inode.c revision 83196b52053068f0240371ad2efd9d6ad685bbeb
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; 745 746 if ((value = down_interruptible (&data->lock)) < 0) 747 return value; 748 749 if (data->state != STATE_EP_READY) { 750 value = -EL2HLT; 751 goto fail; 752 } 753 754 value = len; 755 if (len < USB_DT_ENDPOINT_SIZE + 4) 756 goto fail0; 757 758 /* we might need to change message format someday */ 759 if (copy_from_user (&tag, buf, 4)) { 760 goto fail1; 761 } 762 if (tag != 1) { 763 DBG(data->dev, "config %s, bad tag %d\n", data->name, tag); 764 goto fail0; 765 } 766 buf += 4; 767 len -= 4; 768 769 /* NOTE: audio endpoint extensions not accepted here; 770 * just don't include the extra bytes. 771 */ 772 773 /* full/low speed descriptor, then high speed */ 774 if (copy_from_user (&data->desc, buf, USB_DT_ENDPOINT_SIZE)) { 775 goto fail1; 776 } 777 if (data->desc.bLength != USB_DT_ENDPOINT_SIZE 778 || data->desc.bDescriptorType != USB_DT_ENDPOINT) 779 goto fail0; 780 if (len != USB_DT_ENDPOINT_SIZE) { 781 if (len != 2 * USB_DT_ENDPOINT_SIZE) 782 goto fail0; 783 if (copy_from_user (&data->hs_desc, buf + USB_DT_ENDPOINT_SIZE, 784 USB_DT_ENDPOINT_SIZE)) { 785 goto fail1; 786 } 787 if (data->hs_desc.bLength != USB_DT_ENDPOINT_SIZE 788 || data->hs_desc.bDescriptorType 789 != USB_DT_ENDPOINT) { 790 DBG(data->dev, "config %s, bad hs length or type\n", 791 data->name); 792 goto fail0; 793 } 794 } 795 value = len; 796 797 spin_lock_irq (&data->dev->lock); 798 if (data->dev->state == STATE_DEV_UNBOUND) { 799 value = -ENOENT; 800 goto gone; 801 } else if ((ep = data->ep) == NULL) { 802 value = -ENODEV; 803 goto gone; 804 } 805 switch (data->dev->gadget->speed) { 806 case USB_SPEED_LOW: 807 case USB_SPEED_FULL: 808 value = usb_ep_enable (ep, &data->desc); 809 if (value == 0) 810 data->state = STATE_EP_ENABLED; 811 break; 812#ifdef CONFIG_USB_GADGET_DUALSPEED 813 case USB_SPEED_HIGH: 814 /* fails if caller didn't provide that descriptor... */ 815 value = usb_ep_enable (ep, &data->hs_desc); 816 if (value == 0) 817 data->state = STATE_EP_ENABLED; 818 break; 819#endif 820 default: 821 DBG (data->dev, "unconnected, %s init deferred\n", 822 data->name); 823 data->state = STATE_EP_DEFER_ENABLE; 824 } 825 if (value == 0) 826 fd->f_op = &ep_io_operations; 827gone: 828 spin_unlock_irq (&data->dev->lock); 829 if (value < 0) { 830fail: 831 data->desc.bDescriptorType = 0; 832 data->hs_desc.bDescriptorType = 0; 833 } 834 up (&data->lock); 835 return value; 836fail0: 837 value = -EINVAL; 838 goto fail; 839fail1: 840 value = -EFAULT; 841 goto fail; 842} 843 844static int 845ep_open (struct inode *inode, struct file *fd) 846{ 847 struct ep_data *data = inode->u.generic_ip; 848 int value = -EBUSY; 849 850 if (down_interruptible (&data->lock) != 0) 851 return -EINTR; 852 spin_lock_irq (&data->dev->lock); 853 if (data->dev->state == STATE_DEV_UNBOUND) 854 value = -ENOENT; 855 else if (data->state == STATE_EP_DISABLED) { 856 value = 0; 857 data->state = STATE_EP_READY; 858 get_ep (data); 859 fd->private_data = data; 860 VDEBUG (data->dev, "%s ready\n", data->name); 861 } else 862 DBG (data->dev, "%s state %d\n", 863 data->name, data->state); 864 spin_unlock_irq (&data->dev->lock); 865 up (&data->lock); 866 return value; 867} 868 869/* used before endpoint configuration */ 870static struct file_operations ep_config_operations = { 871 .owner = THIS_MODULE, 872 .llseek = no_llseek, 873 874 .open = ep_open, 875 .write = ep_config, 876 .release = ep_release, 877}; 878 879/*----------------------------------------------------------------------*/ 880 881/* EP0 IMPLEMENTATION can be partly in userspace. 882 * 883 * Drivers that use this facility receive various events, including 884 * control requests the kernel doesn't handle. Drivers that don't 885 * use this facility may be too simple-minded for real applications. 