inode.c revision 8a7471aba19dc526978a03bfe2e3c122712b5900
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 unsigned setup_wLength; 139 140 /* the rest is basically write-once */ 141 struct usb_config_descriptor *config, *hs_config; 142 struct usb_device_descriptor *dev; 143 struct usb_request *req; 144 struct usb_gadget *gadget; 145 struct list_head epfiles; 146 void *buf; 147 wait_queue_head_t wait; 148 struct super_block *sb; 149 struct dentry *dentry; 150 151 /* except this scratch i/o buffer for ep0 */ 152 u8 rbuf [256]; 153}; 154 155static inline void get_dev (struct dev_data *data) 156{ 157 atomic_inc (&data->count); 158} 159 160static void put_dev (struct dev_data *data) 161{ 162 if (likely (!atomic_dec_and_test (&data->count))) 163 return; 164 /* needs no more cleanup */ 165 BUG_ON (waitqueue_active (&data->wait)); 166 kfree (data); 167} 168 169static struct dev_data *dev_new (void) 170{ 171 struct dev_data *dev; 172 173 dev = kzalloc(sizeof(*dev), GFP_KERNEL); 174 if (!dev) 175 return NULL; 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; /* NULL for writes */ 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 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 (priv->ubuf == NULL 583 || unlikely(req->actual == 0) 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; 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 = (ubuf ? -EIOCBRETRY : -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, length = len; 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 } 795 796 spin_lock_irq (&data->dev->lock); 797 if (data->dev->state == STATE_DEV_UNBOUND) { 798 value = -ENOENT; 799 goto gone; 800 } else if ((ep = data->ep) == NULL) { 801 value = -ENODEV; 802 goto gone; 803 } 804 switch (data->dev->gadget->speed) { 805 case USB_SPEED_LOW: 806 case USB_SPEED_FULL: 807 value = usb_ep_enable (ep, &data->desc); 808 if (value == 0) 809 data->state = STATE_EP_ENABLED; 810 break; 811#ifdef CONFIG_USB_GADGET_DUALSPEED 812 case USB_SPEED_HIGH: 813 /* fails if caller didn't provide that descriptor... */ 814 value = usb_ep_enable (ep, &data->hs_desc); 815 if (value == 0) 816 data->state = STATE_EP_ENABLED; 817 break; 818#endif 819 default: 820 DBG (data->dev, "unconnected, %s init deferred\n", 821 data->name); 822 data->state = STATE_EP_DEFER_ENABLE; 823 } 824 if (value == 0) { 825 fd->f_op = &ep_io_operations; 826 value = length; 827 } 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->i_private; 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 req->zero = 0; 946 return 0; 947} 948 949static ssize_t 950ep0_read (struct file *fd, char __user *buf, size_t len, loff_t *ptr) 951{ 952 struct dev_data *dev = fd->private_data; 953 ssize_t retval; 954 enum ep0_state state; 955 956 spin_lock_irq (&dev->lock); 957 958 /* report fd mode change before acting on it */ 959 if (dev->setup_abort) { 960 dev->setup_abort = 0; 961 retval = -EIDRM; 962 goto done; 963 } 964 965 /* control DATA stage */ 966 if ((state = dev->state) == STATE_SETUP) { 967 968 if (dev->setup_in) { /* stall IN */ 969 VDEBUG(dev, "ep0in stall\n"); 970 (void) usb_ep_set_halt (dev->gadget->ep0); 971 retval = -EL2HLT; 972 dev->state = STATE_CONNECTED; 973 974 } else if (len == 0) { /* ack SET_CONFIGURATION etc */ 975 struct usb_ep *ep = dev->gadget->ep0; 976 struct usb_request *req = dev->req; 977 978 if ((retval = setup_req (ep, req, 0)) == 0) 979 retval = usb_ep_queue (ep, req, GFP_ATOMIC); 980 dev->state = STATE_CONNECTED; 981 982 /* assume that was SET_CONFIGURATION */ 983 if (dev->current_config) { 984 unsigned power; 985#ifdef CONFIG_USB_GADGET_DUALSPEED 986 if (dev->gadget->speed == USB_SPEED_HIGH) 987 power = dev->hs_config->bMaxPower; 988 else 989#endif 990 power = dev->config->bMaxPower; 991 usb_gadget_vbus_draw(dev->gadget, 2 * power); 992 } 993 994 } else { /* collect OUT data */ 995 if ((fd->f_flags & O_NONBLOCK) != 0 996 && !dev->setup_out_ready) { 997 retval = -EAGAIN; 998 goto done; 999 } 1000 spin_unlock_irq (&dev->lock); 1001 retval = wait_event_interruptible (dev->wait, 1002 dev->setup_out_ready != 0); 1003 1004 /* FIXME state could change from under us */ 1005 spin_lock_irq (&dev->lock); 1006 if (retval) 1007 goto done; 1008 if (dev->setup_out_error) 1009 retval = -EIO; 1010 else { 1011 len = min (len, (size_t)dev->req->actual); 1012// FIXME don't call this with the spinlock held ... 