inode.c revision 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2
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 36#include <linux/device.h> 37#include <linux/moduleparam.h> 38 39#include <linux/usb_gadgetfs.h> 40#include <linux/usb_gadget.h> 41 42 43/* 44 * The gadgetfs API maps each endpoint to a file descriptor so that you 45 * can use standard synchronous read/write calls for I/O. There's some 46 * O_NONBLOCK and O_ASYNC/FASYNC style i/o support. Example usermode 47 * drivers show how this works in practice. You can also use AIO to 48 * eliminate I/O gaps between requests, to help when streaming data. 49 * 50 * Key parts that must be USB-specific are protocols defining how the 51 * read/write operations relate to the hardware state machines. There 52 * are two types of files. One type is for the device, implementing ep0. 53 * The other type is for each IN or OUT endpoint. In both cases, the 54 * user mode driver must configure the hardware before using it. 55 * 56 * - First, dev_config() is called when /dev/gadget/$CHIP is configured 57 * (by writing configuration and device descriptors). Afterwards it 58 * may serve as a source of device events, used to handle all control 59 * requests other than basic enumeration. 60 * 61 * - Then either immediately, or after a SET_CONFIGURATION control request, 62 * ep_config() is called when each /dev/gadget/ep* file is configured 63 * (by writing endpoint descriptors). Afterwards these files are used 64 * to write() IN data or to read() OUT data. To halt the endpoint, a 65 * "wrong direction" request is issued (like reading an IN endpoint). 66 * 67 * Unlike "usbfs" the only ioctl()s are for things that are rare, and maybe 68 * not possible on all hardware. For example, precise fault handling with 69 * respect to data left in endpoint fifos after aborted operations; or 70 * selective clearing of endpoint halts, to implement SET_INTERFACE. 71 */ 72 73#define DRIVER_DESC "USB Gadget filesystem" 74#define DRIVER_VERSION "24 Aug 2004" 75 76static const char driver_desc [] = DRIVER_DESC; 77static const char shortname [] = "gadgetfs"; 78 79MODULE_DESCRIPTION (DRIVER_DESC); 80MODULE_AUTHOR ("David Brownell"); 81MODULE_LICENSE ("GPL"); 82 83 84/*----------------------------------------------------------------------*/ 85 86#define GADGETFS_MAGIC 0xaee71ee7 87#define DMA_ADDR_INVALID (~(dma_addr_t)0) 88 89/* /dev/gadget/$CHIP represents ep0 and the whole device */ 90enum ep0_state { 91 /* DISBLED is the initial state. 92 */ 93 STATE_DEV_DISABLED = 0, 94 95 /* Only one open() of /dev/gadget/$CHIP; only one file tracks 96 * ep0/device i/o modes and binding to the controller. Driver 97 * must always write descriptors to initialize the device, then 98 * the device becomes UNCONNECTED until enumeration. 99 */ 100 STATE_OPENED, 101 102 /* From then on, ep0 fd is in either of two basic modes: 103 * - (UN)CONNECTED: read usb_gadgetfs_event(s) from it 104 * - SETUP: read/write will transfer control data and succeed; 105 * or if "wrong direction", performs protocol stall 106 */ 107 STATE_UNCONNECTED, 108 STATE_CONNECTED, 109 STATE_SETUP, 110 111 /* UNBOUND means the driver closed ep0, so the device won't be 112 * accessible again (DEV_DISABLED) until all fds are closed. 113 */ 114 STATE_DEV_UNBOUND, 115}; 116 117/* enough for the whole queue: most events invalidate others */ 118#define N_EVENT 5 119 120struct dev_data { 121 spinlock_t lock; 122 atomic_t count; 123 enum ep0_state state; 124 struct usb_gadgetfs_event event [N_EVENT]; 125 unsigned ev_next; 126 struct fasync_struct *fasync; 127 u8 current_config; 128 129 /* drivers reading ep0 MUST handle control requests (SETUP) 130 * reported that way; else the host will time out. 131 */ 132 unsigned usermode_setup : 1, 133 setup_in : 1, 134 setup_can_stall : 1, 135 setup_out_ready : 1, 136 setup_out_error : 1, 137 setup_abort : 1; 138 139 /* the rest is basically write-once */ 140 struct usb_config_descriptor *config, *hs_config; 141 struct usb_device_descriptor *dev; 142 struct usb_request *req; 143 struct usb_gadget *gadget; 144 struct list_head epfiles; 145 void *buf; 146 wait_queue_head_t wait; 147 struct super_block *sb; 148 struct dentry *dentry; 149 150 /* except this scratch i/o buffer for ep0 */ 151 u8 rbuf [256]; 152}; 153 154static inline void get_dev (struct dev_data *data) 155{ 156 atomic_inc (&data->count); 157} 158 159static void put_dev (struct dev_data *data) 160{ 161 if (likely (!atomic_dec_and_test (&data->count))) 162 return; 163 /* needs no more cleanup */ 164 BUG_ON (waitqueue_active (&data->wait)); 165 kfree (data); 166} 167 168static struct dev_data *dev_new (void) 169{ 170 struct dev_data *dev; 171 172 dev = kmalloc (sizeof *dev, GFP_KERNEL); 173 if (!dev) 174 return NULL; 175 memset (dev, 0, sizeof *dev); 176 dev->state = STATE_DEV_DISABLED; 177 atomic_set (&dev->count, 1); 178 spin_lock_init (&dev->lock); 179 INIT_LIST_HEAD (&dev->epfiles); 180 init_waitqueue_head (&dev->wait); 181 return dev; 182} 183 184/*----------------------------------------------------------------------*/ 185 186/* other /dev/gadget/$ENDPOINT files represent endpoints */ 187enum ep_state { 188 STATE_EP_DISABLED = 0, 189 STATE_EP_READY, 190 STATE_EP_DEFER_ENABLE, 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 BUG_ON (down_trylock (&data->lock) != 0); 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 cancelation. 