inode.c revision 997694defd085f4dd168c6e7e0e82382c5be9db4
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/$CHIP is configured 58 * (by writing configuration and device descriptors). Afterwards it 59 * may serve as a source of device events, used to handle all control 60 * requests other than basic enumeration. 61 * 62 * - Then either immediately, or after a SET_CONFIGURATION control request, 63 * ep_config() is called when each /dev/gadget/ep* file is configured 64 * (by writing endpoint descriptors). Afterwards these files are used 65 * to write() IN data or to read() OUT data. To halt the endpoint, a 66 * "wrong direction" request is issued (like reading an IN endpoint). 67 * 68 * Unlike "usbfs" the only ioctl()s are for things that are rare, and maybe 69 * not possible on all hardware. For example, precise fault handling with 70 * respect to data left in endpoint fifos after aborted operations; or 71 * selective clearing of endpoint halts, to implement SET_INTERFACE. 72 */ 73 74#define DRIVER_DESC "USB Gadget filesystem" 75#define DRIVER_VERSION "24 Aug 2004" 76 77static const char driver_desc [] = DRIVER_DESC; 78static const char shortname [] = "gadgetfs"; 79 80MODULE_DESCRIPTION (DRIVER_DESC); 81MODULE_AUTHOR ("David Brownell"); 82MODULE_LICENSE ("GPL"); 83 84 85/*----------------------------------------------------------------------*/ 86 87#define GADGETFS_MAGIC 0xaee71ee7 88#define DMA_ADDR_INVALID (~(dma_addr_t)0) 89 90/* /dev/gadget/$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_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_UNCONNECTED, 109 STATE_CONNECTED, 110 STATE_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; 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_DEFER_ENABLE, 192 STATE_EP_ENABLED, 193 STATE_EP_UNBOUND, 194}; 195 196struct ep_data { 197 struct semaphore 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 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 WARN(dev,fmt,args...) \ 267 xprintk(dev , KERN_WARNING , fmt , ## args) 268#define INFO(dev,fmt,args...) \ 269 xprintk(dev , KERN_INFO , fmt , ## args) 270 271 272/*----------------------------------------------------------------------*/ 273 274/* SYNCHRONOUS ENDPOINT OPERATIONS (bulk/intr/iso) 275 * 276 * After opening, configure non-control endpoints. Then use normal 277 * stream read() and write() requests; and maybe ioctl() to get more 278 * precise FIFO status when recovering from cancellation. 279 */ 280 281static void epio_complete (struct usb_ep *ep, struct usb_request *req) 282{ 283 struct ep_data *epdata = ep->driver_data; 284 285 if (!req->context) 286 return; 287 if (req->status) 288 epdata->status = req->status; 289 else 290 epdata->status = req->actual; 291 complete ((struct completion *)req->context); 292} 293 294/* tasklock endpoint, returning when it's connected. 295 * still need dev->lock to use epdata->ep. 296 */ 297static int 298get_ready_ep (unsigned f_flags, struct ep_data *epdata) 299{ 300 int val; 301 302 if (f_flags & O_NONBLOCK) { 303 if (down_trylock (&epdata->lock) != 0) 304 goto nonblock; 305 if (epdata->state != STATE_EP_ENABLED) { 306 up (&epdata->lock); 307nonblock: 308 val = -EAGAIN; 309 } else 310 val = 0; 311 return val; 312 } 313 314 if ((val = down_interruptible (&epdata->lock)) < 0) 315 return val; 316newstate: 317 switch (epdata->state) { 318 case STATE_EP_ENABLED: 319 break; 320 case STATE_EP_DEFER_ENABLE: 321 DBG (epdata->dev, "%s wait for host\n", epdata->name); 322 if ((val = wait_event_interruptible (epdata->wait, 323 epdata->state != STATE_EP_DEFER_ENABLE 324 || epdata->dev->state == STATE_DEV_UNBOUND 325 )) < 0) 326 goto fail; 327 goto newstate; 328 // case STATE_EP_DISABLED: /* "can't happen" */ 329 // case STATE_EP_READY: /* "can't happen" */ 330 default: /* error! */ 331 pr_debug ("%s: ep %p not available, state %d\n", 332 shortname, epdata, epdata->state); 333 // FALLTHROUGH 334 case STATE_EP_UNBOUND: /* clean disconnect */ 335 val = -ENODEV; 336fail: 337 up (&epdata->lock); 338 } 339 return val; 340} 341 342static ssize_t 343ep_io (struct ep_data *epdata, void *buf, unsigned len) 344{ 345 DECLARE_COMPLETION (done); 346 int value; 347 348 spin_lock_irq (&epdata->dev->lock); 349 if (likely (epdata->ep != NULL)) { 350 struct usb_request *req = epdata->req; 351 352 req->context = &done; 353 req->complete = epio_complete; 354 req->buf = buf; 355 req->length = len; 356 value = usb_ep_queue (epdata->ep, req, GFP_ATOMIC); 357 } else 358 value = -ENODEV; 359 spin_unlock_irq (&epdata->dev->lock); 360 361 if (likely (value == 0)) { 362 value = wait_event_interruptible (done.wait, done.done); 363 if (value != 0) { 364 spin_lock_irq (&epdata->dev->lock); 365 if (likely (epdata->ep != NULL)) { 366 DBG (epdata->dev, "%s i/o interrupted\n", 367 epdata->name); 368 usb_ep_dequeue (epdata->ep, epdata->req); 369 spin_unlock_irq (&epdata->dev->lock); 370 371 wait_event (done.wait, done.done); 372 if (epdata->status == -ECONNRESET) 373 epdata->status = -EINTR; 374 } else { 375 spin_unlock_irq (&epdata->dev->lock); 376 377 DBG (epdata->dev, "endpoint gone\n"); 378 epdata->status = -ENODEV; 379 } 380 } 381 return epdata->status; 382 } 383 return value; 384} 385 386 387/* handle a synchronous OUT bulk/intr/iso transfer */ 388static ssize_t 389ep_read (struct file *fd, char __user *buf, size_t len, loff_t *ptr) 390{ 391 struct ep_data *data = fd->private_data; 392 void *kbuf; 393 ssize_t value; 394 395 if ((value = get_ready_ep (fd->f_flags, data)) < 0) 396 return value; 397 398 /* halt any endpoint by doing a "wrong direction" i/o call */ 399 if (data->desc.bEndpointAddress & USB_DIR_IN) { 400 if ((data->desc.bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) 401 == USB_ENDPOINT_XFER_ISOC) 402 return -EINVAL; 403 DBG (data->dev, "%s halt\n", data->name); 404 spin_lock_irq (&data->dev->lock); 405 if (likely (data->ep != NULL)) 406 usb_ep_set_halt (data->ep); 407 spin_unlock_irq (&data->dev->lock); 408 up (&data->lock); 409 return -EBADMSG; 410 } 411 412 /* FIXME readahead for O_NONBLOCK and poll(); careful with ZLPs */ 413 414 value = -ENOMEM; 415 kbuf = kmalloc (len, SLAB_KERNEL); 416 if (unlikely (!kbuf)) 417 goto free1; 418 419 value = ep_io (data, kbuf, len); 420 VDEBUG (data->dev, "%s read %zu OUT, status %d\n", 421 data->name, len, (int) value); 422 if (value >= 0 && copy_to_user (buf, kbuf, value)) 423 value = -EFAULT; 424 425free1: 426 up (&data->lock); 427 kfree (kbuf); 428 return value; 429} 430 431/* handle a synchronous IN bulk/intr/iso transfer */ 432static ssize_t 433ep_write (struct file *fd, const char __user *buf, size_t len, loff_t *ptr) 434{ 435 struct ep_data *data = fd->private_data; 436 void *kbuf; 437 ssize_t value; 438 439 if ((value = get_ready_ep (fd->f_flags, data)) < 0) 440 return value; 441 442 /* halt any endpoint by doing a "wrong direction" i/o call */ 443 if (!