 1325static void make_qualifier (struct dev_data *dev) 1326{ 1327 struct usb_qualifier_descriptor qual; 1328 struct usb_device_descriptor *desc; 1329 1330 qual.bLength = sizeof qual; 1331 qual.bDescriptorType = USB_DT_DEVICE_QUALIFIER; 1332 qual.bcdUSB = __constant_cpu_to_le16 (0x0200); 1333 1334 desc = dev->dev; 1335 qual.bDeviceClass = desc->bDeviceClass; 1336 qual.bDeviceSubClass = desc->bDeviceSubClass; 1337 qual.bDeviceProtocol = desc->bDeviceProtocol; 1338 1339 /* assumes ep0 uses the same value for both speeds ... */ 1340 qual.bMaxPacketSize0 = desc->bMaxPacketSize0; 1341 1342 qual.bNumConfigurations = 1; 1343 qual.bRESERVED = 0; 1344 1345 memcpy (dev->rbuf, &qual, sizeof qual); 1346} 1347#endif 1348 1349static int 1350config_buf (struct dev_data *dev, u8 type, unsigned index) 1351{ 1352 int len; 1353#ifdef CONFIG_USB_GADGET_DUALSPEED 1354 int hs; 1355#endif 1356 1357 /* only one configuration */ 1358 if (index > 0) 1359 return -EINVAL; 1360 1361#ifdef CONFIG_USB_GADGET_DUALSPEED 1362 hs = (dev->gadget->speed == USB_SPEED_HIGH); 1363 if (type == USB_DT_OTHER_SPEED_CONFIG) 1364 hs = !hs; 1365 if (hs) { 1366 dev->req->buf = dev->hs_config; 1367 len = le16_to_cpup (&dev->hs_config->wTotalLength); 1368 } else 1369#endif 1370 { 1371 dev->req->buf = dev->config; 1372 len = le16_to_cpup (&dev->config->wTotalLength); 1373 } 1374 ((u8 *)dev->req->buf) [1] = type; 1375 return len; 1376} 1377 1378static int 1379gadgetfs_setup (struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl) 1380{ 1381 struct dev_data *dev = get_gadget_data (gadget); 1382 struct usb_request *req = dev->req; 1383 int value = -EOPNOTSUPP; 1384 struct usb_gadgetfs_event *event; 1385 u16 w_value = le16_to_cpu(ctrl->wValue); 1386 u16 w_length = le16_to_cpu(ctrl->wLength); 1387 1388 spin_lock (&dev->lock); 1389 dev->setup_abort = 0; 1390 if (dev->state == STATE_DEV_UNCONNECTED) { 1391 1392 dev->state = STATE_DEV_CONNECTED; 1393 dev->dev->bMaxPacketSize0 = gadget->ep0->maxpacket; 1394 1395#ifdef CONFIG_USB_GADGET_DUALSPEED 1396 if (gadget->speed == USB_SPEED_HIGH && dev->hs_config == 0) { 1397 ERROR (dev, "no high speed config??\n"); 1398 return -EINVAL; 1399 } 1400#endif /* CONFIG_USB_GADGET_DUALSPEED */ 1401 1402 INFO (dev, "connected\n"); 1403 event = next_event (dev, GADGETFS_CONNECT); 1404 event->u.speed = gadget->speed; 1405 ep0_readable (dev); 1406 1407 /* host may have given up waiting for response. we can miss control 1408 * requests handled lower down (device/endpoint status and features); 1409 * then ep0_{read,write} will report the wrong status. controller 1410 * driver will have aborted pending i/o. 1411 */ 1412 } else if (dev->state == STATE_DEV_SETUP) 1413 dev->setup_abort = 1; 1414 1415 req->buf = dev->rbuf; 1416 req->dma = DMA_ADDR_INVALID; 1417 req->context = NULL; 1418 value = -EOPNOTSUPP; 1419 switch (ctrl->bRequest) { 1420 1421 case USB_REQ_GET_DESCRIPTOR: 1422 if (ctrl->bRequestType != USB_DIR_IN) 1423 goto unrecognized; 1424 switch (w_value >> 8) { 1425 1426 case USB_DT_DEVICE: 1427 value = min (w_length, (u16) sizeof *dev->dev); 1428 req->buf = dev->dev; 1429 break; 1430#ifdef CONFIG_USB_GADGET_DUALSPEED 1431 case USB_DT_DEVICE_QUALIFIER: 1432 if (!dev->hs_config) 1433 break; 1434 value = min (w_length, (u16) 1435 sizeof (struct usb_qualifier_descriptor)); 