886 */ 887 888static inline void ep0_readable (struct dev_data *dev) 889{ 890 wake_up (&dev->wait); 891 kill_fasync (&dev->fasync, SIGIO, POLL_IN); 892} 893 894static void clean_req (struct usb_ep *ep, struct usb_request *req) 895{ 896 struct dev_data *dev = ep->driver_data; 897 898 if (req->buf != dev->rbuf) { 899 usb_ep_free_buffer (ep, req->buf, req->dma, req->length); 900 req->buf = dev->rbuf; 901 req->dma = DMA_ADDR_INVALID; 902 } 903 req->complete = epio_complete; 904 dev->setup_out_ready = 0; 905} 906 907static void ep0_complete (struct usb_ep *ep, struct usb_request *req) 908{ 909 struct dev_data *dev = ep->driver_data; 910 int free = 1; 911 912 /* for control OUT, data must still get to userspace */ 913 if (!dev->setup_in) { 914 dev->setup_out_error = (req->status != 0); 915 if (!dev->setup_out_error) 916 free = 0; 917 dev->setup_out_ready = 1; 918 ep0_readable (dev); 919 } else if (dev->state == STATE_SETUP) 920 dev->state = STATE_CONNECTED; 921 922 /* clean up as appropriate */ 923 if (free && req->buf != &dev->rbuf) 924 clean_req (ep, req); 925 req->complete = epio_complete; 926} 927 928static int setup_req (struct usb_ep *ep, struct usb_request *req, u16 len) 929{ 930 struct dev_data *dev = ep->driver_data; 931 932 if (dev->setup_out_ready) { 933 DBG (dev, "ep0 request busy!\n"); 934 return -EBUSY; 935 } 936 if (len > sizeof (dev->rbuf)) 937 req->buf = usb_ep_alloc_buffer (ep, len, &req->dma, GFP_ATOMIC); 938 if (req->buf == 0) { 939 req->buf = dev->rbuf; 940 return -ENOMEM; 941 } 942 req->complete = ep0_complete; 943 req->length = len; 944 req->zero = 0; 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 CONFIG_USB_GADGET_DUALSPEED 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 if (len < dev->setup_wLength) 1166 dev->req->zero = 1; 1167 retval = usb_ep_queue ( 1168 dev->gadget->ep0, dev->req, 1169 GFP_KERNEL); 1170 } 1171 if (retval < 0) { 1172 spin_lock_irq (&dev->lock); 1173 clean_req (dev->gadget->ep0, dev->req); 1174 spin_unlock_irq (&dev->lock); 1175 } else 1176 retval = len; 1177 1178 return retval; 1179 } 1180 1181 /* can stall some OUT transfers */ 1182 } else if (dev->setup_can_stall) { 1183 VDEBUG(dev, "ep0out stall\n"); 1184 (void) usb_ep_set_halt (dev->gadget->ep0); 1185 retval = -EL2HLT; 1186 dev->state = STATE_CONNECTED; 1187 } else { 1188 DBG(dev, "bogus ep0out stall!\n"); 1189 } 1190 } else 1191 DBG (dev, "fail %s, state %d\n", __FUNCTION__, dev->state); 1192 1193 spin_unlock_irq (&dev->lock); 1194 return retval; 1195} 1196 1197static int 1198ep0_fasync (int f, struct file *fd, int on) 1199{ 1200 struct dev_data *dev = fd->private_data; 1201 // caller must F_SETOWN before signal delivery happens 1202 VDEBUG (dev, "%s %s\n", __FUNCTION__, on ? "on" : "off"); 1203 return fasync_helper (f, fd, on, &dev->fasync); 1204} 1205 1206static struct usb_gadget_driver gadgetfs_driver; 1207 1208static int 1209dev_release (struct inode *inode, struct file *fd) 1210{ 1211 struct dev_data *dev = fd->private_data; 1212 1213 /* closing ep0 === shutdown all */ 1214 1215 usb_gadget_unregister_driver (&gadgetfs_driver); 1216 1217 /* at this point "good" hardware has disconnected the 1218 * device from USB; the host won't see it any more. 1219 * alternatively, all host requests will time out. 1220 */ 1221 1222 fasync_helper (-1, fd, 0, &dev->fasync); 1223 kfree (dev->buf); 1224 dev->buf = NULL; 1225 put_dev (dev); 1226 1227 /* other endpoints were all decoupled from this device */ 1228 dev->state = STATE_DEV_DISABLED; 1229 return 0; 1230} 1231 1232static int dev_ioctl (struct inode *inode, struct file *fd, 1233 unsigned code, unsigned long value) 1234{ 1235 struct dev_data *dev = fd->private_data; 1236 struct usb_gadget *gadget = dev->gadget; 1237 1238 if (gadget->ops->ioctl) 1239 return gadget->ops->ioctl (gadget, code, value); 1240 return -ENOTTY; 1241} 1242 1243/* used after device configuration */ 1244static struct file_operations ep0_io_operations = { 1245 .owner = THIS_MODULE, 1246 .llseek = no_llseek, 1247 1248 .read = ep0_read, 1249 .write = ep0_write, 1250 .fasync = ep0_fasync, 1251 // .poll = ep0_poll, 1252 .ioctl = dev_ioctl, 1253 .release = dev_release, 1254}; 1255 1256/*----------------------------------------------------------------------*/ 1257 1258/* The in-kernel gadget driver handles most ep0 issues, in particular 1259 * enumerating the single configuration (as provided from user space). 