inode.c revision 1b1dcc1b57a49136f118a0f16367256ff9994a69
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 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; 480 481 /* 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 usb_ep_disable(data->ep); 487 } 488 put_ep (data); 489 return 0; 490} 491 492static int ep_ioctl (struct inode *inode, struct file *fd, 493 unsigned code, unsigned long value) 494{ 495 struct ep_data *data = fd->private_data; 496 int status; 497 498 if ((status = get_ready_ep (fd->f_flags, data)) < 0) 499 return status; 500 501 spin_lock_irq (&data->dev->lock); 502 if (likely (data->ep != NULL)) { 503 switch (code) { 504 case GADGETFS_FIFO_STATUS: 505 status = usb_ep_fifo_status (data->ep); 506 break; 507 case GADGETFS_FIFO_FLUSH: 508 usb_ep_fifo_flush (data->ep); 509 break; 510 case GADGETFS_CLEAR_HALT: 511 status = usb_ep_clear_halt (data->ep); 512 break; 513 default: 514 status = -ENOTTY; 515 } 516 } else 517 status = -ENODEV; 518 spin_unlock_irq (&data->dev->lock); 519 up (&data->lock); 520 return status; 521} 522 523/*----------------------------------------------------------------------*/ 524 525/* ASYNCHRONOUS ENDPOINT I/O OPERATIONS (bulk/intr/iso) */ 526 527struct kiocb_priv { 528 struct usb_request *req; 529 struct ep_data *epdata; 530 void *buf; 531 char __user *ubuf; 532 unsigned actual; 533}; 534 535static int ep_aio_cancel(struct kiocb *iocb, struct io_event *e) 536{ 537 struct kiocb_priv *priv = iocb->private; 538 struct ep_data *epdata; 539 int value; 540 541 local_irq_disable(); 542 epdata = priv->epdata; 543 // spin_lock(&epdata->dev->lock); 544 kiocbSetCancelled(iocb); 545 if (likely(epdata && epdata->ep && priv->req)) 546 value = usb_ep_dequeue (epdata->ep, priv->req); 547 else 548 value = -EINVAL; 549 // spin_unlock(&epdata->dev->lock); 550 local_irq_enable(); 551 552 aio_put_req(iocb); 553 return value; 554} 555 556static ssize_t ep_aio_read_retry(struct kiocb *iocb) 557{ 558 struct kiocb_priv *priv = iocb->private; 559 ssize_t status = priv->actual; 560 561 /* we "retry" to get the right mm context for this: */ 562 status = copy_to_user(priv->ubuf, priv->buf, priv->actual); 563 if (unlikely(0 != status)) 564 status = -EFAULT; 565 else 566 status = priv->actual; 567 kfree(priv->buf); 568 kfree(priv); 569 aio_put_req(iocb); 570 return status; 571} 572 573static void ep_aio_complete(struct usb_ep *ep, struct usb_request *req) 574{ 575 struct kiocb *iocb = req->context; 576 struct kiocb_priv *priv = iocb->private; 577 struct ep_data *epdata = priv->epdata; 578 579 /* lock against disconnect (and ideally, cancel) */ 580 spin_lock(&epdata->dev->lock); 581 priv->req = NULL; 582 priv->epdata = NULL; 583 if (NULL == iocb->ki_retry 584 || unlikely(0 == req->actual) 585 || unlikely(kiocbIsCancelled(iocb))) { 586 kfree(req->buf); 587 kfree(priv); 588 iocb->private = NULL; 589 /* aio_complete() reports bytes-transferred _and_ faults */ 590 if (unlikely(kiocbIsCancelled(iocb))) 591 aio_put_req(iocb); 592 else 593 aio_complete(iocb, 594 req->actual ? req->actual : req->status, 595 req->status); 596 } else { 597 /* retry() won't report both; so we hide some faults */ 598 if (unlikely(0 != req->status)) 599 DBG(epdata->dev, "%s fault %d len %d\n", 600 ep->name, req->status, req->actual); 601 602 priv->buf = req->buf; 603 priv->actual = req->actual; 604 kick_iocb(iocb); 605 } 606 spin_unlock(&epdata->dev->lock); 607 608 usb_ep_free_request(ep, req); 609 put_ep(epdata); 610} 611 612static ssize_t 613ep_aio_rwtail( 614 struct kiocb *iocb, 615 char *buf, 616 size_t len, 617 struct ep_data *epdata, 618 char __user *ubuf 619) 620{ 621 struct kiocb_priv *priv = (void *) &iocb->private; 622 struct usb_request *req; 623 ssize_t value; 624 625 priv = kmalloc(sizeof *priv, GFP_KERNEL); 626 if (!priv) { 627 value = -ENOMEM; 628fail: 629 kfree(buf); 630 return value; 631 } 632 iocb->private = priv; 633 priv->ubuf = ubuf; 634 635 value = get_ready_ep(iocb->ki_filp->f_flags, epdata); 636 if (unlikely(value < 0)) { 637 kfree(priv); 638 goto fail; 639 } 640 641 iocb->ki_cancel = ep_aio_cancel; 642 get_ep(epdata); 643 priv->epdata = epdata; 644 priv->actual = 0; 645 646 /* each kiocb is coupled to one usb_request, but we can't 647 * allocate or submit those if the host disconnected. 648 */ 649 spin_lock_irq(&epdata->dev->lock); 650 if (likely(epdata->ep)) { 651 req = usb_ep_alloc_request(epdata->ep, GFP_ATOMIC); 652 if (likely(req)) { 653 priv->req = req; 654 req->buf = buf; 655 req->length = len; 656 req->complete = ep_aio_complete; 657 req->context = iocb; 658 value = usb_ep_queue(epdata->ep, req, GFP_ATOMIC); 659 if (unlikely(0 != value)) 660 usb_ep_free_request(epdata->ep, req); 661 } else 662 value = -EAGAIN; 663 } else 664 value = -ENODEV; 665 spin_unlock_irq(&epdata->dev->lock); 666 667 up(&epdata->lock); 668 669 if (unlikely(value)) { 670 kfree(priv); 671 put_ep(epdata); 672 } else 673 value = -EIOCBQUEUED; 674 return value; 675} 676 677static ssize_t 678ep_aio_read(struct kiocb *iocb, char __user *ubuf, size_t len, loff_t o) 679{ 680 struct ep_data *epdata = iocb->ki_filp->private_data; 681 char *buf; 682 683 if (unlikely(epdata->desc.bEndpointAddress & USB_DIR_IN)) 684 return -EINVAL; 685 buf = kmalloc(len, GFP_KERNEL); 686 if (unlikely(!buf)) 687 return -ENOMEM; 688 iocb->ki_retry = ep_aio_read_retry; 689 return ep_aio_rwtail(iocb, buf, len, epdata, ubuf); 690} 691 692static ssize_t 693ep_aio_write(struct kiocb *iocb, const char __user *ubuf, size_t len, loff_t o) 694{ 695 struct ep_data *epdata = iocb->ki_filp->private_data; 696 char *buf; 697 698 if (unlikely(!