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 %d OUT, status %d\n", 421 data->name, len, 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 %d IN, status %d\n", 469 data->name, len, 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; 480 481 /* clean up if this can be reopened */ 482 if (data->state != STATE_EP_UNBOUND) { 483 data->state = STATE_EP_DISABLED; 484 data->desc.bDescriptorType = 0; 485 data->hs_desc.bDescriptorType = 0; 486 } 487 put_ep (data); 488 return 0; 489} 490 491static int ep_ioctl (struct inode *inode, struct file *fd, 492 unsigned code, unsigned long value) 493{ 494 struct ep_data *data = fd->private_data; 495 int status; 496 497 if ((status = get_ready_ep (fd->f_flags, data)) < 0) 498 return status; 499 500 spin_lock_irq (&data->dev->lock); 501 if (likely (data->ep != NULL)) { 502 switch (code) { 503 case GADGETFS_FIFO_STATUS: 504 status = usb_ep_fifo_status (data->ep); 505 break; 506 case GADGETFS_FIFO_FLUSH: 507 usb_ep_fifo_flush (data->ep); 508 break; 509 case GADGETFS_CLEAR_HALT: 510 status = usb_ep_clear_halt (data->ep); 511 break; 512 default: 513 status = -ENOTTY; 514 } 515 } else 516 status = -ENODEV; 517 spin_unlock_irq (&data->dev->lock); 518 up (&data->lock); 519 return status; 520} 521 522/*----------------------------------------------------------------------*/ 523 524/* ASYNCHRONOUS ENDPOINT I/O OPERATIONS (bulk/intr/iso) */ 525 526struct kiocb_priv { 527 struct usb_request *req; 528 struct ep_data *epdata; 529 void *buf; 530 char __user *ubuf; 531 unsigned actual; 532}; 533 534static int ep_aio_cancel(struct kiocb *iocb, struct io_event *e) 535{ 536 struct kiocb_priv *priv = iocb->private; 537 struct ep_data *epdata; 538 int value; 539 540 local_irq_disable(); 541 epdata = priv->epdata; 542 // spin_lock(&epdata->dev->lock); 543 kiocbSetCancelled(iocb); 544 if (likely(epdata && epdata->ep && priv->req)) 545 value = usb_ep_dequeue (epdata->ep, priv->req); 546 else 547 value = -EINVAL; 548 // spin_unlock(&epdata->dev->lock); 549 local_irq_enable(); 550 551 aio_put_req(iocb); 552 return value; 553} 554 555static ssize_t ep_aio_read_retry(struct kiocb *iocb) 556{ 557 struct kiocb_priv *priv = iocb->private; 558 ssize_t status = priv->actual; 559 560 /* we "retry" to get the right mm context for this: */ 561 status = copy_to_user(priv->ubuf, priv->buf, priv->actual); 562 if (unlikely(0 != status)) 563 status = -EFAULT; 564 else 565 status = priv->actual; 566 kfree(priv->buf); 567 kfree(priv); 568 aio_put_req(iocb); 569 return status; 570} 571 572static void ep_aio_complete(struct usb_ep *ep, struct usb_request *req) 573{ 574 struct kiocb *iocb = req->context; 575 struct kiocb_priv *priv = iocb->private; 576 struct ep_data *epdata = priv->epdata; 577 578 /* lock against disconnect (and ideally, cancel) */ 579 spin_lock(&epdata->dev->lock); 580 priv->req = NULL; 581 priv->epdata = NULL; 582 if (NULL == iocb->ki_retry 583 || unlikely(0 == req->actual) 584 || unlikely(kiocbIsCancelled(iocb))) { 585 kfree(req->buf); 586 kfree(priv); 587 iocb->private = NULL; 588 /* aio_complete() reports bytes-transferred _and_ faults */ 589 if (unlikely(kiocbIsCancelled(iocb))) 590 aio_put_req(iocb); 591 else 592 aio_complete(iocb, 593 req->actual ? req->actual : req->status, 594 req->status); 595 } else { 596 /* retry() won't report both; so we hide some faults */ 597 if (unlikely(0 != req->status)) 598 DBG(epdata->dev, "%s fault %d len %d\n", 599 ep->name, req->status, req->actual); 600 601 priv->buf = req->buf; 602 priv->actual = req->actual; 603 kick_iocb(iocb); 604 } 605 spin_unlock(&epdata->dev->lock); 606 607 usb_ep_free_request(ep, req); 608 put_ep(epdata); 609} 610 611static ssize_t 612ep_aio_rwtail( 613 struct kiocb *iocb, 614 char *buf, 615 size_t len, 616 struct ep_data *epdata, 617 char __user *ubuf 618) 619{ 620 struct kiocb_priv *priv = (void *) &iocb->private; 621 struct usb_request *req; 622 ssize_t value; 623 624 priv = kmalloc(sizeof *priv, GFP_KERNEL); 625 if (!priv) { 626 value = -ENOMEM; 627fail: 628 kfree(buf); 629 return value; 630 } 631 iocb->private = priv; 632 priv->ubuf = ubuf; 633 634 value = get_ready_ep(iocb->ki_filp->f_flags, epdata); 635 if (unlikely(value < 0)) { 636 kfree(priv); 637 goto fail; 638 } 639 640 iocb->ki_cancel = ep_aio_cancel; 641 get_ep(epdata); 642 priv->epdata = epdata; 643 priv->actual = 0; 644 645 /* each kiocb is coupled to one usb_request, but we can't 646 * allocate or submit those if the host disconnected. 647 */ 648 spin_lock_irq(&epdata->dev->lock); 649 if (likely(epdata->ep)) { 650 req = usb_ep_alloc_request(epdata->ep, GFP_ATOMIC); 651 if (likely(req)) { 652 priv->req = req; 653 req->buf = buf; 654 req->length = len; 655 req->complete = ep_aio_complete; 656 req->context = iocb; 657 value = usb_ep_queue(epdata->ep, req, GFP_ATOMIC); 658 if (unlikely(0 != value)) 659 usb_ep_free_request(epdata->ep, req); 660 } else 661 value = -EAGAIN; 662 } else 663 value = -ENODEV; 664 spin_unlock_irq(&epdata->dev->lock); 665 666 up(&epdata->lock); 667 668 if (unlikely(value)) { 669 kfree(priv); 670 put_ep(epdata); 671 } else 672 value = -EIOCBQUEUED; 673 return value; 674} 675 676static ssize_t 677ep_aio_read(struct kiocb *iocb, char __user *ubuf, size_t len, loff_t o) 678{ 679 struct ep_data *epdata = iocb->ki_filp->private_data; 680 char *buf; 681 682 if (unlikely(epdata->desc.bEndpointAddress & USB_DIR_IN)) 683 return -EINVAL; 684 buf = kmalloc(len, GFP_KERNEL); 685 if (unlikely(!buf)) 686 return -ENOMEM; 687 iocb->ki_retry = ep_aio_read_retry; 688 return ep_aio_rwtail(iocb, buf, len, epdata, ubuf); 689} 690 691static ssize_t 692ep_aio_write(struct kiocb *iocb, const char __user *ubuf, size_t len, loff_t o) 693{ 694 struct ep_data *epdata = iocb->ki_filp->private_data; 695 char *buf; 696 697 if (unlikely(!(epdata->desc.bEndpointAddress & USB_DIR_IN))) 698 return -EINVAL; 699 buf = kmalloc(len, GFP_KERNEL); 700 if (unlikely(!buf)) 701 return -ENOMEM; 702 if (unlikely(copy_from_user(buf, ubuf, len) != 0)) { 703 kfree(buf); 704 return -EFAULT; 705 } 706 return ep_aio_rwtail(iocb, buf, len, epdata, NULL); 707} 708 709/*----------------------------------------------------------------------*/ 710 711/* used after endpoint configuration */ 712static struct file_operations ep_io_operations = { 713 .owner = THIS_MODULE, 714 .llseek = no_llseek, 715 716 .read = ep_read, 717 .write = ep_write, 718 .ioctl = ep_ioctl, 719 .release = ep_release, 720 721 .aio_read = ep_aio_read, 722 .aio_write = ep_aio_write, 723}; 724 725/* ENDPOINT INITIALIZATION 726 * 727 * fd = open ("/dev/gadget/$ENDPOINT", O_RDWR) 728 * status = write (fd, descriptors, sizeof descriptors) 729 * 730 * That write establishes the endpoint configuration, configuring 731 * the controller to process bulk, interrupt, or isochronous transfers 732 * at the right maxpacket size, and so on. 733 * 734 * The descriptors are message type 1, identified by a host order u32 735 * at the beginning of what's written. Descriptor order is: full/low 736 * speed descriptor, then optional high speed descriptor. 