1260 * 1261 * Unrecognized ep0 requests may be handled in user space. 1262 */ 1263 1264#ifdef CONFIG_USB_GADGET_DUALSPEED 1265static void make_qualifier (struct dev_data *dev) 1266{ 1267 struct usb_qualifier_descriptor qual; 1268 struct usb_device_descriptor *desc; 1269 1270 qual.bLength = sizeof qual; 1271 qual.bDescriptorType = USB_DT_DEVICE_QUALIFIER; 1272 qual.bcdUSB = __constant_cpu_to_le16 (0x0200); 1273 1274 desc = dev->dev; 1275 qual.bDeviceClass = desc->bDeviceClass; 1276 qual.bDeviceSubClass = desc->bDeviceSubClass; 1277 qual.bDeviceProtocol = desc->bDeviceProtocol; 1278 1279 /* assumes ep0 uses the same value for both speeds ... */ 1280 qual.bMaxPacketSize0 = desc->bMaxPacketSize0; 1281 1282 qual.bNumConfigurations = 1; 1283 qual.bRESERVED = 0; 1284 1285 memcpy (dev->rbuf, &qual, sizeof qual); 1286} 1287#endif 1288 1289static int 1290config_buf (struct dev_data *dev, u8 type, unsigned index) 1291{ 1292 int len; 1293#ifdef CONFIG_USB_GADGET_DUALSPEED 1294 int hs; 1295#endif 1296 1297 /* only one configuration */ 1298 if (index > 0) 1299 return -EINVAL; 1300 1301#ifdef CONFIG_USB_GADGET_DUALSPEED 1302 hs = (dev->gadget->speed == USB_SPEED_HIGH); 1303 if (type == USB_DT_OTHER_SPEED_CONFIG) 1304 hs = !hs; 1305 if (hs) { 1306 dev->req->buf = dev->hs_config; 1307 len = le16_to_cpup (&dev->hs_config->wTotalLength); 1308 } else 1309#endif 1310 { 1311 dev->req->buf = dev->config; 1312 len = le16_to_cpup (&dev->config->wTotalLength); 1313 } 1314 ((u8 *)dev->req->buf) [1] = type; 1315 return len; 1316} 1317 1318static int 1319gadgetfs_setup (struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl) 1320{ 1321 struct dev_data *dev = get_gadget_data (gadget); 1322 struct usb_request *req = dev->req; 1323 int value = -EOPNOTSUPP; 1324 struct usb_gadgetfs_event *event; 1325 u16 w_value = le16_to_cpu(ctrl->wValue); 1326 u16 w_length = le16_to_cpu(ctrl->wLength); 1327 1328 spin_lock (&dev->lock); 1329 dev->setup_abort = 0; 1330 if (dev->state == STATE_UNCONNECTED) { 1331 struct usb_ep *ep; 1332 struct ep_data *data; 1333 1334 dev->state = STATE_CONNECTED; 1335 dev->dev->bMaxPacketSize0 = gadget->ep0->maxpacket; 1336 1337#ifdef CONFIG_USB_GADGET_DUALSPEED 1338 if (gadget->speed == USB_SPEED_HIGH && dev->hs_config == 0) { 1339 ERROR (dev, "no high speed config??\n"); 1340 return -EINVAL; 1341 } 1342#endif /* CONFIG_USB_GADGET_DUALSPEED */ 1343 1344 INFO (dev, "connected\n"); 1345 event = next_event (dev, GADGETFS_CONNECT); 1346 event->u.speed = gadget->speed; 1347 ep0_readable (dev); 1348 1349 list_for_each_entry (ep, &gadget->ep_list, ep_list) { 1350 data = ep->driver_data; 1351 /* ... down_trylock (&data->lock) ... */ 1352 if (data->state != STATE_EP_DEFER_ENABLE) 1353 continue; 1354#ifdef CONFIG_USB_GADGET_DUALSPEED 1355 if (gadget->speed == USB_SPEED_HIGH) 1356 value = usb_ep_enable (ep, &data->hs_desc); 1357 else 1358#endif /* CONFIG_USB_GADGET_DUALSPEED */ 1359 value = usb_ep_enable (ep, &data->desc); 1360 if (value) { 1361 ERROR (dev, "deferred %s enable --> %d\n", 1362 data->name, value); 1363 continue; 1364 } 1365 data->state = STATE_EP_ENABLED; 1366 wake_up (&data->wait); 1367 DBG (dev, "woke up %s waiters\n", data->name); 1368 } 1369 1370 /* host may have given up waiting for response. we can miss control 1371 * requests handled lower down (device/endpoint status and features); 1372 * then ep0_{read,write} will report the wrong status. controller 1373 * driver will have aborted pending i/o. 1374 */ 1375 } else if (dev->state == STATE_SETUP) 1376 dev->setup_abort = 1; 1377 1378 req->buf = dev->rbuf; 1379 req->dma = DMA_ADDR_INVALID; 1380 req->context = NULL; 1381 value = -EOPNOTSUPP; 1382 switch (ctrl->bRequest) { 1383 1384 case USB_REQ_GET_DESCRIPTOR: 1385 if (ctrl->bRequestType != USB_DIR_IN) 1386 goto unrecognized; 1387 switch (w_value >> 8) { 1388 1389 case USB_DT_DEVICE: 