(epdata->desc.bEndpointAddress & USB_DIR_IN))) 699 return -EINVAL; 700 buf = kmalloc(len, GFP_KERNEL); 701 if (unlikely(!buf)) 702 return -ENOMEM; 703 if (unlikely(copy_from_user(buf, ubuf, len) != 0)) { 704 kfree(buf); 705 return -EFAULT; 706 } 707 return ep_aio_rwtail(iocb, buf, len, epdata, NULL); 708} 709 710/*----------------------------------------------------------------------*/ 711 712/* used after endpoint configuration */ 713static struct file_operations ep_io_operations = { 714 .owner = THIS_MODULE, 715 .llseek = no_llseek, 716 717 .read = ep_read, 718 .write = ep_write, 719 .ioctl = ep_ioctl, 720 .release = ep_release, 721 722 .aio_read = ep_aio_read, 723 .aio_write = ep_aio_write, 724}; 725 726/* ENDPOINT INITIALIZATION 727 * 728 * fd = open ("/dev/gadget/$ENDPOINT", O_RDWR) 729 * status = write (fd, descriptors, sizeof descriptors) 730 * 731 * That write establishes the endpoint configuration, configuring 732 * the controller to process bulk, interrupt, or isochronous transfers 733 * at the right maxpacket size, and so on. 734 * 735 * The descriptors are message type 1, identified by a host order u32 736 * at the beginning of what's written. Descriptor order is: full/low 737 * speed descriptor, then optional high speed descriptor. 738 */ 739static ssize_t 740ep_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr) 741{ 742 struct ep_data *data = fd->private_data; 743 struct usb_ep *ep; 744 u32 tag; 745 int value; 746 747 if ((value = down_interruptible (&data->lock)) < 0) 748 return value; 749 750 if (data->state != STATE_EP_READY) { 751 value = -EL2HLT; 752 goto fail; 753 } 754 755 value = len; 756 if (len < USB_DT_ENDPOINT_SIZE + 4) 757 goto fail0; 758 759 /* we might need to change message format someday */ 760 if (copy_from_user (&tag, buf, 4)) { 761 goto fail1; 762 } 763 if (tag != 1) { 764 DBG(data->dev, "config %s, bad tag %d\n", data->name, tag); 765 goto fail0; 766 } 767 buf += 4; 768 len -= 4; 769 770 /* NOTE: audio endpoint extensions not accepted here; 771 * just don't include the extra bytes. 772 */ 773 774 /* full/low speed descriptor, then high speed */ 775 if (copy_from_user (&data->desc, buf, USB_DT_ENDPOINT_SIZE)) { 776 goto fail1; 777 } 778 if (data->desc.bLength != USB_DT_ENDPOINT_SIZE 779 || data->desc.bDescriptorType != USB_DT_ENDPOINT) 780 goto fail0; 781 if (len != USB_DT_ENDPOINT_SIZE) { 782 if (len != 2 * USB_DT_ENDPOINT_SIZE) 783 goto fail0; 784 if (copy_from_user (&data->hs_desc, buf + USB_DT_ENDPOINT_SIZE, 785 USB_DT_ENDPOINT_SIZE)) { 786 goto fail1; 787 } 788 if (data->hs_desc.bLength != USB_DT_ENDPOINT_SIZE 789 || data->hs_desc.bDescriptorType 790 != USB_DT_ENDPOINT) { 791 DBG(data->dev, "config %s, bad hs length or type\n", 792 data->name); 793 goto fail0; 794 } 795 } 796 value = len; 797 798 spin_lock_irq (&data->dev->lock); 799 if (data->dev->state == STATE_DEV_UNBOUND) { 800 value = -ENOENT; 801 goto gone; 802 } else if ((ep = data->ep) == NULL) { 803 value = -ENODEV; 804 goto gone; 805 } 806 switch (data->dev->gadget->speed) { 807 case USB_SPEED_LOW: 808 case USB_SPEED_FULL: 809 value = usb_ep_enable (ep, &data->desc); 810 if (value == 0) 811 data->state = STATE_EP_ENABLED; 812 break; 813#ifdef HIGHSPEED 814 case USB_SPEED_HIGH: 815 /* fails if caller didn't provide that descriptor... */ 816 value = usb_ep_enable (ep, &data->hs_desc); 817 if (value == 0) 818 data->state = STATE_EP_ENABLED; 819 break; 820#endif 821 default: 822 DBG (data->dev, "unconnected, %s init deferred\n", 823 data->name); 824 data->state = STATE_EP_DEFER_ENABLE; 825 } 826 if (value == 0) 827 fd->f_op = &ep_io_operations; 828gone: 829 spin_unlock_irq (&data->dev->lock); 830 if (value < 0) { 831fail: 832 data->desc.bDescriptorType = 0; 833 data->hs_desc.bDescriptorType = 0; 834 } 835 up (&data->lock); 836 return value; 837fail0: 838 value = -EINVAL; 839 goto fail; 840fail1: 841 value = -EFAULT; 842 goto fail; 843} 844 845static int 846ep_open (struct inode *inode, struct file *fd) 847{ 848 struct ep_data *data = inode->u.generic_ip; 849 int value = -EBUSY; 850 851 if (down_interruptible (&data->lock) != 0) 852 return -EINTR; 853 spin_lock_irq (&data->dev->lock); 854 if (data->dev->state == STATE_DEV_UNBOUND) 855 value = -ENOENT; 856 else if (data->state == STATE_EP_DISABLED) { 857 value = 0; 858 data->state = STATE_EP_READY; 859 get_ep (data); 860 fd->private_data = data; 861 VDEBUG (data->dev, "%s ready\n", data->name); 862 } else 863 DBG (data->dev, "%s state %d\n", 864 data->name, data->state); 865 spin_unlock_irq (&data->dev->lock); 866 up (&data->lock); 867 return value; 868} 869 870/* used before endpoint configuration */ 871static struct file_operations ep_config_operations = { 872 .owner = THIS_MODULE, 873 .llseek = no_llseek, 874 875 .open = ep_open, 876 .write = ep_config, 877 .release = ep_release, 878}; 879 880/*----------------------------------------------------------------------*/ 881 882/* EP0 IMPLEMENTATION can be partly in userspace. 883 * 884 * Drivers that use this facility receive various events, including 885 * control requests the kernel doesn't handle. Drivers that don't 886 * use this facility may be too simple-minded for real applications. 