737 */ 738static ssize_t 739ep_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr) 740{ 741 struct ep_data *data = fd->private_data; 742 struct usb_ep *ep; 743 u32 tag; 744 int value; 745 746 if ((value = down_interruptible (&data->lock)) < 0) 747 return value; 748 749 if (data->state != STATE_EP_READY) { 750 value = -EL2HLT; 751 goto fail; 752 } 753 754 value = len; 755 if (len < USB_DT_ENDPOINT_SIZE + 4) 756 goto fail0; 757 758 /* we might need to change message format someday */ 759 if (copy_from_user (&tag, buf, 4)) { 760 goto fail1; 761 } 762 if (tag != 1) { 763 DBG(data->dev, "config %s, bad tag %d\n", data->name, tag); 764 goto fail0; 765 } 766 buf += 4; 767 len -= 4; 768 769 /* NOTE: audio endpoint extensions not accepted here; 770 * just don't include the extra bytes. 771 */ 772 773 /* full/low speed descriptor, then high speed */ 774 if (copy_from_user (&data->desc, buf, USB_DT_ENDPOINT_SIZE)) { 775 goto fail1; 776 } 777 if (data->desc.bLength != USB_DT_ENDPOINT_SIZE 778 || data->desc.bDescriptorType != USB_DT_ENDPOINT) 779 goto fail0; 780 if (len != USB_DT_ENDPOINT_SIZE) { 781 if (len != 2 * USB_DT_ENDPOINT_SIZE) 782 goto fail0; 783 if (copy_from_user (&data->hs_desc, buf + USB_DT_ENDPOINT_SIZE, 784 USB_DT_ENDPOINT_SIZE)) { 785 goto fail1; 786 } 787 if (data->hs_desc.bLength != USB_DT_ENDPOINT_SIZE 788 || data->hs_desc.bDescriptorType 789 != USB_DT_ENDPOINT) { 790 DBG(data->dev, "config %s, bad hs length or type\n", 791 data->name); 792 goto fail0; 793 } 794 } 795 value = len; 796 797 spin_lock_irq (&data->dev->lock); 798 if (data->dev->state == STATE_DEV_UNBOUND) { 799 value = -ENOENT; 800 goto gone; 801 } else if ((ep = data->ep) == NULL) { 802 value = -ENODEV; 803 goto gone; 804 } 805 switch (data->dev->gadget->speed) { 806 case USB_SPEED_LOW: 807 case USB_SPEED_FULL: 808 value = usb_ep_enable (ep, &data->desc); 809 if (value == 0) 810 data->state = STATE_EP_ENABLED; 811 break; 812#ifdef HIGHSPEED 813 case USB_SPEED_HIGH: 814 /* fails if caller didn't provide that descriptor... */ 815 value = usb_ep_enable (ep, &data->hs_desc); 816 if (value == 0) 817 data->state = STATE_EP_ENABLED; 818 break; 819#endif 820 default: 821 DBG (data->dev, "unconnected, %s init deferred\n", 822 data->name); 823 data->state = STATE_EP_DEFER_ENABLE; 824 } 825 if (value == 0) 826 fd->f_op = &ep_io_operations; 827gone: 828 spin_unlock_irq (&data->dev->lock); 829 if (value < 0) { 830fail: 831 data->desc.bDescriptorType = 0; 832 data->hs_desc.bDescriptorType = 0; 833 } 834 up (&data->lock); 835 return value; 836fail0: 837 value = -EINVAL; 838 goto fail; 839fail1: 840 value = -EFAULT; 841 goto fail; 842} 843 844static int 845ep_open (struct inode *inode, struct file *fd) 846{ 847 struct ep_data *data = inode->u.generic_ip; 848 int value = -EBUSY; 849 850 if (down_interruptible (&data->lock) != 0) 851 return -EINTR; 852 spin_lock_irq (&data->dev->lock); 853 if (data->dev->state == STATE_DEV_UNBOUND) 854 value = -ENOENT; 855 else if (data->state == STATE_EP_DISABLED) { 856 value = 0; 857 data->state = STATE_EP_READY; 858 get_ep (data); 859 fd->private_data = data; 860 VDEBUG (data->dev, "%s ready\n", data->name); 861 } else 862 DBG (data->dev, "%s state %d\n", 863 data->name, data->state); 864 spin_unlock_irq (&data->dev->lock); 865 up (&data->lock); 866 return value; 867} 868 869/* used before endpoint configuration */ 870static struct file_operations ep_config_operations = { 871 .owner = THIS_MODULE, 872 .llseek = no_llseek, 873 874 .open = ep_open, 875 .write = ep_config, 876 .release = ep_release, 877}; 878 879/*----------------------------------------------------------------------*/ 880 881/* EP0 IMPLEMENTATION can be partly in userspace. 882 * 883 * Drivers that use this facility receive various events, including 884 * control requests the kernel doesn't handle. Drivers that don't 885 * use this facility may be too simple-minded for real applications. 886 */ 887 888static inline void ep0_readable (struct dev_data *dev) 889{ 890 wake_up (&dev->wait); 891 kill_fasync (&dev->fasync, SIGIO, POLL_IN); 892} 893 894static void clean_req (struct usb_ep *ep, struct usb_request *req) 895{ 896 struct dev_data *dev = ep->driver_data; 897 898 if (req->buf != dev->rbuf) { 899 usb_ep_free_buffer (ep, req->buf, req->dma, req->length); 900 req->buf = dev->rbuf; 901 req->dma = DMA_ADDR_INVALID; 902 } 903 req->complete = epio_complete; 904 dev->setup_out_ready = 0; 905} 906 907static void ep0_complete (struct usb_ep *ep, struct usb_request *req) 908{ 909 struct dev_data *dev = ep->driver_data; 910 int free = 1; 911 912 /* for control OUT, data must still get to userspace */ 913 if (!dev->setup_in) { 914 dev->setup_out_error = (req->status != 0); 915 if (!dev->setup_out_error) 916 free = 0; 917 dev->setup_out_ready = 1; 918 ep0_readable (dev); 919 } else if (dev->state == STATE_SETUP) 920 dev->state = STATE_CONNECTED; 921 922 /* clean up as appropriate */ 923 if (free && req->buf != &dev->rbuf) 924 clean_req (ep, req); 925 req->complete = epio_complete; 926} 927 928static int setup_req (struct usb_ep *ep, struct usb_request *req, u16 len) 929{ 930 struct dev_data *dev = ep->driver_data; 931 932 if (dev->setup_out_ready) { 933 DBG (dev, "ep0 request busy!\n"); 934 return -EBUSY; 935 } 936 if (len > sizeof (dev->rbuf)) 937 req->buf = usb_ep_alloc_buffer (ep, len, &req->dma, GFP_ATOMIC); 938 if (req->buf == 0) { 939 req->buf = dev->rbuf; 940 return -ENOMEM; 941 } 942 req->complete = ep0_complete; 943 req->length = len; 944 return 0; 945} 946 947static ssize_t 948ep0_read (struct file *fd, char __user *buf, size_t len, loff_t *ptr) 949{ 950 struct dev_data *dev = fd->private_data; 951 ssize_t retval; 952 enum ep0_state state; 953 954 spin_lock_irq (&dev->lock); 955 956 /* report fd mode change before acting on it */ 957 if (dev->setup_abort) { 958 dev->setup_abort = 0; 959 retval = -EIDRM; 960 goto done; 961 } 962 963 /* control DATA stage */ 964 if ((state = dev->state) == STATE_SETUP) { 965 966 if (dev->setup_in) { /* stall IN */ 967 VDEBUG(dev, "ep0in stall\n"); 968 (void) usb_ep_set_halt (dev->gadget->ep0); 969 retval = -EL2HLT; 970 dev->state = STATE_CONNECTED; 971 972 } else if (len == 0) { /* ack SET_CONFIGURATION etc */ 973 struct usb_ep *ep = dev->gadget->ep0; 974 struct usb_request *req = dev->req; 975 976 if ((retval = setup_req (ep, req, 0)) == 0) 977 retval = usb_ep_queue (ep, req, GFP_ATOMIC); 978 dev->state = STATE_CONNECTED; 979 980 /* assume that was SET_CONFIGURATION */ 981 if (dev->current_config) { 982 unsigned power; 983#ifdef HIGHSPEED 984 if (dev->gadget->speed == USB_SPEED_HIGH) 985 power = dev->hs_config->bMaxPower; 986 else 987#endif 988 power = dev->config->bMaxPower; 989 usb_gadget_vbus_draw(dev->gadget, 2 * power); 990 } 991 992 } else { /* collect OUT data */ 993 if ((fd->f_flags & O_NONBLOCK) != 0 994 && !dev->setup_out_ready) { 995 retval = -EAGAIN; 996 goto done; 997 } 998 spin_unlock_irq (&dev->lock); 999 retval = wait_event_interruptible (dev->wait, 1000 dev->setup_out_ready != 0); 1001 1002 /* FIXME state could change from under us */ 1003 spin_lock_irq (&dev->lock); 1004 if (retval) 1005 goto done; 1006 if (dev->setup_out_error) 1007 retval = -EIO; 1008 else { 1009 len = min (len, (size_t)dev->req->actual); 1010// FIXME don't call this with the spinlock held ... 