1013 if (copy_to_user (buf, &dev->req->buf, len)) 1014 retval = -EFAULT; 1015 clean_req (dev->gadget->ep0, dev->req); 1016 /* NOTE userspace can't yet choose to stall */ 1017 } 1018 } 1019 goto done; 1020 } 1021 1022 /* else normal: return event data */ 1023 if (len < sizeof dev->event [0]) { 1024 retval = -EINVAL; 1025 goto done; 1026 } 1027 len -= len % sizeof (struct usb_gadgetfs_event); 1028 dev->usermode_setup = 1; 1029 1030scan: 1031 /* return queued events right away */ 1032 if (dev->ev_next != 0) { 1033 unsigned i, n; 1034 int tmp = dev->ev_next; 1035 1036 len = min (len, tmp * sizeof (struct usb_gadgetfs_event)); 1037 n = len / sizeof (struct usb_gadgetfs_event); 1038 1039 /* ep0 can't deliver events when STATE_SETUP */ 1040 for (i = 0; i < n; i++) { 1041 if (dev->event [i].type == GADGETFS_SETUP) { 1042 len = i + 1; 1043 len *= sizeof (struct usb_gadgetfs_event); 1044 n = 0; 1045 break; 1046 } 1047 } 1048 spin_unlock_irq (&dev->lock); 1049 if (copy_to_user (buf, &dev->event, len)) 1050 retval = -EFAULT; 1051 else 1052 retval = len; 1053 if (len > 0) { 1054 len /= sizeof (struct usb_gadgetfs_event); 1055 1056 /* NOTE this doesn't guard against broken drivers; 1057 * concurrent ep0 readers may lose events. 1058 */ 1059 spin_lock_irq (&dev->lock); 1060 dev->ev_next -= len; 1061 if (dev->ev_next != 0) 1062 memmove (&dev->event, &dev->event [len], 1063 sizeof (struct usb_gadgetfs_event) 1064 * (tmp - len)); 1065 if (n == 0) 1066 dev->state = STATE_SETUP; 1067 spin_unlock_irq (&dev->lock); 1068 } 1069 return retval; 1070 } 1071 if (fd->f_flags & O_NONBLOCK) { 1072 retval = -EAGAIN; 1073 goto done; 1074 } 1075 1076 switch (state) { 1077 default: 1078 DBG (dev, "fail %s, state %d\n", __FUNCTION__, state); 1079 retval = -ESRCH; 1080 break; 1081 case STATE_UNCONNECTED: 1082 case STATE_CONNECTED: 1083 spin_unlock_irq (&dev->lock); 1084 DBG (dev, "%s wait\n", __FUNCTION__); 1085 1086 /* wait for events */ 1087 retval = wait_event_interruptible (dev->wait, 1088 dev->ev_next != 0); 1089 if (retval < 0) 1090 return retval; 1091 spin_lock_irq (&dev->lock); 1092 goto scan; 1093 } 1094 1095done: 1096 spin_unlock_irq (&dev->lock); 1097 return retval; 1098} 1099 1100static struct usb_gadgetfs_event * 1101next_event (struct dev_data *dev, enum usb_gadgetfs_event_type type) 1102{ 1103 struct usb_gadgetfs_event *event; 1104 unsigned i; 1105 1106 switch (type) { 1107 /* these events purge the queue */ 1108 case GADGETFS_DISCONNECT: 1109 if (dev->state == STATE_SETUP) 1110 dev->setup_abort = 1; 1111 // FALL THROUGH 1112 case GADGETFS_CONNECT: 1113 dev->ev_next = 0; 1114 break; 1115 case GADGETFS_SETUP: /* previous request timed out */ 1116 case GADGETFS_SUSPEND: /* same effect */ 1117 /* these events can't be repeated */ 1118 for (i = 0; i != dev->ev_next; i++) { 1119 if (dev->event [i].type != type) 1120 continue; 1121 DBG (dev, "discard old event %d\n", type); 1122 dev->ev_next--; 1123 if (i == dev->ev_next) 1124 break; 1125 /* indices start at zero, for simplicity */ 1126 memmove (&dev->event [i], &dev->event [i + 1], 1127 sizeof (struct usb_gadgetfs_event) 1128 * (dev->ev_next - i)); 1129 } 1130 break; 1131 default: 1132 BUG (); 1133 } 1134 event = &dev->event [dev->ev_next++]; 1135 BUG_ON (dev->ev_next > N_EVENT); 1136 VDEBUG (dev, "ev %d, next %d\n", type, dev->ev_next); 1137 memset (event, 0, sizeof *event); 1138 event->type = type; 1139 return event; 1140} 1141 1142static ssize_t 1143ep0_write (struct file *fd, const char __user *buf, size_t len, loff_t *ptr) 1144{ 1145 struct dev_data *dev = fd->private_data; 1146 ssize_t retval = -ESRCH; 1147 1148 spin_lock_irq (&dev->lock); 1149 1150 /* report fd mode change before acting on it */ 1151 if (dev->setup_abort) { 1152 dev->setup_abort = 0; 1153 retval = -EIDRM; 1154 1155 /* data and/or status stage for control request */ 1156 } else if (dev->state == STATE_SETUP) { 1157 1158 /* IN DATA+STATUS caller makes len <= wLength */ 1159 if (dev->setup_in) { 1160 retval = setup_req (dev->gadget->ep0, dev->req, len); 1161 if (retval == 0) { 1162 spin_unlock_irq (&dev->lock); 1163 if (copy_from_user (dev->req->buf, buf, len)) 1164 retval = -EFAULT; 1165 else { 1166 if (len < dev->setup_wLength) 1167 dev->req->zero = 1; 1168 retval = usb_ep_queue ( 1169 dev->gadget->ep0, dev->req, 1170 GFP_KERNEL); 1171 } 1172 if (retval < 0) { 1173 spin_lock_irq (&dev->lock); 1174 clean_req (dev->gadget->ep0, dev->req); 1175 spin_unlock_irq (&dev->lock); 1176 } else 1177 retval = len; 1178 1179 return retval; 1180 } 1181 1182 /* can stall some OUT transfers */ 1183 } else if (dev->setup_can_stall) { 1184 VDEBUG(dev, "ep0out stall\n"); 1185 (void) usb_ep_set_halt (dev->gadget->ep0); 1186 retval = -EL2HLT; 1187 dev->state = STATE_CONNECTED; 1188 } else { 1189 DBG(dev, "bogus ep0out stall!