1390 value = min (w_length, (u16) sizeof *dev->dev); 1391 req->buf = dev->dev; 1392 break; 1393#ifdef CONFIG_USB_GADGET_DUALSPEED 1394 case USB_DT_DEVICE_QUALIFIER: 1395 if (!dev->hs_config) 1396 break; 1397 value = min (w_length, (u16) 1398 sizeof (struct usb_qualifier_descriptor)); 1399 make_qualifier (dev); 1400 break; 1401 case USB_DT_OTHER_SPEED_CONFIG: 1402 // FALLTHROUGH 1403#endif 1404 case USB_DT_CONFIG: 1405 value = config_buf (dev, 1406 w_value >> 8, 1407 w_value & 0xff); 1408 if (value >= 0) 1409 value = min (w_length, (u16) value); 1410 break; 1411 case USB_DT_STRING: 1412 goto unrecognized; 1413 1414 default: // all others are errors 1415 break; 1416 } 1417 break; 1418 1419 /* currently one config, two speeds */ 1420 case USB_REQ_SET_CONFIGURATION: 1421 if (ctrl->bRequestType != 0) 1422 break; 1423 if (0 == (u8) w_value) { 1424 value = 0; 1425 dev->current_config = 0; 1426 usb_gadget_vbus_draw(gadget, 8 /* mA */ ); 1427 // user mode expected to disable endpoints 1428 } else { 1429 u8 config, power; 1430#ifdef CONFIG_USB_GADGET_DUALSPEED 1431 if (gadget->speed == USB_SPEED_HIGH) { 1432 config = dev->hs_config->bConfigurationValue; 1433 power = dev->hs_config->bMaxPower; 1434 } else 1435#endif 1436 { 1437 config = dev->config->bConfigurationValue; 1438 power = dev->config->bMaxPower; 1439 } 1440 1441 if (config == (u8) w_value) { 1442 value = 0; 1443 dev->current_config = config; 1444 usb_gadget_vbus_draw(gadget, 2 * power); 1445 } 1446 } 1447 1448 /* report SET_CONFIGURATION like any other control request, 1449 * except that usermode may not stall this. the next 1450 * request mustn't be allowed start until this finishes: 1451 * endpoints and threads set up, etc. 1452 * 1453 * NOTE: older PXA hardware (before PXA 255: without UDCCFR) 1454 * has bad/racey automagic that prevents synchronizing here. 1455 * even kernel mode drivers often miss them. 1456 */ 1457 if (value == 0) { 1458 INFO (dev, "configuration #%d\n", dev->current_config); 1459 if (dev->usermode_setup) { 1460 dev->setup_can_stall = 0; 1461 goto delegate; 1462 } 1463 } 1464 break; 1465 1466#ifndef CONFIG_USB_GADGETFS_PXA2XX 1467 /* PXA automagically handles this request too */ 1468 case USB_REQ_GET_CONFIGURATION: 1469 if (ctrl->bRequestType != 0x80) 1470 break; 1471 *(u8 *)req->buf = dev->current_config; 1472 value = min (w_length, (u16) 1); 1473 break; 1474#endif 1475 1476 default: 1477unrecognized: 1478 VDEBUG (dev, "%s req%02x.%02x v%04x i%04x l%d\n", 1479 dev->usermode_setup ? "delegate" : "fail", 1480 ctrl->bRequestType, ctrl->bRequest, 1481 w_value, le16_to_cpu(ctrl->wIndex), w_length); 1482 1483 /* if there's an ep0 reader, don't stall */ 1484 if (dev->usermode_setup) { 1485 dev->setup_can_stall = 1; 1486delegate: 1487 dev->setup_in = (ctrl->bRequestType & USB_DIR_IN) 1488 ? 1 : 0; 1489 dev->setup_wLength = w_length; 1490 dev->setup_out_ready = 0; 1491 dev->setup_out_error = 0; 1492 value = 0; 1493 1494 /* read DATA stage for OUT right away */ 1495 if (unlikely (!dev->setup_in && w_length)) { 1496 value = setup_req (gadget->ep0, dev->req, 1497 w_length); 1498 if (value < 0) 1499 break; 1500 value = usb_ep_queue (gadget->ep0, dev->req, 1501 GFP_ATOMIC); 1502 if (value < 0) { 1503 clean_req (gadget->ep0, dev->req); 1504 break; 1505 } 1506 1507 /* we can't currently stall these */ 1508 dev->setup_can_stall = 0; 1509 } 1510 1511 /* state changes when reader collects event */ 1512 event = next_event (dev, GADGETFS_SETUP); 1513 event->u.setup = *ctrl; 1514 ep0_readable (dev); 1515 spin_unlock (&dev->lock); 1516 return 0; 1517 } 1518 } 1519 1520 /* proceed with data transfer and status phases? */ 1521 if (value >= 0 && dev->state != STATE_SETUP) { 1522 req->length = value; 1523 req->zero = value < w_length; 1524 value = usb_ep_queue (gadget->ep0, req, GFP_ATOMIC); 1525 if (value < 0) { 1526 DBG (dev, "ep_queue --> %d\n", value); 1527 req->status = 0; 1528 } 1529 } 1530 1531 /* device stalls when value < 0 */ 1532 spin_unlock (&dev->lock); 1533 return value; 1534} 1535 1536static void