(data->desc.bEndpointAddress & USB_DIR_IN)) { 444 if ((data->desc.bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) 445 == USB_ENDPOINT_XFER_ISOC) 446 return -EINVAL; 447 DBG (data->dev, "%s halt\n", data->name); 448 spin_lock_irq (&data->dev->lock); 449 if (likely (data->ep != NULL)) 450 usb_ep_set_halt (data->ep); 451 spin_unlock_irq (&data->dev->lock); 452 up (&data->lock); 453 return -EBADMSG; 454 } 455 456 /* FIXME writebehind for O_NONBLOCK and poll(), qlen = 1 */ 457 458 value = -ENOMEM; 459 kbuf = kmalloc (len, SLAB_KERNEL); 460 if (!kbuf) 461 goto free1; 462 if (copy_from_user (kbuf, buf, len)) { 463 value = -EFAULT; 464 goto free1; 465 } 466 467 value = ep_io (data, kbuf, len); 468 VDEBUG (data->dev, "%s write %zu IN, status %d\n", 469 data->name, len, (int) value); 470free1: 471 up (&data->lock); 472 kfree (kbuf); 473 return value; 474} 475 476static int 477ep_release (struct inode *inode, struct file *fd) 478{ 479 struct ep_data *data = fd->private_data; 480 int value; 481 482 if ((value = down_interruptible(&data->lock)) < 0) 483 return value; 484 485 /* clean up if this can be reopened */ 486 if (data->state != STATE_EP_UNBOUND) { 487 data->state = STATE_EP_DISABLED; 488 data->desc.bDescriptorType = 0; 489 data->hs_desc.bDescriptorType = 0; 490 usb_ep_disable(data->ep); 491 } 492 up (&data->lock); 493 put_ep (data); 494 return 0; 495} 496 497static int ep_ioctl (struct inode *inode, struct file *fd, 498 unsigned code, unsigned long value) 499{ 500 struct ep_data *data = fd->private_data; 501 int status; 502 503 if ((status = get_ready_ep (fd->f_flags, data)) < 0) 504 return status; 505 506 spin_lock_irq (&data->dev->lock); 507 if (likely (data->ep != NULL)) { 508 switch (code) { 509 case GADGETFS_FIFO_STATUS: 510 status = usb_ep_fifo_status (data->ep); 511 break; 512 case GADGETFS_FIFO_FLUSH: 513 usb_ep_fifo_flush (data->ep); 514 break; 515 case GADGETFS_CLEAR_HALT: 516 status = usb_ep_clear_halt (data->ep); 517 break; 518 default: 519 status = -ENOTTY; 520 } 521 } else 522 status = -ENODEV; 523 spin_unlock_irq (&data->dev->lock); 524 up (&data->lock); 525 return status; 526} 527 528/*----------------------------------------------------------------------*/ 529 530/* ASYNCHRONOUS ENDPOINT I/O OPERATIONS (bulk/intr/iso) */ 531 532struct kiocb_priv { 533 struct usb_request *req; 534 struct ep_data *epdata; 535 void *buf; 536 char __user *ubuf; /* NULL for writes */ 537 unsigned actual; 538}; 539 540static int ep_aio_cancel(struct kiocb *iocb, struct io_event *e) 541{ 542 struct kiocb_priv *priv = iocb->private; 543 struct ep_data *epdata; 544 int value; 545 546 local_irq_disable(); 547 epdata = priv->epdata; 548 // spin_lock(&epdata->dev->lock); 549 kiocbSetCancelled(iocb); 550 if (likely(epdata && epdata->ep && priv->req)) 551 value = usb_ep_dequeue (epdata->ep, priv->req); 552 else 553 value = -EINVAL; 554 // spin_unlock(&epdata->dev->lock); 555 local_irq_enable(); 556 557 aio_put_req(iocb); 558 return value; 559} 560 561static ssize_t ep_aio_read_retry(struct kiocb *iocb) 562{ 563 struct kiocb_priv *priv = iocb->private; 564 ssize_t status = priv->actual; 565 566 /* we "retry" to get the right mm context for this: */ 567 status = copy_to_user(priv->ubuf, priv->buf, priv->actual); 568 if (unlikely(0 != status)) 569 status = -EFAULT; 570 else 571 status = priv->actual; 572 kfree(priv->buf); 573 kfree(priv); 574 return status; 575} 576 577static void ep_aio_complete(struct usb_ep *ep, struct usb_request *req) 578{ 579 struct kiocb *iocb = req->context; 580 struct kiocb_priv *priv = iocb->private; 581 struct ep_data *epdata = priv->epdata; 582 583 /* lock against disconnect (and ideally, cancel) */ 584 spin_lock(&epdata->dev->lock); 585 priv->req = NULL; 586 priv->epdata = NULL; 587 if (priv->ubuf == NULL 588 || unlikely(req->actual == 0) 589 || unlikely(kiocbIsCancelled(iocb))) { 590 kfree(req->buf); 591 kfree(priv); 592 iocb->private = NULL; 593 /* aio_complete() reports bytes-transferred _and_ faults */ 594 if (unlikely(kiocbIsCancelled(iocb))) 595 aio_put_req(iocb); 596 else 597 aio_complete(iocb, 598 req->actual ? req->actual : req->status, 599 req->status); 600 } else { 601 /* retry() won't report both; so we hide some faults */ 602 if (unlikely(0 != req->status)) 603 DBG(epdata->dev, "%s fault %d len %d\n", 604 ep->name, req->status, req->actual); 605 606 priv->buf = req->buf; 607 priv->actual = req->actual; 608 kick_iocb(iocb); 609 } 610 spin_unlock(&epdata->dev->lock); 611 612 usb_ep_free_request(ep, req); 613 put_ep(epdata); 614} 615 616static ssize_t 617ep_aio_rwtail( 618 struct kiocb *iocb, 619 char *buf, 620 size_t len, 621 struct ep_data *epdata, 622 char __user *ubuf 623) 624{ 625 struct kiocb_priv *priv; 626 struct usb_request *req; 627 ssize_t value; 628 629 priv = kmalloc(sizeof *priv, GFP_KERNEL); 630 if (!priv) { 631 value = -ENOMEM; 632fail: 633 kfree(buf); 634 return value; 635 } 636 iocb->private = priv; 637 priv->ubuf = ubuf; 638 639 value = get_ready_ep(iocb->ki_filp->f_flags, epdata); 640 if (unlikely(value < 0)) { 641 kfree(priv); 642 goto fail; 643 } 644 645 iocb->ki_cancel = ep_aio_cancel; 646 get_ep(epdata); 647 priv->epdata = epdata; 648 priv->actual = 0; 649 650 /* each kiocb is coupled to one usb_request, but we can't 651 * allocate or submit those if the host disconnected. 652 */ 653 spin_lock_irq(&epdata->dev->lock); 654 if (likely(epdata->ep)) { 655 req = usb_ep_alloc_request(epdata->ep, GFP_ATOMIC); 656 if (likely(req)) { 657 priv->req = req; 658 req->buf = buf; 659 req->length = len; 660 req->complete = ep_aio_complete; 661 req->context = iocb; 662 value = usb_ep_queue(epdata->ep, req, GFP_ATOMIC); 663 if (unlikely(0 != value)) 664 usb_ep_free_request(epdata->ep, req); 665 } else 666 value = -EAGAIN; 667 } else 668 value = -ENODEV; 669 spin_unlock_irq(&epdata->dev->lock); 670 671 up(&epdata->lock); 672 673 if (unlikely(value)) { 674 kfree(priv); 675 put_ep(epdata); 676 } else 677 value = (ubuf ? -EIOCBRETRY : -EIOCBQUEUED); 678 return value; 679} 680 681static ssize_t 682ep_aio_read(struct kiocb *iocb, char __user *ubuf, size_t len, loff_t o) 683{ 684 struct ep_data *epdata = iocb->ki_filp->private_data; 685 char *buf; 686 687 if (unlikely(epdata->desc.bEndpointAddress & USB_DIR_IN)) 688 return -EINVAL; 689 buf = kmalloc(len, GFP_KERNEL); 690 if (unlikely(!buf)) 691 return -ENOMEM; 692 iocb->ki_retry = ep_aio_read_retry; 693 return ep_aio_rwtail(iocb, buf, len, epdata, ubuf); 694} 695 696static ssize_t 697ep_aio_write(struct kiocb *iocb, const char __user *ubuf, size_t len, loff_t o) 698{ 699 struct ep_data *epdata = iocb->ki_filp->private_data; 700 char *buf; 701 702 if (unlikely(!