1011 if (copy_to_user (buf, &dev->req->buf, len)) 1012 retval = -EFAULT; 1013 clean_req (dev->gadget->ep0, dev->req); 1014 /* NOTE userspace can't yet choose to stall */ 1015 } 1016 } 1017 goto done; 1018 } 1019 1020 /* else normal: return event data */ 1021 if (len < sizeof dev->event [0]) { 1022 retval = -EINVAL; 1023 goto done; 1024 } 1025 len -= len % sizeof (struct usb_gadgetfs_event); 1026 dev->usermode_setup = 1; 1027 1028scan: 1029 /* return queued events right away */ 1030 if (dev->ev_next != 0) { 1031 unsigned i, n; 1032 int tmp = dev->ev_next; 1033 1034 len = min (len, tmp * sizeof (struct usb_gadgetfs_event)); 1035 n = len / sizeof (struct usb_gadgetfs_event); 1036 1037 /* ep0 can't deliver events when STATE_SETUP */ 1038 for (i = 0; i < n; i++) { 1039 if (dev->event [i].type == GADGETFS_SETUP) { 1040 len = n = i + 1; 1041 len *= sizeof (struct usb_gadgetfs_event); 1042 n = 0; 1043 break; 1044 } 1045 } 1046 spin_unlock_irq (&dev->lock); 1047 if (copy_to_user (buf, &dev->event, len)) 1048 retval = -EFAULT; 1049 else 1050 retval = len; 1051 if (len > 0) { 1052 len /= sizeof (struct usb_gadgetfs_event); 1053 1054 /* NOTE this doesn't guard against broken drivers; 1055 * concurrent ep0 readers may lose events. 1056 */ 1057 spin_lock_irq (&dev->lock); 1058 dev->ev_next -= len; 1059 if (dev->ev_next != 0) 1060 memmove (&dev->event, &dev->event [len], 1061 sizeof (struct usb_gadgetfs_event) 1062 * (tmp - len)); 1063 if (n == 0) 1064 dev->state = STATE_SETUP; 1065 spin_unlock_irq (&dev->lock); 1066 } 1067 return retval; 1068 } 1069 if (fd->f_flags & O_NONBLOCK) { 1070 retval = -EAGAIN; 1071 goto done; 1072 } 1073 1074 switch (state) { 1075 default: 1076 DBG (dev, "fail %s, state %d\n", __FUNCTION__, state); 1077 retval = -ESRCH; 1078 break; 1079 case STATE_UNCONNECTED: 1080 case STATE_CONNECTED: 1081 spin_unlock_irq (&dev->lock); 1082 DBG (dev, "%s wait\n", __FUNCTION__); 1083 1084 /* wait for events */ 1085 retval = wait_event_interruptible (dev->wait, 1086 dev->ev_next != 0); 1087 if (retval < 0) 1088 return retval; 1089 spin_lock_irq (&dev->lock); 1090 goto scan; 1091 } 1092 1093done: 1094 spin_unlock_irq (&dev->lock); 1095 return retval; 1096} 1097 1098static struct usb_gadgetfs_event * 1099next_event (struct dev_data *dev, enum usb_gadgetfs_event_type type) 1100{ 1101 struct usb_gadgetfs_event *event; 1102 unsigned i; 1103 1104 switch (type) { 1105 /* these events purge the queue */ 1106 case GADGETFS_DISCONNECT: 1107 if (dev->state == STATE_SETUP) 1108 dev->setup_abort = 1; 1109 // FALL THROUGH 1110 case GADGETFS_CONNECT: 1111 dev->ev_next = 0; 1112 break; 1113 case GADGETFS_SETUP: /* previous request timed out */ 1114 case GADGETFS_SUSPEND: /* same effect */ 1115 /* these events can't be repeated */ 1116 for (i = 0; i != dev->ev_next; i++) { 1117 if (dev->event [i].type != type) 1118 continue; 1119 DBG (dev, "discard old event %d\n", type); 1120 dev->ev_next--; 1121 if (i == dev->ev_next) 1122 break; 1123 /* indices start at zero, for simplicity */ 1124 memmove (&dev->event [i], &dev->event [i + 1], 1125 sizeof (struct usb_gadgetfs_event) 1126 * (dev->ev_next - i)); 1127 } 1128 break; 1129 default: 1130 BUG (); 1131 } 1132 event = &dev->event [dev->ev_next++]; 1133 BUG_ON (dev->ev_next > N_EVENT); 1134 VDEBUG (dev, "ev %d, next %d\n", type, dev->ev_next); 1135 memset (event, 0, sizeof *event); 1136 event->type = type; 1137 return event; 1138} 1139 1140static ssize_t 1141ep0_write (struct file *fd, const char __user *buf, size_t len, loff_t *ptr) 1142{ 1143 struct dev_data *dev = fd->private_data; 1144 ssize_t retval = -ESRCH; 1145 1146 spin_lock_irq (&dev->lock); 1147 1148 /* report fd mode change before acting on it */ 1149 if (dev->setup_abort) { 1150 dev->setup_abort = 0; 1151 retval = -EIDRM; 1152 1153 /* data and/or status stage for control request */ 1154 } else if (dev->state == STATE_SETUP) { 1155 1156 /* IN DATA+STATUS caller makes len <= wLength */ 1157 if (dev->setup_in) { 1158 retval = setup_req (dev->gadget->ep0, dev->req, len); 1159 if (retval == 0) { 1160 spin_unlock_irq (&dev->lock); 1161 if (copy_from_user (dev->req->buf, buf, len)) 1162 retval = -EFAULT; 1163 else 1164 retval = usb_ep_queue ( 1165 dev->gadget->ep0, dev->req, 1166 GFP_KERNEL); 1167 if (retval < 0) { 1168 spin_lock_irq (&dev->lock); 1169 clean_req (dev->gadget->ep0, dev->req); 1170 spin_unlock_irq (&dev->lock); 1171 } else 1172 retval = len; 1173 1174 return retval; 1175 } 1176 1177 /* can stall some OUT transfers */ 1178 } else if (dev->setup_can_stall) { 1179 VDEBUG(dev, "ep0out stall\n"); 1180 (void) usb_ep_set_halt (dev->gadget->ep0); 1181 retval = -EL2HLT; 1182 dev->state = STATE_CONNECTED; 1183 } else { 1184 DBG(dev, "bogus ep0out stall!