inode.c revision a2457ee691edeffb511dbff9a69008f480192197
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 13 14/* #define VERBOSE_DEBUG */ 15 16#include <linux/init.h> 17#include <linux/module.h> 18#include <linux/fs.h> 19#include <linux/pagemap.h> 20#include <linux/uts.h> 21#include <linux/wait.h> 22#include <linux/compiler.h> 23#include <asm/uaccess.h> 24#include <linux/sched.h> 25#include <linux/slab.h> 26#include <linux/poll.h> 27 28#include <linux/device.h> 29#include <linux/moduleparam.h> 30 31#include <linux/usb/gadgetfs.h> 32#include <linux/usb/gadget.h> 33 34 35/* 36 * The gadgetfs API maps each endpoint to a file descriptor so that you 37 * can use standard synchronous read/write calls for I/O. There's some 38 * O_NONBLOCK and O_ASYNC/FASYNC style i/o support. Example usermode 39 * drivers show how this works in practice. You can also use AIO to 40 * eliminate I/O gaps between requests, to help when streaming data. 41 * 42 * Key parts that must be USB-specific are protocols defining how the 43 * read/write operations relate to the hardware state machines. There 44 * are two types of files. One type is for the device, implementing ep0. 45 * The other type is for each IN or OUT endpoint. In both cases, the 46 * user mode driver must configure the hardware before using it. 47 * 48 * - First, dev_config() is called when /dev/gadget/$CHIP is configured 49 * (by writing configuration and device descriptors). Afterwards it 50 * may serve as a source of device events, used to handle all control 51 * requests other than basic enumeration. 52 * 53 * - Then, after a SET_CONFIGURATION control request, ep_config() is 54 * called when each /dev/gadget/ep* file is configured (by writing 55 * endpoint descriptors). Afterwards these files are used to write() 56 * IN data or to read() OUT data. To halt the endpoint, a "wrong 57 * direction" request is issued (like reading an IN endpoint). 58 * 59 * Unlike "usbfs" the only ioctl()s are for things that are rare, and maybe 60 * not possible on all hardware. For example, precise fault handling with 61 * respect to data left in endpoint fifos after aborted operations; or 62 * selective clearing of endpoint halts, to implement SET_INTERFACE. 63 */ 64 65#define DRIVER_DESC "USB Gadget filesystem" 66#define DRIVER_VERSION "24 Aug 2004" 67 68static const char driver_desc [] = DRIVER_DESC; 69static const char shortname [] = "gadgetfs"; 70 71MODULE_DESCRIPTION (DRIVER_DESC); 72MODULE_AUTHOR ("David Brownell"); 73MODULE_LICENSE ("GPL"); 74 75 76/*----------------------------------------------------------------------*/ 77 78#define GADGETFS_MAGIC 0xaee71ee7 79#define DMA_ADDR_INVALID (~(dma_addr_t)0) 80 81/* /dev/gadget/$CHIP represents ep0 and the whole device */ 82enum ep0_state { 83 /* DISBLED is the initial state. 84 */ 85 STATE_DEV_DISABLED = 0, 86 87 /* Only one open() of /dev/gadget/$CHIP; only one file tracks 88 * ep0/device i/o modes and binding to the controller. Driver 89 * must always write descriptors to initialize the device, then 90 * the device becomes UNCONNECTED until enumeration. 91 */ 92 STATE_DEV_OPENED, 93 94 /* From then on, ep0 fd is in either of two basic modes: 95 * - (UN)CONNECTED: read usb_gadgetfs_event(s) from it 96 * - SETUP: read/write will transfer control data and succeed; 97 * or if "wrong direction", performs protocol stall 98 */ 99 STATE_DEV_UNCONNECTED, 100 STATE_DEV_CONNECTED, 101 STATE_DEV_SETUP, 102 103 /* UNBOUND means the driver closed ep0, so the device won't be 104 * accessible again (DEV_DISABLED) until all fds are closed. 105 */ 106 STATE_DEV_UNBOUND, 107}; 108 109/* enough for the whole queue: most events invalidate others */ 110#define N_EVENT 5 111 112struct dev_data { 113 spinlock_t lock; 114 atomic_t count; 115 enum ep0_state state; /* P: lock */ 116 struct usb_gadgetfs_event event [N_EVENT]; 117 unsigned ev_next; 118 struct fasync_struct *fasync; 119 u8 current_config; 120 121 /* drivers reading ep0 MUST handle control requests (SETUP) 122 * reported that way; else the host will time out. 123 */ 124 unsigned usermode_setup : 1, 125 setup_in : 1, 126 setup_can_stall : 1, 127 setup_out_ready : 1, 128 setup_out_error : 1, 129 setup_abort : 1; 130 unsigned setup_wLength; 131 132 /* the rest is basically write-once */ 133 struct usb_config_descriptor *config, *hs_config; 134 struct usb_device_descriptor *dev; 135 struct usb_request *req; 136 struct usb_gadget *gadget; 137 struct list_head epfiles; 138 void *buf; 139 wait_queue_head_t wait; 140 struct super_block *sb; 141 struct dentry *dentry; 142 143 /* except this scratch i/o buffer for ep0 */ 144 u8 rbuf [256]; 145}; 146 147static inline void get_dev (struct dev_data *data) 148{ 149 atomic_inc (&data->count); 150} 151 152static void put_dev (struct dev_data *data) 153{ 154 if (likely (!atomic_dec_and_test (&data->count))) 155 return; 156 /* needs no more cleanup */ 157 BUG_ON (waitqueue_active (&data->wait)); 158 kfree (data); 159} 160 161static struct dev_data *dev_new (void) 162{ 163 struct dev_data *dev; 164 165 dev = kzalloc(sizeof(*dev), GFP_KERNEL); 166 if (!dev) 167 return NULL; 168 dev->state = STATE_DEV_DISABLED; 169 atomic_set (&dev->count, 1); 170 spin_lock_init (&dev->lock); 171 INIT_LIST_HEAD (&dev->epfiles); 172 init_waitqueue_head (&dev->wait); 173 return dev; 174} 175 176/*----------------------------------------------------------------------*/ 177 178/* other /dev/gadget/$ENDPOINT files represent endpoints */ 179enum ep_state { 180 STATE_EP_DISABLED = 0, 181 STATE_EP_READY, 182 STATE_EP_ENABLED, 183 STATE_EP_UNBOUND, 