destroy_ep_files (struct dev_data *dev) 1537{ 1538 struct list_head *entry, *tmp; 1539 1540 DBG (dev, "%s %d\n", __FUNCTION__, dev->state); 1541 1542 /* dev->state must prevent interference */ 1543restart: 1544 spin_lock_irq (&dev->lock); 1545 list_for_each_safe (entry, tmp, &dev->epfiles) { 1546 struct ep_data *ep; 1547 struct inode *parent; 1548 struct dentry *dentry; 1549 1550 /* break link to FS */ 1551 ep = list_entry (entry, struct ep_data, epfiles); 1552 list_del_init (&ep->epfiles); 1553 dentry = ep->dentry; 1554 ep->dentry = NULL; 1555 parent = dentry->d_parent->d_inode; 1556 1557 /* break link to controller */ 1558 if (ep->state == STATE_EP_ENABLED) 1559 (void) usb_ep_disable (ep->ep); 1560 ep->state = STATE_EP_UNBOUND; 1561 usb_ep_free_request (ep->ep, ep->req); 1562 ep->ep = NULL; 1563 wake_up (&ep->wait); 1564 put_ep (ep); 1565 1566 spin_unlock_irq (&dev->lock); 1567 1568 /* break link to dcache */ 1569 mutex_lock (&parent->i_mutex); 1570 d_delete (dentry); 1571 dput (dentry); 1572 mutex_unlock (&parent->i_mutex); 1573 1574 /* fds may still be open */ 1575 goto restart; 1576 } 1577 spin_unlock_irq (&dev->lock); 1578} 1579 1580 1581static struct inode * 1582gadgetfs_create_file (struct super_block *sb, char const *name, 1583 void *data, const struct file_operations *fops, 1584 struct dentry **dentry_p); 1585 1586static int activate_ep_files (struct dev_data *dev) 1587{ 1588 struct usb_ep *ep; 1589 1590 gadget_for_each_ep (ep, dev->gadget) { 1591 struct ep_data *data; 1592 1593 data = kzalloc(sizeof(*data), GFP_KERNEL); 1594 if (!data) 1595 goto enomem; 1596 data->state = STATE_EP_DISABLED; 1597 init_MUTEX (&data->lock); 1598 init_waitqueue_head (&data->wait); 1599 1600 strncpy (data->name, ep->name, sizeof (data->name) - 1); 1601 atomic_set (&data->count, 1); 1602 data->dev = dev; 1603 get_dev (dev); 1604 1605 data->ep = ep; 1606 ep->driver_data = data; 1607 1608 data->req = usb_ep_alloc_request (ep, GFP_KERNEL); 1609 if (!data->req) 1610 goto enomem; 1611 1612 data->inode = gadgetfs_create_file (dev->sb, data->name, 1613 data, &ep_config_operations, 1614 &data->dentry); 1615 if (!data->inode) { 1616 usb_ep_free_request(ep, data->req); 1617 kfree (data); 1618 goto enomem; 1619 } 1620 list_add_tail (&data->epfiles, &dev->epfiles); 1621 } 1622 return 0; 1623 1624enomem: 1625 DBG (dev, "%s enomem\n", __FUNCTION__); 1626 destroy_ep_files (dev); 1627 return -ENOMEM; 1628} 1629 1630static void 1631gadgetfs_unbind (struct usb_gadget *gadget) 1632{ 1633 struct dev_data *dev = get_gadget_data (gadget); 1634 1635 DBG (dev, "%s\n", __FUNCTION__); 1636 1637 spin_lock_irq (&dev->lock); 1638 dev->state = STATE_DEV_UNBOUND; 1639 spin_unlock_irq (&dev->lock); 1640 1641 destroy_ep_files (dev); 1642 gadget->ep0->driver_data = NULL; 1643 set_gadget_data (gadget, NULL); 1644 1645 /* we've already been disconnected ... no i/o is active */ 1646 if (dev->req) 1647 usb_ep_free_request (gadget->ep0, dev->req); 1648 DBG (dev, "%s done\n", __FUNCTION__); 1649 put_dev (dev); 1650} 1651 1652static struct dev_data *the_device; 1653 1654static int 1655gadgetfs_bind (struct usb_gadget *gadget) 1656{ 1657 struct dev_data *dev = the_device; 1658 1659 if (!dev) 1660 return -ESRCH; 1661 if (0 != strcmp (CHIP, gadget->name)) { 1662 printk (KERN_ERR "%s expected %s controller not %s\n", 1663 shortname, CHIP, gadget->name); 1664 return -ENODEV; 1665 } 1666 1667 set_gadget_data (gadget, dev); 1668 dev->gadget = gadget; 1669 gadget->ep0->driver_data = dev; 1670 dev->dev->bMaxPacketSize0 = gadget->ep0->maxpacket; 1671 1672 /* preallocate control response and buffer */ 1673 dev->req = usb_ep_alloc_request (gadget->ep0, GFP_KERNEL); 1674 if (!dev->req) 1675 goto enomem; 1676 dev->req->context = NULL; 1677 dev->req->complete = epio_complete; 1678 1679 if (activate_ep_files (dev) < 0) 1680 goto enomem; 1681 1682 INFO (dev, "bound to %s driver\n", gadget->name); 1683 dev->state = STATE_UNCONNECTED; 1684 get_dev (dev); 1685 return 0; 1686 1687enomem: 1688 gadgetfs_unbind (gadget); 1689 return -ENOMEM; 1690} 1691 1692static void 1693gadgetfs_disconnect (struct usb_gadget *gadget) 1694{ 1695 struct dev_data *dev = get_gadget_data (gadget); 1696 1697 if (dev->state == STATE_UNCONNECTED) { 1698 DBG (dev, "already unconnected\n"); 1699 return; 1700 } 1701 dev->state = STATE_UNCONNECTED; 1702 1703 INFO (dev, "disconnected\n"); 1704 spin_lock (&dev->lock); 1705 next_event (dev, GADGETFS_DISCONNECT); 1706 ep0_readable (dev); 1707 spin_unlock (&dev->lock); 1708} 1709 1710static void 1711gadgetfs_suspend (struct usb_gadget *gadget) 1712{ 1713 struct dev_data *dev = get_gadget_data (gadget); 1714 1715 INFO (dev, "suspended from state %d\n", dev->state); 1716 spin_lock (&dev->lock); 1717 switch (dev->state) { 1718 case STATE_SETUP: // VERY odd... host died?? 1719 case STATE_CONNECTED: 1720 case STATE_UNCONNECTED: 1721 next_event (dev, GADGETFS_SUSPEND); 1722 ep0_readable (dev); 1723 /* FALLTHROUGH */ 1724 default: 1725 break; 1726 } 1727 spin_unlock (&dev->lock); 1728} 1729 1730static struct usb_gadget_driver gadgetfs_driver = { 1731#ifdef CONFIG_USB_GADGET_DUALSPEED 1732 .speed = USB_SPEED_HIGH, 1733#else 1734 .speed = USB_SPEED_FULL, 1735#endif 1736 .function = (char *) driver_desc, 1737 .bind = gadgetfs_bind, 1738 .unbind = gadgetfs_unbind, 1739 .setup = gadgetfs_setup, 1740 .disconnect = gadgetfs_disconnect, 1741 .suspend = gadgetfs_suspend, 1742 1743 .driver = { 1744 .name = (char *) shortname, 1745 }, 1746}; 1747 1748/*----------------------------------------------------------------------*/ 1749 1750static void gadgetfs_nop(struct usb_gadget *arg) { } 1751 1752static int gadgetfs_probe (struct usb_gadget *gadget) 1753{ 1754 CHIP = gadget->name; 1755 return -EISNAM; 1756} 1757 1758static struct usb_gadget_driver probe_driver = { 1759 .speed = USB_SPEED_HIGH, 1760 .bind = gadgetfs_probe, 1761 .unbind = gadgetfs_nop, 1762 .setup = (void *)gadgetfs_nop, 1763 .disconnect = gadgetfs_nop, 1764 .driver = { 1765 .name = "nop", 1766 }, 1767}; 1768 1769 1770/* DEVICE INITIALIZATION 1771 * 1772 * fd = open ("/dev/gadget/$CHIP", O_RDWR) 1773 * status = write (fd, descriptors, sizeof descriptors) 1774 * 1775 * That write establishes the device configuration, so the kernel can 1776 * bind to the controller ... guaranteeing it can handle enumeration 1777 * at all necessary speeds. Descriptor order is: 1778 * 1779 * . message tag (u32, host order) ... for now, must be zero; it 1780 * would change to support features like multi-config devices 1781 * . full/low speed config ... all wTotalLength bytes (with interface, 1782 * class, altsetting, endpoint, and other descriptors) 1783 * . high speed config ... all descriptors, for high speed operation; 1784 * this one's optional except for high-speed hardware 1785 * . device descriptor 1786 * 1787 * Endpoints are not yet enabled. Drivers may want to immediately 1788 * initialize them, using the /dev/gadget/ep* files that are available 1789 * as soon as the kernel sees the configuration, or they can wait 1790 * until device configuration and interface altsetting changes create 1791 * the need to configure (or unconfigure) them. 1792 * 1793 * After initialization, the device stays active for as long as that 1794 * $CHIP file is open. Events may then be read from that descriptor, 1795 * such configuration notifications. More complex drivers will handle 1796 * some control requests in user space. 1797 */ 1798 1799static int is_valid_config (struct usb_config_descriptor *config) 1800{ 1801 return config->bDescriptorType == USB_DT_CONFIG 1802 && config->bLength == USB_DT_CONFIG_SIZE 1803 && config->bConfigurationValue != 0 1804 && (config->bmAttributes & USB_CONFIG_ATT_ONE) != 0 1805 && (config->bmAttributes & USB_CONFIG_ATT_WAKEUP) == 0; 1806 /* FIXME if gadget->is_otg, _must_ include an otg descriptor */ 1807 /* FIXME check lengths: walk to end */ 1808} 1809 1810static ssize_t 1811dev_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr) 1812{ 1813 struct dev_data *dev = fd->private_data; 1814 ssize_t value = len, length = len; 1815 