\n"); 1185 } 1186 } else 1187 DBG (dev, "fail %s, state %d\n", __FUNCTION__, dev->state); 1188 1189 spin_unlock_irq (&dev->lock); 1190 return retval; 1191} 1192 1193static int 1194ep0_fasync (int f, struct file *fd, int on) 1195{ 1196 struct dev_data *dev = fd->private_data; 1197 // caller must F_SETOWN before signal delivery happens 1198 VDEBUG (dev, "%s %s\n", __FUNCTION__, on ? "on" : "off"); 1199 return fasync_helper (f, fd, on, &dev->fasync); 1200} 1201 1202static struct usb_gadget_driver gadgetfs_driver; 1203 1204static int 1205dev_release (struct inode *inode, struct file *fd) 1206{ 1207 struct dev_data *dev = fd->private_data; 1208 1209 /* closing ep0 === shutdown all */ 1210 1211 usb_gadget_unregister_driver (&gadgetfs_driver); 1212 1213 /* at this point "good" hardware has disconnected the 1214 * device from USB; the host won't see it any more. 1215 * alternatively, all host requests will time out. 1216 */ 1217 1218 fasync_helper (-1, fd, 0, &dev->fasync); 1219 kfree (dev->buf); 1220 dev->buf = NULL; 1221 put_dev (dev); 1222 1223 /* other endpoints were all decoupled from this device */ 1224 dev->state = STATE_DEV_DISABLED; 1225 return 0; 1226} 1227 1228static int dev_ioctl (struct inode *inode, struct file *fd, 1229 unsigned code, unsigned long value) 1230{ 1231 struct dev_data *dev = fd->private_data; 1232 struct usb_gadget *gadget = dev->gadget; 1233 1234 if (gadget->ops->ioctl) 1235 return gadget->ops->ioctl (gadget, code, value); 1236 return -ENOTTY; 1237} 1238 1239/* used after device configuration */ 1240static struct file_operations ep0_io_operations = { 1241 .owner = THIS_MODULE, 1242 .llseek = no_llseek, 1243 1244 .read = ep0_read, 1245 .write = ep0_write, 1246 .fasync = ep0_fasync, 1247 // .poll = ep0_poll, 1248 .ioctl = dev_ioctl, 1249 .release = dev_release, 1250}; 1251 1252/*----------------------------------------------------------------------*/ 1253 1254/* The in-kernel gadget driver handles most ep0 issues, in particular 1255 * enumerating the single configuration (as provided from user space). 1256 * 1257 * Unrecognized ep0 requests may be handled in user space. 1258 */ 1259 1260#ifdef HIGHSPEED 1261static void make_qualifier (struct dev_data *dev) 1262{ 1263 struct usb_qualifier_descriptor qual; 1264 struct usb_device_descriptor *desc; 1265 1266 qual.bLength = sizeof qual; 1267 qual.bDescriptorType = USB_DT_DEVICE_QUALIFIER; 1268 qual.bcdUSB = __constant_cpu_to_le16 (0x0200); 1269 1270 desc = dev->dev; 1271 qual.bDeviceClass = desc->bDeviceClass; 1272 qual.bDeviceSubClass = desc->bDeviceSubClass; 1273 qual.bDeviceProtocol = desc->bDeviceProtocol; 1274 1275 /* assumes ep0 uses the same value for both speeds ... */ 1276 qual.bMaxPacketSize0 = desc->bMaxPacketSize0; 1277 1278 qual.bNumConfigurations = 1; 1279 qual.bRESERVED = 0; 1280 1281 memcpy (dev->rbuf, &qual, sizeof qual); 1282} 1283#endif 1284 1285static int 1286config_buf (struct dev_data *dev, u8 type, unsigned index) 1287{ 1288 int len; 1289#ifdef HIGHSPEED 1290 int hs; 1291#endif 1292 1293 /* only one configuration */ 1294 if (index > 0) 1295 return -EINVAL; 1296 1297#ifdef HIGHSPEED 1298 hs = (dev->gadget->speed == USB_SPEED_HIGH); 1299 if (type == USB_DT_OTHER_SPEED_CONFIG) 1300 hs = !hs; 1301 if (hs) { 1302 dev->req->buf = dev->hs_config; 1303 len = le16_to_cpup (&dev->hs_config->wTotalLength); 1304 } else 1305#endif 1306 { 1307 dev->req->buf = dev->config; 1308 len = le16_to_cpup (&dev->config->wTotalLength); 1309 } 1310 ((u8 *)dev->req->buf) [1] = type; 1311 return len; 1312} 1313 1314static int 1315gadgetfs_setup (struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl) 1316{ 1317 struct dev_data *dev = get_gadget_data (gadget); 1318 struct usb_request *req = dev->req; 1319 int value = -EOPNOTSUPP; 1320 struct usb_gadgetfs_event *event; 1321 u16 w_value = ctrl->wValue; 1322 u16 w_length = ctrl->wLength; 1323 1324 spin_lock (&dev->lock); 1325 dev->setup_abort = 0; 1326 if (dev->state == STATE_UNCONNECTED) { 1327 struct usb_ep *ep; 1328 struct ep_data *data; 1329 1330 dev->state = STATE_CONNECTED; 1331 dev->dev->bMaxPacketSize0 = gadget->ep0->maxpacket; 1332 1333#ifdef HIGHSPEED 1334 if (gadget->speed == USB_SPEED_HIGH && dev->hs_config == 0) { 1335 ERROR (dev, "no high speed config??\n"); 1336 return -EINVAL; 1337 } 1338#endif /* HIGHSPEED */ 1339 1340 INFO (dev, "connected\n"); 1341 event = next_event (dev, GADGETFS_CONNECT); 1342 event->u.speed = gadget->speed; 1343 ep0_readable (dev); 1344 1345 list_for_each_entry (ep, &gadget->ep_list, ep_list) { 1346 data = ep->driver_data; 1347 /* ... down_trylock (&data->lock) ... */ 1348 if (data->state != STATE_EP_DEFER_ENABLE) 1349 continue; 1350#ifdef HIGHSPEED 1351 if (gadget->speed == USB_SPEED_HIGH) 1352 value = usb_ep_enable (ep, &data->hs_desc); 1353 else 1354#endif /* HIGHSPEED */ 1355 value = usb_ep_enable (ep, &data->desc); 1356 if (value) { 1357 ERROR (dev, "deferred %s enable --> %d\n", 1358 data->name, value); 1359 continue; 1360 } 1361 data->state = STATE_EP_ENABLED; 1362 wake_up (&data->wait); 1363 DBG (dev, "woke up %s waiters\n", data->name); 1364 } 1365 1366 /* host may have given up waiting for response. we can miss control 1367 * requests handled lower down (device/endpoint status and features); 1368 * then ep0_{read,write} will report the wrong status. controller 1369 * driver will have aborted pending i/o. 1370 */ 1371 } else if (dev->state == STATE_SETUP) 1372 dev->setup_abort = 1; 1373 1374 req->buf = dev->rbuf; 1375 req->dma = DMA_ADDR_INVALID; 1376 req->context = NULL; 1377 value = -EOPNOTSUPP; 1378 switch (ctrl->bRequest) { 1379 1380 case USB_REQ_GET_DESCRIPTOR: 1381 if (ctrl->bRequestType != USB_DIR_IN) 1382 goto unrecognized; 1383 switch (w_value >> 8) { 1384 1385 case USB_DT_DEVICE: 1386 value = min (w_length, (u16) sizeof *dev->dev); 1387 req->buf = dev->dev; 1388 break; 1389#ifdef HIGHSPEED 1390 case USB_DT_DEVICE_QUALIFIER: 1391 if (!dev->hs_config) 1392 break; 1393 value = min (w_length, (u16) 1394 sizeof (struct usb_qualifier_descriptor)); 1395 make_qualifier (dev); 1396 break; 1397 case USB_DT_OTHER_SPEED_CONFIG: 1398 // FALLTHROUGH 1399#endif 1400 case USB_DT_CONFIG: 1401 value = config_buf (dev, 1402 w_value >> 8, 1403 w_value & 0xff); 1404 if (value >= 0) 1405 value = min (w_length, (u16) value); 1406 break; 1407 case USB_DT_STRING: 1408 goto unrecognized; 1409 1410 default: // all others are errors 1411 break; 1412 } 1413 break; 1414 1415 /* currently one config, two speeds */ 1416 case USB_REQ_SET_CONFIGURATION: 1417 if (ctrl->bRequestType != 0) 1418 break; 1419 if (0 == (u8) w_value) { 1420 value = 0; 1421 dev->current_config = 0; 1422 usb_gadget_vbus_draw(gadget, 8 /* mA */ ); 1423 // user mode expected to disable endpoints 1424 } else { 1425 u8 config, power; 1426#ifdef HIGHSPEED 1427 if (gadget->speed == USB_SPEED_HIGH) { 1428 config = dev->hs_config->bConfigurationValue; 1429 power = dev->hs_config->bMaxPower; 1430 } else 1431#endif 1432 { 1433 config = dev->config->bConfigurationValue; 