184}; 185 186struct ep_data { 187 struct mutex lock; 188 enum ep_state state; 189 atomic_t count; 190 struct dev_data *dev; 191 /* must hold dev->lock before accessing ep or req */ 192 struct usb_ep *ep; 193 struct usb_request *req; 194 ssize_t status; 195 char name [16]; 196 struct usb_endpoint_descriptor desc, hs_desc; 197 struct list_head epfiles; 198 wait_queue_head_t wait; 199 struct dentry *dentry; 200 struct inode *inode; 201}; 202 203static inline void get_ep (struct ep_data *data) 204{ 205 atomic_inc (&data->count); 206} 207 208static void put_ep (struct ep_data *data) 209{ 210 if (likely (!atomic_dec_and_test (&data->count))) 211 return; 212 put_dev (data->dev); 213 /* needs no more cleanup */ 214 BUG_ON (!list_empty (&data->epfiles)); 215 BUG_ON (waitqueue_active (&data->wait)); 216 kfree (data); 217} 218 219/*----------------------------------------------------------------------*/ 220 221/* most "how to use the hardware" policy choices are in userspace: 222 * mapping endpoint roles (which the driver needs) to the capabilities 223 * which the usb controller has. most of those capabilities are exposed 224 * implicitly, starting with the driver name and then endpoint names. 225 */ 226 227static const char *CHIP; 228 229/*----------------------------------------------------------------------*/ 230 231/* NOTE: don't use dev_printk calls before binding to the gadget 232 * at the end of ep0 configuration, or after unbind. 233 */ 234 235/* too wordy: dev_printk(level , &(d)->gadget->dev , fmt , ## args) */ 236#define xprintk(d,level,fmt,args...) \ 237 printk(level "%s: " fmt , shortname , ## args) 238 239#ifdef DEBUG 240#define DBG(dev,fmt,args...) \ 241 xprintk(dev , KERN_DEBUG , fmt , ## args) 242#else 243#define DBG(dev,fmt,args...) \ 244 do { } while (0) 245#endif /* DEBUG */ 246 247#ifdef VERBOSE_DEBUG 248#define VDEBUG DBG 249#else 250#define VDEBUG(dev,fmt,args...) \ 251 do { } while (0) 252#endif /* DEBUG */ 253 254#define ERROR(dev,fmt,args...) \ 255 xprintk(dev , KERN_ERR , fmt , ## args) 256#define INFO(dev,fmt,args...) \ 257 xprintk(dev , KERN_INFO , fmt , ## args) 258 259 260/*----------------------------------------------------------------------*/ 261 262/* SYNCHRONOUS ENDPOINT OPERATIONS (bulk/intr/iso) 263 * 264 * After opening, configure non-control endpoints. Then use normal 265 * stream read() and write() requests; and maybe ioctl() to get more 266 * precise FIFO status when recovering from cancellation. 267 */ 268 269static void epio_complete (struct usb_ep *ep, struct usb_request *req) 270{ 271 struct ep_data *epdata = ep->driver_data; 272 273 if (!req->context) 274 return; 275 if (req->status) 276 epdata->status = req->status; 277 else 278 epdata->status = req->actual; 279 complete ((struct completion *)req->context); 280} 281 282/* tasklock endpoint, returning when it's connected. 283 * still need dev->lock to use epdata->ep. 284 */ 285static int 286get_ready_ep (unsigned f_flags, struct ep_data *epdata) 287{ 288 int val; 289 290 if (f_flags & O_NONBLOCK) { 291 if (!mutex_trylock(&epdata->lock)) 292 goto nonblock; 293 if (epdata->state != STATE_EP_ENABLED) { 294 mutex_unlock(&epdata->lock); 295nonblock: 296 val = -EAGAIN; 297 } else 298 val = 0; 299 return val; 300 } 301 302 val = mutex_lock_interruptible(&epdata->lock); 303 if (val < 0) 304 return val; 305 306 switch (epdata->state) { 307 case STATE_EP_ENABLED: 308 break; 309 // case STATE_EP_DISABLED: /* "can't happen" */ 310 // case STATE_EP_READY: /* "can't happen" */ 311 default: /* error! */ 312 pr_debug ("%s: ep %p not available, state %d\n", 313 shortname, epdata, epdata->state); 314 // FALLTHROUGH 315 case STATE_EP_UNBOUND: /* clean disconnect */ 316 val = -ENODEV; 317 mutex_unlock(&epdata->lock); 318 } 319 return val; 320} 321 322static ssize_t 323ep_io (struct ep_data *epdata, void *buf, unsigned len) 324{ 325 DECLARE_COMPLETION_ONSTACK (done); 326 int value; 327 328 spin_lock_irq (&epdata->dev->lock); 329 if (likely (epdata->ep != NULL)) { 330 struct usb_request *req = epdata->req; 331 332 req->context = &done; 333 req->complete = epio_complete; 334 req->buf = buf; 335 req->length = len; 336 value = usb_ep_queue (epdata->ep, req, GFP_ATOMIC); 337 } else 338 value = -ENODEV; 339 spin_unlock_irq (&epdata->dev->lock); 340 341 if (likely (value == 0)) { 342 value = wait_event_interruptible (done.wait, done.done); 343 if (value != 0) { 344 spin_lock_irq (&epdata->dev->lock); 345 if (likely (epdata->ep != NULL)) { 346 DBG (epdata->dev, "%s i/o interrupted\n", 347 epdata->name); 348 usb_ep_dequeue (epdata->ep, epdata->req); 349 spin_unlock_irq (&epdata->dev->lock); 350 351 wait_event (done.wait, done.done); 352 if (epdata->status == -ECONNRESET) 353 epdata->status = -EINTR; 354 } else { 355 spin_unlock_irq (&epdata->dev->lock); 356 357 DBG (epdata->dev, "endpoint gone\n"); 358 epdata->status = -ENODEV; 359 } 360 } 361 return epdata->status; 362 } 363 return value; 364} 365 366 367/* handle a synchronous OUT bulk/intr/iso transfer */ 368static ssize_t 369ep_read (struct file *fd, char __user *buf, size_t len, loff_t *ptr) 370{ 371 struct ep_data *data = fd->private_data; 372 void *kbuf; 373 ssize_t value; 374 375 if ((value = get_ready_ep (fd->f_flags, data)) < 0) 376 return value; 377 378 /* halt any endpoint by doing a "wrong direction" i/o call */ 379 if (usb_endpoint_dir_in(&data->desc)) { 380 if (usb_endpoint_xfer_isoc(&data->desc)) { 381 mutex_unlock(&data->lock); 382 return -EINVAL; 383 } 384 DBG (data->dev, "%s halt\n", data->name); 385 spin_lock_irq (&data->dev->lock); 386 if (likely (data->ep != NULL)) 387 usb_ep_set_halt (data->ep); 388 spin_unlock_irq (&data->dev->lock); 389 mutex_unlock(&data->lock); 390 return -EBADMSG; 391 } 392 393 /* FIXME readahead for O_NONBLOCK and poll(); careful with ZLPs */ 394 395 value = -ENOMEM; 396 kbuf = kmalloc (len, GFP_KERNEL); 397 if (unlikely (!kbuf)) 398 goto free1; 399 400 value = ep_io (data, kbuf, len); 401 VDEBUG (data->dev, "%s read %zu OUT, status %d\n", 402 data->name, len, (int) value); 403 if (value >= 0 && copy_to_user (buf, kbuf, value)) 404 value = -EFAULT; 405 406free1: 407 mutex_unlock(&data->lock); 408 kfree (kbuf); 409 return value; 410} 411 412/* handle a synchronous IN bulk/intr/iso transfer */ 413static ssize_t 414ep_write (struct file *fd, const char __user *buf, size_t len, loff_t *ptr) 415{ 416 struct ep_data *data = fd->private_data; 417 void *kbuf; 418 ssize_t value; 419 420 if ((value = get_ready_ep (fd->f_flags, data)) < 0) 421 return value; 422 423 /* halt any endpoint by doing a "wrong direction" i/o call */ 424 if (!usb_endpoint_dir_in(&data->desc)) { 425 if (usb_endpoint_xfer_isoc(&data->desc)) { 426 mutex_unlock(&data->lock); 427 return -EINVAL; 428 } 429 DBG (data->dev, "%s halt\n", data->name); 430 spin_lock_irq (&data->dev->lock); 431 if (likely (data->ep != NULL)) 432 usb_ep_set_halt (data->ep); 433 spin_unlock_irq (&data->dev->lock); 434 mutex_unlock(&data->lock); 435 return -EBADMSG; 436 } 437 438 /* FIXME writebehind for O_NONBLOCK and poll(), qlen = 1 */ 439 440 value = -ENOMEM; 441 kbuf = kmalloc (len, GFP_KERNEL); 442 if (!kbuf) 443 goto free1; 444 if (copy_from_user (kbuf, buf, len)) { 445 value = -EFAULT; 446 goto free1; 447 } 448 449 value = ep_io (data, kbuf, len); 450 VDEBUG (data->dev, "%s write %zu IN, status %d\n", 451 data->name, len, (int) value); 452free1: 453 mutex_unlock(&data->lock); 454 kfree (kbuf); 455 return value; 456} 457 458static int 459ep_release (struct inode *inode, struct file *fd) 460{ 461 struct ep_data *data = fd->private_data; 462 int value; 463 464 value = mutex_lock_interruptible(&data->lock); 465 if (value < 0) 466 return value; 467 468 /* clean up if this can be reopened */ 469 if (data->state != STATE_EP_UNBOUND) { 470 data->state = STATE_EP_DISABLED; 471 data->desc.bDescriptorType = 0; 472 data->hs_desc.bDescriptorType = 0; 473 usb_ep_disable(data->ep); 474 } 475 mutex_unlock(&data->lock); 476 put_ep (data); 477 return 0; 478} 479 480static long ep_ioctl(struct file *fd, unsigned code, unsigned long value) 481{ 482 struct ep_data *data = fd->private_data; 483 int status; 484 485 if ((status = get_ready_ep (fd->f_flags, data)) < 0) 486 return status; 487 488 spin_lock_irq (&data->dev->lock); 489 if (likely (data->ep != NULL)) { 490 switch (code) { 491 case GADGETFS_FIFO_STATUS: 492 status = usb_ep_fifo_status (data->ep); 493 break; 494 case GADGETFS_FIFO_FLUSH: 495 usb_ep_fifo_flush (data->ep); 496 break; 497 case GADGETFS_CLEAR_HALT: 498 status = usb_ep_clear_halt (data->ep); 499 break; 500 default: 501 status = -ENOTTY; 502 } 503 } else 504 status = -ENODEV; 505 spin_unlock_irq (&data->dev->lock); 506 mutex_unlock(&data->lock); 507 return status; 508} 509 510/*----------------------------------------------------------------------*/ 511 512/* ASYNCHRONOUS ENDPOINT I/O OPERATIONS (bulk/intr/iso) */ 513 514struct kiocb_priv { 515 struct usb_request *req; 516 struct ep_data *epdata; 517 void *buf; 518 const struct iovec *iv; 519 unsigned long nr_segs; 520 unsigned actual; 521}; 522 523static int ep_aio_cancel(struct kiocb *iocb, struct io_event *e) 524{ 525 struct kiocb_priv *priv = iocb->private; 526 struct ep_data *epdata; 527 int value; 528 529 local_irq_disable(); 530 epdata = priv->epdata; 531 // spin_lock(&epdata->dev->lock); 532 kiocbSetCancelled(iocb); 533 if (likely(epdata && epdata->ep && priv->req)) 534 value = usb_ep_dequeue (epdata->ep, priv->req); 535 else 536 value = -EINVAL; 537 // spin_unlock(&epdata->dev->lock); 538 local_irq_enable(); 539 540 aio_put_req(iocb); 541 return value; 542} 543 544static ssize_t ep_aio_read_retry(struct kiocb *iocb) 545{ 546 struct kiocb_priv *priv = iocb->private; 547 ssize_t len, total; 548 void *to_copy; 549 int i; 550 551 /* we "retry" to get the right mm context for this: */ 552 553 /* copy stuff into user buffers */ 554 total = priv->actual; 555 len = 0; 556 to_copy = priv->buf; 557 for (i=0; i < priv->nr_segs; i++) { 558 ssize_t this = min((ssize_t)(priv->iv[i].iov_len), total); 559 560 if (copy_to_user(priv->iv[i].iov_base, to_copy, this)) { 561 if (len == 0) 562 len = -EFAULT; 563 break; 564 } 565 566 total -= this; 567 len += this; 568 to_copy += this; 569 if (total == 0) 570 break; 571 } 572 kfree(priv->buf); 573 kfree(priv); 574 return len; 575} 576 577static void ep_aio_complete(struct usb_ep *ep, struct usb_request *req) 578{ 579 struct kiocb *iocb = req->context; 580 struct kiocb_priv *priv = iocb->private; 581 struct ep_data *epdata = priv->epdata; 582 583 /* lock against disconnect (and ideally, cancel) */ 584 spin_lock(&epdata->dev->lock); 585 priv->req = NULL; 586 priv->epdata = NULL; 587 588 /* if this was a write or a read returning no data then we 589 * don't need to copy anything to userspace, so we can 590 * complete the aio request immediately. 