(epdata->desc.bEndpointAddress & USB_DIR_IN))) 703 return -EINVAL; 704 buf = kmalloc(len, GFP_KERNEL); 705 if (unlikely(!buf)) 706 return -ENOMEM; 707 if (unlikely(copy_from_user(buf, ubuf, len) != 0)) { 708 kfree(buf); 709 return -EFAULT; 710 } 711 return ep_aio_rwtail(iocb, buf, len, epdata, NULL); 712} 713 714/*----------------------------------------------------------------------*/ 715 716/* used after endpoint configuration */ 717static const struct file_operations ep_io_operations = { 718 .owner = THIS_MODULE, 719 .llseek = no_llseek, 720 721 .read = ep_read, 722 .write = ep_write, 723 .ioctl = ep_ioctl, 724 .release = ep_release, 725 726 .aio_read = ep_aio_read, 727 .aio_write = ep_aio_write, 728}; 729 730/* ENDPOINT INITIALIZATION 731 * 732 * fd = open ("/dev/gadget/$ENDPOINT", O_RDWR) 733 * status = write (fd, descriptors, sizeof descriptors) 734 * 735 * That write establishes the endpoint configuration, configuring 736 * the controller to process bulk, interrupt, or isochronous transfers 737 * at the right maxpacket size, and so on. 738 * 739 * The descriptors are message type 1, identified by a host order u32 740 * at the beginning of what's written. Descriptor order is: full/low 741 * speed descriptor, then optional high speed descriptor. 742 */ 743static ssize_t 744ep_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr) 745{ 746 struct ep_data *data = fd->private_data; 747 struct usb_ep *ep; 748 u32 tag; 749 int value, length = len; 750 751 if ((value = down_interruptible (&data->lock)) < 0) 752 return value; 753 754 if (data->state != STATE_EP_READY) { 755 value = -EL2HLT; 756 goto fail; 757 } 758 759 value = len; 760 if (len < USB_DT_ENDPOINT_SIZE + 4) 761 goto fail0; 762 763 /* we might need to change message format someday */ 764 if (copy_from_user (&tag, buf, 4)) { 765 goto fail1; 766 } 767 if (tag != 1) { 768 DBG(data->dev, "config %s, bad tag %d\n", data->name, tag); 769 goto fail0; 770 } 771 buf += 4; 772 len -= 4; 773 774 /* NOTE: audio endpoint extensions not accepted here; 775 * just don't include the extra bytes. 776 */ 777 778 /* full/low speed descriptor, then high speed */ 779 if (copy_from_user (&data->desc, buf, USB_DT_ENDPOINT_SIZE)) { 780 goto fail1; 781 } 782 if (data->desc.bLength != USB_DT_ENDPOINT_SIZE 783 || data->desc.bDescriptorType != USB_DT_ENDPOINT) 784 goto fail0; 785 if (len != USB_DT_ENDPOINT_SIZE) { 786 if (len != 2 * USB_DT_ENDPOINT_SIZE) 787 goto fail0; 788 if (copy_from_user (&data->hs_desc, buf + USB_DT_ENDPOINT_SIZE, 789 USB_DT_ENDPOINT_SIZE)) { 790 goto fail1; 791 } 792 if (data->hs_desc.bLength != USB_DT_ENDPOINT_SIZE 793 || data->hs_desc.bDescriptorType 794 != USB_DT_ENDPOINT) { 795 DBG(data->dev, "config %s, bad hs length or type\n", 796 data->name); 797 goto fail0; 798 } 799 } 800 801 spin_lock_irq (&data->dev->lock); 802 if (data->dev->state == STATE_DEV_UNBOUND) { 803 value = -ENOENT; 804 goto gone; 805 } else if ((ep = data->ep) == NULL) { 806 value = -ENODEV; 807 goto gone; 808 } 809 switch (data->dev->gadget->speed) { 810 case USB_SPEED_LOW: 811 case USB_SPEED_FULL: 812 value = usb_ep_enable (ep, &data->desc); 813 if (value == 0) 814 data->state = STATE_EP_ENABLED; 815 break; 816#ifdef CONFIG_USB_GADGET_DUALSPEED 817 case USB_SPEED_HIGH: 818 /* fails if caller didn't provide that descriptor... */ 819 value = usb_ep_enable (ep, &data->hs_desc); 820 if (value == 0) 821 data->state = STATE_EP_ENABLED; 822 break; 823#endif 824 default: 825 DBG (data->dev, "unconnected, %s init deferred\n", 826 data->name); 827 data->state = STATE_EP_DEFER_ENABLE; 828 } 829 if (value == 0) { 830 fd->f_op = &ep_io_operations; 831 value = length; 832 } 833gone: 834 spin_unlock_irq (&data->dev->lock); 835 if (value < 0) { 836fail: 837 data->desc.bDescriptorType = 0; 838 data->hs_desc.bDescriptorType = 0; 839 } 840 up (&data->lock); 841 return value; 842fail0: 843 value = -EINVAL; 844 goto fail; 845fail1: 846 value = -EFAULT; 847 goto fail; 848} 849 850static int 851ep_open (struct inode *inode, struct file *fd) 852{ 853 struct ep_data *data = inode->i_private; 854 int value = -EBUSY; 855 856 if (down_interruptible (&data->lock) != 0) 857 return -EINTR; 858 spin_lock_irq (&data->dev->lock); 859 if (data->dev->state == STATE_DEV_UNBOUND) 860 value = -ENOENT; 861 else if (data->state == STATE_EP_DISABLED) { 862 value = 0; 863 data->state = STATE_EP_READY; 864 get_ep (data); 865 fd->private_data = data; 866 VDEBUG (data->dev, "%s ready\n", data->name); 867 } else 868 DBG (data->dev, "%s state %d\n", 869 data->name, data->state); 870 spin_unlock_irq (&data->dev->lock); 871 up (&data->lock); 872 return value; 873} 874 875/* used before endpoint configuration */ 876static const struct file_operations ep_config_operations = { 877 .owner = THIS_MODULE, 878 .llseek = no_llseek, 879 880 .open = ep_open, 881 .write = ep_config, 882 .release = ep_release, 883}; 884 885/*----------------------------------------------------------------------*/ 886 887/* EP0 IMPLEMENTATION can be partly in userspace. 888 * 889 * Drivers that use this facility receive various events, including 890 * control requests the kernel doesn't handle. Drivers that don't 891 * use this facility may be too simple-minded for real applications. 892 */ 893 894static inline void ep0_readable (struct dev_data *dev) 895{ 896 wake_up (&dev->wait); 897 kill_fasync (&dev->fasync, SIGIO, POLL_IN); 898} 899 900static void clean_req (struct usb_ep *ep, struct usb_request *req) 901{ 902 struct dev_data *dev = ep->driver_data; 903 904 if (req->buf != dev->rbuf) { 905 usb_ep_free_buffer (ep, req->buf, req->dma, req->length); 906 req->buf = dev->rbuf; 907 req->dma = DMA_ADDR_INVALID; 908 } 909 req->complete = epio_complete; 910 dev->setup_out_ready = 0; 911} 912 913static void ep0_complete (struct usb_ep *ep, struct usb_request *req) 914{ 915 struct dev_data *dev = ep->driver_data; 916 int free = 1; 917 918 /* for control OUT, data must still get to userspace */ 919 if (!dev->setup_in) { 920 dev->setup_out_error = (req->status != 0); 921 if (!dev->setup_out_error) 922 free = 0; 923 dev->setup_out_ready = 1; 924 ep0_readable (dev); 925 } else if (dev->state == STATE_SETUP) 926 dev->state = STATE_CONNECTED; 927 928 /* clean up as appropriate */ 929 if (free && req->buf != &dev->rbuf) 930 clean_req (ep, req); 931 req->complete = epio_complete; 932} 933 934static int setup_req (struct usb_ep *ep, struct usb_request *req, u16 len) 935{ 936 struct dev_data *dev = ep->driver_data; 937 938 if (dev->setup_out_ready) { 939 DBG (dev, "ep0 request busy!