\n"); 1190 } 1191 } else 1192 DBG (dev, "fail %s, state %d\n", __FUNCTION__, dev->state); 1193 1194 spin_unlock_irq (&dev->lock); 1195 return retval; 1196} 1197 1198static int 1199ep0_fasync (int f, struct file *fd, int on) 1200{ 1201 struct dev_data *dev = fd->private_data; 1202 // caller must F_SETOWN before signal delivery happens 1203 VDEBUG (dev, "%s %s\n", __FUNCTION__, on ? "on" : "off"); 1204 return fasync_helper (f, fd, on, &dev->fasync); 1205} 1206 1207static struct usb_gadget_driver gadgetfs_driver; 1208 1209static int 1210dev_release (struct inode *inode, struct file *fd) 1211{ 1212 struct dev_data *dev = fd->private_data; 1213 1214 /* closing ep0 === shutdown all */ 1215 1216 usb_gadget_unregister_driver (&gadgetfs_driver); 1217 1218 /* at this point "good" hardware has disconnected the 1219 * device from USB; the host won't see it any more. 1220 * alternatively, all host requests will time out. 1221 */ 1222 1223 fasync_helper (-1, fd, 0, &dev->fasync); 1224 kfree (dev->buf); 1225 dev->buf = NULL; 1226 put_dev (dev); 1227 1228 /* other endpoints were all decoupled from this device */ 1229 dev->state = STATE_DEV_DISABLED; 1230 return 0; 1231} 1232 1233static int dev_ioctl (struct inode *inode, struct file *fd, 1234 unsigned code, unsigned long value) 1235{ 1236 struct dev_data *dev = fd->private_data; 1237 struct usb_gadget *gadget = dev->gadget; 1238 1239 if (gadget->ops->ioctl) 1240 return gadget->ops->ioctl (gadget, code, value); 1241 return -ENOTTY; 1242} 1243 1244/* used after device configuration */ 1245static struct file_operations ep0_io_operations = { 1246 .owner = THIS_MODULE, 1247 .llseek = no_llseek, 1248 1249 .read = ep0_read, 1250 .write = ep0_write, 1251 .fasync = ep0_fasync, 1252 // .poll = ep0_poll, 1253 .ioctl = dev_ioctl, 1254 .release = dev_release, 1255}; 1256 1257/*----------------------------------------------------------------------*/ 1258 1259/* The in-kernel gadget driver handles most ep0 issues, in particular 1260 * enumerating the single configuration (as provided from user space). 1261 * 1262 * Unrecognized ep0 requests may be handled in user space. 1263 */ 1264 1265#ifdef CONFIG_USB_GADGET_DUALSPEED 1266static void make_qualifier (struct dev_data *dev) 1267{ 1268 struct usb_qualifier_descriptor qual; 1269 struct usb_device_descriptor *desc; 1270 1271 qual.bLength = sizeof qual; 1272 qual.bDescriptorType = USB_DT_DEVICE_QUALIFIER; 1273 qual.bcdUSB = __constant_cpu_to_le16 (0x0200); 1274 1275 desc = dev->dev; 1276 qual.bDeviceClass = desc->bDeviceClass; 1277 qual.bDeviceSubClass = desc->bDeviceSubClass; 1278 qual.bDeviceProtocol = desc->bDeviceProtocol; 1279 1280 /* assumes ep0 uses the same value for both speeds ... */ 1281 qual.bMaxPacketSize0 = desc->bMaxPacketSize0; 1282 1283 qual.bNumConfigurations = 1; 1284 qual.bRESERVED = 0; 1285 1286 memcpy (dev->rbuf, &qual, sizeof qual); 1287} 1288#endif 1289 1290static int 1291config_buf (struct dev_data *dev, u8 type, unsigned index) 1292{ 1293 int len; 1294#ifdef CONFIG_USB_GADGET_DUALSPEED 1295 int hs; 1296#endif 1297 1298 /* only one configuration */ 1299 if (index > 0) 1300 return -EINVAL; 1301 1302#ifdef CONFIG_USB_GADGET_DUALSPEED 1303 hs = (dev->gadget->speed == USB_SPEED_HIGH); 1304 if (type == USB_DT_OTHER_SPEED_CONFIG) 1305 hs = !hs; 1306 if (hs) { 1307 dev->req->buf = dev->hs_config; 1308 len = le16_to_cpup (&dev->hs_config->wTotalLength); 1309 } else 1310#endif 1311 { 1312 dev->req->buf = dev->config; 1313 len = le16_to_cpup (&dev->config->wTotalLength); 1314 } 1315 ((u8 *)dev->req->buf) [1] = type; 1316 return len; 1317} 1318 1319static int 1320gadgetfs_setup (struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl) 1321{ 1322 struct dev_data *dev = get_gadget_data (gadget); 1323 struct usb_request *req = dev->req; 1324 int value = -EOPNOTSUPP; 1325 struct usb_gadgetfs_event *event; 1326 u16 w_value = le16_to_cpu(ctrl->wValue); 1327 u16 w_length = le16_to_cpu(ctrl->wLength); 1328 1329 spin_lock (&dev->lock); 1330 dev->setup_abort = 0; 1331 if (dev->state == STATE_UNCONNECTED) { 1332 struct usb_ep *ep; 1333 struct ep_data *data; 1334 1335 dev->state = STATE_CONNECTED; 1336 dev->dev->bMaxPacketSize0 = gadget->ep0->maxpacket; 1337 1338#ifdef CONFIG_USB_GADGET_DUALSPEED 1339 if (gadget->speed == USB_SPEED_HIGH && dev->hs_config == 0) { 1340 ERROR (dev, "no high speed config??