1436 make_qualifier (dev); 1437 break; 1438 case USB_DT_OTHER_SPEED_CONFIG: 1439 // FALLTHROUGH 1440#endif 1441 case USB_DT_CONFIG: 1442 value = config_buf (dev, 1443 w_value >> 8, 1444 w_value & 0xff); 1445 if (value >= 0) 1446 value = min (w_length, (u16) value); 1447 break; 1448 case USB_DT_STRING: 1449 goto unrecognized; 1450 1451 default: // all others are errors 1452 break; 1453 } 1454 break; 1455 1456 /* currently one config, two speeds */ 1457 case USB_REQ_SET_CONFIGURATION: 1458 if (ctrl->bRequestType != 0) 1459 break; 1460 if (0 == (u8) w_value) { 1461 value = 0; 1462 dev->current_config = 0; 1463 usb_gadget_vbus_draw(gadget, 8 /* mA */ ); 1464 // user mode expected to disable endpoints 1465 } else { 1466 u8 config, power; 1467#ifdef CONFIG_USB_GADGET_DUALSPEED 1468 if (gadget->speed == USB_SPEED_HIGH) { 1469 config = dev->hs_config->bConfigurationValue; 1470 power = dev->hs_config->bMaxPower; 1471 } else 1472#endif 1473 { 1474 config = dev->config->bConfigurationValue; 1475 power = dev->config->bMaxPower; 1476 } 1477 1478 if (config == (u8) w_value) { 1479 value = 0; 1480 dev->current_config = config; 1481 usb_gadget_vbus_draw(gadget, 2 * power); 1482 } 1483 } 1484 1485 /* report SET_CONFIGURATION like any other control request, 1486 * except that usermode may not stall this. the next 1487 * request mustn't be allowed start until this finishes: 1488 * endpoints and threads set up, etc. 1489 * 1490 * NOTE: older PXA hardware (before PXA 255: without UDCCFR) 1491 * has bad/racey automagic that prevents synchronizing here. 1492 * even kernel mode drivers often miss them. 1493 */ 1494 if (value == 0) { 1495 INFO (dev, "configuration #%d\n", dev->current_config); 1496 if (dev->usermode_setup) { 1497 dev->setup_can_stall = 0; 1498 goto delegate; 1499 } 1500 } 1501 break; 1502 1503#ifndef CONFIG_USB_GADGETFS_PXA2XX 1504 /* PXA automagically handles this request too */ 1505 case USB_REQ_GET_CONFIGURATION: 1506 if (ctrl->bRequestType != 0x80) 1507 break; 1508 *(u8 *)req->buf = dev->current_config; 1509 value = min (w_length, (u16) 1); 1510 break; 1511#endif 1512 1513 default: 1514unrecognized: 1515 VDEBUG (dev, "%s req%02x.%02x v%04x i%04x l%d\n", 1516 dev->usermode_setup ? "delegate" : "fail", 1517 ctrl->bRequestType, ctrl->bRequest, 1518 w_value, le16_to_cpu(ctrl->wIndex), w_length); 1519 1520 /* if there's an ep0 reader, don't stall */ 1521 if (dev->usermode_setup) { 1522 dev->setup_can_stall = 1; 1523delegate: 1524 dev->setup_in = (ctrl->bRequestType & USB_DIR_IN) 1525 ? 1 : 0; 1526 dev->setup_wLength = w_length; 1527 dev->setup_out_ready = 0; 1528 dev->setup_out_error = 0; 1529 value = 0; 1530 1531 /* read DATA stage for OUT right away */ 1532 if (unlikely (!dev->setup_in && w_length)) { 1533 value = setup_req (gadget->ep0, dev->req, 1534 w_length); 1535 if (value < 0) 1536 break; 1537 value = usb_ep_queue (gadget->ep0, dev->req, 1538 GFP_ATOMIC); 1539 if (value < 0) { 1540 clean_req (gadget->ep0, dev->req); 1541 break; 1542 } 1543 1544 /* we can't currently stall these */ 1545 dev->setup_can_stall = 0; 1546 } 1547 1548 /* state changes when reader collects event */ 1549 event = next_event (dev, GADGETFS_SETUP); 1550 event->u.setup = *ctrl; 1551 ep0_readable (dev); 1552 spin_unlock (&dev->lock); 1553 return 0; 1554 } 1555 } 1556 