\n"); 940 return -EBUSY; 941 } 942 if (len > sizeof (dev->rbuf)) 943 req->buf = usb_ep_alloc_buffer (ep, len, &req->dma, GFP_ATOMIC); 944 if (req->buf == 0) { 945 req->buf = dev->rbuf; 946 return -ENOMEM; 947 } 948 req->complete = ep0_complete; 949 req->length = len; 950 req->zero = 0; 951 return 0; 952} 953 954static ssize_t 955ep0_read (struct file *fd, char __user *buf, size_t len, loff_t *ptr) 956{ 957 struct dev_data *dev = fd->private_data; 958 ssize_t retval; 959 enum ep0_state state; 960 961 spin_lock_irq (&dev->lock); 962 963 /* report fd mode change before acting on it */ 964 if (dev->setup_abort) { 965 dev->setup_abort = 0; 966 retval = -EIDRM; 967 goto done; 968 } 969 970 /* control DATA stage */ 971 if ((state = dev->state) == STATE_SETUP) { 972 973 if (dev->setup_in) { /* stall IN */ 974 VDEBUG(dev, "ep0in stall\n"); 975 (void) usb_ep_set_halt (dev->gadget->ep0); 976 retval = -EL2HLT; 977 dev->state = STATE_CONNECTED; 978 979 } else if (len == 0) { /* ack SET_CONFIGURATION etc */ 980 struct usb_ep *ep = dev->gadget->ep0; 981 struct usb_request *req = dev->req; 982 983 if ((retval = setup_req (ep, req, 0)) == 0) 984 retval = usb_ep_queue (ep, req, GFP_ATOMIC); 985 dev->state = STATE_CONNECTED; 986 987 /* assume that was SET_CONFIGURATION */ 988 if (dev->current_config) { 989 unsigned power; 990#ifdef CONFIG_USB_GADGET_DUALSPEED 991 if (dev->gadget->speed == USB_SPEED_HIGH) 992 power = dev->hs_config->bMaxPower; 993 else 994#endif 995 power = dev->config->bMaxPower; 996 usb_gadget_vbus_draw(dev->gadget, 2 * power); 997 } 998 999 } else { /* collect OUT data */ 1000 if ((fd->f_flags & O_NONBLOCK) != 0 1001 && !dev->setup_out_ready) { 1002 retval = -EAGAIN; 1003 goto done; 1004 } 1005 spin_unlock_irq (&dev->lock); 1006 retval = wait_event_interruptible (dev->wait, 1007 dev->setup_out_ready != 0); 1008 1009 /* FIXME state could change from under us */ 1010 spin_lock_irq (&dev->lock); 1011 if (retval) 1012 goto done; 1013 if (dev->setup_out_error) 1014 retval = -EIO; 1015 else { 1016 len = min (len, (size_t)dev->req->actual); 1017// FIXME don't call this with the spinlock held ... 1018 if (copy_to_user (buf, dev->req->buf, len)) 1019 retval = -EFAULT; 1020 clean_req (dev->gadget->ep0, dev->req); 1021 /* NOTE userspace can't yet choose to stall */ 1022 } 1023 } 1024 goto done; 1025 } 1026 1027 /* else normal: return event data */ 1028 if (len < sizeof dev->event [0]) { 1029 retval = -EINVAL; 1030 goto done; 1031 } 1032 len -= len % sizeof (struct usb_gadgetfs_event); 1033 dev->usermode_setup = 1; 1034 1035scan: 1036 /* return queued events right away */ 1037 if (dev->ev_next != 0) { 1038 unsigned i, n; 1039 int tmp = dev->ev_next; 1040 1041 len = min (len, tmp * sizeof (struct usb_gadgetfs_event)); 1042 n = len / sizeof (struct usb_gadgetfs_event); 1043 1044 /* ep0 can't deliver events when STATE_SETUP */ 1045 for (i = 0; i < n; i++) { 1046 if (dev->event [i].type == GADGETFS_SETUP) { 1047 len = i + 1; 1048 len *= sizeof (struct usb_gadgetfs_event); 1049 n = 0; 1050 break; 1051 } 1052 } 1053 spin_unlock_irq (&dev->lock); 1054 if (copy_to_user (buf, &dev->event, len)) 1055 retval = -EFAULT; 1056 else 1057 retval = len; 1058 if (len > 0) { 1059 len /= sizeof (struct usb_gadgetfs_event); 1060 1061 /* NOTE this doesn't guard against broken drivers; 1062 * concurrent ep0 readers may lose events. 1063 */ 1064 spin_lock_irq (&dev->lock); 1065 dev->ev_next -= len; 1066 if (dev->ev_next != 0) 1067 memmove (&dev->event, &dev->event [len], 1068 sizeof (struct usb_gadgetfs_event) 1069 * (tmp - len)); 1070 if (n == 0) 1071 dev->state = STATE_SETUP; 1072 spin_unlock_irq (&dev->lock); 1073 } 1074 return retval; 1075 } 1076 if (fd->f_flags & O_NONBLOCK) { 1077 retval = -EAGAIN; 1078 goto done; 1079 } 1080 1081 switch (state) { 1082 default: 1083 DBG (dev, "fail %s, state %d\n", __FUNCTION__, state); 1084 retval = -ESRCH; 1085 break; 1086 case STATE_UNCONNECTED: 1087 case STATE_CONNECTED: 1088 spin_unlock_irq (&dev->lock); 1089 DBG (dev, "%s wait\n", __FUNCTION__); 1090 1091 /* wait for events */ 1092 retval = wait_event_interruptible (dev->wait, 1093 dev->ev_next != 0); 1094 if (retval < 0) 1095 return retval; 1096 spin_lock_irq (&dev->lock); 1097 goto scan; 1098 } 1099 1100done: 1101 spin_unlock_irq (&dev->lock); 1102 return retval; 1103} 1104 1105static struct usb_gadgetfs_event * 1106next_event (struct dev_data *dev, enum usb_gadgetfs_event_type type) 1107{ 1108 struct usb_gadgetfs_event *event; 1109 unsigned i; 1110 1111 switch (type) { 1112 /* these events purge the queue */ 1113 case GADGETFS_DISCONNECT: 1114 if (dev->state == STATE_SETUP) 1115 dev->setup_abort = 1; 1116 // FALL THROUGH 1117 case GADGETFS_CONNECT: 1118 dev->ev_next = 0; 1119 break; 1120 case GADGETFS_SETUP: /* previous request timed out */ 1121 case GADGETFS_SUSPEND: /* same effect */ 1122 /* these events can't be repeated */ 1123 for (i = 0; i != dev->ev_next; i++) { 1124 if (dev->event [i].type != type) 1125 continue; 1126 DBG (dev, "discard old event %d\n", type); 1127 dev->ev_next--; 1128 if (i == dev->ev_next) 1129 break; 1130 /* indices start at zero, for simplicity */ 1131 memmove (&dev->event [i], &dev->event [i + 1], 1132 sizeof (struct usb_gadgetfs_event) 1133 * (dev->ev_next - i)); 1134 } 1135 break; 1136 default: 1137 BUG (); 1138 } 1139 event = &dev->event [dev->ev_next++]; 1140 BUG_ON (dev->ev_next > N_EVENT); 1141 VDEBUG (dev, "ev %d, next %d\n", type, dev->ev_next); 1142 memset (event, 0, sizeof *event); 1143 event->type = type; 1144 return event; 1145} 1146 1147static ssize_t 1148ep0_write (struct file *fd, const char __user *buf, size_t len, loff_t *ptr) 1149{ 1150 struct dev_data *dev = fd->private_data; 1151 ssize_t retval = -ESRCH; 1152 1153 spin_lock_irq (&dev->lock); 1154 1155 /* report fd mode change before acting on it */ 1156 if (dev->setup_abort) { 1157 dev->setup_abort = 0; 1158 retval = -EIDRM; 1159 1160 /* data and/or status stage for control request */ 1161 } else if (dev->state == STATE_SETUP) { 1162 1163 /* IN DATA+STATUS caller makes len <= wLength */ 1164 if (dev->setup_in) { 1165 retval = setup_req (dev->gadget->ep0, dev->req, len); 1166 if (retval == 0) { 1167 spin_unlock_irq (&dev->lock); 1168 if (copy_from_user (dev->req->buf, buf, len)) 1169 retval = -EFAULT; 1170 else { 1171 if (len < dev->setup_wLength) 1172 dev->req->zero = 1; 1173 retval = usb_ep_queue ( 1174 dev->gadget->ep0, dev->req, 1175 GFP_KERNEL); 1176 } 1177 if (retval < 0) { 1178 spin_lock_irq (&dev->lock); 1179 clean_req (dev->gadget->ep0, dev->req); 1180 spin_unlock_irq (&dev->lock); 1181 } else 1182 retval = len; 1183 1184 return retval; 1185 } 1186 1187 /* can stall some OUT transfers */ 1188 } else if (dev->setup_can_stall) { 1189 VDEBUG(dev, "ep0out stall\n"); 1190 (void) usb_ep_set_halt (dev->gadget->ep0); 1191 retval = -EL2HLT; 1192 dev->state = STATE_CONNECTED; 1193 } else { 1194 DBG(dev, "bogus ep0out stall!