591 */ 592 if (priv->iv == NULL || unlikely(req->actual == 0)) { 593 kfree(req->buf); 594 kfree(priv); 595 iocb->private = NULL; 596 /* aio_complete() reports bytes-transferred _and_ faults */ 597 aio_complete(iocb, req->actual ? req->actual : req->status, 598 req->status); 599 } else { 600 /* retry() won't report both; so we hide some faults */ 601 if (unlikely(0 != req->status)) 602 DBG(epdata->dev, "%s fault %d len %d\n", 603 ep->name, req->status, req->actual); 604 605 priv->buf = req->buf; 606 priv->actual = req->actual; 607 kick_iocb(iocb); 608 } 609 spin_unlock(&epdata->dev->lock); 610 611 usb_ep_free_request(ep, req); 612 put_ep(epdata); 613} 614 615static ssize_t 616ep_aio_rwtail( 617 struct kiocb *iocb, 618 char *buf, 619 size_t len, 620 struct ep_data *epdata, 621 const struct iovec *iv, 622 unsigned long nr_segs 623) 624{ 625 struct kiocb_priv *priv; 626 struct usb_request *req; 627 ssize_t value; 628 629 priv = kmalloc(sizeof *priv, GFP_KERNEL); 630 if (!priv) { 631 value = -ENOMEM; 632fail: 633 kfree(buf); 634 return value; 635 } 636 iocb->private = priv; 637 priv->iv = iv; 638 priv->nr_segs = nr_segs; 639 640 value = get_ready_ep(iocb->ki_filp->f_flags, epdata); 641 if (unlikely(value < 0)) { 642 kfree(priv); 643 goto fail; 644 } 645 646 iocb->ki_cancel = ep_aio_cancel; 647 get_ep(epdata); 648 priv->epdata = epdata; 649 priv->actual = 0; 650 651 /* each kiocb is coupled to one usb_request, but we can't 652 * allocate or submit those if the host disconnected. 653 */ 654 spin_lock_irq(&epdata->dev->lock); 655 if (likely(epdata->ep)) { 656 req = usb_ep_alloc_request(epdata->ep, GFP_ATOMIC); 657 if (likely(req)) { 658 priv->req = req; 659 req->buf = buf; 660 req->length = len; 661 req->complete = ep_aio_complete; 662 req->context = iocb; 663 value = usb_ep_queue(epdata->ep, req, GFP_ATOMIC); 664 if (unlikely(0 != value)) 665 usb_ep_free_request(epdata->ep, req); 666 } else 667 value = -EAGAIN; 668 } else 669 value = -ENODEV; 670 spin_unlock_irq(&epdata->dev->lock); 671 672 mutex_unlock(&epdata->lock); 673 674 if (unlikely(value)) { 675 kfree(priv); 676 put_ep(epdata); 677 } else 678 value = (iv ? -EIOCBRETRY : -EIOCBQUEUED); 679 return value; 680} 681 682static ssize_t 683ep_aio_read(struct kiocb *iocb, const struct iovec *iov, 684 unsigned long nr_segs, loff_t o) 685{ 686 struct ep_data *epdata = iocb->ki_filp->private_data; 687 char *buf; 688 689 if (unlikely(usb_endpoint_dir_in(&epdata->desc))) 690 return -EINVAL; 691 692 buf = kmalloc(iocb->ki_left, GFP_KERNEL); 693 if (unlikely(!buf)) 694 return -ENOMEM; 695 696 iocb->ki_retry = ep_aio_read_retry; 697 return ep_aio_rwtail(iocb, buf, iocb->ki_left, epdata, iov, nr_segs); 698} 699 700static ssize_t 701ep_aio_write(struct kiocb *iocb, const struct iovec *iov, 702 unsigned long nr_segs, loff_t o) 703{ 704 struct ep_data *epdata = iocb->ki_filp->private_data; 705 char *buf; 706 size_t len = 0; 707 int i = 0; 708 709 if (unlikely(!usb_endpoint_dir_in(&epdata->desc))) 710 return -EINVAL; 711 712 buf = kmalloc(iocb->ki_left, GFP_KERNEL); 713 if (unlikely(!buf)) 714 return -ENOMEM; 715 716 for (i=0; i < nr_segs; i++) { 717 if (unlikely(copy_from_user(&buf[len], iov[i].iov_base, 718 iov[i].iov_len) != 0)) { 719 kfree(buf); 720 return -EFAULT; 721 } 722 len += iov[i].iov_len; 723 } 724 return ep_aio_rwtail(iocb, buf, len, epdata, NULL, 0); 725} 726 727/*----------------------------------------------------------------------*/ 728 729/* used after endpoint configuration */ 730static const struct file_operations ep_io_operations = { 731 .owner = THIS_MODULE, 732 .llseek = no_llseek, 733 734 .read = ep_read, 735 .write = ep_write, 736 .unlocked_ioctl = ep_ioctl, 737 .release = ep_release, 738 739 .aio_read = ep_aio_read, 740 .aio_write = ep_aio_write, 741}; 742 743/* ENDPOINT INITIALIZATION 744 * 745 * fd = open ("/dev/gadget/$ENDPOINT", O_RDWR) 746 * status = write (fd, descriptors, sizeof descriptors) 747 * 748 * That write establishes the endpoint configuration, configuring 749 * the controller to process bulk, interrupt, or isochronous transfers 750 * at the right maxpacket size, and so on. 751 * 752 * The descriptors are message type 1, identified by a host order u32 753 * at the beginning of what's written. Descriptor order is: full/low 754 * speed descriptor, then optional high speed descriptor. 755 */ 756static ssize_t 757ep_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr) 758{ 759 struct ep_data *data = fd->private_data; 760 struct usb_ep *ep; 761 u32 tag; 762 int value, length = len; 763 764 value = mutex_lock_interruptible(&data->lock); 765 if (value < 0) 766 return value; 767 768 if (data->state != STATE_EP_READY) { 769 value = -EL2HLT; 770 goto fail; 771 } 772 773 value = len; 774 if (len < USB_DT_ENDPOINT_SIZE + 4) 775 goto fail0; 776 777 /* we might need to change message format someday */ 778 if (copy_from_user (&tag, buf, 4)) { 779 goto fail1; 780 } 781 if (tag != 1) { 782 DBG(data->dev, "config %s, bad tag %d\n", data->name, tag); 783 goto fail0; 784 } 785 buf += 4; 786 len -= 4; 787 788 /* NOTE: audio endpoint extensions not accepted here; 789 * just don't include the extra bytes. 