\n"); 1341 return -EINVAL; 1342 } 1343#endif /* CONFIG_USB_GADGET_DUALSPEED */ 1344 1345 INFO (dev, "connected\n"); 1346 event = next_event (dev, GADGETFS_CONNECT); 1347 event->u.speed = gadget->speed; 1348 ep0_readable (dev); 1349 1350 list_for_each_entry (ep, &gadget->ep_list, ep_list) { 1351 data = ep->driver_data; 1352 /* ... down_trylock (&data->lock) ... */ 1353 if (data->state != STATE_EP_DEFER_ENABLE) 1354 continue; 1355#ifdef CONFIG_USB_GADGET_DUALSPEED 1356 if (gadget->speed == USB_SPEED_HIGH) 1357 value = usb_ep_enable (ep, &data->hs_desc); 1358 else 1359#endif /* CONFIG_USB_GADGET_DUALSPEED */ 1360 value = usb_ep_enable (ep, &data->desc); 1361 if (value) { 1362 ERROR (dev, "deferred %s enable --> %d\n", 1363 data->name, value); 1364 continue; 1365 } 1366 data->state = STATE_EP_ENABLED; 1367 wake_up (&data->wait); 1368 DBG (dev, "woke up %s waiters\n", data->name); 1369 } 1370 1371 /* host may have given up waiting for response. we can miss control 1372 * requests handled lower down (device/endpoint status and features); 1373 * then ep0_{read,write} will report the wrong status. controller 1374 * driver will have aborted pending i/o. 1375 */ 1376 } else if (dev->state == STATE_SETUP) 1377 dev->setup_abort = 1; 1378 1379 req->buf = dev->rbuf; 1380 req->dma = DMA_ADDR_INVALID; 1381 req->context = NULL; 1382 value = -EOPNOTSUPP; 1383 switch (ctrl->bRequest) { 1384 1385 case USB_REQ_GET_DESCRIPTOR: 1386 if (ctrl->bRequestType != USB_DIR_IN) 1387 goto unrecognized; 1388 switch (w_value >> 8) { 1389 1390 case USB_DT_DEVICE: 1391 value = min (w_length, (u16) sizeof *dev->dev); 1392 req->buf = dev->dev; 1393 break; 1394#ifdef CONFIG_USB_GADGET_DUALSPEED 1395 case USB_DT_DEVICE_QUALIFIER: 1396 if (!dev->hs_config) 1397 break; 1398 value = min (w_length, (u16) 1399 sizeof (struct usb_qualifier_descriptor)); 1400 make_qualifier (dev); 1401 break; 1402 case USB_DT_OTHER_SPEED_CONFIG: 1403 // FALLTHROUGH 1404#endif 1405 case USB_DT_CONFIG: 1406 value = config_buf (dev, 1407 w_value >> 8, 1408 w_value & 0xff); 1409 if (value >= 0) 1410 value = min (w_length, (u16) value); 1411 break; 1412 case USB_DT_STRING: 1413 goto unrecognized; 1414 1415 default: // all others are errors 1416 break; 1417 } 1418 break; 1419 1420 /* currently one config, two speeds */ 1421 case USB_REQ_SET_CONFIGURATION: 1422 if (ctrl->bRequestType != 0) 1423 break; 1424 if (0 == (u8) w_value) { 1425 value = 0; 1426 dev->current_config = 0; 1427 usb_gadget_vbus_draw(gadget, 8 /* mA */ ); 1428 // user mode expected to disable endpoints 1429 } else { 1430 u8 config, power; 1431#ifdef CONFIG_USB_GADGET_DUALSPEED 1432 if (gadget->speed == USB_SPEED_HIGH) { 1433 config = dev->hs_config->bConfigurationValue; 1434 power = dev->hs_config->bMaxPower; 1435 } else 1436#endif 1437 { 1438 config = dev->config->bConfigurationValue; 1439 power = dev->config->bMaxPower; 1440 } 1441 1442 if (config == (u8) w_value) { 1443 value = 0; 1444 dev->current_config = config; 1445 usb_gadget_vbus_draw(gadget, 2 * power); 1446 } 1447 } 1448 1449 /* report SET_CONFIGURATION like any other control request, 1450 * except that usermode may not stall this. the next 1451 * request mustn't be allowed start until this finishes: 1452 * endpoints and threads set up, etc. 1453 * 1454 * NOTE: older PXA hardware (before PXA 255: without UDCCFR) 1455 * has bad/racey automagic that prevents synchronizing here. 1456 * even kernel mode drivers often miss them. 1457 */ 1458 if (value == 0) { 1459 INFO (dev, "configuration #%d\n", dev->current_config); 1460 if (dev->usermode_setup) { 1461 dev->setup_can_stall = 0; 1462 goto delegate; 1463 } 1464 } 1465 break; 1466 1467#ifndef CONFIG_USB_GADGETFS_PXA2XX 1468 /* PXA automagically handles this request too */ 1469 case USB_REQ_GET_CONFIGURATION: 1470 if (ctrl->bRequestType != 0x80) 1471 break; 1472 *(u8 *)req->buf = dev->current_config; 1473 value = min (w_length, (u16) 1); 1474 break; 1475#endif 1476 1477 default: 1478unrecognized: 1479 VDEBUG (dev, "%s req%02x.