1557 /* proceed with data transfer and status phases? */ 1558 if (value >= 0 && dev->state != STATE_DEV_SETUP) { 1559 req->length = value; 1560 req->zero = value < w_length; 1561 value = usb_ep_queue (gadget->ep0, req, GFP_ATOMIC); 1562 if (value < 0) { 1563 DBG (dev, "ep_queue --> %d\n", value); 1564 req->status = 0; 1565 } 1566 } 1567 1568 /* device stalls when value < 0 */ 1569 spin_unlock (&dev->lock); 1570 return value; 1571} 1572 1573static void destroy_ep_files (struct dev_data *dev) 1574{ 1575 struct list_head *entry, *tmp; 1576 1577 DBG (dev, "%s %d\n", __FUNCTION__, dev->state); 1578 1579 /* dev->state must prevent interference */ 1580restart: 1581 spin_lock_irq (&dev->lock); 1582 list_for_each_safe (entry, tmp, &dev->epfiles) { 1583 struct ep_data *ep; 1584 struct inode *parent; 1585 struct dentry *dentry; 1586 1587 /* break link to FS */ 1588 ep = list_entry (entry, struct ep_data, epfiles); 1589 list_del_init (&ep->epfiles); 1590 dentry = ep->dentry; 1591 ep->dentry = NULL; 1592 parent = dentry->d_parent->d_inode; 1593 1594 /* break link to controller */ 1595 if (ep->state == STATE_EP_ENABLED) 1596 (void) usb_ep_disable (ep->ep); 1597 ep->state = STATE_EP_UNBOUND; 1598 usb_ep_free_request (ep->ep, ep->req); 1599 ep->ep = NULL; 1600 wake_up (&ep->wait); 1601 put_ep (ep); 1602 1603 spin_unlock_irq (&dev->lock); 1604 1605 /* break link to dcache */ 1606 mutex_lock (&parent->i_mutex); 1607 d_delete (dentry); 1608 dput (dentry); 1609 mutex_unlock (&parent->i_mutex); 1610 1611 /* fds may still be open */ 1612 goto restart; 1613 } 1614 spin_unlock_irq (&dev->lock); 1615} 1616 1617 1618static struct inode * 1619gadgetfs_create_file (struct super_block *sb, char const *name, 1620 void *data, const struct file_operations *fops, 1621 struct dentry **dentry_p); 1622 1623static int activate_ep_files (struct dev_data *dev) 1624{ 1625 struct usb_ep *ep; 1626 struct ep_data *data; 1627 1628 gadget_for_each_ep (ep, dev->gadget) { 1629 1630 data = kzalloc(sizeof(*data), GFP_KERNEL); 1631 if (!data) 1632 goto enomem0; 1633 data->state = STATE_EP_DISABLED; 1634 init_MUTEX (&data->lock); 1635 init_waitqueue_head (&data->wait); 1636 1637 strncpy (data->name, ep->name, sizeof (data->name) - 1); 1638 atomic_set (&data->count, 1); 1639 data->dev = dev; 1640 get_dev (dev); 1641 1642 data->ep = ep; 1643 ep->driver_data = data; 1644 1645 data->req = usb_ep_alloc_request (ep, GFP_KERNEL); 1646 if (!data->req) 1647 goto enomem1; 1648 1649 data->inode = gadgetfs_create_file (dev->sb, data->name, 1650 data, &ep_config_operations, 1651 &data->dentry); 1652 if (!data->inode) 1653 goto enomem2; 1654 list_add_tail (&data->epfiles, &dev->epfiles); 1655 } 1656 return 0; 1657 1658enomem2: 1659 usb_ep_free_request (ep, data->req); 1660enomem1: 1661 put_dev (dev); 1662 kfree (data); 1663enomem0: 1664 DBG (dev, "%s enomem\n", __FUNCTION__); 1665 destroy_ep_files (dev); 1666 return -ENOMEM; 1667} 1668 1669static void 1670gadgetfs_unbind (struct usb_gadget *gadget) 1671{ 1672 struct dev_data *dev = get_gadget_data (gadget); 1673 1674 DBG (dev, "%s\n", __FUNCTION__); 1675 1676 spin_lock_irq (&dev->lock); 1677 dev->state = STATE_DEV_UNBOUND; 1678 spin_unlock_irq (&dev->lock); 1679 1680 destroy_ep_files (dev); 1681 gadget->ep0->driver_data = NULL; 1682 set_gadget_data (gadget, NULL); 1683 1684 /* we've already been disconnected ... no i/o is active */ 1685 if (dev->req) 1686 usb_ep_free_request (gadget->ep0, dev->req); 1687 DBG (dev, "%s done\n", __FUNCTION__); 1688 put_dev (dev); 1689} 1690 1691static struct dev_data *the_device; 1692 1693static int 1694gadgetfs_bind (struct usb_gadget *gadget) 1695{ 1696 struct dev_data *dev = the_device; 1697 1698 if (!dev) 1699 return -ESRCH; 1700 if (0 != strcmp (CHIP, gadget->name)) { 1701 printk (KERN_ERR "%s expected %s controller not %s\n", 1702 shortname, CHIP, gadget->name); 1703 return -ENODEV; 1704 } 1705 1706 set_gadget_data (gadget, dev); 1707 dev->gadget = gadget; 1708 gadget->ep0->driver_data = dev; 1709 dev->dev->bMaxPacketSize0 = gadget->ep0->maxpacket; 1710 1711 /* preallocate control response and buffer */ 1712 dev->req = usb_ep_alloc_request (gadget->ep0, GFP_KERNEL); 1713 if (!dev->req) 1714 goto enomem; 1715 dev->req->context = NULL; 1716 dev->req->complete = epio_complete; 1717 1718 if (activate_ep_files (dev) < 0) 1719 goto enomem; 1720 1721 INFO (dev, "bound to %s driver\n", gadget->name); 1722 spin_lock_irq(&dev->lock); 1723 dev->state = STATE_DEV_UNCONNECTED; 1724 spin_unlock_irq(&dev->lock); 1725 get_dev (dev); 1726 return 0; 1727 1728enomem: 1729 gadgetfs_unbind (gadget); 1730 return -ENOMEM; 1731} 1732 1733static void 1734gadgetfs_disconnect (struct usb_gadget *gadget) 1735{ 1736 struct dev_data *dev = get_gadget_data (gadget); 1737 1738 spin_lock (&dev->lock); 1739 if (dev->state == STATE_DEV_UNCONNECTED) 1740 goto exit; 1741 dev->state = STATE_DEV_UNCONNECTED; 1742 1743 INFO (dev, "disconnected\n"); 1744 next_event (dev, GADGETFS_DISCONNECT); 1745 ep0_readable (dev); 1746exit: 1747 spin_unlock (&dev->lock); 1748} 1749 1750static void 1751gadgetfs_suspend (struct usb_gadget *gadget) 1752{ 1753 struct dev_data *dev = get_gadget_data (gadget); 1754 1755 INFO (dev, "suspended from state %d\n", dev->state); 1756 spin_lock (&dev->lock); 1757 switch (dev->state) { 1758 case STATE_DEV_SETUP: // VERY odd... host died?? 1759 case STATE_DEV_CONNECTED: 1760 case STATE_DEV_UNCONNECTED: 1761 next_event (dev, GADGETFS_SUSPEND); 1762 ep0_readable (dev); 1763 /* FALLTHROUGH */ 1764 default: 1765 break; 1766 } 1767 spin_unlock (&dev->lock); 1768} 1769 1770static struct usb_gadget_driver gadgetfs_driver = { 1771#ifdef CONFIG_USB_GADGET_DUALSPEED 1772 .speed = USB_SPEED_HIGH, 1773#else 1774 .speed = USB_SPEED_FULL, 1775#endif 1776 .function = (char *) driver_desc, 1777 .bind = gadgetfs_bind, 1778 .unbind = gadgetfs_unbind, 1779 .setup = gadgetfs_setup, 1780 .disconnect = gadgetfs_disconnect, 1781 .suspend = gadgetfs_suspend, 1782 1783 .driver = { 1784 .name = (char *) shortname, 1785 }, 1786}; 1787 1788/*----------------------------------------------------------------------*/ 1789 1790static void gadgetfs_nop(struct usb_gadget *arg) { } 1791 1792static int gadgetfs_probe (struct usb_gadget *gadget) 1793{ 1794 CHIP = gadget->name; 1795 return -EISNAM; 1796} 1797 1798static struct usb_gadget_driver probe_driver = { 1799 .speed = USB_SPEED_HIGH, 1800 .bind = gadgetfs_probe, 1801 .unbind = gadgetfs_nop, 1802 .setup = (void *)gadgetfs_nop, 1803 .disconnect = gadgetfs_nop, 1804 .driver = { 1805 .name = "nop", 1806 }, 1807}; 1808 1809 1810/* DEVICE INITIALIZATION 1811 * 1812 * fd = open ("/dev/gadget/$CHIP", O_RDWR) 1813 * status = write (fd, descriptors, sizeof descriptors) 1814 * 1815 * That write establishes the device configuration, so the kernel can 1816 * bind to the controller ... guaranteeing it can handle enumeration 1817 * at all necessary speeds. Descriptor order is: 1818 * 1819 * . message tag (u32, host order) ... for now, must be zero; it 1820 * would change to support features like multi-config devices 1821 * . full/low speed config ... all wTotalLength bytes (with interface, 1822 * class, altsetting, endpoint, and other descriptors) 1823 * . high speed config ... all descriptors, for high speed operation; 1824 * this one's optional except for high-speed hardware 1825 * . device descriptor 1826 * 1827 * Endpoints are not yet enabled. Drivers must wait until device 1828 * configuration and interface altsetting changes create 1829 * the need to configure (or unconfigure) them. 1830 * 1831 * After initialization, the device stays active for as long as that 1832 * $CHIP file is open. Events must then be read from that descriptor, 1833 * such as configuration notifications. 1834 */ 1835 1836static int is_valid_config (struct usb_config_descriptor *config) 1837{ 1838 return config->bDescriptorType == USB_DT_CONFIG 1839 && config->bLength == USB_DT_CONFIG_SIZE 1840 && config->bConfigurationValue != 0 1841 && (config->bmAttributes & USB_CONFIG_ATT_ONE) != 0 1842 && (config->bmAttributes & USB_CONFIG_ATT_WAKEUP) == 0; 1843 /* FIXME if gadget->is_otg, _must_ include an otg descriptor */ 1844 /* FIXME check lengths: walk to end */ 1845} 1846 1847static ssize_t 1848dev_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr) 1849{ 1850 struct dev_data *dev = fd->private_data; 1851 ssize_t value = len, length = len; 1852 unsigned total; 1853 u32 tag; 1854 char *kbuf; 1855 1856 if (len < (USB_DT_CONFIG_SIZE + USB_DT_DEVICE_SIZE + 4)) 1857 return -EINVAL; 1858 1859 /* we might need to change message format someday */ 1860 if (copy_from_user (&tag, buf, 4)) 1861 return -EFAULT; 1862 if (tag != 0) 1863 return -EINVAL; 1864 buf += 4; 1865 length -= 4; 1866 1867 kbuf = kmalloc (length, GFP_KERNEL); 1868 if (!kbuf) 1869 return -ENOMEM; 1870 if (copy_from_user (kbuf, buf, length)) { 1871 kfree (kbuf); 1872 return -EFAULT; 1873 } 1874 1875 spin_lock_irq (&dev->lock); 1876 value = -EINVAL; 1877 if (dev->buf) 1878 goto fail; 1879 dev->buf = kbuf; 1880 1881 /* full or low speed config */ 1882 dev->config = (void *) kbuf; 1883 total = le16_to_cpup (&dev->config->wTotalLength); 1884 if (!is_valid_config (dev->config) || total >= length) 1885 goto fail; 1886 kbuf += total; 1887 length -= total; 1888 1889 /* optional high speed config */ 1890 if (kbuf [1] == USB_DT_CONFIG) { 1891 dev->hs_config = (void *) kbuf; 1892 total = le16_to_cpup (&dev->hs_config->wTotalLength); 1893 if (!is_valid_config (dev->hs_config) || total >= length) 1894 goto fail; 1895 kbuf += total; 1896 length -= total; 1897 } 1898 1899 /* could support multiple configs, using another encoding! */ 1900 1901 /* device descriptor (tweaked for paranoia) */ 1902 if (length != USB_DT_DEVICE_SIZE) 1903 goto fail; 1904 dev->dev = (void *)kbuf; 1905 if (dev->dev->bLength != USB_DT_DEVICE_SIZE 1906 || dev->dev->bDescriptorType != USB_DT_DEVICE 1907 || dev->dev->bNumConfigurations != 1) 1908 goto fail; 1909 dev->dev->bNumConfigurations = 1; 1910 dev->dev->bcdUSB = __constant_cpu_to_le16 (0x0200); 1911 1912 /* triggers gadgetfs_bind(); then we can enumerate. */ 1913 spin_unlock_irq (&dev->lock); 1914 value = usb_gadget_register_driver (&gadgetfs_driver); 1915 if (value != 0) { 1916 kfree (dev->buf); 1917 dev->buf = NULL; 1918 } else { 1919 /* at this point "good" hardware has for the first time 1920 * let the USB the host see us. alternatively, if users 1921 * unplug/replug that will clear all the error state. 1922 * 1923 * note: everything running before here was guaranteed 1924 * to choke driver model style diagnostics. from here 1925 * on, they can work ... except in cleanup paths that 1926 * kick in after the ep0 descriptor is closed. 1927 */ 1928 fd->f_op = &ep0_io_operations; 1929 value = len; 1930 } 1931 return value; 1932 1933fail: 1934 spin_unlock_irq (&dev->lock); 1935 pr_debug ("%s: %s fail %Zd, %p\n", shortname, __FUNCTION__, value, dev); 1936 kfree (dev->buf); 1937 dev->buf = NULL; 1938 return value; 1939} 1940 1941static int 1942dev_open (struct inode *inode, struct file *fd) 1943{ 1944 struct dev_data *dev = inode->i_private; 1945 int value = -EBUSY; 1946 1947 spin_lock_irq(&dev->lock); 1948 if (dev->state == STATE_DEV_DISABLED) { 1949 dev->ev_next = 0; 1950 dev->state = STATE_DEV_OPENED; 1951 fd->private_data = dev; 1952 get_dev (dev); 1953 value = 0; 1954 } 1955 spin_unlock_irq(&dev->lock); 1956 return value; 1957} 1958 1959static const struct file_operations dev_init_operations = { 1960 .owner = THIS_MODULE, 1961 .llseek = no_llseek, 1962 1963 .open = dev_open, 1964 .write = dev_config, 1965 .fasync = ep0_fasync, 1966 .ioctl = dev_ioctl, 1967 .release = dev_release, 1968}; 1969 1970/*----------------------------------------------------------------------*/ 1971 1972/* FILESYSTEM AND SUPERBLOCK OPERATIONS 1973 * 1974 * Mounting the filesystem creates a controller file, used first for 1975 * device configuration then later for event monitoring. 1976 */ 1977 1978 1979/* FIXME PAM etc could set this security policy without mount options 1980 * if epfiles inherited ownership and permissons from ep0 ... 1981 */ 1982 1983static unsigned default_uid; 1984static unsigned default_gid; 1985static unsigned default_perm = S_IRUSR | S_IWUSR; 1986 1987module_param (default_uid, uint, 0644); 1988module_param (default_gid, uint, 0644); 1989module_param (default_perm, uint, 0644); 1990 1991 1992static struct inode * 1993gadgetfs_make_inode (struct super_block *sb, 1994 void *data, const struct file_operations *fops, 1995 int mode) 1996{ 1997 struct inode *inode = new_inode (sb); 1998 1999 if (inode) { 2000 inode->i_mode = mode; 2001 inode->i_uid = default_uid; 2002 inode->i_gid = default_gid; 2003 inode->i_blocks = 0; 2004 inode->i_atime = inode->i_mtime = inode->i_ctime 2005 = CURRENT_TIME; 2006 inode->i_private = data; 2007 inode->i_fop = fops; 2008 } 2009 return inode; 2010} 2011 2012/* creates in fs root directory, so non-renamable and non-linkable. 2013 * so inode and dentry are paired, until device reconfig. 