790 */ 791 792 /* full/low speed descriptor, then high speed */ 793 if (copy_from_user (&data->desc, buf, USB_DT_ENDPOINT_SIZE)) { 794 goto fail1; 795 } 796 if (data->desc.bLength != USB_DT_ENDPOINT_SIZE 797 || data->desc.bDescriptorType != USB_DT_ENDPOINT) 798 goto fail0; 799 if (len != USB_DT_ENDPOINT_SIZE) { 800 if (len != 2 * USB_DT_ENDPOINT_SIZE) 801 goto fail0; 802 if (copy_from_user (&data->hs_desc, buf + USB_DT_ENDPOINT_SIZE, 803 USB_DT_ENDPOINT_SIZE)) { 804 goto fail1; 805 } 806 if (data->hs_desc.bLength != USB_DT_ENDPOINT_SIZE 807 || data->hs_desc.bDescriptorType 808 != USB_DT_ENDPOINT) { 809 DBG(data->dev, "config %s, bad hs length or type\n", 810 data->name); 811 goto fail0; 812 } 813 } 814 815 spin_lock_irq (&data->dev->lock); 816 if (data->dev->state == STATE_DEV_UNBOUND) { 817 value = -ENOENT; 818 goto gone; 819 } else if ((ep = data->ep) == NULL) { 820 value = -ENODEV; 821 goto gone; 822 } 823 switch (data->dev->gadget->speed) { 824 case USB_SPEED_LOW: 825 case USB_SPEED_FULL: 826 ep->desc = &data->desc; 827 value = usb_ep_enable(ep); 828 if (value == 0) 829 data->state = STATE_EP_ENABLED; 830 break; 831#ifdef CONFIG_USB_GADGET_DUALSPEED 832 case USB_SPEED_HIGH: 833 /* fails if caller didn't provide that descriptor... */ 834 ep->desc = &data->hs_desc; 835 value = usb_ep_enable(ep); 836 if (value == 0) 837 data->state = STATE_EP_ENABLED; 838 break; 839#endif 840 default: 841 DBG(data->dev, "unconnected, %s init abandoned\n", 842 data->name); 843 value = -EINVAL; 844 } 845 if (value == 0) { 846 fd->f_op = &ep_io_operations; 847 value = length; 848 } 849gone: 850 spin_unlock_irq (&data->dev->lock); 851 if (value < 0) { 852fail: 853 data->desc.bDescriptorType = 0; 854 data->hs_desc.bDescriptorType = 0; 855 } 856 mutex_unlock(&data->lock); 857 return value; 858fail0: 859 value = -EINVAL; 860 goto fail; 861fail1: 862 value = -EFAULT; 863 goto fail; 864} 865 866static int 867ep_open (struct inode *inode, struct file *fd) 868{ 869 struct ep_data *data = inode->i_private; 870 int value = -EBUSY; 871 872 if (mutex_lock_interruptible(&data->lock) != 0) 873 return -EINTR; 874 spin_lock_irq (&data->dev->lock); 875 if (data->dev->state == STATE_DEV_UNBOUND) 876 value = -ENOENT; 877 else if (data->state == STATE_EP_DISABLED) { 878 value = 0; 879 data->state = STATE_EP_READY; 880 get_ep (data); 881 fd->private_data = data; 882 VDEBUG (data->dev, "%s ready\n", data->name); 883 } else 884 DBG (data->dev, "%s state %d\n", 885 data->name, data->state); 886 spin_unlock_irq (&data->dev->lock); 887 mutex_unlock(&data->lock); 888 return value; 889} 890 891/* used before endpoint configuration */ 892static const struct file_operations ep_config_operations = { 893 .owner = THIS_MODULE, 894 .llseek = no_llseek, 895 896 .open = ep_open, 897 .write = ep_config, 898 .release = ep_release, 899}; 900 901/*----------------------------------------------------------------------*/ 902 903/* EP0 IMPLEMENTATION can be partly in userspace. 904 * 905 * Drivers that use this facility receive various events, including 906 * control requests the kernel doesn't handle. Drivers that don't 907 * use this facility may be too simple-minded for real applications. 908 */ 909 910static inline void ep0_readable (struct dev_data *dev) 911{ 912 wake_up (&dev->wait); 913 kill_fasync (&dev->fasync, SIGIO, POLL_IN); 914} 915 916static void clean_req (struct usb_ep *ep, struct usb_request *req) 917{ 918 struct dev_data *dev = ep->driver_data; 919 920 if (req->buf != dev->rbuf) { 921 kfree(req->buf); 922 req->buf = dev->rbuf; 923 req->dma = DMA_ADDR_INVALID; 924 } 925 req->complete = epio_complete; 926 dev->setup_out_ready = 0; 927} 928 929static void ep0_complete (struct usb_ep *ep, struct usb_request *req) 930{ 931 struct dev_data *dev = ep->driver_data; 932 unsigned long flags; 933 int free = 1; 934 935 /* for control OUT, data must still get to userspace */ 936 spin_lock_irqsave(&dev->lock, flags); 937 if (!dev->setup_in) { 938 dev->setup_out_error = (req->status != 0); 939 if (!dev->setup_out_error) 940 free = 0; 941 dev->setup_out_ready = 1; 942 ep0_readable (dev); 943 } 944 945 /* clean up as appropriate */ 946 if (free && req->buf != &dev->rbuf) 947 clean_req (ep, req); 948 req->complete = epio_complete; 949 spin_unlock_irqrestore(&dev->lock, flags); 950} 951 952static int setup_req (struct usb_ep *ep, struct usb_request *req, u16 len) 953{ 954 struct dev_data *dev = ep->driver_data; 955 956 if (dev->setup_out_ready) { 957 DBG (dev, "ep0 request busy!\n"); 958 return -EBUSY; 959 } 960 if (len > sizeof (dev->rbuf)) 961 req->buf = kmalloc(len, GFP_ATOMIC); 962 if (req->buf == NULL) { 963 req->buf = dev->rbuf; 964 return -ENOMEM; 965 } 966 req->complete = ep0_complete; 967 req->length = len; 968 req->zero = 0; 969 return 0; 970} 971 972static ssize_t 973ep0_read (struct file *fd, char __user *buf, size_t len, loff_t *ptr) 974{ 975 struct dev_data *dev = fd->private_data; 976 ssize_t retval; 977 enum ep0_state state; 978 979 spin_lock_irq (&dev->lock); 980 981 /* report fd mode change before acting on it */ 982 if (dev->setup_abort) { 983 dev->setup_abort = 0; 984 retval = -EIDRM; 985 goto done; 986 } 987 988 /* control DATA stage */ 989 if ((state = dev->state) == STATE_DEV_SETUP) { 990 991 if (dev->setup_in) { /* stall IN */ 992 VDEBUG(dev, "ep0in stall\n"); 993 (void) usb_ep_set_halt (dev->gadget->ep0); 994 retval = -EL2HLT; 995 dev->state = STATE_DEV_CONNECTED; 996 997 } else if (len == 0) { /* ack SET_CONFIGURATION etc */ 998 struct usb_ep *ep = dev->gadget->ep0; 999 struct usb_request *req = dev->req; 1000 1001 if ((retval = setup_req (ep, req, 0)) == 0) 1002 retval = usb_ep_queue (ep, req, GFP_ATOMIC); 1003 dev->state = STATE_DEV_CONNECTED; 1004 1005 /* assume that was SET_CONFIGURATION */ 1006 if (dev->current_config) { 1007 unsigned power; 1008 1009 if (gadget_is_dualspeed(dev->gadget) 1010 && (dev->gadget->speed 1011 == USB_SPEED_HIGH)) 1012 power = dev->hs_config->bMaxPower; 1013 else 1014 power = dev->config->bMaxPower; 1015 usb_gadget_vbus_draw(dev->gadget, 2 * power); 1016 } 1017 1018 } else { /* collect OUT data */ 1019 if ((fd->f_flags & O_NONBLOCK) != 0 1020 && !dev->setup_out_ready) { 1021 retval = -EAGAIN; 1022 goto done; 1023 } 1024 spin_unlock_irq (&dev->lock); 1025 retval = wait_event_interruptible (dev->wait, 1026 dev->setup_out_ready != 0); 1027 1028 /* FIXME state could change from under us */ 1029 spin_lock_irq (&dev->lock); 1030 if (retval) 1031 goto done; 1032 1033 if (dev->state != STATE_DEV_SETUP) { 1034 retval = -ECANCELED; 1035 goto done; 1036 } 1037 dev->state = STATE_DEV_CONNECTED; 1038 1039 if (dev->setup_out_error) 1040 retval = -EIO; 1041 else { 1042 len = min (len, (size_t)dev->req->actual); 1043// FIXME don't call this with the spinlock held ... 