unsigned total; 1816 u32 tag; 1817 char *kbuf; 1818 1819 if (dev->state != STATE_OPENED) 1820 return -EEXIST; 1821 1822 if (len < (USB_DT_CONFIG_SIZE + USB_DT_DEVICE_SIZE + 4)) 1823 return -EINVAL; 1824 1825 /* we might need to change message format someday */ 1826 if (copy_from_user (&tag, buf, 4)) 1827 return -EFAULT; 1828 if (tag != 0) 1829 return -EINVAL; 1830 buf += 4; 1831 length -= 4; 1832 1833 kbuf = kmalloc (length, SLAB_KERNEL); 1834 if (!kbuf) 1835 return -ENOMEM; 1836 if (copy_from_user (kbuf, buf, length)) { 1837 kfree (kbuf); 1838 return -EFAULT; 1839 } 1840 1841 spin_lock_irq (&dev->lock); 1842 value = -EINVAL; 1843 if (dev->buf) 1844 goto fail; 1845 dev->buf = kbuf; 1846 1847 /* full or low speed config */ 1848 dev->config = (void *) kbuf; 1849 total = le16_to_cpup (&dev->config->wTotalLength); 1850 if (!is_valid_config (dev->config) || total >= length) 1851 goto fail; 1852 kbuf += total; 1853 length -= total; 1854 1855 /* optional high speed config */ 1856 if (kbuf [1] == USB_DT_CONFIG) { 1857 dev->hs_config = (void *) kbuf; 1858 total = le16_to_cpup (&dev->hs_config->wTotalLength); 1859 if (!is_valid_config (dev->hs_config) || total >= length) 1860 goto fail; 1861 kbuf += total; 1862 length -= total; 1863 } 1864 1865 /* could support multiple configs, using another encoding! */ 1866 1867 /* device descriptor (tweaked for paranoia) */ 1868 if (length != USB_DT_DEVICE_SIZE) 1869 goto fail; 1870 dev->dev = (void *)kbuf; 1871 if (dev->dev->bLength != USB_DT_DEVICE_SIZE 1872 || dev->dev->bDescriptorType != USB_DT_DEVICE 1873 || dev->dev->bNumConfigurations != 1) 1874 goto fail; 1875 dev->dev->bNumConfigurations = 1; 1876 dev->dev->bcdUSB = __constant_cpu_to_le16 (0x0200); 1877 1878 /* triggers gadgetfs_bind(); then we can enumerate. */ 1879 spin_unlock_irq (&dev->lock); 1880 value = usb_gadget_register_driver (&gadgetfs_driver); 1881 if (value != 0) { 1882 kfree (dev->buf); 1883 dev->buf = NULL; 1884 } else { 1885 /* at this point "good" hardware has for the first time 1886 * let the USB the host see us. alternatively, if users 1887 * unplug/replug that will clear all the error state. 1888 * 1889 * note: everything running before here was guaranteed 1890 * to choke driver model style diagnostics. from here 1891 * on, they can work ... except in cleanup paths that 1892 * kick in after the ep0 descriptor is closed. 1893 */ 1894 fd->f_op = &ep0_io_operations; 1895 value = len; 1896 } 1897 return value; 1898 1899fail: 1900 spin_unlock_irq (&dev->lock); 1901 pr_debug ("%s: %s fail %Zd, %p\n", shortname, __FUNCTION__, value, dev); 1902 kfree (dev->buf); 1903 dev->buf = NULL; 1904 return value; 1905} 1906 1907static int 1908dev_open (struct inode *inode, struct file *fd) 1909{ 1910 struct dev_data *dev = inode->u.generic_ip; 1911 int value = -EBUSY; 1912 1913 if (dev->state == STATE_DEV_DISABLED) { 1914 dev->ev_next = 0; 1915 dev->state = STATE_OPENED; 1916 fd->private_data = dev; 1917 get_dev (dev); 1918 value = 0; 1919 } 1920 return value; 1921} 1922 1923static struct file_operations dev_init_operations = { 1924 .owner = THIS_MODULE, 1925 .llseek = no_llseek, 1926 1927 .open = dev_open, 1928 .write = dev_config, 1929 .fasync = ep0_fasync, 1930 .ioctl = dev_ioctl, 1931 .release = dev_release, 1932}; 1933 1934/*----------------------------------------------------------------------*/ 1935 1936/* FILESYSTEM AND SUPERBLOCK OPERATIONS 1937 * 1938 * Mounting the filesystem creates a controller file, used first for 1939 * device configuration then later for event monitoring. 1940 */ 1941 1942 1943/* FIXME PAM etc could set this security policy without mount options 1944 * if epfiles inherited ownership and permissons from ep0 ... 