1434 power = dev->config->bMaxPower; 1435 } 1436 1437 if (config == (u8) w_value) { 1438 value = 0; 1439 dev->current_config = config; 1440 usb_gadget_vbus_draw(gadget, 2 * power); 1441 } 1442 } 1443 1444 /* report SET_CONFIGURATION like any other control request, 1445 * except that usermode may not stall this. the next 1446 * request mustn't be allowed start until this finishes: 1447 * endpoints and threads set up, etc. 1448 * 1449 * NOTE: older PXA hardware (before PXA 255: without UDCCFR) 1450 * has bad/racey automagic that prevents synchronizing here. 1451 * even kernel mode drivers often miss them. 1452 */ 1453 if (value == 0) { 1454 INFO (dev, "configuration #%d\n", dev->current_config); 1455 if (dev->usermode_setup) { 1456 dev->setup_can_stall = 0; 1457 goto delegate; 1458 } 1459 } 1460 break; 1461 1462#ifndef CONFIG_USB_GADGETFS_PXA2XX 1463 /* PXA automagically handles this request too */ 1464 case USB_REQ_GET_CONFIGURATION: 1465 if (ctrl->bRequestType != 0x80) 1466 break; 1467 *(u8 *)req->buf = dev->current_config; 1468 value = min (w_length, (u16) 1); 1469 break; 1470#endif 1471 1472 default: 1473unrecognized: 1474 VDEBUG (dev, "%s req%02x.%02x v%04x i%04x l%d\n", 1475 dev->usermode_setup ? "delegate" : "fail", 1476 ctrl->bRequestType, ctrl->bRequest, 1477 w_value, le16_to_cpu(ctrl->wIndex), w_length); 1478 1479 /* if there's an ep0 reader, don't stall */ 1480 if (dev->usermode_setup) { 1481 dev->setup_can_stall = 1; 1482delegate: 1483 dev->setup_in = (ctrl->bRequestType & USB_DIR_IN) 1484 ? 1 : 0; 1485 dev->setup_out_ready = 0; 1486 dev->setup_out_error = 0; 1487 value = 0; 1488 1489 /* read DATA stage for OUT right away */ 1490 if (unlikely (!dev->setup_in && w_length)) { 1491 value = setup_req (gadget->ep0, dev->req, 1492 w_length); 1493 if (value < 0) 1494 break; 1495 value = usb_ep_queue (gadget->ep0, dev->req, 1496 GFP_ATOMIC); 1497 if (value < 0) { 1498 clean_req (gadget->ep0, dev->req); 1499 break; 1500 } 1501 1502 /* we can't currently stall these */ 1503 dev->setup_can_stall = 0; 1504 } 1505 1506 /* state changes when reader collects event */ 1507 event = next_event (dev, GADGETFS_SETUP); 1508 event->u.setup = *ctrl; 1509 ep0_readable (dev); 1510 spin_unlock (&dev->lock); 1511 return 0; 1512 } 1513 } 1514 1515 /* proceed with data transfer and status phases? */ 1516 if (value >= 0 && dev->state != STATE_SETUP) { 1517 req->length = value; 1518 req->zero = value < w_length; 1519 value = usb_ep_queue (gadget->ep0, req, GFP_ATOMIC); 1520 if (value < 0) { 1521 DBG (dev, "ep_queue --> %d\n", value); 1522 req->status = 0; 1523 } 1524 } 1525 1526 /* device stalls when value < 0 */ 1527 spin_unlock (&dev->lock); 1528 return value; 1529} 1530 1531static void destroy_ep_files (struct dev_data *dev) 1532{ 1533 struct list_head *entry, *tmp; 1534 1535 DBG (dev, "%s %d\n", __FUNCTION__, dev->state); 1536 1537 /* dev->state must prevent interference */ 1538restart: 1539 spin_lock_irq (&dev->lock); 1540 list_for_each_safe (entry, tmp, &dev->epfiles) { 1541 struct ep_data *ep; 1542 struct inode *parent; 1543 struct dentry *dentry; 1544 1545 /* break link to FS */ 1546 ep = list_entry (entry, struct ep_data, epfiles); 1547 list_del_init (&ep->epfiles); 1548 dentry = ep->dentry; 1549 ep->dentry = NULL; 1550 parent = dentry->d_parent->d_inode; 1551 1552 /* break link to controller */ 1553 if (ep->state == STATE_EP_ENABLED) 1554 (void) usb_ep_disable (ep->ep); 1555 ep->state = STATE_EP_UNBOUND; 1556 usb_ep_free_request (ep->ep, ep->req); 1557 ep->ep = NULL; 1558 wake_up (&ep->wait); 1559 put_ep (ep); 1560 1561 spin_unlock_irq (&dev->lock); 1562 1563 /* break link to dcache */ 1564 down (&parent->i_sem); 1565 d_delete (dentry); 1566 dput (dentry); 1567 up (&parent->i_sem); 1568 1569 /* fds may still be open */ 1570 goto restart; 1571 } 1572 spin_unlock_irq (&dev->lock); 1573} 1574 1575 1576static struct inode * 1577gadgetfs_create_file (struct super_block *sb, char const *name, 1578 void *data, struct file_operations *fops, 1579 struct dentry **dentry_p); 1580 1581static int activate_ep_files (struct dev_data *dev) 1582{ 1583 struct usb_ep *ep; 1584 1585 gadget_for_each_ep (ep, dev->gadget) { 1586 struct ep_data *data; 1587 1588 data = kmalloc (sizeof *data, GFP_KERNEL); 1589 if (!data) 1590 goto enomem; 1591 memset (data, 0, sizeof data); 1592 data->state = STATE_EP_DISABLED; 1593 init_MUTEX (&data->lock); 1594 init_waitqueue_head (&data->wait); 1595 1596 strncpy (data->name, ep->name, sizeof (data->name) - 1); 1597 atomic_set (&data->count, 1); 1598 data->dev = dev; 1599 get_dev (dev); 1600 1601 data->ep = ep; 1602 ep->driver_data = data; 1603 1604 data->req = usb_ep_alloc_request (ep, GFP_KERNEL); 1605 if (!data->req) 1606 goto enomem; 1607 1608 data->inode = gadgetfs_create_file (dev->sb, data->name, 1609 data, &ep_config_operations, 1610 &data->dentry); 1611 if (!data->inode) { 1612 kfree (data); 1613 goto enomem; 1614 } 1615 list_add_tail (&data->epfiles, &dev->epfiles); 1616 } 1617 return 0; 1618 1619enomem: 1620 DBG (dev, "%s enomem\n", __FUNCTION__); 1621 destroy_ep_files (dev); 1622 return -ENOMEM; 1623} 1624 1625static void 1626gadgetfs_unbind (struct usb_gadget *gadget) 1627{ 1628 struct dev_data *dev = get_gadget_data (gadget); 1629 1630 DBG (dev, "%s\n", __FUNCTION__); 1631 1632 spin_lock_irq (&dev->lock); 1633 dev->state = STATE_DEV_UNBOUND; 1634 spin_unlock_irq (&dev->lock); 1635 1636 destroy_ep_files (dev); 1637 gadget->ep0->driver_data = NULL; 1638 set_gadget_data (gadget, NULL); 1639 1640 /* we've already been disconnected ... no i/o is active */ 1641 if (dev->req) 1642 usb_ep_free_request (gadget->ep0, dev->req); 1643 DBG (dev, "%s done\n", __FUNCTION__); 1644 put_dev (dev); 1645} 1646 1647static struct dev_data *the_device; 1648 1649static int 1650gadgetfs_bind (struct usb_gadget *gadget) 1651{ 1652 struct dev_data *dev = the_device; 1653 1654 if (!dev) 1655 return -ESRCH; 1656 if (0 != strcmp (CHIP, gadget->name)) { 1657 printk (KERN_ERR "%s expected %s controller not %s\n", 1658 shortname, CHIP, gadget->name); 1659 return -ENODEV; 1660 } 1661 1662 set_gadget_data (gadget, dev); 1663 dev->gadget = gadget; 1664 gadget->ep0->driver_data = dev; 1665 dev->dev->bMaxPacketSize0 = gadget->ep0->maxpacket; 1666 1667 /* preallocate control response and