1044 if (copy_to_user (buf, dev->req->buf, len)) 1045 retval = -EFAULT; 1046 else 1047 retval = len; 1048 clean_req (dev->gadget->ep0, dev->req); 1049 /* NOTE userspace can't yet choose to stall */ 1050 } 1051 } 1052 goto done; 1053 } 1054 1055 /* else normal: return event data */ 1056 if (len < sizeof dev->event [0]) { 1057 retval = -EINVAL; 1058 goto done; 1059 } 1060 len -= len % sizeof (struct usb_gadgetfs_event); 1061 dev->usermode_setup = 1; 1062 1063scan: 1064 /* return queued events right away */ 1065 if (dev->ev_next != 0) { 1066 unsigned i, n; 1067 1068 n = len / sizeof (struct usb_gadgetfs_event); 1069 if (dev->ev_next < n) 1070 n = dev->ev_next; 1071 1072 /* ep0 i/o has special semantics during STATE_DEV_SETUP */ 1073 for (i = 0; i < n; i++) { 1074 if (dev->event [i].type == GADGETFS_SETUP) { 1075 dev->state = STATE_DEV_SETUP; 1076 n = i + 1; 1077 break; 1078 } 1079 } 1080 spin_unlock_irq (&dev->lock); 1081 len = n * sizeof (struct usb_gadgetfs_event); 1082 if (copy_to_user (buf, &dev->event, len)) 1083 retval = -EFAULT; 1084 else 1085 retval = len; 1086 if (len > 0) { 1087 /* NOTE this doesn't guard against broken drivers; 1088 * concurrent ep0 readers may lose events. 1089 */ 1090 spin_lock_irq (&dev->lock); 1091 if (dev->ev_next > n) { 1092 memmove(&dev->event[0], &dev->event[n], 1093 sizeof (struct usb_gadgetfs_event) 1094 * (dev->ev_next - n)); 1095 } 1096 dev->ev_next -= n; 1097 spin_unlock_irq (&dev->lock); 1098 } 1099 return retval; 1100 } 1101 if (fd->f_flags & O_NONBLOCK) { 1102 retval = -EAGAIN; 1103 goto done; 1104 } 1105 1106 switch (state) { 1107 default: 1108 DBG (dev, "fail %s, state %d\n", __func__, state); 1109 retval = -ESRCH; 1110 break; 1111 case STATE_DEV_UNCONNECTED: 1112 case STATE_DEV_CONNECTED: 1113 spin_unlock_irq (&dev->lock); 1114 DBG (dev, "%s wait\n", __func__); 1115 1116 /* wait for events */ 1117 retval = wait_event_interruptible (dev->wait, 1118 dev->ev_next != 0); 1119 if (retval < 0) 1120 return retval; 1121 spin_lock_irq (&dev->lock); 1122 goto scan; 1123 } 1124 1125done: 1126 spin_unlock_irq (&dev->lock); 1127 return retval; 1128} 1129 1130static struct usb_gadgetfs_event * 1131next_event (struct dev_data *dev, enum usb_gadgetfs_event_type type) 1132{ 1133 struct usb_gadgetfs_event *event; 1134 unsigned i; 1135 1136 switch (type) { 1137 /* these events purge the queue */ 1138 case GADGETFS_DISCONNECT: 1139 if (dev->state == STATE_DEV_SETUP) 1140 dev->setup_abort = 1; 1141 // FALL THROUGH 1142 case GADGETFS_CONNECT: 1143 dev->ev_next = 0; 1144 break; 1145 case GADGETFS_SETUP: /* previous request timed out */ 1146 case GADGETFS_SUSPEND: /* same effect */ 1147 /* these events can't be repeated */ 1148 for (i = 0; i != dev->ev_next; i++) { 1149 if (dev->event [i].type != type) 1150 continue; 1151 DBG(dev, "discard old event[%d] %d\n", i, type); 1152 dev->ev_next--; 1153 if (i == dev->ev_next) 1154 break; 1155 /* indices start at zero, for simplicity */ 1156 memmove (&dev->event [i], &dev->event [i + 1], 1157 sizeof (struct usb_gadgetfs_event) 1158 * (dev->ev_next - i)); 1159 } 1160 break; 1161 default: 1162 BUG (); 1163 } 1164 VDEBUG(dev, "event[%d] = %d\n", dev->ev_next, type); 1165 event = &dev->event [dev->ev_next++]; 1166 BUG_ON (dev->ev_next > N_EVENT); 1167 memset (event, 0, sizeof *event); 1168 event->type = type; 1169 return event; 1170} 1171 1172static ssize_t 1173ep0_write (struct file *fd, const char __user *buf, size_t len, loff_t *ptr) 1174{ 1175 struct dev_data *dev = fd->private_data; 1176 ssize_t retval = -ESRCH; 1177 1178 spin_lock_irq (&dev->lock); 1179 1180 /* report fd mode change before acting on it */ 1181 if (dev->setup_abort) { 1182 dev->setup_abort = 0; 1183 retval = -EIDRM; 1184 1185 /* data and/or status stage for control request */ 1186 } else if (dev->state == STATE_DEV_SETUP) { 1187 1188 /* IN DATA+STATUS caller makes len <= wLength */ 1189 if (dev->setup_in) { 1190 retval = setup_req (dev->gadget->ep0, dev->req, len); 1191 if (retval == 0) { 1192 dev->state = STATE_DEV_CONNECTED; 1193 spin_unlock_irq (&dev->lock); 1194 if (copy_from_user (dev->req->buf, buf, len)) 1195 retval = -EFAULT; 1196 else { 1197 if (len < dev->setup_wLength) 1198 dev->req->zero = 1; 1199 retval = usb_ep_queue ( 1200 dev->gadget->ep0, dev->req, 1201 GFP_KERNEL); 1202 } 1203 if (retval < 0) { 1204 spin_lock_irq (&dev->lock); 1205 clean_req (dev->gadget->ep0, dev->req); 1206 spin_unlock_irq (&dev->lock); 1207 } else 1208 retval = len; 1209 1210 return retval; 1211 } 1212 1213 /* can stall some OUT transfers */ 1214 } else if (dev->setup_can_stall) { 1215 VDEBUG(dev, "ep0out stall\n"); 1216 (void) usb_ep_set_halt (dev->gadget->ep0); 1217 retval = -EL2HLT; 1218 dev->state = STATE_DEV_CONNECTED; 1219 } else { 1220 DBG(dev, "bogus ep0out stall!