887 */ 888 889static inline void ep0_readable (struct dev_data *dev) 890{ 891 wake_up (&dev->wait); 892 kill_fasync (&dev->fasync, SIGIO, POLL_IN); 893} 894 895static void clean_req (struct usb_ep *ep, struct usb_request *req) 896{ 897 struct dev_data *dev = ep->driver_data; 898 899 if (req->buf != dev->rbuf) { 900 usb_ep_free_buffer (ep, req->buf, req->dma, req->length); 901 req->buf = dev->rbuf; 902 req->dma = DMA_ADDR_INVALID; 903 } 904 req->complete = epio_complete; 905 dev->setup_out_ready = 0; 906} 907 908static void ep0_complete (struct usb_ep *ep, struct usb_request *req) 909{ 910 struct dev_data *dev = ep->driver_data; 911 int free = 1; 912 913 /* for control OUT, data must still get to userspace */ 914 if (!dev->setup_in) { 915 dev->setup_out_error = (req->status != 0); 916 if (!dev->setup_out_error) 917 free = 0; 918 dev->setup_out_ready = 1; 919 ep0_readable (dev); 920 } else if (dev->state == STATE_SETUP) 921 dev->state = STATE_CONNECTED; 922 923 /* clean up as appropriate */ 924 if (free && req->buf != &dev->rbuf) 925 clean_req (ep, req); 926 req->complete = epio_complete; 927} 928 929static int setup_req (struct usb_ep *ep, struct usb_request *req, u16 len) 930{ 931 struct dev_data *dev = ep->driver_data; 932 933 if (dev->setup_out_ready) { 934 DBG (dev, "ep0 request busy!\n"); 935 return -EBUSY; 936 } 937 if (len > sizeof (dev->rbuf)) 938 req->buf = usb_ep_alloc_buffer (ep, len, &req->dma, GFP_ATOMIC); 939 if (req->buf == 0) { 940 req->buf = dev->rbuf; 941 return -ENOMEM; 942 } 943 req->complete = ep0_complete; 944 req->length = len; 945 return 0; 946} 947 948static ssize_t 949ep0_read (struct file *fd, char __user *buf, size_t len, loff_t *ptr) 950{ 951 struct dev_data *dev = fd->private_data; 952 ssize_t retval; 953 enum ep0_state state; 954 955 spin_lock_irq (&dev->lock); 956 957 /* report fd mode change before acting on it */ 958 if (dev->setup_abort) { 959 dev->setup_abort = 0; 960 retval = -EIDRM; 961 goto done; 962 } 963 964 /* control DATA stage */ 965 if ((state = dev->state) == STATE_SETUP) { 966 967 if (dev->setup_in) { /* stall IN */ 968 VDEBUG(dev, "ep0in stall\n"); 969 (void) usb_ep_set_halt (dev->gadget->ep0); 970 retval = -EL2HLT; 971 dev->state = STATE_CONNECTED; 972 973 } else if (len == 0) { /* ack SET_CONFIGURATION etc */ 974 struct usb_ep *ep = dev->gadget->ep0; 975 struct usb_request *req = dev->req; 976 977 if ((retval = setup_req (ep, req, 0)) == 0) 978 retval = usb_ep_queue (ep, req, GFP_ATOMIC); 979 dev->state = STATE_CONNECTED; 980 981 /* assume that was SET_CONFIGURATION */ 982 if (dev->current_config) { 983 unsigned power; 984#ifdef HIGHSPEED 985 if (dev->gadget->speed == USB_SPEED_HIGH) 986 power = dev->hs_config->bMaxPower; 987 else 988#endif 989 power = dev->config->bMaxPower; 990 usb_gadget_vbus_draw(dev->gadget, 2 * power); 991 } 992 993 } else { /* collect OUT data */ 994 if ((fd->f_flags & O_NONBLOCK) != 0 995 && !dev->setup_out_ready) { 996 retval = -EAGAIN; 997 goto done; 998 } 999 spin_unlock_irq (&dev->lock); 1000 retval = wait_event_interruptible (dev->wait, 1001 dev->setup_out_ready != 0); 1002 1003 /* FIXME state could change from under us */ 1004 spin_lock_irq (&dev->lock); 1005 if (retval) 1006 goto done; 1007 if (dev->setup_out_error) 1008 retval = -EIO; 1009 else { 1010 len = min (len, (size_t)dev->req->actual); 1011// FIXME don't call this with the spinlock held ... 1012 if (copy_to_user (buf, &dev->req->buf, len)) 1013 retval = -EFAULT; 1014 clean_req (dev->gadget->ep0, dev->req); 1015 /* NOTE userspace can't yet choose to stall */ 1016 } 1017 } 1018 goto done; 1019 } 1020 1021 /* else normal: return event data */ 1022 if (len < sizeof dev->event [0]) { 1023 retval = -EINVAL; 1024 goto done; 1025 } 1026 len -= len % sizeof (struct usb_gadgetfs_event); 1027 dev->usermode_setup = 1; 1028 1029scan: 1030 /* return queued events right away */ 1031 if (dev->ev_next != 0) { 1032 unsigned i, n; 1033 int tmp = dev->ev_next; 1034 1035 len = min (len, tmp * sizeof (struct usb_gadgetfs_event)); 1036 n = len / sizeof (struct usb_gadgetfs_event); 1037 1038 /* ep0 can't deliver events when STATE_SETUP */ 1039 for (i = 0; i < n; i++) { 1040 if (dev->event [i].type == GADGETFS_SETUP) { 1041 len = n = i + 1; 1042 len *= sizeof (struct usb_gadgetfs_event); 1043 n = 0; 1044 break; 1045 } 1046 } 1047 spin_unlock_irq (&dev->lock); 1048 if (copy_to_user (buf, &dev->event, len)) 1049 retval = -EFAULT; 1050 else 1051 retval = len; 1052 if (len > 0) { 1053 len /= sizeof (struct usb_gadgetfs_event); 1054 1055 /* NOTE this doesn't guard against broken drivers; 1056 * concurrent ep0 readers may lose events. 1057 */ 1058 spin_lock_irq (&dev->lock); 1059 dev->ev_next -= len; 1060 if (dev->ev_next != 0) 1061 memmove (&dev->event, &dev->event [len], 1062 sizeof (struct usb_gadgetfs_event) 1063 * (tmp - len)); 1064 if (n == 0) 1065 dev->state = STATE_SETUP; 1066 spin_unlock_irq (&dev->lock); 1067 } 1068 return retval; 1069 } 1070 if (fd->f_flags & O_NONBLOCK) { 1071 retval = -EAGAIN; 1072 goto done; 1073 } 1074 1075 switch (state) { 1076 default: 1077 DBG (dev, "fail %s, state %d\n", __FUNCTION__, state); 1078 retval = -ESRCH; 1079 break; 1080 case STATE_UNCONNECTED: 1081 case STATE_CONNECTED: 1082 spin_unlock_irq (&dev->lock); 1083 DBG (dev, "%s wait\n", __FUNCTION__); 1084 1085 /* wait for events */ 1086 retval = wait_event_interruptible (dev->wait, 1087 dev->ev_next != 0); 1088 if (retval < 0) 1089 return retval; 1090 spin_lock_irq (&dev->lock); 1091 goto scan; 1092 } 1093 1094done: 1095 spin_unlock_irq (&dev->lock); 1096 return retval; 1097} 1098 1099static struct usb_gadgetfs_event * 1100next_event (struct dev_data *dev, enum usb_gadgetfs_event_type type) 1101{ 1102 struct usb_gadgetfs_event *event; 1103 unsigned i; 1104 1105 switch (type) { 1106 /* these events purge the queue */ 1107 case GADGETFS_DISCONNECT: 1108 if (dev->state == STATE_SETUP) 1109 dev->setup_abort = 1; 1110 // FALL THROUGH 1111 case GADGETFS_CONNECT: 1112 dev->ev_next = 0; 1113 break; 1114 case GADGETFS_SETUP: /* previous request timed out */ 1115 case GADGETFS_SUSPEND: /* same effect */ 1116 /* these events can't be repeated */ 1117 for (i = 0; i != dev->ev_next; i++) { 1118 if (dev->event [i].type != type) 1119 continue; 1120 DBG (dev, "discard old event %d\n", type); 1121 dev->ev_next--; 1122 if (i == dev->ev_next) 1123 break; 1124 /* indices start at zero, for simplicity */ 1125 memmove (&dev->event [i], &dev->event [i + 1], 1126 sizeof (struct usb_gadgetfs_event) 1127 * (dev->ev_next - i)); 1128 } 1129 break; 1130 default: 1131 BUG (); 1132 } 1133 event = &dev->event [dev->ev_next++]; 1134 BUG_ON (dev->ev_next > N_EVENT); 1135 VDEBUG (dev, "ev %d, next %d\n", type, dev->ev_next); 1136 memset (event, 0, sizeof *event); 1137 event->type = type; 1138 return event; 1139} 1140 1141static ssize_t 1142ep0_write (struct file *fd, const char __user *buf, size_t len, loff_t *ptr) 1143{ 1144 struct dev_data *dev = fd->private_data; 1145 ssize_t retval = -ESRCH; 1146 1147 spin_lock_irq (&dev->lock); 1148 1149 /* report fd mode change before acting on it */ 1150 if (dev->setup_abort) { 1151 dev->setup_abort = 0; 1152 retval = -EIDRM; 1153 1154 /* data and/or status stage for control request */ 1155 } else if (dev->state == STATE_SETUP) { 1156 1157 /* IN DATA+STATUS caller makes len <= wLength */ 1158 if (dev->setup_in) { 1159 retval = setup_req (dev->gadget->ep0, dev->req, len); 1160 if (retval == 0) { 1161 spin_unlock_irq (&dev->lock); 1162 if (copy_from_user (dev->req->buf, buf, len)) 1163 retval = -EFAULT; 1164 else 1165 retval = usb_ep_queue ( 1166 dev->gadget->ep0, dev->req, 1167 GFP_KERNEL); 1168 if (retval < 0) { 1169 spin_lock_irq (&dev->lock); 1170 clean_req (dev->gadget->ep0, dev->req); 1171 spin_unlock_irq (&dev->lock); 1172 } else 1173 retval = len; 1174 1175 return retval; 1176 } 1177 1178 /* can stall some OUT transfers */ 1179 } else if (dev->setup_can_stall) { 1180 VDEBUG(dev, "ep0out stall\n"); 1181 (void) usb_ep_set_halt (dev->gadget->ep0); 1182 retval = -EL2HLT; 1183 dev->state = STATE_CONNECTED; 1184 } else { 1185 DBG(dev, "bogus ep0out stall!\n"); 1186 } 1187 } else 1188 DBG (dev, "fail %s, state %d\n", __FUNCTION__, dev->state); 1189 1190 spin_unlock_irq (&dev->lock); 1191 return retval; 1192} 1193 1194static int 1195ep0_fasync (int f, struct file *fd, int on) 1196{ 1197 struct dev_data *dev = fd->private_data; 1198 // caller must F_SETOWN before signal delivery happens 1199 VDEBUG (dev, "%s %s\n", __FUNCTION__, on ? "on" : "off"); 1200 return fasync_helper (f, fd, on, &dev->fasync); 1201} 1202 1203static struct usb_gadget_driver gadgetfs_driver; 1204 1205static int 1206dev_release (struct inode *inode, struct file *fd) 1207{ 1208 struct dev_data *dev = fd->private_data; 1209 1210 /* closing ep0 === shutdown all */ 1211 1212 usb_gadget_unregister_driver (&gadgetfs_driver); 1213 1214 /* at this point "good" hardware has disconnected the 1215 * device from USB; the host won't see it any more. 1216 * alternatively, all host requests will time out. 1217 */ 1218 1219 fasync_helper (-1, fd, 0, &dev->fasync); 1220 kfree (dev->buf); 1221 dev->buf = NULL; 1222 put_dev (dev); 1223 1224 /* other endpoints were all decoupled from this device */ 1225 dev->state = STATE_DEV_DISABLED; 1226 return 0; 1227} 1228 1229static int dev_ioctl (struct inode *inode, struct file *fd, 1230 unsigned code, unsigned long value) 1231{ 1232 struct dev_data *dev = fd->private_data; 1233 struct usb_gadget *gadget = dev->gadget; 1234 1235 if (gadget->ops->ioctl) 1236 return gadget->ops->ioctl (gadget, code, value); 1237 return -ENOTTY; 1238} 1239 1240/* used after device configuration */ 1241static struct file_operations ep0_io_operations = { 1242 .owner = THIS_MODULE, 1243 .llseek = no_llseek, 1244 1245 .read = ep0_read, 1246 .write = ep0_write, 1247 .fasync = ep0_fasync, 1248 // .poll = ep0_poll, 1249 .ioctl = dev_ioctl, 1250 .release = dev_release, 1251}; 1252 1253/*----------------------------------------------------------------------*/ 1254 1255/* The in-kernel gadget driver handles most ep0 issues, in particular 1256 * enumerating the single configuration (as provided from user space). 1257 * 1258 * Unrecognized ep0 requests may be handled in user space. 1259 */ 1260 1261#ifdef HIGHSPEED 1262static void make_qualifier (struct dev_data *dev) 1263{ 1264 struct usb_qualifier_descriptor qual; 1265 struct usb_device_descriptor *desc; 1266 1267 qual.bLength = sizeof qual; 1268 qual.bDescriptorType = USB_DT_DEVICE_QUALIFIER; 1269 qual.bcdUSB = __constant_cpu_to_le16 (0x0200); 1270 1271 desc = dev->dev; 1272 qual.bDeviceClass = desc->bDeviceClass; 1273 qual.bDeviceSubClass = desc->bDeviceSubClass; 1274 qual.bDeviceProtocol = desc->bDeviceProtocol; 1275 1276 /* assumes ep0 uses the same value for both speeds ... */ 1277 qual.bMaxPacketSize0 = desc->bMaxPacketSize0; 1278 1279 qual.bNumConfigurations = 1; 1280 qual.bRESERVED = 0; 1281 1282 memcpy (dev->rbuf, &qual, sizeof qual); 1283} 1284#endif 1285 1286static int 1287config_buf (struct dev_data *dev, u8 type, unsigned index) 1288{ 1289 int len; 1290#ifdef HIGHSPEED 1291 int hs; 1292#endif 1293 1294 /* only one configuration */ 1295 if (index > 0) 1296 return -EINVAL; 1297 1298#ifdef HIGHSPEED 1299 hs = (dev->gadget->speed == USB_SPEED_HIGH); 1300 if (type == USB_DT_OTHER_SPEED_CONFIG) 1301 hs = !hs; 1302 if (hs) { 1303 dev->req->buf = dev->hs_config; 1304 len = le16_to_cpup (&dev->hs_config->wTotalLength); 1305 } else 1306#endif 1307 { 1308 dev->req->buf = dev->config; 1309 len = le16_to_cpup (&dev->config->wTotalLength); 1310 } 1311 ((u8 *)dev->req->buf) [1] = type; 1312 return len; 1313} 1314 1315static int 1316gadgetfs_setup (struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl) 1317{ 1318 struct dev_data *dev = get_gadget_data (gadget); 1319 struct usb_request *req = dev->req; 1320 int value = -EOPNOTSUPP; 1321 struct usb_gadgetfs_event *event; 1322 u16 w_value = le16_to_cpu(ctrl->wValue); 1323 u16 w_length = le16_to_cpu(ctrl->wLength); 1324 1325 spin_lock (&dev->lock); 1326 dev->setup_abort = 0; 1327 if (dev->state == STATE_UNCONNECTED) { 1328 struct usb_ep *ep; 1329 struct ep_data *data; 1330 1331 dev->state = STATE_CONNECTED; 1332 dev->dev->bMaxPacketSize0 = gadget->ep0->maxpacket; 1333 1334#ifdef HIGHSPEED 1335 if (gadget->speed == USB_SPEED_HIGH && dev->hs_config == 0) { 1336 ERROR (dev, "no high speed config??