%02x v%04x i%04x l%d\n", 1480 dev->usermode_setup ? "delegate" : "fail", 1481 ctrl->bRequestType, ctrl->bRequest, 1482 w_value, le16_to_cpu(ctrl->wIndex), w_length); 1483 1484 /* if there's an ep0 reader, don't stall */ 1485 if (dev->usermode_setup) { 1486 dev->setup_can_stall = 1; 1487delegate: 1488 dev->setup_in = (ctrl->bRequestType & USB_DIR_IN) 1489 ? 1 : 0; 1490 dev->setup_wLength = w_length; 1491 dev->setup_out_ready = 0; 1492 dev->setup_out_error = 0; 1493 value = 0; 1494 1495 /* read DATA stage for OUT right away */ 1496 if (unlikely (!dev->setup_in && w_length)) { 1497 value = setup_req (gadget->ep0, dev->req, 1498 w_length); 1499 if (value < 0) 1500 break; 1501 value = usb_ep_queue (gadget->ep0, dev->req, 1502 GFP_ATOMIC); 1503 if (value < 0) { 1504 clean_req (gadget->ep0, dev->req); 1505 break; 1506 } 1507 1508 /* we can't currently stall these */ 1509 dev->setup_can_stall = 0; 1510 } 1511 1512 /* state changes when reader collects event */ 1513 event = next_event (dev, GADGETFS_SETUP); 1514 event->u.setup = *ctrl; 1515 ep0_readable (dev); 1516 spin_unlock (&dev->lock); 1517 return 0; 1518 } 1519 } 1520 1521 /* proceed with data transfer and status phases? */ 1522 if (value >= 0 && dev->state != STATE_SETUP) { 1523 req->length = value; 1524 req->zero = value < w_length; 1525 value = usb_ep_queue (gadget->ep0, req, GFP_ATOMIC); 1526 if (value < 0) { 1527 DBG (dev, "ep_queue --> %d\n", value); 1528 req->status = 0; 1529 } 1530 } 1531 1532 /* device stalls when value < 0 */ 1533 spin_unlock (&dev->lock); 1534 return value; 1535} 1536 1537static void destroy_ep_files (struct dev_data *dev) 1538{ 1539 struct list_head *entry, *tmp; 1540 1541 DBG (dev, "%s %d\n", __FUNCTION__, dev->state); 1542 1543 /* dev->state must prevent interference */ 1544restart: 1545 spin_lock_irq (&dev->lock); 1546 list_for_each_safe (entry, tmp, &dev->epfiles) { 1547 struct ep_data *ep; 1548 struct inode *parent; 1549 struct dentry *dentry; 1550 1551 /* break link to FS */ 1552 ep = list_entry (entry, struct ep_data, epfiles); 1553 list_del_init (&ep->epfiles); 1554 dentry = ep->dentry; 1555 ep->dentry = NULL; 1556 parent = dentry->d_parent->d_inode; 1557 1558 /* break link to controller */ 1559 if (ep->state == STATE_EP_ENABLED) 1560 (void) usb_ep_disable (ep->ep); 1561 ep->state = STATE_EP_UNBOUND; 1562 usb_ep_free_request (ep->ep, ep->req); 1563 ep->ep = NULL; 1564 wake_up (&ep->wait); 1565 put_ep (ep); 1566 1567 spin_unlock_irq (&dev->lock); 1568 1569 /* break link to dcache */ 1570 mutex_lock (&parent->i_mutex); 1571 d_delete (dentry); 1572 dput (dentry); 1573 mutex_unlock (&parent->i_mutex); 1574 1575 /* fds may still be open */ 1576 goto restart; 1577 } 1578 spin_unlock_irq (&dev->lock); 1579} 1580 1581 1582static struct inode * 1583gadgetfs_create_file (struct super_block *sb, char const *name, 1584 void *data, const struct file_operations *fops, 1585 struct dentry **dentry_p); 1586 1587static int activate_ep_files (struct dev_data *dev) 1588{ 1589 struct usb_ep *ep; 1590 struct ep_data *data; 1591 1592 gadget_for_each_ep (ep, dev->gadget) { 1593 1594 data = kzalloc(sizeof(*data), GFP_KERNEL); 1595 if (!data) 1596 goto enomem0; 1597 data->state = STATE_EP_DISABLED; 1598 init_MUTEX (&data->lock); 1599 init_waitqueue_head (&data->wait); 1600 1601 strncpy (data->name, ep->name, sizeof (data->name) - 1); 1602 atomic_set (&data->count, 1); 1603 data->dev = dev; 1604 get_dev (dev); 1605 1606 data->ep = ep; 1607 ep->driver_data = data; 1608 1609 data->req = usb_ep_alloc_request (ep, GFP_KERNEL); 1610 if (!data->req) 1611 goto enomem1; 1612 1613 data->inode = gadgetfs_create_file (dev->sb, data->name, 1614 data, &ep_config_operations, 1615 &data->dentry); 1616 if (!data->inode) 1617 goto enomem2; 1618 list_add_tail (&data->epfiles, &dev->epfiles); 1619 } 1620 return 0; 1621 1622enomem2: 1623 usb_ep_free_request (ep, data->req); 1624enomem1: 1625 put_dev (dev); 1626 kfree (data); 1627enomem0: 1628 DBG (dev, "%s enomem\n", __FUNCTION__); 1629 destroy_ep_files (dev); 1630 return -ENOMEM; 1631} 1632 1633static void 1634gadgetfs_unbind (struct usb_gadget *gadget) 1635{ 1636 struct dev_data *dev = get_gadget_data (gadget); 1637 1638 DBG (dev, "%s\n", __FUNCTION__); 1639 1640 spin_lock_irq (&dev->lock); 1641 dev->state = STATE_DEV_UNBOUND; 1642 spin_unlock_irq (&dev->lock); 1643 1644 destroy_ep_files (dev); 1645 gadget->ep0->driver_data = NULL; 1646 set_gadget_data (gadget, NULL); 1647 1648 /* we've already been disconnected ... no i/o is