2014 */ 2015static struct inode * 2016gadgetfs_create_file (struct super_block *sb, char const *name, 2017 void *data, const struct file_operations *fops, 2018 struct dentry **dentry_p) 2019{ 2020 struct dentry *dentry; 2021 struct inode *inode; 2022 2023 dentry = d_alloc_name(sb->s_root, name); 2024 if (!dentry) 2025 return NULL; 2026 2027 inode = gadgetfs_make_inode (sb, data, fops, 2028 S_IFREG | (default_perm & S_IRWXUGO)); 2029 if (!inode) { 2030 dput(dentry); 2031 return NULL; 2032 } 2033 d_add (dentry, inode); 2034 *dentry_p = dentry; 2035 return inode; 2036} 2037 2038static struct super_operations gadget_fs_operations = { 2039 .statfs = simple_statfs, 2040 .drop_inode = generic_delete_inode, 2041}; 2042 2043static int 2044gadgetfs_fill_super (struct super_block *sb, void *opts, int silent) 2045{ 2046 struct inode *inode; 2047 struct dentry *d; 2048 struct dev_data *dev; 2049 2050 if (the_device) 2051 return -ESRCH; 2052 2053 /* fake probe to determine $CHIP */ 2054 (void) usb_gadget_register_driver (&probe_driver); 2055 if (!CHIP) 2056 return -ENODEV; 2057 2058 /* superblock */ 2059 sb->s_blocksize = PAGE_CACHE_SIZE; 2060 sb->s_blocksize_bits = PAGE_CACHE_SHIFT; 2061 sb->s_magic = GADGETFS_MAGIC; 2062 sb->s_op = &gadget_fs_operations; 2063 sb->s_time_gran = 1; 2064 2065 /* root inode */ 2066 inode = gadgetfs_make_inode (sb, 2067 NULL, &simple_dir_operations, 2068 S_IFDIR | S_IRUGO | S_IXUGO); 2069 if (!inode) 2070 goto enomem0; 2071 inode->i_op = &simple_dir_inode_operations; 2072 if (!(d = d_alloc_root (inode))) 2073 goto enomem1; 2074 sb->s_root = d; 2075 2076 /* the ep0 file is named after the controller we expect; 2077 * user mode code can use it for sanity checks, like we do. 2078 */ 2079 dev = dev_new (); 2080 if (!dev) 2081 goto enomem2; 2082 2083 dev->sb = sb; 2084 if (!gadgetfs_create_file (sb, CHIP, 2085 dev, &dev_init_operations, 2086 &dev->dentry)) 2087 goto enomem3; 2088 2089 /* other endpoint files are available after hardware setup, 2090 * from binding to a controller. 2091 */ 2092 the_device = dev; 2093 return 0; 2094 2095enomem3: 2096 put_dev (dev); 2097enomem2: 2098 dput (d); 2099enomem1: 2100 iput (inode); 2101enomem0: 2102 return -ENOMEM; 2103} 2104 2105/* "mount -t gadgetfs path /dev/gadget" ends up here */ 2106static int 2107gadgetfs_get_sb (struct file_system_type *t, int flags, 2108 const char *path, void *opts, struct vfsmount *mnt) 2109{ 2110 return get_sb_single (t, flags, opts, gadgetfs_fill_super, mnt); 2111} 2112 2113static void 2114gadgetfs_kill_sb (struct super_block *sb) 2115{ 2116 kill_litter_super (sb); 2117 if (the_device) { 2118 put_dev (the_device); 2119 the_device = NULL; 2120 } 2121} 2122 2123/*----------------------------------------------------------------------*/ 2124 2125static struct file_system_type gadgetfs_type = { 2126 .owner = THIS_MODULE, 2127 .name = shortname, 2128 .get_sb = gadgetfs_get_sb, 2129 .kill_sb = gadgetfs_kill_sb, 2130}; 2131 2132/*----------------------------------------------------------------------*/ 2133 2134static int __init init (void) 2135{ 2136 int status; 2137 2138 status = register_filesystem (&gadgetfs_type); 2139 if (status == 0) 2140 pr_info ("%s: %s, version " DRIVER_VERSION "\n", 2141 shortname, driver_desc); 2142 return status; 2143} 2144module_init (init); 2145 2146static void __exit cleanup (void) 2147{ 2148 pr_debug ("unregister %s\n", shortname); 2149 unregister_filesystem (&gadgetfs_type); 2150} 2151module_exit (cleanup); 2152 2153