\n"); 1337 return -EINVAL; 1338 } 1339#endif /* HIGHSPEED */ 1340 1341 INFO (dev, "connected\n"); 1342 event = next_event (dev, GADGETFS_CONNECT); 1343 event->u.speed = gadget->speed; 1344 ep0_readable (dev); 1345 1346 list_for_each_entry (ep, &gadget->ep_list, ep_list) { 1347 data = ep->driver_data; 1348 /* ... down_trylock (&data->lock) ... */ 1349 if (data->state != STATE_EP_DEFER_ENABLE) 1350 continue; 1351#ifdef HIGHSPEED 1352 if (gadget->speed == USB_SPEED_HIGH) 1353 value = usb_ep_enable (ep, &data->hs_desc); 1354 else 1355#endif /* HIGHSPEED */ 1356 value = usb_ep_enable (ep, &data->desc); 1357 if (value) { 1358 ERROR (dev, "deferred %s enable --> %d\n", 1359 data->name, value); 1360 continue; 1361 } 1362 data->state = STATE_EP_ENABLED; 1363 wake_up (&data->wait); 1364 DBG (dev, "woke up %s waiters\n", data->name); 1365 } 1366 1367 /* host may have given up waiting for response. we can miss control 1368 * requests handled lower down (device/endpoint status and features); 1369 * then ep0_{read,write} will report the wrong status. controller 1370 * driver will have aborted pending i/o. 1371 */ 1372 } else if (dev->state == STATE_SETUP) 1373 dev->setup_abort = 1; 1374 1375 req->buf = dev->rbuf; 1376 req->dma = DMA_ADDR_INVALID; 1377 req->context = NULL; 1378 value = -EOPNOTSUPP; 1379 switch (ctrl->bRequest) { 1380 1381 case USB_REQ_GET_DESCRIPTOR: 1382 if (ctrl->bRequestType != USB_DIR_IN) 1383 goto unrecognized; 1384 switch (w_value >> 8) { 1385 1386 case USB_DT_DEVICE: 1387 value = min (w_length, (u16) sizeof *dev->dev); 1388 req->buf = dev->dev; 1389 break; 1390#ifdef HIGHSPEED 1391 case USB_DT_DEVICE_QUALIFIER: 1392 if (!dev->hs_config) 1393 break; 1394 value = min (w_length, (u16) 1395 sizeof (struct usb_qualifier_descriptor)); 1396 make_qualifier (dev); 1397 break; 1398 case USB_DT_OTHER_SPEED_CONFIG: 1399 // FALLTHROUGH 1400#endif 1401 case USB_DT_CONFIG: 1402 value = config_buf (dev, 1403 w_value >> 8, 1404 w_value & 0xff); 1405 if (value >= 0) 1406 value = min (w_length, (u16) value); 1407 break; 1408 case USB_DT_STRING: 1409 goto unrecognized; 1410 1411 default: // all others are errors 1412 break; 1413 } 1414 break; 1415 1416 /* currently one config, two speeds */ 1417 case USB_REQ_SET_CONFIGURATION: 1418 if (ctrl->bRequestType != 0) 1419 break; 1420 if (0 == (u8) w_value) { 1421 value = 0; 1422 dev->current_config = 0; 1423 usb_gadget_vbus_draw(gadget, 8 /* mA */ ); 1424 // user mode expected to disable endpoints 1425 } else { 1426 u8 config, power; 1427#ifdef HIGHSPEED 1428 if (gadget->speed == USB_SPEED_HIGH) { 1429 config = dev->hs_config->bConfigurationValue; 1430 power = dev->hs_config->bMaxPower; 1431 } else 1432#endif 1433 { 1434 config = dev->config->bConfigurationValue; 1435 power = dev->config->bMaxPower; 1436 } 1437 1438 if (config == (u8) w_value) { 1439 value = 0; 1440 dev->current_config = config; 1441 usb_gadget_vbus_draw(gadget, 2 * power); 1442 } 1443 } 1444 1445 /* report SET_CONFIGURATION like any other control request, 1446 * except that usermode may not stall this. the next 1447 * request mustn't be allowed start until this finishes: 1448 * endpoints and threads set up, etc. 1449 * 1450 * NOTE: older PXA hardware (before PXA 255: without UDCCFR) 1451 * has bad/racey automagic that prevents synchronizing here. 1452 * even kernel mode drivers often miss them. 1453 */ 1454 if (value == 0) { 1455 INFO (dev, "configuration #%d\n", dev->current_config); 1456 if (dev->usermode_setup) { 1457 dev->setup_can_stall = 0; 1458 goto delegate; 1459 } 1460 } 1461 break; 1462 1463#ifndef CONFIG_USB_GADGETFS_PXA2XX 1464 /* PXA automagically handles this request too */ 1465 case USB_REQ_GET_CONFIGURATION: 1466 if (ctrl->bRequestType != 0x80) 1467 break; 1468 *(u8 *)req->buf = dev->current_config; 1469 value = min (w_length, (u16) 1); 1470 break; 1471#endif 1472 1473 default: 1474unrecognized: 1475 VDEBUG (dev, "%s req%02x.%02x v%04x i%04x l%d\n", 1476 dev->usermode_setup ? "delegate" : "fail", 1477 ctrl->bRequestType, ctrl->bRequest, 1478 w_value, le16_to_cpu(ctrl->wIndex), w_length); 1479 1480 /* if there's an ep0 reader, don't stall */ 1481 if (dev->usermode_setup) { 1482 dev->setup_can_stall = 1; 1483delegate: 1484 dev->setup_in = (ctrl->bRequestType & USB_DIR_IN) 1485 ? 