\n"); 1195 } 1196 } else 1197 DBG (dev, "fail %s, state %d\n", __FUNCTION__, dev->state); 1198 1199 spin_unlock_irq (&dev->lock); 1200 return retval; 1201} 1202 1203static int 1204ep0_fasync (int f, struct file *fd, int on) 1205{ 1206 struct dev_data *dev = fd->private_data; 1207 // caller must F_SETOWN before signal delivery happens 1208 VDEBUG (dev, "%s %s\n", __FUNCTION__, on ? "on" : "off"); 1209 return fasync_helper (f, fd, on, &dev->fasync); 1210} 1211 1212static struct usb_gadget_driver gadgetfs_driver; 1213 1214static int 1215dev_release (struct inode *inode, struct file *fd) 1216{ 1217 struct dev_data *dev = fd->private_data; 1218 1219 /* closing ep0 === shutdown all */ 1220 1221 usb_gadget_unregister_driver (&gadgetfs_driver); 1222 1223 /* at this point "good" hardware has disconnected the 1224 * device from USB; the host won't see it any more. 1225 * alternatively, all host requests will time out. 1226 */ 1227 1228 fasync_helper (-1, fd, 0, &dev->fasync); 1229 kfree (dev->buf); 1230 dev->buf = NULL; 1231 put_dev (dev); 1232 1233 /* other endpoints were all decoupled from this device */ 1234 dev->state = STATE_DEV_DISABLED; 1235 return 0; 1236} 1237 1238static unsigned int 1239ep0_poll (struct file *fd, poll_table *wait) 1240{ 1241 struct dev_data *dev = fd->private_data; 1242 int mask = 0; 1243 1244 poll_wait(fd, &dev->wait, wait); 1245 1246 spin_lock_irq (&dev->lock); 1247 1248 /* report fd mode change before acting on it */ 1249 if (dev->setup_abort) { 1250 dev->setup_abort = 0; 1251 mask = POLLHUP; 1252 goto out; 1253 } 1254 1255 if (dev->state == STATE_SETUP) { 1256 if (dev->setup_in || dev->setup_can_stall) 1257 mask = POLLOUT; 1258 } else { 1259 if (dev->ev_next != 0) 1260 mask = POLLIN; 1261 } 1262out: 1263 spin_unlock_irq(&dev->lock); 1264 return mask; 1265} 1266 1267static int dev_ioctl (struct inode *inode, struct file *fd, 1268 unsigned code, unsigned long value) 1269{ 1270 struct dev_data *dev = fd->private_data; 1271 struct usb_gadget *gadget = dev->gadget; 1272 1273 if (gadget->ops->ioctl) 1274 return gadget->ops->ioctl (gadget, code, value); 1275 return -ENOTTY; 1276} 1277 1278/* used after device configuration */ 1279static const struct file_operations ep0_io_operations = { 1280 .owner = THIS_MODULE, 1281 .llseek = no_llseek, 1282 1283 .read = ep0_read, 1284 .write = ep0_write, 1285 .fasync = ep0_fasync, 1286 .poll = ep0_poll, 1287 .ioctl = dev_ioctl, 1288 .release = dev_release, 1289}; 1290 1291/*----------------------------------------------------------------------*/ 1292 1293/* The in-kernel gadget driver handles most ep0 issues, in particular 1294 * enumerating the single configuration (as provided from user space). 1295 * 1296 * Unrecognized ep0 requests may be handled in user space. 1297 */ 1298 1299#ifdef CONFIG_USB_GADGET_DUALSPEED 1300static void make_qualifier (struct dev_data *dev) 1301{ 1302 struct usb_qualifier_descriptor qual; 1303 struct usb_device_descriptor *desc; 1304 1305 qual.bLength = sizeof qual; 1306 qual.bDescriptorType = USB_DT_DEVICE_QUALIFIER; 1307 qual.bcdUSB = __constant_cpu_to_le16 (0x0200); 1308 1309 desc = dev->dev; 1310 qual.bDeviceClass = desc->bDeviceClass; 1311 qual.bDeviceSubClass = desc->bDeviceSubClass; 1312 qual.bDeviceProtocol = desc->bDeviceProtocol; 1313 1314 /* assumes ep0 uses the same value for both speeds ... */ 1315 qual.bMaxPacketSize0 = desc->bMaxPacketSize0; 1316 1317 qual.bNumConfigurations = 1; 1318 qual.bRESERVED = 0; 1319 1320 memcpy (dev->rbuf, &qual, sizeof qual); 1321} 1322#endif 1323 1324static int 1325config_buf (struct dev_data *dev, u8 type, unsigned index) 1326{ 1327 int len; 1328#ifdef CONFIG_USB_GADGET_DUALSPEED 1329 int hs; 1330#endif 1331 1332 /* only one configuration */ 1333 if (index > 0) 1334 return -EINVAL; 1335 1336#ifdef CONFIG_USB_GADGET_DUALSPEED 1337 hs = (dev->gadget->speed == USB_SPEED_HIGH); 1338 if (type == USB_DT_OTHER_SPEED_CONFIG) 1339 hs = !hs; 1340 if (hs) { 1341 dev->req->buf = dev->hs_config; 1342 len = le16_to_cpup (&dev->hs_config->wTotalLength); 1343 } else 1344#endif 1345 { 1346 dev->req->buf = dev->config; 1347 len = le16_to_cpup (&dev->config->wTotalLength); 1348 } 1349 ((u8 *)dev->req->buf) [1] = type; 1350 return len; 1351} 1352 1353static int 1354gadgetfs_setup (struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl) 1355{ 1356 struct dev_data *dev = get_gadget_data (gadget); 1357 struct usb_request *req = dev->req; 1358 int value = -EOPNOTSUPP; 1359 struct usb_gadgetfs_event *event; 1360 u16 w_value = le16_to_cpu(ctrl->wValue); 1361 u16 w_length = le16_to_cpu(ctrl->wLength); 1362 1363 spin_lock (&dev->lock); 1364 dev->setup_abort = 0; 1365 if (dev->state == STATE_UNCONNECTED) { 1366 struct usb_ep *ep; 1367 struct ep_data *data; 1368 1369 dev->state = STATE_CONNECTED; 1370 dev->dev->bMaxPacketSize0 = gadget->ep0->maxpacket; 1371 1372#ifdef CONFIG_USB_GADGET_DUALSPEED 1373 if (gadget->speed == USB_SPEED_HIGH && dev->hs_config == 0) { 1374 ERROR (dev, "no high speed config??\n"); 1375 return -EINVAL; 1376 } 1377#endif /* CONFIG_USB_GADGET_DUALSPEED */ 1378 1379 INFO (dev, "connected\n"); 1380 event = next_event (dev, GADGETFS_CONNECT); 1381 event->u.speed = gadget->speed; 1382 ep0_readable (dev); 1383 1384 list_for_each_entry (ep, &gadget->ep_list, ep_list) { 1385 data = ep->driver_data; 1386 /* ... down_trylock (&data->lock) ... */ 1387 if (data->state != STATE_EP_DEFER_ENABLE) 1388 continue; 1389#ifdef CONFIG_USB_GADGET_DUALSPEED 1390 if (gadget->speed == USB_SPEED_HIGH) 1391 value = usb_ep_enable (ep, &data->hs_desc); 1392 else 1393#endif /* CONFIG_USB_GADGET_DUALSPEED */ 1394 value = usb_ep_enable (ep, &data->desc); 1395 if (value) { 1396 ERROR (dev, "deferred %s enable --> %d\n", 1397 data->name, value); 1398 continue; 1399 } 1400 data->state = STATE_EP_ENABLED; 1401 wake_up (&data->wait); 1402 DBG (dev, "woke up %s waiters\n", data->name); 1403 } 1404 1405 /* host may have given up waiting for response. we can miss control 1406 * requests handled lower down (device/endpoint status and features); 1407 * then ep0_{read,write} will report the wrong status. controller 1408 * driver