active */ 1649 if (dev->req) 1650 usb_ep_free_request (gadget->ep0, dev->req); 1651 DBG (dev, "%s done\n", __FUNCTION__); 1652 put_dev (dev); 1653} 1654 1655static struct dev_data *the_device; 1656 1657static int 1658gadgetfs_bind (struct usb_gadget *gadget) 1659{ 1660 struct dev_data *dev = the_device; 1661 1662 if (!dev) 1663 return -ESRCH; 1664 if (0 != strcmp (CHIP, gadget->name)) { 1665 printk (KERN_ERR "%s expected %s controller not %s\n", 1666 shortname, CHIP, gadget->name); 1667 return -ENODEV; 1668 } 1669 1670 set_gadget_data (gadget, dev); 1671 dev->gadget = gadget; 1672 gadget->ep0->driver_data = dev; 1673 dev->dev->bMaxPacketSize0 = gadget->ep0->maxpacket; 1674 1675 /* preallocate control response and buffer */ 1676 dev->req = usb_ep_alloc_request (gadget->ep0, GFP_KERNEL); 1677 if (!dev->req) 1678 goto enomem; 1679 dev->req->context = NULL; 1680 dev->req->complete = epio_complete; 1681 1682 if (activate_ep_files (dev) < 0) 1683 goto enomem; 1684 1685 INFO (dev, "bound to %s driver\n", gadget->name); 1686 dev->state = STATE_UNCONNECTED; 1687 get_dev (dev); 1688 return 0; 1689 1690enomem: 1691 gadgetfs_unbind (gadget); 1692 return -ENOMEM; 1693} 1694 1695static void 1696gadgetfs_disconnect (struct usb_gadget *gadget) 1697{ 1698 struct dev_data *dev = get_gadget_data (gadget); 1699 1700 spin_lock (&dev->lock); 1701 if (dev->state == STATE_UNCONNECTED) { 1702 DBG (dev, "already unconnected\n"); 1703 goto exit; 1704 } 1705 dev->state = STATE_UNCONNECTED; 1706 1707 INFO (dev, "disconnected\n"); 1708 next_event (dev, GADGETFS_DISCONNECT); 1709 ep0_readable (dev); 1710exit: 1711 spin_unlock (&dev->lock); 1712} 1713 1714static void 1715gadgetfs_suspend (struct usb_gadget *gadget) 1716{ 1717 struct dev_data *dev = get_gadget_data (gadget); 1718 1719 INFO (dev, "suspended from state %d\n", dev->state); 1720 spin_lock (&dev->lock); 1721 switch (dev->state) { 1722 case STATE_SETUP: // VERY odd... host died?? 1723 case STATE_CONNECTED: 1724 case STATE_UNCONNECTED: 1725 next_event (dev, GADGETFS_SUSPEND); 1726 ep0_readable (dev); 1727 /* FALLTHROUGH */ 1728 default: 1729 break; 1730 } 1731 spin_unlock (&dev->lock); 1732} 1733 1734static struct usb_gadget_driver gadgetfs_driver = { 1735#ifdef CONFIG_USB_GADGET_DUALSPEED 1736 .speed = USB_SPEED_HIGH, 1737#else 1738 .speed = USB_SPEED_FULL, 1739#endif 1740 .function = (char *) driver_desc, 1741 .bind = gadgetfs_bind, 1742 .unbind = gadgetfs_unbind, 1743 .setup = gadgetfs_setup, 1744 .disconnect = gadgetfs_disconnect, 1745 .suspend = gadgetfs_suspend, 1746 1747 .driver = { 1748 .name = (char *) shortname, 1749 }, 1750}; 1751 1752/*----------------------------------------------------------------------*/ 1753 1754static void gadgetfs_nop(struct usb_gadget *arg) { } 1755 1756static int gadgetfs_probe (struct usb_gadget *gadget) 1757{ 1758 CHIP = gadget->name; 1759 return -EISNAM; 1760} 1761 1762static struct usb_gadget_driver probe_driver = { 1763 .speed = USB_SPEED_HIGH, 1764 .bind = gadgetfs_probe, 1765 .unbind = gadgetfs_nop, 1766 .setup = (void *)gadgetfs_nop, 1767 .disconnect = gadgetfs_nop, 1768 .driver = { 1769 .name = "nop", 1770 }, 1771}; 1772 1773 1774/* DEVICE INITIALIZATION 1775 * 1776 * fd = open ("/dev/gadget/$CHIP", O_RDWR) 1777 * status = write (fd, descriptors, sizeof descriptors) 1778 * 1779 * That write establishes the device configuration, so the kernel can 1780 * bind to the controller ... guaranteeing it can handle enumeration 1781 * at all necessary speeds. Descriptor order is: 1782 * 1783 * . message tag (u32, host order) ... for now, must be zero; it 1784 * would change to support features like multi-config devices 1785 * . full/low speed config ... all wTotalLength bytes (with interface, 1786 * class, altsetting, endpoint, and other descriptors) 1787 * . high speed config ... all descriptors, for high speed operation; 1788 * this one's optional except for high-speed hardware 1789 * . device descriptor 1790 * 1791 * Endpoints are not yet enabled. Drivers may want to immediately 1792 * initialize them, using the /dev/gadget/ep* files that are available 1793 * as soon as the kernel sees the configuration, or they can wait 1794 * until device configuration and interface altsetting changes create 1795 * the need to configure (or unconfigure) them. 1796 * 1797 * After initialization, the device stays active for as long as that 1798 * $CHIP file is open. Events may then be read from that descriptor, 1799 * such as configuration notifications. More complex drivers will handle 1800 * some control requests in user space. 