1 : 0; 1486 dev->setup_out_ready = 0; 1487 dev->setup_out_error = 0; 1488 value = 0; 1489 1490 /* read DATA stage for OUT right away */ 1491 if (unlikely (!dev->setup_in && w_length)) { 1492 value = setup_req (gadget->ep0, dev->req, 1493 w_length); 1494 if (value < 0) 1495 break; 1496 value = usb_ep_queue (gadget->ep0, dev->req, 1497 GFP_ATOMIC); 1498 if (value < 0) { 1499 clean_req (gadget->ep0, dev->req); 1500 break; 1501 } 1502 1503 /* we can't currently stall these */ 1504 dev->setup_can_stall = 0; 1505 } 1506 1507 /* state changes when reader collects event */ 1508 event = next_event (dev, GADGETFS_SETUP); 1509 event->u.setup = *ctrl; 1510 ep0_readable (dev); 1511 spin_unlock (&dev->lock); 1512 return 0; 1513 } 1514 } 1515 1516 /* proceed with data transfer and status phases? */ 1517 if (value >= 0 && dev->state != STATE_SETUP) { 1518 req->length = value; 1519 req->zero = value < w_length; 1520 value = usb_ep_queue (gadget->ep0, req, GFP_ATOMIC); 1521 if (value < 0) { 1522 DBG (dev, "ep_queue --> %d\n", value); 1523 req->status = 0; 1524 } 1525 } 1526 1527 /* device stalls when value < 0 */ 1528 spin_unlock (&dev->lock); 1529 return value; 1530} 1531 1532static void destroy_ep_files (struct dev_data *dev) 1533{ 1534 struct list_head *entry, *tmp; 1535 1536 DBG (dev, "%s %d\n", __FUNCTION__, dev->state); 1537 1538 /* dev->state must prevent interference */ 1539restart: 1540 spin_lock_irq (&dev->lock); 1541 list_for_each_safe (entry, tmp, &dev->epfiles) { 1542 struct ep_data *ep; 1543 struct inode *parent; 1544 struct dentry *dentry; 1545 1546 /* break link to FS */ 1547 ep = list_entry (entry, struct ep_data, epfiles); 1548 list_del_init (&ep->epfiles); 1549 dentry = ep->dentry; 1550 ep->dentry = NULL; 1551 parent = dentry->d_parent->d_inode; 1552 1553 /* break link to controller */ 1554 if (ep->state == STATE_EP_ENABLED) 1555 (void) usb_ep_disable (ep->ep); 1556 ep->state = STATE_EP_UNBOUND; 1557 usb_ep_free_request (ep->ep, ep->req); 1558 ep->ep = NULL; 1559 wake_up (&ep->wait); 1560 put_ep (ep); 1561 1562 spin_unlock_irq (&dev->lock); 1563 1564 /* break link to dcache */ 1565 mutex_lock (&parent->i_mutex); 1566 d_delete (dentry); 1567 dput (dentry); 1568 mutex_unlock (&parent->i_mutex); 1569 1570 /* fds may still be open */ 1571 goto restart; 1572 } 1573 spin_unlock_irq (&dev->lock); 1574} 1575 1576 1577static struct inode * 1578gadgetfs_create_file (struct super_block *sb, char const *name, 1579 void *data, struct file_operations *fops, 1580 struct dentry **dentry_p); 1581 1582static int activate_ep_files (struct dev_data *dev) 1583{ 1584 struct usb_ep *ep; 1585 1586 gadget_for_each_ep (ep, dev->gadget) { 1587 struct ep_data *data; 1588 1589 data = kmalloc (sizeof *data, GFP_KERNEL); 1590 if (!data) 1591 goto enomem; 1592 memset (data, 0, sizeof data); 1593 data->state = STATE_EP_DISABLED; 1594 init_MUTEX (&data->lock); 1595 init_waitqueue_head (&data->wait); 1596 1597 strncpy (data->name, ep->name, sizeof (data->name) - 1); 1598 atomic_set (&data->count, 1); 1599 data->dev = dev; 1600 get_dev (dev); 1601 1602 data->ep = ep; 1603 ep->driver_data = data; 1604 1605 data->req = usb_ep_alloc_request (ep, GFP_KERNEL); 1606 if (!data->req) 1607 goto enomem; 1608 1609 data->inode = gadgetfs_create_file (dev->sb, data->name, 1610 data, &ep_config_operations, 1611 &data->dentry); 1612 if (!data->inode) { 1613 kfree (data); 1614 goto enomem; 1615 } 1616 list_add_tail (&data->epfiles, &dev->epfiles); 1617 } 1618 return 0; 1619 1620enomem: 1621 DBG (dev, "%s enomem\n", __FUNCTION__); 1622 destroy_ep_files (dev); 1623 return -ENOMEM; 1624} 1625 1626static void 1627gadgetfs_unbind (struct usb_gadget *gadget) 1628{ 1629 struct dev_data *dev = get_gadget_data (gadget); 1630 1631 DBG (dev, "%s\n", __FUNCTION__); 1632 1633 spin_lock_irq (&dev->lock); 1634 dev->state = STATE_DEV_UNBOUND; 1635 spin_unlock_irq (&dev->lock); 1636 1637 destroy_ep_files (dev); 1638 gadget->ep0->driver_data = NULL; 1639 set_gadget_data (gadget, NULL); 1640 1641 /* we've already been disconnected ... no i/o is active */ 1642 if (dev->req) 1643 usb_ep_free_request (gadget->ep0, dev->req); 1644 DBG (dev, "%s done\n", __FUNCTION__); 1645 put_dev (dev); 1646} 1647 1648static struct dev_data *the_device; 1649 1650static int 1651gadgetfs_bind (struct usb_gadget *gadget) 1652{ 1653 struct dev_data *dev = the_device; 1654 1655 if (!dev) 1656 return -ESRCH; 1657 if (0 != strcmp (CHIP, gadget->name)) { 1658 printk (KERN_ERR "%s expected %s controller not %s\n", 1659 shortname, CHIP, gadget->name); 1660 return -ENODEV; 1661 } 1662 1663 set_gadget_data (gadget, dev); 1664 dev->gadget = gadget; 1665 gadget->ep0->driver_data = dev; 1666 dev->dev->bMaxPacketSize0 = gadget->ep0->maxpacket; 1667 1668 /* preallocate control response and buffer */ 1669 dev->req = usb_ep_alloc_request (gadget->ep0, GFP_KERNEL); 1670 if (!dev->req) 1671 goto enomem; 1672 dev->req->context = NULL; 1673 dev->req->complete = epio_complete; 1674 1675 if (activate_ep_files (dev) < 0) 1676 goto enomem; 1677 1678 INFO (dev, "bound to %s driver\n", gadget->name); 1679 dev->state = STATE_UNCONNECTED; 1680 get_dev (dev); 1681 return 0; 1682 1683enomem: 1684 gadgetfs_unbind (gadget); 1685 return -ENOMEM; 1686} 1687 1688static void 1689gadgetfs_disconnect (struct usb_gadget *gadget) 1690{ 1691 struct dev_data *dev = get_gadget_data (gadget); 1692 1693 if (dev->state == STATE_UNCONNECTED) { 1694 DBG (dev, "already unconnected\n"); 1695 return; 1696 } 1697 dev->state = STATE_UNCONNECTED; 1698 1699 INFO (dev, "disconnected\n"); 1700 spin_lock (&dev->lock); 1701 next_event (dev, GADGETFS_DISCONNECT); 1702 ep0_readable (dev); 1703 spin_unlock (&dev->lock); 1704} 1705 1706static void 1707gadgetfs_suspend (struct usb_gadget *gadget) 1708{ 1709 struct dev_data *dev = get_gadget_data (gadget); 1710 1711 INFO (dev, "suspended from state %d\n", dev->state); 1712 spin_lock (&dev->lock); 1713 switch (dev->state) { 1714 case STATE_SETUP: // VERY odd... host died?? 1715 case STATE_CONNECTED: 1716 case STATE_UNCONNECTED: 1717 next_event (dev, GADGETFS_SUSPEND); 1718 ep0_readable (dev); 1719 /* FALLTHROUGH */ 1720 default: 1721 break; 1722 } 1723 spin_unlock (&dev->lock); 1724} 1725 1726static struct usb_gadget_driver gadgetfs_driver = { 1727#ifdef HIGHSPEED 1728 .speed = USB_SPEED_HIGH, 1729#else 1730 .speed = USB_SPEED_FULL, 1731#endif 1732 .function = (char *) driver_desc, 1733 .bind = gadgetfs_bind, 1734 .unbind = gadgetfs_unbind, 1735 .setup = gadgetfs_setup, 1736 .disconnect = gadgetfs_disconnect, 1737 .suspend = gadgetfs_suspend, 1738 1739 .driver = { 1740 .name = (char *) shortname, 1741 // .shutdown = ... 