will have aborted pending i/o. 1409 */ 1410 } else if (dev->state == STATE_SETUP) 1411 dev->setup_abort = 1; 1412 1413 req->buf = dev->rbuf; 1414 req->dma = DMA_ADDR_INVALID; 1415 req->context = NULL; 1416 value = -EOPNOTSUPP; 1417 switch (ctrl->bRequest) { 1418 1419 case USB_REQ_GET_DESCRIPTOR: 1420 if (ctrl->bRequestType != USB_DIR_IN) 1421 goto unrecognized; 1422 switch (w_value >> 8) { 1423 1424 case USB_DT_DEVICE: 1425 value = min (w_length, (u16) sizeof *dev->dev); 1426 req->buf = dev->dev; 1427 break; 1428#ifdef CONFIG_USB_GADGET_DUALSPEED 1429 case USB_DT_DEVICE_QUALIFIER: 1430 if (!dev->hs_config) 1431 break; 1432 value = min (w_length, (u16) 1433 sizeof (struct usb_qualifier_descriptor)); 1434 make_qualifier (dev); 1435 break; 1436 case USB_DT_OTHER_SPEED_CONFIG: 1437 // FALLTHROUGH 1438#endif 1439 case USB_DT_CONFIG: 1440 value = config_buf (dev, 1441 w_value >> 8, 1442 w_value & 0xff); 1443 if (value >= 0) 1444 value = min (w_length, (u16) value); 1445 break; 1446 case USB_DT_STRING: 1447 goto unrecognized; 1448 1449 default: // all others are errors 1450 break; 1451 } 1452 break; 1453 1454 /* currently one config, two speeds */ 1455 case USB_REQ_SET_CONFIGURATION: 1456 if (ctrl->bRequestType != 0) 1457 break; 1458 if (0 == (u8) w_value) { 1459 value = 0; 1460 dev->current_config = 0; 1461 usb_gadget_vbus_draw(gadget, 8 /* mA */ ); 1462 // user mode expected to disable endpoints 1463 } else { 1464 u8 config, power; 1465#ifdef CONFIG_USB_GADGET_DUALSPEED 1466 if (gadget->speed == USB_SPEED_HIGH) { 1467 config = dev->hs_config->bConfigurationValue; 1468 power = dev->hs_config->bMaxPower; 1469 } else 1470#endif 1471 { 1472 config = dev->config->bConfigurationValue; 1473 power = dev->config->bMaxPower; 1474 } 1475 1476 if (config == (u8) w_value) { 1477 value = 0; 1478 dev->current_config = config; 1479 usb_gadget_vbus_draw(gadget, 2 * power); 1480 } 1481 } 1482 1483 /* report SET_CONFIGURATION like any other control request, 1484 * except that usermode may not stall this. the next 1485 * request mustn't be allowed start until this finishes: 1486 * endpoints and threads set up, etc. 1487 * 1488 * NOTE: older PXA hardware (before PXA 255: without UDCCFR) 1489 * has bad/racey automagic that prevents synchronizing here. 1490 * even kernel mode drivers often miss them. 1491 */ 1492 if (value == 0) { 1493 INFO (dev, "configuration #%d\n", dev->current_config); 1494 if (dev->usermode_setup) { 1495 dev->setup_can_stall = 0; 1496 goto delegate; 1497 } 1498 } 1499 break; 1500 1501#ifndef CONFIG_USB_GADGETFS_PXA2XX 1502 /* PXA automagically handles this request too */ 1503 case USB_REQ_GET_CONFIGURATION: 1504 if (ctrl->bRequestType != 0x80) 1505 break; 1506 *(u8 *)req->buf = dev->current_config; 1507 value = min (w_length, (u16) 1); 1508 break; 1509#endif 1510 1511 default: 1512unrecognized: 1513 VDEBUG (dev, "%s req%02x.%02x v%04x i%04x l%d\n", 1514 dev->usermode_setup ? "delegate" : "fail", 1515 ctrl->bRequestType, ctrl->bRequest, 1516 w_value, le16_to_cpu(ctrl->wIndex), w_length); 1517 1518 /* if there's an ep0 reader, don't stall */ 1519 if (dev->usermode_setup) { 1520 dev->setup_can_stall = 1; 1521delegate: 1522 dev->setup_in = (ctrl->bRequestType & USB_DIR_IN) 1523 ? 1 : 0; 1524 dev->setup_wLength = w_length; 1525 dev->setup_out_ready = 0; 1526 dev->setup_out_error = 0; 1527 value = 0; 1528 1529 /* read DATA stage for OUT right away */ 1530 if (unlikely (!dev->setup_in && w_length)) { 1531 value = setup_req (gadget->ep0, dev->req, 1532 w_length); 1533 if (value < 0) 1534 break; 1535 value = usb_ep_queue (gadget->ep0, dev->req, 1536 GFP_ATOMIC); 1537 if (value < 0) { 1538 clean_req (gadget->ep0, dev->req); 1539 break; 1540 } 1541 1542 /* we can't currently stall these */ 1543 dev->setup_can_stall = 0; 1544 } 1545 1546 /* state changes when reader collects event */ 1547 event = next_event (dev, GADGETFS_SETUP); 1548 event->u.setup = *ctrl; 1549 ep0_readable (dev); 1550 spin_unlock (&dev->lock); 1551 return 0; 1552 } 1553 } 1554 1555 /* proceed with data transfer and status phases? */ 1556 if (value >= 0 && dev->state != STATE_SETUP) { 1557 req->length = value; 1558 req->zero = value < w_length; 1559 value = usb_ep_queue (gadget->ep0, req, GFP_ATOMIC); 1560 if (value < 0) { 1561 DBG (dev, "ep_queue --> %d\n", value); 1562 req->status = 0; 1563 } 1564 } 1565 1566 /* device stalls when value < 0 */ 1567 spin_unlock (&dev->lock); 1568 return value; 1569} 1570 1571static void destroy_ep_files (struct dev_data *dev) 1572{ 1573 struct list_head *entry, *tmp; 1574 1575 DBG (dev, "%s %d\n", __FUNCTION__, dev->state); 1576 1577 /* dev->state must prevent interference */ 1578restart: 1579 spin_lock_irq (&dev->lock); 1580 list_for_each_safe (entry, tmp, &dev->epfiles) { 1581 struct ep_data *ep; 1582 struct inode *parent; 1583 struct dentry *dentry; 1584 1585 /* break link to FS */ 1586 ep = list_entry (entry, struct ep_data, epfiles); 1587 list_del_init (&ep->epfiles); 1588 dentry = ep->dentry; 1589 ep->dentry = NULL; 1590 parent = dentry->d_parent->d_inode; 1591 1592 /* break link to controller */ 1593 if (ep->state == STATE_EP_ENABLED) 1594 (void) usb_ep_disable (ep->ep); 1595 ep->state = STATE_EP_UNBOUND; 1596 usb_ep_free_request (ep->ep, ep->req); 1597 ep->ep = NULL; 1598 wake_up (&ep->wait); 1599 put_ep (ep); 1600 1601 spin_unlock_irq (&dev->lock); 1602 1603 /* break link to dcache */ 1604 mutex_lock (&parent->i_mutex); 1605 d_delete (dentry); 1606 dput (dentry); 1607 mutex_unlock (&parent->i_mutex); 1608 1609 /* fds may still be open */ 1610 goto restart; 1611 } 1612 spin_unlock_irq (&dev->lock); 1613} 1614 1615 1616static struct inode * 1617gadgetfs_create_file (struct super_block *sb, char const *name, 1618 void *data, const struct file_operations *fops, 1619 struct dentry **dentry_p); 1620 1621static int activate_ep_files (struct dev_data *dev) 1622{ 1623 struct usb_ep *ep; 1624 struct ep_data *data; 1625 1626 gadget_for_each_ep (ep, dev->gadget) { 1627 1628 data = kzalloc(sizeof(*data), GFP_KERNEL); 1629 if (!data) 1630 goto enomem0; 1631 data->state = STATE_EP_DISABLED; 1632 init_MUTEX (&data->lock); 1633 init_waitqueue_head (&data->wait); 1634 1635 strncpy (data->name, ep->name, sizeof (data->name) - 1); 1636 atomic_set (&data->count, 1); 1637 data->dev = dev; 1638 get_dev (dev); 1639 1640 data->ep = ep; 1641 ep->driver_data = data; 1642 1643 data->req = usb_ep_alloc_request (ep, GFP_KERNEL); 1644 if (!data->req) 1645 goto enomem1; 1646 1647 data->inode = gadgetfs_create_file (dev->sb, data->name, 1648 data, &ep_config_operations, 1649 &data->dentry); 1650 if (!data->inode) 1651 goto enomem2; 