1801 */ 1802 1803static int is_valid_config (struct usb_config_descriptor *config) 1804{ 1805 return config->bDescriptorType == USB_DT_CONFIG 1806 && config->bLength == USB_DT_CONFIG_SIZE 1807 && config->bConfigurationValue != 0 1808 && (config->bmAttributes & USB_CONFIG_ATT_ONE) != 0 1809 && (config->bmAttributes & USB_CONFIG_ATT_WAKEUP) == 0; 1810 /* FIXME if gadget->is_otg, _must_ include an otg descriptor */ 1811 /* FIXME check lengths: walk to end */ 1812} 1813 1814static ssize_t 1815dev_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr) 1816{ 1817 struct dev_data *dev = fd->private_data; 1818 ssize_t value = len, length = len; 1819 unsigned total; 1820 u32 tag; 1821 char *kbuf; 1822 1823 if (dev->state != STATE_OPENED) 1824 return -EEXIST; 1825 1826 if (len < (USB_DT_CONFIG_SIZE + USB_DT_DEVICE_SIZE + 4)) 1827 return -EINVAL; 1828 1829 /* we might need to change message format someday */ 1830 if (copy_from_user (&tag, buf, 4)) 1831 return -EFAULT; 1832 if (tag != 0) 1833 return -EINVAL; 1834 buf += 4; 1835 length -= 4; 1836 1837 kbuf = kmalloc (length, SLAB_KERNEL); 1838 if (!kbuf) 1839 return -ENOMEM; 1840 if (copy_from_user (kbuf, buf, length)) { 1841 kfree (kbuf); 1842 return -EFAULT; 1843 } 1844 1845 spin_lock_irq (&dev->lock); 1846 value = -EINVAL; 1847 if (dev->buf) 1848 goto fail; 1849 dev->buf = kbuf; 1850 1851 /* full or low speed config */ 1852 dev->config = (void *) kbuf; 1853 total = le16_to_cpup (&dev->config->wTotalLength); 1854 if (!is_valid_config (dev->config) || total >= length) 1855 goto fail; 1856 kbuf += total; 1857 length -= total; 1858 1859 /* optional high speed config */ 1860 if (kbuf [1] == USB_DT_CONFIG) { 1861 dev->hs_config = (void *) kbuf; 1862 total = le16_to_cpup (&dev->hs_config->wTotalLength); 1863 if (!is_valid_config (dev->hs_config) || total >= length) 1864 goto fail; 1865 kbuf += total; 1866 length -= total; 1867 } 1868 1869 /* could support multiple configs, using another encoding! */ 1870 1871 /* device descriptor (tweaked for paranoia) */ 1872 if (length != USB_DT_DEVICE_SIZE) 1873 goto fail; 1874 dev->dev = (void *)kbuf; 1875 if (dev->dev->bLength != USB_DT_DEVICE_SIZE 1876 || dev->dev->bDescriptorType != USB_DT_DEVICE 1877 || dev->dev->bNumConfigurations != 1) 1878 goto fail; 1879 dev->dev->bNumConfigurations = 1; 1880 dev->dev->bcdUSB = __constant_cpu_to_le16 (0x0200); 1881 1882 /* triggers gadgetfs_bind(); then we can enumerate. */ 1883 spin_unlock_irq (&dev->lock); 1884 value = usb_gadget_register_driver (&gadgetfs_driver); 1885 if (value != 0) { 1886 kfree (dev->buf); 1887 dev->buf = NULL; 1888 } else { 1889 /* at this point "good" hardware has for the first time 1890 * let the USB the host see us. alternatively, if users 1891 * unplug/replug that will clear all the error state. 1892 * 1893 * note: everything running before here was guaranteed 1894 * to choke driver model style diagnostics. from here 1895 * on, they can work ... except in cleanup paths that 1896 * kick in after the ep0 descriptor is closed. 1897 */ 1898 fd->f_op = &ep0_io_operations; 1899 value = len; 1900 } 1901 return value; 1902 1903fail: 1904 spin_unlock_irq (&dev->lock); 1905 pr_debug ("%s: %s fail %Zd, %p\n", shortname, __FUNCTION__, value, dev); 1906 kfree (dev->buf); 1907 dev->buf = NULL; 1908 return value; 1909} 1910 1911static int 1912dev_open (struct inode *inode, struct file *fd) 1913{ 1914 struct dev_data *dev = inode->i_private; 1915 int value = -EBUSY; 1916 1917 if (dev->state == STATE_DEV_DISABLED) { 1918 dev->ev_next = 0; 1919 dev->state = STATE_OPENED; 1920 fd->private_data = dev; 1921 get_dev (dev); 1922 value = 0; 1923 } 1924 return value; 1925} 1926 1927static struct file_operations dev_init_operations = { 1928 .owner = THIS_MODULE, 1929 .llseek = no_llseek, 1930 1931 .open = dev_open, 1932 .write = dev_config, 1933 .fasync = ep0_fasync, 1934 .ioctl = dev_ioctl, 1935 .release = dev_release, 1936}; 1937 1938/*----------------------------------------------------------------------*/ 1939 1940/* FILESYSTEM AND SUPERBLOCK OPERATIONS 1941 * 1942 * Mounting the filesystem creates a controller file, used first for 1943 * device configuration then later for event monitoring. 