1742 // .suspend = ... 1743 // .resume = ... 1744 }, 1745}; 1746 1747/*----------------------------------------------------------------------*/ 1748 1749static void gadgetfs_nop(struct usb_gadget *arg) { } 1750 1751static int gadgetfs_probe (struct usb_gadget *gadget) 1752{ 1753 CHIP = gadget->name; 1754 return -EISNAM; 1755} 1756 1757static struct usb_gadget_driver probe_driver = { 1758 .speed = USB_SPEED_HIGH, 1759 .bind = gadgetfs_probe, 1760 .unbind = gadgetfs_nop, 1761 .setup = (void *)gadgetfs_nop, 1762 .disconnect = gadgetfs_nop, 1763 .driver = { 1764 .name = "nop", 1765 }, 1766}; 1767 1768 1769/* DEVICE INITIALIZATION 1770 * 1771 * fd = open ("/dev/gadget/$CHIP", O_RDWR) 1772 * status = write (fd, descriptors, sizeof descriptors) 1773 * 1774 * That write establishes the device configuration, so the kernel can 1775 * bind to the controller ... guaranteeing it can handle enumeration 1776 * at all necessary speeds. Descriptor order is: 1777 * 1778 * . message tag (u32, host order) ... for now, must be zero; it 1779 * would change to support features like multi-config devices 1780 * . full/low speed config ... all wTotalLength bytes (with interface, 1781 * class, altsetting, endpoint, and other descriptors) 1782 * . high speed config ... all descriptors, for high speed operation; 1783 * this one's optional except for high-speed hardware 1784 * . device descriptor 1785 * 1786 * Endpoints are not yet enabled. Drivers may want to immediately 1787 * initialize them, using the /dev/gadget/ep* files that are available 1788 * as soon as the kernel sees the configuration, or they can wait 1789 * until device configuration and interface altsetting changes create 1790 * the need to configure (or unconfigure) them. 1791 * 1792 * After initialization, the device stays active for as long as that 1793 * $CHIP file is open. Events may then be read from that descriptor, 1794 * such configuration notifications. More complex drivers will handle 1795 * some control requests in user space. 1796 */ 1797 1798static int is_valid_config (struct usb_config_descriptor *config) 1799{ 1800 return config->bDescriptorType == USB_DT_CONFIG 1801 && config->bLength == USB_DT_CONFIG_SIZE 1802 && config->bConfigurationValue != 0 1803 && (config->bmAttributes & USB_CONFIG_ATT_ONE) != 0 1804 && (config->bmAttributes & USB_CONFIG_ATT_WAKEUP) == 0; 1805 /* FIXME if gadget->is_otg, _must_ include an otg descriptor */ 1806 /* FIXME check lengths: walk to end */ 1807} 1808 1809static ssize_t 1810dev_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr) 1811{ 1812 struct dev_data *dev = fd->private_data; 1813 ssize_t value = len, length = len; 1814 unsigned total; 1815 u32 tag; 1816 char *kbuf; 1817 1818 if (dev->state != STATE_OPENED) 1819 return -EEXIST; 1820 1821 if (len < (USB_DT_CONFIG_SIZE + USB_DT_DEVICE_SIZE + 4)) 1822 return -EINVAL; 1823 1824 /* we might need to change message format someday */ 1825 if (copy_from_user (&tag, buf, 4)) 1826 return -EFAULT; 1827 if (tag != 0) 1828 return -EINVAL; 1829 buf += 4; 1830 length -= 4; 1831 1832 kbuf = kmalloc (length, SLAB_KERNEL); 1833 if (!kbuf) 1834 return -ENOMEM; 1835 if (copy_from_user (kbuf, buf, length)) { 1836 kfree (kbuf); 1837 return -EFAULT; 1838 } 1839 1840 spin_lock_irq (&dev->lock); 1841 value = -EINVAL; 1842 if (dev->buf) 1843 goto fail; 1844 dev->buf = kbuf; 1845 1846 /* full or low speed config */ 1847 dev->config = (void *) kbuf; 1848 total = le16_to_cpup (&dev->config->wTotalLength); 1849 if (!is_valid_config (dev->config) || total >= length) 1850 goto fail; 1851 kbuf += total; 1852 length -= total; 1853 1854 /* optional high speed config */ 1855 if (kbuf [1] == USB_DT_CONFIG) { 1856 dev->hs_config = (void *) kbuf; 1857 total = le16_to_cpup (&dev->hs_config->wTotalLength); 1858 if (!is_valid_config (dev->hs_config) || total >= length) 1859 goto fail; 1860 kbuf += total; 1861 length -= total; 1862 } 1863 1864 /* could support multiple configs, using another encoding! */ 1865 1866 /* device descriptor (tweaked for paranoia) */ 1867 if (length != USB_DT_DEVICE_SIZE) 1868 goto fail; 1869 dev->dev = (void *)kbuf; 1870 if (dev->dev->bLength != USB_DT_DEVICE_SIZE 1871 || dev->dev->bDescriptorType != USB_DT_DEVICE 1872 || dev->dev->bNumConfigurations != 1) 1873 goto fail; 1874 dev->dev->bNumConfigurations = 1; 1875 dev->dev->bcdUSB = __constant_cpu_to_le16 (0x0200); 1876 1877 /* triggers gadgetfs_bind(); then we can enumerate. */ 1878 spin_unlock_irq (&dev->lock); 1879 value = usb_gadget_register_driver (&gadgetfs_driver); 1880 if (value != 0) { 1881 kfree (dev->buf); 1882 dev->buf = NULL; 1883 } else { 1884 /* at this point "good" hardware has for the first time 1885 * let the USB the host see us. alternatively, if users 1886 * unplug/replug that will clear all the error state. 1887 * 1888 * note: everything running before here was guaranteed 1889 * to choke driver model style diagnostics. from here 1890 * on, they can work ... except in cleanup paths that 1891 * kick in after the ep0 descriptor is closed. 