buffer */ 1668 dev->req = usb_ep_alloc_request (gadget->ep0, GFP_KERNEL); 1669 if (!dev->req) 1670 goto enomem; 1671 dev->req->context = NULL; 1672 dev->req->complete = epio_complete; 1673 1674 if (activate_ep_files (dev) < 0) 1675 goto enomem; 1676 1677 INFO (dev, "bound to %s driver\n", gadget->name); 1678 dev->state = STATE_UNCONNECTED; 1679 get_dev (dev); 1680 return 0; 1681 1682enomem: 1683 gadgetfs_unbind (gadget); 1684 return -ENOMEM; 1685} 1686 1687static void 1688gadgetfs_disconnect (struct usb_gadget *gadget) 1689{ 1690 struct dev_data *dev = get_gadget_data (gadget); 1691 1692 if (dev->state == STATE_UNCONNECTED) { 1693 DBG (dev, "already unconnected\n"); 1694 return; 1695 } 1696 dev->state = STATE_UNCONNECTED; 1697 1698 INFO (dev, "disconnected\n"); 1699 spin_lock (&dev->lock); 1700 next_event (dev, GADGETFS_DISCONNECT); 1701 ep0_readable (dev); 1702 spin_unlock (&dev->lock); 1703} 1704 1705static void 1706gadgetfs_suspend (struct usb_gadget *gadget) 1707{ 1708 struct dev_data *dev = get_gadget_data (gadget); 1709 1710 INFO (dev, "suspended from state %d\n", dev->state); 1711 spin_lock (&dev->lock); 1712 switch (dev->state) { 1713 case STATE_SETUP: // VERY odd... host died?? 1714 case STATE_CONNECTED: 1715 case STATE_UNCONNECTED: 1716 next_event (dev, GADGETFS_SUSPEND); 1717 ep0_readable (dev); 1718 /* FALLTHROUGH */ 1719 default: 1720 break; 1721 } 1722 spin_unlock (&dev->lock); 1723} 1724 1725static struct usb_gadget_driver gadgetfs_driver = { 1726#ifdef HIGHSPEED 1727 .speed = USB_SPEED_HIGH, 1728#else 1729 .speed = USB_SPEED_FULL, 1730#endif 1731 .function = (char *) driver_desc, 1732 .bind = gadgetfs_bind, 1733 .unbind = gadgetfs_unbind, 1734 .setup = gadgetfs_setup, 1735 .disconnect = gadgetfs_disconnect, 1736 .suspend = gadgetfs_suspend, 1737 1738 .driver = { 1739 .name = (char *) shortname, 1740 // .shutdown = ... 1741 // .suspend = ... 1742 // .resume = ... 1743 }, 1744}; 1745 1746/*----------------------------------------------------------------------*/ 1747 1748static void gadgetfs_nop(struct usb_gadget *arg) { } 1749 1750static int gadgetfs_probe (struct usb_gadget *gadget) 1751{ 1752 CHIP = gadget->name; 1753 return -EISNAM; 1754} 1755 1756static struct usb_gadget_driver probe_driver = { 1757 .speed = USB_SPEED_HIGH, 1758 .bind = gadgetfs_probe, 1759 .unbind = gadgetfs_nop, 1760 .setup = (void *)gadgetfs_nop, 1761 .disconnect = gadgetfs_nop, 1762 .driver = { 1763 .name = "nop", 1764 }, 1765}; 1766 1767 1768/* DEVICE INITIALIZATION 1769 * 1770 * fd = open ("/dev/gadget/$CHIP", O_RDWR) 1771 * status = write (fd, descriptors, sizeof descriptors) 1772 * 1773 * That write establishes the device configuration, so the kernel can 1774 * bind to the controller ... guaranteeing it can handle enumeration 1775 * at all necessary speeds. Descriptor order is: 1776 * 1777 * . message tag (u32, host order) ... for now, must be zero; it 1778 * would change to support features like multi-config devices 1779 * . full/low speed config ... all wTotalLength bytes (with interface, 1780 * class, altsetting, endpoint, and other descriptors) 1781 * . high speed config ... all descriptors, for high speed operation; 1782 * this one's optional except for high-speed hardware 1783 * . device descriptor 1784 * 1785 * Endpoints are not yet enabled. Drivers may want to immediately 1786 * initialize them, using the /dev/gadget/ep* files that are available 1787 * as soon as the kernel sees the configuration, or they can wait 1788 * until device configuration and interface altsetting changes create 1789 * the need to configure (or unconfigure) them. 1790 * 1791 * After initialization, the device stays active for as long as that 1792 * $CHIP file is open. Events may then be read from that descriptor, 1793 * such configuration notifications. More complex drivers will handle 1794 * some control requests in user space. 1795 */ 1796 1797static int is_valid_config (struct usb_config_descriptor *config) 1798{ 1799 return config->bDescriptorType == USB_DT_CONFIG 1800 && config->bLength == USB_DT_CONFIG_SIZE 1801 && config->bConfigurationValue != 0 1802 && (config->bmAttributes & USB_CONFIG_ATT_ONE) != 0 1803 && (config->bmAttributes & USB_CONFIG_ATT_WAKEUP) == 0; 1804 /* FIXME if gadget->is_otg, _must_ include an otg descriptor */ 1805 /* FIXME check lengths: walk to end */ 1806} 1807 1808static ssize_t 1809dev_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr) 1810{ 1811 struct dev_data *dev = fd->private_data; 1812 ssize_t value = len, length = len; 1813 unsigned total; 1814 u32 tag; 1815 char *kbuf; 1816 1817 if (dev->state != STATE_OPENED) 1818 return -EEXIST; 1819 1820 if (len < (USB_DT_CONFIG_SIZE + USB_DT_DEVICE_SIZE + 4)) 1821 return -EINVAL; 1822 1823 /* we might need to change message format someday */ 1824 if (copy_from_user (&tag, buf, 4)) 1825 return -EFAULT; 1826 if (tag != 0) 1827 return -EINVAL; 1828 buf += 4; 1829 length -= 4; 1830 1831 kbuf = kmalloc (length, SLAB_KERNEL); 1832 if (!kbuf) 1833 return -ENOMEM; 1834 if (copy_from_user (kbuf, buf, length)) { 1835 kfree (kbuf); 1836 return -EFAULT; 1837 } 1838 1839 spin_lock_irq (&dev->lock); 1840 value = -EINVAL; 1841 if (dev->buf) 1842 goto fail; 1843 dev->buf = kbuf; 1844 1845 /* full or low speed config */ 1846 dev->config = (void *) kbuf; 1847 total = le16_to_cpup (&dev->config->wTotalLength); 1848 if (!is_valid_config (dev->config) || total >= length) 1849 goto fail; 1850 kbuf += total; 1851 length -= total; 1852 1853 /* optional high speed config */ 1854 if (kbuf [1] == USB_DT_CONFIG) { 1855 dev->hs_config = (void *) kbuf; 1856 total = le16_to_cpup (&dev->hs_config->wTotalLength); 1857 if (!is_valid_config (dev->hs_config) || total >= length) 1858 goto fail; 1859 kbuf += total; 1860 length -= total; 1861 } 1862 1863 /* could support multiple configs, using another encoding! */ 1864 1865 /* device descriptor (tweaked for paranoia) */ 1866 if (length != USB_DT_DEVICE_SIZE) 1867 goto fail; 1868 dev->dev = (void *)kbuf; 1869 if (dev->dev->bLength != USB_DT_DEVICE_SIZE 1870 || dev->dev->bDescriptorType != USB_DT_DEVICE 1871 || dev->dev->bNumConfigurations != 1) 1872 goto fail; 1873 dev->dev->bNumConfigurations = 1; 1874 dev->dev->bcdUSB = __constant_cpu_to_le16 (0x0200); 1875 1876 /* triggers gadgetfs_bind(); then we can enumerate. */ 1877 spin_unlock_irq (&dev->lock); 1878 value = usb_gadget_register_driver (&gadgetfs_driver); 1879 if (value != 0) { 1880 kfree (dev->buf); 1881 dev->buf = NULL; 1882 } else { 1883 /* at this point "good" hardware has for the first time 1884 * let the USB the host see us. alternatively, if users 1885 * unplug/replug that will clear all the error state. 