\n"); 1221 } 1222 } else 1223 DBG (dev, "fail %s, state %d\n", __func__, dev->state); 1224 1225 spin_unlock_irq (&dev->lock); 1226 return retval; 1227} 1228 1229static int 1230ep0_fasync (int f, struct file *fd, int on) 1231{ 1232 struct dev_data *dev = fd->private_data; 1233 // caller must F_SETOWN before signal delivery happens 1234 VDEBUG (dev, "%s %s\n", __func__, on ? "on" : "off"); 1235 return fasync_helper (f, fd, on, &dev->fasync); 1236} 1237 1238static struct usb_gadget_driver gadgetfs_driver; 1239 1240static int 1241dev_release (struct inode *inode, struct file *fd) 1242{ 1243 struct dev_data *dev = fd->private_data; 1244 1245 /* closing ep0 === shutdown all */ 1246 1247 usb_gadget_unregister_driver (&gadgetfs_driver); 1248 1249 /* at this point "good" hardware has disconnected the 1250 * device from USB; the host won't see it any more. 1251 * alternatively, all host requests will time out. 1252 */ 1253 1254 kfree (dev->buf); 1255 dev->buf = NULL; 1256 put_dev (dev); 1257 1258 /* other endpoints were all decoupled from this device */ 1259 spin_lock_irq(&dev->lock); 1260 dev->state = STATE_DEV_DISABLED; 1261 spin_unlock_irq(&dev->lock); 1262 return 0; 1263} 1264 1265static unsigned int 1266ep0_poll (struct file *fd, poll_table *wait) 1267{ 1268 struct dev_data *dev = fd->private_data; 1269 int mask = 0; 1270 1271 poll_wait(fd, &dev->wait, wait); 1272 1273 spin_lock_irq (&dev->lock); 1274 1275 /* report fd mode change before acting on it */ 1276 if (dev->setup_abort) { 1277 dev->setup_abort = 0; 1278 mask = POLLHUP; 1279 goto out; 1280 } 1281 1282 if (dev->state == STATE_DEV_SETUP) { 1283 if (dev->setup_in || dev->setup_can_stall) 1284 mask = POLLOUT; 1285 } else { 1286 if (dev->ev_next != 0) 1287 mask = POLLIN; 1288 } 1289out: 1290 spin_unlock_irq(&dev->lock); 1291 return mask; 1292} 1293 1294static long dev_ioctl (struct file *fd, unsigned code, unsigned long value) 1295{ 1296 struct dev_data *dev = fd->private_data; 1297 struct usb_gadget *gadget = dev->gadget; 1298 long ret = -ENOTTY; 1299 1300 if (gadget->ops->ioctl) 1301 ret = gadget->ops->ioctl (gadget, code, value); 1302 1303 return ret; 1304} 1305 1306/* used after device configuration */ 1307static const struct file_operations ep0_io_operations = { 1308 .owner = THIS_MODULE, 1309 .llseek = no_llseek, 1310 1311 .read = ep0_read, 1312 .write = ep0_write, 1313 .fasync = ep0_fasync, 1314 .poll = ep0_poll, 1315 .unlocked_ioctl = dev_ioctl, 1316 .release = dev_release, 1317}; 1318 1319/*----------------------------------------------------------------------*/ 1320 1321/* The in-kernel gadget driver handles most ep0 issues, in particular 1322 * enumerating the single configuration (as provided from user space). 1323 * 1324 * Unrecognized ep0 requests may be handled in user space. 1325 */ 1326 1327#ifdef CONFIG_USB_GADGET_DUALSPEED 1328static void make_qualifier (struct dev_data *dev) 1329{ 1330 struct usb_qualifier_descriptor qual; 1331 struct usb_device_descriptor *desc; 1332 1333 qual.bLength = sizeof qual; 1334 qual.bDescriptorType = USB_DT_DEVICE_QUALIFIER; 1335 qual.bcdUSB = cpu_to_le16 (0x0200); 1336 1337 desc = dev->dev; 1338 qual.bDeviceClass = desc->bDeviceClass; 1339 qual.bDeviceSubClass = desc->bDeviceSubClass; 1340 qual.bDeviceProtocol = desc->bDeviceProtocol; 1341 1342 /* assumes ep0 uses the same value for both speeds ... */ 1343 qual.bMaxPacketSize0 = dev->gadget->ep0->maxpacket; 1344 1345 qual.bNumConfigurations = 1; 1346 qual.bRESERVED = 0; 1347 1348 memcpy (dev->rbuf, &qual, sizeof qual); 1349} 1350#endif 1351 1352static int 1353config_buf (struct dev_data *dev, u8 type, unsigned index) 1354{ 1355 int len; 1356 int hs = 0; 1357 1358 /* only one configuration */ 1359 if (index > 0) 1360 return -EINVAL; 1361 1362 if (gadget_is_dualspeed(dev->gadget)) { 1363 hs = (dev->gadget->speed == USB_SPEED_HIGH); 1364 if (type == USB_DT_OTHER_SPEED_CONFIG) 1365 hs = !hs; 1366 } 1367 if (hs) { 1368 dev->req->buf = dev->hs_config; 1369 len = le16_to_cpu(dev->hs_config->wTotalLength); 1370 } else { 1371 dev->req->buf = dev->config; 1372 len = le16_to_cpu(dev->config->wTotalLength); 1373 } 1374 ((u8 *)dev->req->buf) [1] = type; 1375 return len; 1376} 1377 1378static int 1379gadgetfs_setup (struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl) 1380{ 1381 struct dev_data *dev = get_gadget_data (gadget); 1382 struct usb_request *req = dev->req; 1383 int value = -EOPNOTSUPP; 1384 struct usb_gadgetfs_event *event; 1385 u16 w_value = le16_to_cpu(ctrl->wValue); 1386 u16 w_length = le16_to_cpu(ctrl->wLength); 1387 1388 spin_lock (&dev->lock); 1389 dev->setup_abort = 0; 1390 if (dev->state == STATE_DEV_UNCONNECTED) { 1391 if (gadget_is_dualspeed(gadget) 1392 && gadget->speed == USB_SPEED_HIGH 1393 && dev->hs_config == NULL) { 1394 spin_unlock(&dev->lock); 1395 ERROR (dev, "no high speed config??\n"); 1396 return -EINVAL; 1397 } 1398 1399 dev->state = STATE_DEV_CONNECTED; 1400 1401 INFO (dev, "connected\n"); 1402 event = next_event (dev, GADGETFS_CONNECT); 1403 event->u.speed = gadget->speed; 1404 ep0_readable (dev); 1405 1406 /* host may have given up waiting for response. we can miss control 1407 * requests handled lower down (device/endpoint status and features); 1408 * then ep0_{read,write} will report the wrong status. controller 1409 * driver will have aborted pending i/o. 1410 */ 1411 } else if (dev->state == STATE_DEV_SETUP) 1412 dev->setup_abort = 1; 1413 1414 req->buf = dev->rbuf; 1415 req->dma = DMA_ADDR_INVALID; 1416 req->context = NULL; 1417 value = -EOPNOTSUPP; 1418 switch (ctrl->bRequest) { 1419 1420 case USB_REQ_GET_DESCRIPTOR: 1421 if (ctrl->bRequestType != USB_DIR_IN) 1422 goto unrecognized; 1423 switch (w_value >> 8) { 1424 1425 case USB_DT_DEVICE: 1426 value = min (w_length, (u16) sizeof *dev->dev); 1427 dev->dev->bMaxPacketSize0 = dev->gadget->ep0->maxpacket; 1428 req->buf = dev->dev; 1429 break; 1430#ifdef