1892 */ 1893 fd->f_op = &ep0_io_operations; 1894 value = len; 1895 } 1896 return value; 1897 1898fail: 1899 spin_unlock_irq (&dev->lock); 1900 pr_debug ("%s: %s fail %Zd, %p\n", shortname, __FUNCTION__, value, dev); 1901 kfree (dev->buf); 1902 dev->buf = NULL; 1903 return value; 1904} 1905 1906static int 1907dev_open (struct inode *inode, struct file *fd) 1908{ 1909 struct dev_data *dev = inode->u.generic_ip; 1910 int value = -EBUSY; 1911 1912 if (dev->state == STATE_DEV_DISABLED) { 1913 dev->ev_next = 0; 1914 dev->state = STATE_OPENED; 1915 fd->private_data = dev; 1916 get_dev (dev); 1917 value = 0; 1918 } 1919 return value; 1920} 1921 1922static struct file_operations dev_init_operations = { 1923 .owner = THIS_MODULE, 1924 .llseek = no_llseek, 1925 1926 .open = dev_open, 1927 .write = dev_config, 1928 .fasync = ep0_fasync, 1929 .ioctl = dev_ioctl, 1930 .release = dev_release, 1931}; 1932 1933/*----------------------------------------------------------------------*/ 1934 1935/* FILESYSTEM AND SUPERBLOCK OPERATIONS 1936 * 1937 * Mounting the filesystem creates a controller file, used first for 1938 * device configuration then later for event monitoring. 1939 */ 1940 1941 1942/* FIXME PAM etc could set this security policy without mount options 1943 * if epfiles inherited ownership and permissons from ep0 ... 1944 */ 1945 1946static unsigned default_uid; 1947static unsigned default_gid; 1948static unsigned default_perm = S_IRUSR | S_IWUSR; 1949 1950module_param (default_uid, uint, 0644); 1951module_param (default_gid, uint, 0644); 1952module_param (default_perm, uint, 0644); 1953 1954 1955static struct inode * 1956gadgetfs_make_inode (struct super_block *sb, 1957 void *data, struct file_operations *fops, 1958 int mode) 1959{ 1960 struct inode *inode = new_inode (sb); 1961 1962 if (inode) { 1963 inode->i_mode = mode; 1964 inode->i_uid = default_uid; 1965 inode->i_gid = default_gid; 1966 inode->i_blksize = PAGE_CACHE_SIZE; 1967 inode->i_blocks = 0; 1968 inode->i_atime = inode->i_mtime = inode->i_ctime 1969 = CURRENT_TIME; 1970 inode->u.generic_ip = data; 1971 inode->i_fop = fops; 1972 } 1973 return inode; 1974} 1975 1976/* creates in fs root directory, so non-renamable and non-linkable. 1977 * so inode and dentry are paired, until device reconfig. 1978 */ 1979static struct inode * 1980gadgetfs_create_file (struct super_block *sb, char const *name, 1981 void *data, struct file_operations *fops, 1982 struct dentry **dentry_p) 1983{ 1984 struct dentry *dentry; 1985 struct inode *inode; 1986 1987 dentry = d_alloc_name(sb->s_root, name); 1988 if (!dentry) 1989 return NULL; 1990 1991 inode = gadgetfs_make_inode (sb, data, fops, 1992 S_IFREG | (default_perm & S_IRWXUGO)); 1993 if (!inode) { 1994 dput(dentry); 1995 return NULL; 1996 } 1997 d_add (dentry, inode); 1998 *dentry_p = dentry; 1999 return inode; 2000} 2001 2002static struct super_operations gadget_fs_operations = { 2003 .statfs = simple_statfs, 2004 .drop_inode = generic_delete_inode, 2005}; 2006 2007static int 2008gadgetfs_fill_super (struct super_block *sb, void *opts, int silent) 2009{ 2010 struct inode *inode; 2011 struct dentry *d; 2012 struct dev_data *dev; 2013 2014 if (the_device) 2015 return -ESRCH; 2016 2017 /* fake probe to determine $CHIP */ 2018 (void) usb_gadget_register_driver (&probe_driver); 2019 if (!CHIP) 2020 return -ENODEV; 2021 2022 /* superblock */ 2023 sb->s_blocksize = PAGE_CACHE_SIZE; 2024 sb->s_blocksize_bits = PAGE_CACHE_SHIFT; 2025 sb->s_magic = GADGETFS_MAGIC; 2026 sb->s_op = &gadget_fs_operations; 2027 sb->s_time_gran = 1; 2028 2029 /* root inode */ 2030 inode = gadgetfs_make_inode (sb, 2031 NULL, &simple_dir_operations, 2032 S_IFDIR | S_IRUGO | S_IXUGO); 2033 if (!inode) 2034 return -ENOMEM; 2035 inode->i_op = &simple_dir_inode_operations; 2036 if (!(d = d_alloc_root (inode))) { 2037 iput (inode); 2038 return -ENOMEM; 2039 } 2040 sb->s_root = d; 2041 2042 /* the ep0 file is named after the controller we expect; 2043 * user mode code can use it for sanity checks, like we do. 2044 */ 2045 dev = dev_new (); 2046 if (!dev) 2047 return -ENOMEM; 2048 2049 dev->sb = sb; 2050 if (!(inode = gadgetfs_create_file (sb, CHIP, 2051 dev, &dev_init_operations, 2052 &dev->dentry))) { 2053 put_dev(dev); 2054 return -ENOMEM; 2055 } 2056 2057 /* other endpoint files are available after hardware setup, 2058 * from binding to a controller. 2059 */ 2060 the_device = dev; 2061 return 0; 2062} 2063 2064/* "mount -t gadgetfs path /dev/gadget" ends up here */ 2065static struct super_block * 2066gadgetfs_get_sb (struct file_system_type *t, int flags, 2067 const char *path, void *opts) 2068{ 2069 return get_sb_single (t, flags, opts, gadgetfs_fill_super); 2070} 2071 2072static void 2073gadgetfs_kill_sb (struct super_block *sb) 2074{ 2075 kill_litter_super (sb); 2076 if (the_device) { 2077 put_dev (the_device); 2078 the_device = NULL; 2079 } 2080} 2081 2082/*----------------------------------------------------------------------*/ 2083 2084static struct file_system_type gadgetfs_type = { 2085 .owner = THIS_MODULE, 2086 .name = shortname, 2087 .get_sb = gadgetfs_get_sb, 2088 .kill_sb = gadgetfs_kill_sb, 2089}; 2090 2091/*----------------------------------------------------------------------*/ 2092 2093static int __init init (void) 2094{ 2095 int status; 2096 2097 status = register_filesystem (&gadgetfs_type); 2098 if (status == 0) 2099 pr_info ("%s: %s, version " DRIVER_VERSION "\n", 2100 shortname, driver_desc); 2101 return status; 2102} 2103module_init (init); 2104 2105static void __exit cleanup (void) 2106{ 2107 pr_debug ("unregister %s\n", shortname); 2108 unregister_filesystem (&gadgetfs_type); 2109} 2110module_exit (cleanup); 2111 2112