1945 */ 1946 1947static unsigned default_uid; 1948static unsigned default_gid; 1949static unsigned default_perm = S_IRUSR | S_IWUSR; 1950 1951module_param (default_uid, uint, 0644); 1952module_param (default_gid, uint, 0644); 1953module_param (default_perm, uint, 0644); 1954 1955 1956static struct inode * 1957gadgetfs_make_inode (struct super_block *sb, 1958 void *data, const struct file_operations *fops, 1959 int mode) 1960{ 1961 struct inode *inode = new_inode (sb); 1962 1963 if (inode) { 1964 inode->i_mode = mode; 1965 inode->i_uid = default_uid; 1966 inode->i_gid = default_gid; 1967 inode->i_blksize = PAGE_CACHE_SIZE; 1968 inode->i_blocks = 0; 1969 inode->i_atime = inode->i_mtime = inode->i_ctime 1970 = CURRENT_TIME; 1971 inode->u.generic_ip = data; 1972 inode->i_fop = fops; 1973 } 1974 return inode; 1975} 1976 1977/* creates in fs root directory, so non-renamable and non-linkable. 1978 * so inode and dentry are paired, until device reconfig. 1979 */ 1980static struct inode * 1981gadgetfs_create_file (struct super_block *sb, char const *name, 1982 void *data, const struct file_operations *fops, 1983 struct dentry **dentry_p) 1984{ 1985 struct dentry *dentry; 1986 struct inode *inode; 1987 1988 dentry = d_alloc_name(sb->s_root, name); 1989 if (!dentry) 1990 return NULL; 1991 1992 inode = gadgetfs_make_inode (sb, data, fops, 1993 S_IFREG | (default_perm & S_IRWXUGO)); 1994 if (!inode) { 1995 dput(dentry); 1996 return NULL; 1997 } 1998 d_add (dentry, inode); 1999 *dentry_p = dentry; 2000 return inode; 2001} 2002 2003static struct super_operations gadget_fs_operations = { 2004 .statfs = simple_statfs, 2005 .drop_inode = generic_delete_inode, 2006}; 2007 2008static int 2009gadgetfs_fill_super (struct super_block *sb, void *opts, int silent) 2010{ 2011 struct inode *inode; 2012 struct dentry *d; 2013 struct dev_data *dev; 2014 2015 if (the_device) 2016 return -ESRCH; 2017 2018 /* fake probe to determine $CHIP */ 2019 (void) usb_gadget_register_driver (&probe_driver); 2020 if (!CHIP) 2021 return -ENODEV; 2022 2023 /* superblock */ 2024 sb->s_blocksize = PAGE_CACHE_SIZE; 2025 sb->s_blocksize_bits = PAGE_CACHE_SHIFT; 2026 sb->s_magic = GADGETFS_MAGIC; 2027 sb->s_op = &gadget_fs_operations; 2028 sb->s_time_gran = 1; 2029 2030 /* root inode */ 2031 inode = gadgetfs_make_inode (sb, 2032 NULL, &simple_dir_operations, 2033 S_IFDIR | S_IRUGO | S_IXUGO); 2034 if (!inode) 2035 return -ENOMEM; 2036 inode->i_op = &simple_dir_inode_operations; 2037 if (!(d = d_alloc_root (inode))) { 2038 iput (inode); 2039 return -ENOMEM; 2040 } 2041 sb->s_root = d; 2042 2043 /* the ep0 file is named after the controller we expect; 2044 * user mode code can use it for sanity checks, like we do. 2045 */ 2046 dev = dev_new (); 2047 if (!dev) 2048 return -ENOMEM; 2049 2050 dev->sb = sb; 2051 if (!(inode = gadgetfs_create_file (sb, CHIP, 2052 dev, &dev_init_operations, 2053 &dev->dentry))) { 2054 put_dev(dev); 2055 return -ENOMEM; 2056 } 2057 2058 /* other endpoint files are available after hardware setup, 2059 * from binding to a controller. 2060 */ 2061 the_device = dev; 2062 return 0; 2063} 2064 2065/* "mount -t gadgetfs path /dev/gadget" ends up here */ 2066static struct super_block * 2067gadgetfs_get_sb (struct file_system_type *t, int flags, 2068 const char *path, void *opts) 2069{ 2070 return get_sb_single (t, flags, opts, gadgetfs_fill_super); 2071} 2072 2073static void 2074gadgetfs_kill_sb (struct super_block *sb) 2075{ 2076 kill_litter_super (sb); 2077 if (the_device) { 2078 put_dev (the_device); 2079 the_device = NULL; 2080 } 2081} 2082 2083/*----------------------------------------------------------------------*/ 2084 2085static struct file_system_type gadgetfs_type = { 2086 .owner = THIS_MODULE, 2087 .name = shortname, 2088 .get_sb = gadgetfs_get_sb, 2089 .kill_sb = gadgetfs_kill_sb, 2090}; 2091 2092/*----------------------------------------------------------------------*/ 2093 2094static int __init init (void) 2095{ 2096 int status; 2097 2098 status = register_filesystem (&gadgetfs_type); 2099 if (status == 0) 2100 pr_info ("%s: %s, version " DRIVER_VERSION "\n", 2101 shortname, driver_desc); 2102 return status; 2103} 2104module_init (init); 2105 2106static void __exit cleanup (void) 2107{ 2108 pr_debug ("unregister %s\n", shortname); 2109 unregister_filesystem (&gadgetfs_type); 2110} 2111module_exit (cleanup); 2112 2113