1652 list_add_tail (&data->epfiles, &dev->epfiles); 1653 } 1654 return 0; 1655 1656enomem2: 1657 usb_ep_free_request (ep, data->req); 1658enomem1: 1659 put_dev (dev); 1660 kfree (data); 1661enomem0: 1662 DBG (dev, "%s enomem\n", __FUNCTION__); 1663 destroy_ep_files (dev); 1664 return -ENOMEM; 1665} 1666 1667static void 1668gadgetfs_unbind (struct usb_gadget *gadget) 1669{ 1670 struct dev_data *dev = get_gadget_data (gadget); 1671 1672 DBG (dev, "%s\n", __FUNCTION__); 1673 1674 spin_lock_irq (&dev->lock); 1675 dev->state = STATE_DEV_UNBOUND; 1676 spin_unlock_irq (&dev->lock); 1677 1678 destroy_ep_files (dev); 1679 gadget->ep0->driver_data = NULL; 1680 set_gadget_data (gadget, NULL); 1681 1682 /* we've already been disconnected ... no i/o is active */ 1683 if (dev->req) 1684 usb_ep_free_request (gadget->ep0, dev->req); 1685 DBG (dev, "%s done\n", __FUNCTION__); 1686 put_dev (dev); 1687} 1688 1689static struct dev_data *the_device; 1690 1691static int 1692gadgetfs_bind (struct usb_gadget *gadget) 1693{ 1694 struct dev_data *dev = the_device; 1695 1696 if (!dev) 1697 return -ESRCH; 1698 if (0 != strcmp (CHIP, gadget->name)) { 1699 printk (KERN_ERR "%s expected %s controller not %s\n", 1700 shortname, CHIP, gadget->name); 1701 return -ENODEV; 1702 } 1703 1704 set_gadget_data (gadget, dev); 1705 dev->gadget = gadget; 1706 gadget->ep0->driver_data = dev; 1707 dev->dev->bMaxPacketSize0 = gadget->ep0->maxpacket; 1708 1709 /* preallocate control response and buffer */ 1710 dev->req = usb_ep_alloc_request (gadget->ep0, GFP_KERNEL); 1711 if (!dev->req) 1712 goto enomem; 1713 dev->req->context = NULL; 1714 dev->req->complete = epio_complete; 1715 1716 if (activate_ep_files (dev) < 0) 1717 goto enomem; 1718 1719 INFO (dev, "bound to %s driver\n", gadget->name); 1720 dev->state = STATE_UNCONNECTED; 1721 get_dev (dev); 1722 return 0; 1723 1724enomem: 1725 gadgetfs_unbind (gadget); 1726 return -ENOMEM; 1727} 1728 1729static void 1730gadgetfs_disconnect (struct usb_gadget *gadget) 1731{ 1732 struct dev_data *dev = get_gadget_data (gadget); 1733 1734 spin_lock (&dev->lock); 1735 if (dev->state == STATE_UNCONNECTED) { 1736 DBG (dev, "already unconnected\n"); 1737 goto exit; 1738 } 1739 dev->state = STATE_UNCONNECTED; 1740 1741 INFO (dev, "disconnected\n"); 1742 next_event (dev, GADGETFS_DISCONNECT); 1743 ep0_readable (dev); 1744exit: 1745 spin_unlock (&dev->lock); 1746} 1747 1748static void 1749gadgetfs_suspend (struct usb_gadget *gadget) 1750{ 1751 struct dev_data *dev = get_gadget_data (gadget); 1752 1753 INFO (dev, "suspended from state %d\n", dev->state); 1754 spin_lock (&dev->lock); 1755 switch (dev->state) { 1756 case STATE_SETUP: // VERY odd... host died?? 1757 case STATE_CONNECTED: 1758 case STATE_UNCONNECTED: 1759 next_event (dev, GADGETFS_SUSPEND); 1760 ep0_readable (dev); 1761 /* FALLTHROUGH */ 1762 default: 1763 break; 1764 } 1765 spin_unlock (&dev->lock); 1766} 1767 1768static struct usb_gadget_driver gadgetfs_driver = { 1769#ifdef CONFIG_USB_GADGET_DUALSPEED 1770 .speed = USB_SPEED_HIGH, 1771#else 1772 .speed = USB_SPEED_FULL, 1773#endif 1774 .function = (char *) driver_desc, 1775 .bind = gadgetfs_bind, 1776 .unbind = gadgetfs_unbind, 1777 .setup = gadgetfs_setup, 1778 .disconnect = gadgetfs_disconnect, 1779 .suspend = gadgetfs_suspend, 1780 1781 .driver = { 1782 .name = (char *) shortname, 1783 }, 1784}; 1785 1786/*----------------------------------------------------------------------*/ 1787 1788static void gadgetfs_nop(struct usb_gadget *arg) { } 1789 1790static int gadgetfs_probe (struct usb_gadget *gadget) 1791{ 1792 CHIP = gadget->name; 1793 return -EISNAM; 1794} 1795 1796static struct usb_gadget_driver probe_driver = { 1797 .speed = USB_SPEED_HIGH, 1798 .bind = gadgetfs_probe, 1799 .unbind = gadgetfs_nop, 1800 .setup = (void *)gadgetfs_nop, 1801 .disconnect = gadgetfs_nop, 1802 .driver = { 1803 .name = "nop", 1804 }, 1805}; 1806 1807 1808/* DEVICE INITIALIZATION 1809 * 1810 * fd = open ("/dev/gadget/$CHIP", O_RDWR) 1811 * status = write (fd, descriptors, sizeof descriptors) 1812 * 1813 * That write establishes the device configuration, so the kernel can 1814 * bind to the controller ... guaranteeing it can handle enumeration 1815 * at all necessary speeds. Descriptor order is: 1816 * 1817 * . message tag (u32, host order) ... for now, must be zero; it 1818 * would change to support features like multi-config devices 1819 * . full/low speed config ... all wTotalLength bytes (with interface, 1820 * class, altsetting, endpoint, and other descriptors) 1821 * . high speed config ... all descriptors, for high speed operation; 1822 * this one's optional except for high-speed hardware 1823 * . device descriptor 1824 * 1825 * Endpoints are not yet enabled. Drivers may want to immediately 1826 * initialize them, using the /dev/gadget/ep* files that are available 1827 * as soon as the kernel sees the configuration, or they can wait 1828 * until device 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 may then be read from that descriptor, 1833 * such as configuration notifications. More complex drivers will handle 1834 * some control requests in user space. 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 (dev->state != STATE_OPENED) 1858 return -EEXIST; 1859 1860 if (len < (USB_DT_CONFIG_SIZE + USB_DT_DEVICE_SIZE + 4)) 1861 return -EINVAL; 1862 1863 /* we might need to change message format someday */ 1864 if (copy_from_user (&tag, buf, 4)) 1865 return -EFAULT; 1866 if (tag != 0) 1867 return -EINVAL; 1868 buf += 4; 1869 length -= 4; 1870 1871 kbuf = kmalloc (length, SLAB_KERNEL); 1872 if (!kbuf) 1873 return -ENOMEM; 1874 if (copy_from_user (kbuf, buf, length)) { 1875 kfree (kbuf); 1876 return -EFAULT; 1877 } 1878 1879 spin_lock_irq (&dev->lock); 1880 value = -EINVAL; 1881 if (dev->buf) 1882 goto fail; 1883 dev->buf = kbuf; 1884 1885 /* full or low speed config */ 1886 dev->config = (void *) kbuf; 1887 total = le16_to_cpup (&dev->config->wTotalLength); 1888 if (!is_valid_config (dev->config) || total >= length) 1889 goto fail; 1890 kbuf += total; 1891 length -= total; 1892 1893 /* optional high speed config */ 1894 if (kbuf [1] == USB_DT_CONFIG) { 1895 dev->hs_config = (void *) kbuf; 1896 total = le16_to_cpup (&dev->hs_config->wTotalLength); 1897 if (!is_valid_config (dev->hs_config) || total >= length) 1898 goto fail; 1899 kbuf += total; 1900 length -= total; 1901 } 1902 1903 /* could support multiple configs, using another encoding! */ 1904 1905 /* device descriptor (tweaked for paranoia) */ 1906 if (length != USB_DT_DEVICE_SIZE) 1907 goto fail; 1908 dev->dev = (void *)kbuf; 1909 if (dev->dev->bLength != USB_DT_DEVICE_SIZE 1910 || dev->dev->bDescriptorType != USB_DT_DEVICE 1911 || dev->dev->bNumConfigurations != 1) 1912 goto fail; 1913 dev->dev->bNumConfigurations = 1; 1914 dev->dev->bcdUSB = __constant_cpu_to_le16 (0x0200); 1915 1916 /* triggers gadgetfs_bind(); then we can enumerate. */ 1917 spin_unlock_irq (&dev->lock); 1918 value = usb_gadget_register_driver (&gadgetfs_driver); 1919 if (value != 0) { 1920 kfree (dev->buf); 1921 dev->buf = NULL; 1922 } else { 1923 /* at this point "good" hardware has for the first time 1924 * let the USB the host see us. alternatively, if users 1925 * unplug/replug that will clear all the error state. 