1886 * 1887 * note: everything running before here was guaranteed 1888 * to choke driver model style diagnostics. from here 1889 * on, they can work ... except in cleanup paths that 1890 * kick in after the ep0 descriptor is closed. 1891 */ 1892 fd->f_op = &ep0_io_operations; 1893 value = len; 1894 } 1895 return value; 1896 1897fail: 1898 spin_unlock_irq (&dev->lock); 1899 pr_debug ("%s: %s fail %Zd, %p\n", shortname, __FUNCTION__, value, dev); 1900 kfree (dev->buf); 1901 dev->buf = NULL; 1902 return value; 1903} 1904 1905static int 1906dev_open (struct inode *inode, struct file *fd) 1907{ 1908 struct dev_data *dev = inode->u.generic_ip; 1909 int value = -EBUSY; 1910 1911 if (dev->state == STATE_DEV_DISABLED) { 1912 dev->ev_next = 0; 1913 dev->state = STATE_OPENED; 1914 fd->private_data = dev; 1915 get_dev (dev); 1916 value = 0; 1917 } 1918 return value; 1919} 1920 1921static struct file_operations dev_init_operations = { 1922 .owner = THIS_MODULE, 1923 .llseek = no_llseek, 1924 1925 .open = dev_open, 1926 .write = dev_config, 1927 .fasync = ep0_fasync, 1928 .ioctl = dev_ioctl, 1929 .release = dev_release, 1930}; 1931 1932/*----------------------------------------------------------------------*/ 1933 1934/* FILESYSTEM AND SUPERBLOCK OPERATIONS 1935 * 1936 * Mounting the filesystem creates a controller file, used first for 1937 * device configuration then later for event monitoring. 1938 */ 1939 1940 1941/* FIXME PAM etc could set this security policy without mount options 1942 * if epfiles inherited ownership and permissons from ep0 ... 1943 */ 1944 1945static unsigned default_uid; 1946static unsigned default_gid; 1947static unsigned default_perm = S_IRUSR | S_IWUSR; 1948 1949module_param (default_uid, uint, 0644); 1950module_param (default_gid, uint, 0644); 1951module_param (default_perm, uint, 0644); 1952 1953 1954static struct inode * 1955gadgetfs_make_inode (struct super_block *sb, 1956 void *data, struct file_operations *fops, 1957 int mode) 1958{ 1959 struct inode *inode = new_inode (sb); 1960 1961 if (inode) { 1962 inode->i_mode = mode; 1963 inode->i_uid = default_uid; 1964 inode->i_gid = default_gid; 1965 inode->i_blksize = PAGE_CACHE_SIZE; 1966 inode->i_blocks = 0; 1967 inode->i_atime = inode->i_mtime = inode->i_ctime 1968 = CURRENT_TIME; 1969 inode->u.generic_ip = data; 1970 inode->i_fop = fops; 1971 } 1972 return inode; 1973} 1974 1975/* creates in fs root directory, so non-renamable and non-linkable. 1976 * so inode and dentry are paired, until device reconfig. 1977 */ 1978static struct inode * 1979gadgetfs_create_file (struct super_block *sb, char const *name, 1980 void *data, struct file_operations *fops, 1981 struct dentry **dentry_p) 1982{ 1983 struct dentry *dentry; 1984 struct inode *inode; 1985 1986 dentry = d_alloc_name(sb->s_root, name); 1987 if (!dentry) 1988 return NULL; 1989 1990 inode = gadgetfs_make_inode (sb, data, fops, 1991 S_IFREG | (default_perm & S_IRWXUGO)); 1992 if (!inode) { 1993 dput(dentry); 1994 return NULL; 1995 } 1996 d_add (dentry, inode); 1997 *dentry_p = dentry; 1998 return inode; 1999} 2000 2001static struct super_operations gadget_fs_operations = { 2002 .statfs = simple_statfs, 2003 .drop_inode = generic_delete_inode, 2004}; 2005 2006static int 2007gadgetfs_fill_super (struct super_block *sb, void *opts, int silent) 2008{ 2009 struct inode *inode; 2010 struct dentry *d; 2011 struct dev_data *dev; 2012 2013 if (the_device) 2014 return -ESRCH; 2015 2016 /* fake probe to determine $CHIP */ 2017 (void) usb_gadget_register_driver (&probe_driver); 2018 if (!CHIP) 2019 return -ENODEV; 2020 2021 /* superblock */ 2022 sb->s_blocksize = PAGE_CACHE_SIZE; 2023 sb->s_blocksize_bits = PAGE_CACHE_SHIFT; 2024 sb->s_magic = GADGETFS_MAGIC; 2025 sb->s_op = &gadget_fs_operations; 2026 sb->s_time_gran = 1; 2027 2028 /* root inode */ 2029 inode = gadgetfs_make_inode (sb, 2030 NULL, &simple_dir_operations, 2031 S_IFDIR | S_IRUGO | S_IXUGO); 2032 if (!inode) 2033 return -ENOMEM; 2034 inode->i_op = &simple_dir_inode_operations; 2035 if (!(d = d_alloc_root (inode))) { 2036 iput (inode); 2037 return -ENOMEM; 2038 } 2039 sb->s_root = d; 2040 2041 /* the ep0 file is named after the controller we expect; 2042 * user mode code can use it for sanity checks, like we do. 2043 */ 2044 dev = dev_new (); 2045 if (!dev) 2046 return -ENOMEM; 2047 2048 dev->sb = sb; 2049 if (!(inode = gadgetfs_create_file (sb, CHIP, 2050 dev, &dev_init_operations, 2051 &dev->dentry))) { 2052 put_dev(dev); 2053 return -ENOMEM; 2054 } 2055 2056 /* other endpoint files are available after hardware setup, 2057 * from binding to a controller. 2058 */ 2059 the_device = dev; 2060 return 0; 2061} 2062 2063/* "mount -t gadgetfs path /dev/gadget" ends up here */ 2064static struct super_block * 2065gadgetfs_get_sb (struct file_system_type *t, int flags, 2066 const char *path, void *opts) 2067{ 2068 return get_sb_single (t, flags, opts, gadgetfs_fill_super); 2069} 2070 2071static void 2072gadgetfs_kill_sb (struct super_block *sb) 2073{ 2074 kill_litter_super (sb); 2075 if (the_device) { 2076 put_dev (the_device); 2077 the_device = NULL; 2078 } 2079} 2080 2081/*----------------------------------------------------------------------*/ 2082 2083static struct file_system_type gadgetfs_type = { 2084 .owner = THIS_MODULE, 2085 .name = shortname, 2086 .get_sb = gadgetfs_get_sb, 2087 .kill_sb = gadgetfs_kill_sb, 2088}; 2089 2090/*----------------------------------------------------------------------*/ 2091 2092static int __init init (void) 2093{ 2094 int status; 2095 2096 status = register_filesystem (&gadgetfs_type); 2097 if (status == 0) 2098 pr_info ("%s: %s, version " DRIVER_VERSION "\n", 2099 shortname, driver_desc); 2100 return status; 2101} 2102module_init (init); 2103 2104static void __exit cleanup (void) 2105{ 2106 pr_debug ("unregister %s\n", shortname); 2107 unregister_filesystem (&gadgetfs_type); 2108} 2109module_exit (cleanup); 2110 2111