1944 */ 1945 1946 1947/* FIXME PAM etc could set this security policy without mount options 1948 * if epfiles inherited ownership and permissons from ep0 ... 1949 */ 1950 1951static unsigned default_uid; 1952static unsigned default_gid; 1953static unsigned default_perm = S_IRUSR | S_IWUSR; 1954 1955module_param (default_uid, uint, 0644); 1956module_param (default_gid, uint, 0644); 1957module_param (default_perm, uint, 0644); 1958 1959 1960static struct inode * 1961gadgetfs_make_inode (struct super_block *sb, 1962 void *data, const struct file_operations *fops, 1963 int mode) 1964{ 1965 struct inode *inode = new_inode (sb); 1966 1967 if (inode) { 1968 inode->i_mode = mode; 1969 inode->i_uid = default_uid; 1970 inode->i_gid = default_gid; 1971 inode->i_blocks = 0; 1972 inode->i_atime = inode->i_mtime = inode->i_ctime 1973 = CURRENT_TIME; 1974 inode->i_private = data; 1975 inode->i_fop = fops; 1976 } 1977 return inode; 1978} 1979 1980/* creates in fs root directory, so non-renamable and non-linkable. 1981 * so inode and dentry are paired, until device reconfig. 1982 */ 1983static struct inode * 1984gadgetfs_create_file (struct super_block *sb, char const *name, 1985 void *data, const struct file_operations *fops, 1986 struct dentry **dentry_p) 1987{ 1988 struct dentry *dentry; 1989 struct inode *inode; 1990 1991 dentry = d_alloc_name(sb->s_root, name); 1992 if (!dentry) 1993 return NULL; 1994 1995 inode = gadgetfs_make_inode (sb, data, fops, 1996 S_IFREG | (default_perm & S_IRWXUGO)); 1997 if (!inode) { 1998 dput(dentry); 1999 return NULL; 2000 } 2001 d_add (dentry, inode); 2002 *dentry_p = dentry; 2003 return inode; 2004} 2005 2006static struct super_operations gadget_fs_operations = { 2007 .statfs = simple_statfs, 2008 .drop_inode = generic_delete_inode, 2009}; 2010 2011static int 2012gadgetfs_fill_super (struct super_block *sb, void *opts, int silent) 2013{ 2014 struct inode *inode; 2015 struct dentry *d; 2016 struct dev_data *dev; 2017 2018 if (the_device) 2019 return -ESRCH; 2020 2021 /* fake probe to determine $CHIP */ 2022 (void) usb_gadget_register_driver (&probe_driver); 2023 if (!CHIP) 2024 return -ENODEV; 2025 2026 /* superblock */ 2027 sb->s_blocksize = PAGE_CACHE_SIZE; 2028 sb->s_blocksize_bits = PAGE_CACHE_SHIFT; 2029 sb->s_magic = GADGETFS_MAGIC; 2030 sb->s_op = &gadget_fs_operations; 2031 sb->s_time_gran = 1; 2032 2033 /* root inode */ 2034 inode = gadgetfs_make_inode (sb, 2035 NULL, &simple_dir_operations, 2036 S_IFDIR | S_IRUGO | S_IXUGO); 2037 if (!inode) 2038 goto enomem0; 2039 inode->i_op = &simple_dir_inode_operations; 2040 if (!(d = d_alloc_root (inode))) 2041 goto enomem1; 2042 sb->s_root = d; 2043 2044 /* the ep0 file is named after the controller we expect; 2045 * user mode code can use it for sanity checks, like we do. 2046 */ 2047 dev = dev_new (); 2048 if (!dev) 2049 goto enomem2; 2050 2051 dev->sb = sb; 2052 if (!gadgetfs_create_file (sb, CHIP, 2053 dev, &dev_init_operations, 2054 &dev->dentry)) 2055 goto enomem3; 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 2063enomem3: 2064 put_dev (dev); 2065enomem2: 2066 dput (d); 2067enomem1: 2068 iput (inode); 2069enomem0: 2070 return -ENOMEM; 2071} 2072 2073/* "mount -t gadgetfs path /dev/gadget" ends up here */ 2074static int 2075gadgetfs_get_sb (struct file_system_type *t, int flags, 2076 const char *path, void *opts, struct vfsmount *mnt) 2077{ 2078 return get_sb_single (t, flags, opts, gadgetfs_fill_super, mnt); 2079} 2080 2081static void 2082gadgetfs_kill_sb (struct super_block *sb) 2083{ 2084 kill_litter_super (sb); 2085 if (the_device) { 2086 put_dev (the_device); 2087 the_device = NULL; 2088 } 2089} 2090 2091/*----------------------------------------------------------------------*/ 2092 2093static struct file_system_type gadgetfs_type = { 2094 .owner = THIS_MODULE, 2095 .name = shortname, 2096 .get_sb = gadgetfs_get_sb, 2097 .kill_sb = gadgetfs_kill_sb, 2098}; 2099 2100/*----------------------------------------------------------------------*/ 2101 2102static int __init init (void) 2103{ 2104 int status; 2105 2106 status = register_filesystem (&gadgetfs_type); 2107 if (status == 0) 2108 pr_info ("%s: %s, version " DRIVER_VERSION "\n", 2109 shortname, driver_desc); 2110 return status; 2111} 2112module_init (init); 2113 2114static void __exit cleanup (void) 2115{ 2116 pr_debug ("unregister %s\n", shortname); 2117 unregister_filesystem (&gadgetfs_type); 2118} 2119module_exit (cleanup); 2120 2121