1926 * 1927 * note: everything running before here was guaranteed 1928 * to choke driver model style diagnostics. from here 1929 * on, they can work ... except in cleanup paths that 1930 * kick in after the ep0 descriptor is closed. 1931 */ 1932 fd->f_op = &ep0_io_operations; 1933 value = len; 1934 } 1935 return value; 1936 1937fail: 1938 spin_unlock_irq (&dev->lock); 1939 pr_debug ("%s: %s fail %Zd, %p\n", shortname, __FUNCTION__, value, dev); 1940 kfree (dev->buf); 1941 dev->buf = NULL; 1942 return value; 1943} 1944 1945static int 1946dev_open (struct inode *inode, struct file *fd) 1947{ 1948 struct dev_data *dev = inode->i_private; 1949 int value = -EBUSY; 1950 1951 if (dev->state == STATE_DEV_DISABLED) { 1952 dev->ev_next = 0; 1953 dev->state = STATE_OPENED; 1954 fd->private_data = dev; 1955 get_dev (dev); 1956 value = 0; 1957 } 1958 return value; 1959} 1960 1961static const struct file_operations dev_init_operations = { 1962 .owner = THIS_MODULE, 1963 .llseek = no_llseek, 1964 1965 .open = dev_open, 1966 .write = dev_config, 1967 .fasync = ep0_fasync, 1968 .ioctl = dev_ioctl, 1969 .release = dev_release, 1970}; 1971 1972/*----------------------------------------------------------------------*/ 1973 1974/* FILESYSTEM AND SUPERBLOCK OPERATIONS 1975 * 1976 * Mounting the filesystem creates a controller file, used first for 1977 * device configuration then later for event monitoring. 1978 */ 1979 1980 1981/* FIXME PAM etc could set this security policy without mount options 1982 * if epfiles inherited ownership and permissons from ep0 ... 1983 */ 1984 1985static unsigned default_uid; 1986static unsigned default_gid; 1987static unsigned default_perm = S_IRUSR | S_IWUSR; 1988 1989module_param (default_uid, uint, 0644); 1990module_param (default_gid, uint, 0644); 1991module_param (default_perm, uint, 0644); 1992 1993 1994static struct inode * 1995gadgetfs_make_inode (struct super_block *sb, 1996 void *data, const struct file_operations *fops, 1997 int mode) 1998{ 1999 struct inode *inode = new_inode (sb); 2000 2001 if (inode) { 2002 inode->i_mode = mode; 2003 inode->i_uid = default_uid; 2004 inode->i_gid = default_gid; 2005 inode->i_blocks = 0; 2006 inode->i_atime = inode->i_mtime = inode->i_ctime 2007 = CURRENT_TIME; 2008 inode->i_private = data; 2009 inode->i_fop = fops; 2010 } 2011 return inode; 2012} 2013 2014/* creates in fs root directory, so non-renamable and non-linkable. 2015 * so inode and dentry are paired, until device reconfig. 2016 */ 2017static struct inode * 2018gadgetfs_create_file (struct super_block *sb, char const *name, 2019 void *data, const struct file_operations *fops, 2020 struct dentry **dentry_p) 2021{ 2022 struct dentry *dentry; 2023 struct inode *inode; 2024 2025 dentry = d_alloc_name(sb->s_root, name); 2026 if (!dentry) 2027 return NULL; 2028 2029 inode = gadgetfs_make_inode (sb, data, fops, 2030 S_IFREG | (default_perm & S_IRWXUGO)); 2031 if (!inode) { 2032 dput(dentry); 2033 return NULL; 2034 } 2035 d_add (dentry, inode); 2036 *dentry_p = dentry; 2037 return inode; 2038} 2039 2040static struct super_operations gadget_fs_operations = { 2041 .statfs = simple_statfs, 2042 .drop_inode = generic_delete_inode, 2043}; 2044 2045static int 2046gadgetfs_fill_super (struct super_block *sb, void *opts, int silent) 2047{ 2048 struct inode *inode; 2049 struct dentry *d; 2050 struct dev_data *dev; 2051 2052 if (the_device) 2053 return -ESRCH; 2054 2055 /* fake probe to determine $CHIP */ 2056 (void) usb_gadget_register_driver (&probe_driver); 2057 if (!CHIP) 2058 return -ENODEV; 2059 2060 /* superblock */ 2061 sb->s_blocksize = PAGE_CACHE_SIZE; 2062 sb->s_blocksize_bits = PAGE_CACHE_SHIFT; 2063 sb->s_magic = GADGETFS_MAGIC; 2064 sb->s_op = &gadget_fs_operations; 2065 sb->s_time_gran = 1; 2066 2067 /* root inode */ 2068 inode = gadgetfs_make_inode (sb, 2069 NULL, &simple_dir_operations, 2070 S_IFDIR | S_IRUGO | S_IXUGO); 2071 if (!inode) 2072 goto enomem0; 2073 inode->i_op = &simple_dir_inode_operations; 2074 if (!(d = d_alloc_root (inode))) 2075 goto enomem1; 2076 sb->s_root = d; 2077 2078 /* the ep0 file is named after the controller we expect; 2079 * user mode code can use it for sanity checks, like we do. 2080 */ 2081 dev = dev_new (); 2082 if (!dev) 2083 goto enomem2; 2084 2085 dev->sb = sb; 2086 if (!gadgetfs_create_file (sb, CHIP, 2087 dev, &dev_init_operations, 2088 &dev->dentry)) 2089 goto enomem3; 2090 2091 /* other endpoint files are available after hardware setup, 2092 * from binding to a controller. 2093 */ 2094 the_device = dev; 2095 return 0; 2096 2097enomem3: 2098 put_dev (dev); 2099enomem2: 2100 dput (d); 2101enomem1: 2102 iput (inode); 2103enomem0: 2104 return -ENOMEM; 2105} 2106 2107/* "mount -t gadgetfs path /dev/gadget" ends up here */ 2108static int 2109gadgetfs_get_sb (struct file_system_type *t, int flags, 2110 const char *path, void *opts, struct vfsmount *mnt) 2111{ 2112 return get_sb_single (t, flags, opts, gadgetfs_fill_super, mnt); 2113} 2114 2115static void 2116gadgetfs_kill_sb (struct super_block *sb) 2117{ 2118 kill_litter_super (sb); 2119 if (the_device) { 2120 put_dev (the_device); 2121 the_device = NULL; 2122 } 2123} 2124 2125/*----------------------------------------------------------------------*/ 2126 2127static struct file_system_type gadgetfs_type = { 2128 .owner = THIS_MODULE, 2129 .name = shortname, 2130 .get_sb = gadgetfs_get_sb, 2131 .kill_sb = gadgetfs_kill_sb, 2132}; 2133 2134/*----------------------------------------------------------------------*/ 2135 2136static int __init init (void) 2137{ 2138 int status; 2139 2140 status = register_filesystem (&gadgetfs_type); 2141 if (status == 0) 2142 pr_info ("%s: %s, version " DRIVER_VERSION "\n", 2143 shortname, driver_desc); 2144 return status; 2145} 2146module_init (init); 2147 2148static void __exit cleanup (void) 2149{ 2150 pr_debug ("unregister %s\n", shortname); 2151 unregister_filesystem (&gadgetfs_type); 2152} 2153module_exit (cleanup); 2154 2155