CONFIG_USB_GADGET_DUALSPEED 1431 case USB_DT_DEVICE_QUALIFIER: 1432 if (!dev->hs_config) 1433 break; 1434 value = min (w_length, (u16) 1435 sizeof (struct usb_qualifier_descriptor)); 1436 make_qualifier (dev); 1437 break; 1438 case USB_DT_OTHER_SPEED_CONFIG: 1439 // FALLTHROUGH 1440#endif 1441 case USB_DT_CONFIG: 1442 value = config_buf (dev, 1443 w_value >> 8, 1444 w_value & 0xff); 1445 if (value >= 0) 1446 value = min (w_length, (u16) value); 1447 break; 1448 case USB_DT_STRING: 1449 goto unrecognized; 1450 1451 default: // all others are errors 1452 break; 1453 } 1454 break; 1455 1456 /* currently one config, two speeds */ 1457 case USB_REQ_SET_CONFIGURATION: 1458 if (ctrl->bRequestType != 0) 1459 goto unrecognized; 1460 if (0 == (u8) w_value) { 1461 value = 0; 1462 dev->current_config = 0; 1463 usb_gadget_vbus_draw(gadget, 8 /* mA */ ); 1464 // user mode expected to disable endpoints 1465 } else { 1466 u8 config, power; 1467 1468 if (gadget_is_dualspeed(gadget) 1469 && gadget->speed == USB_SPEED_HIGH) { 1470 config = dev->hs_config->bConfigurationValue; 1471 power = dev->hs_config->bMaxPower; 1472 } else { 1473 config = dev->config->bConfigurationValue; 1474 power = dev->config->bMaxPower; 1475 } 1476 1477 if (config == (u8) w_value) { 1478 value = 0; 1479 dev->current_config = config; 1480 usb_gadget_vbus_draw(gadget, 2 * power); 1481 } 1482 } 1483 1484 /* report SET_CONFIGURATION like any other control request, 1485 * except that usermode may not stall this. the next 1486 * request mustn't be allowed start until this finishes: 1487 * endpoints and threads set up, etc. 1488 * 1489 * NOTE: older PXA hardware (before PXA 255: without UDCCFR) 1490 * has bad/racey automagic that prevents synchronizing here. 1491 * even kernel mode drivers often miss them. 1492 */ 1493 if (value == 0) { 1494 INFO (dev, "configuration #%d\n", dev->current_config); 1495 if (dev->usermode_setup) { 1496 dev->setup_can_stall = 0; 1497 goto delegate; 1498 } 1499 } 1500 break; 1501 1502#ifndef CONFIG_USB_GADGET_PXA25X 1503 /* PXA automagically handles this request too */ 1504 case USB_REQ_GET_CONFIGURATION: 1505 if (ctrl->bRequestType != 0x80) 1506 goto unrecognized; 1507 *(u8 *)req->buf = dev->current_config; 1508 value = min (w_length, (u16) 1); 1509 break; 1510#endif 1511 1512 default: 1513unrecognized: 1514 VDEBUG (dev, "%s req%02x.%02x v%04x i%04x l%d\n", 1515 dev->usermode_setup ? "delegate" : "fail", 1516 ctrl->bRequestType, ctrl->bRequest, 1517 w_value, le16_to_cpu(ctrl->wIndex), w_length); 1518 1519 /* if there's an ep0 reader, don't stall */ 1520 if (dev->usermode_setup) { 1521 dev->setup_can_stall = 1; 1522delegate: 1523 dev->setup_in = (ctrl->bRequestType & USB_DIR_IN) 1524 ? 1 : 0; 1525 dev->setup_wLength = w_length; 1526 dev->setup_out_ready = 0; 1527 dev->setup_out_error = 0; 1528 value = 0; 1529 1530 /* read DATA stage for OUT right away */ 1531 if (unlikely (!dev->setup_in && w_length)) { 1532 value = setup_req (gadget->ep0, dev->req, 1533 w_length); 1534 if (value < 0) 1535 break; 1536 value = usb_ep_queue (gadget->ep0, dev->req, 1537 GFP_ATOMIC); 1538 if (value < 0) { 1539 clean_req (gadget->ep0, dev->req); 1540 break; 1541 } 1542 1543 /* we can't currently stall these */ 1544 dev->setup_can_stall = 0; 1545 } 1546 1547 /* state changes when reader collects event */ 1548 event = next_event (dev, GADGETFS_SETUP); 1549 event->u.setup = *ctrl; 1550 ep0_readable (dev); 1551 spin_unlock (&dev->lock); 1552 return 0; 1553 } 1554 } 1555 1556 /* proceed with data transfer and status phases? */ 1557 if (value >= 0 && dev->state != STATE_DEV_SETUP) { 1558 req->length = value; 1559 req->zero = value < w_length; 1560 value = usb_ep_queue (gadget->ep0, req, GFP_ATOMIC); 1561 if (value < 0) { 1562 DBG (dev, "ep_queue --> %d\n", value); 1563 req->status = 0; 1564 } 1565 } 1566 1567 /* device stalls when value < 0 */ 1568 spin_unlock (&dev->lock); 1569 return value; 1570} 1571 1572static void destroy_ep_files (struct dev_data *dev) 1573{ 1574 DBG (dev, "%s %d\n", __func__, dev->state); 1575 1576 /* dev->state must prevent interference */ 1577 spin_lock_irq (&dev->lock); 1578 while (!list_empty(&dev->epfiles)) { 1579 struct ep_data *ep; 1580 struct inode *parent; 1581 struct dentry *dentry; 1582 1583 /* break link to FS */ 1584 ep = list_first_entry (&dev->epfiles, struct ep_data, epfiles); 1585 list_del_init (&ep->epfiles); 1586 dentry = ep->dentry; 1587 ep->dentry = NULL; 1588 parent = dentry->d_parent->d_inode; 1589 1590 /* break link to controller */ 1591 if (ep->state == STATE_EP_ENABLED) 1592 (void) usb_ep_disable (ep->ep); 1593 ep->state = STATE_EP_UNBOUND; 1594 usb_ep_free_request (ep->ep, ep->req); 1595 ep->ep = NULL; 1596 wake_up (&ep->wait); 1597 put_ep (ep); 1598 1599 spin_unlock_irq (&dev->lock); 1600 1601 /* break link to dcache */ 1602 mutex_lock (&parent->i_mutex); 1603 d_delete (dentry); 1604 dput (dentry); 1605 mutex_unlock (&parent->i_mutex); 1606 1607 spin_lock_irq (&dev->lock); 1608 } 1609 spin_unlock_irq (&dev->lock); 1610} 1611 1612 1613static struct inode * 1614gadgetfs_create_file (struct super_block *sb, char const *name, 1615 void *data, const struct file_operations *fops, 1616 struct dentry **dentry_p); 1617 1618static int activate_ep_files (struct dev_data *dev) 1619{ 1620 struct usb_ep *ep; 1621 struct ep_data *data; 1622 1623 gadget_for_each_ep (ep, dev->gadget) { 1624 1625 data = kzalloc(sizeof(*data), GFP_KERNEL); 1626 if (!data) 1627 goto enomem0; 1628 data->state = STATE_EP_DISABLED; 1629 mutex_init(&data->lock); 1630 init_waitqueue_head (&data->wait); 1631 1632 strncpy (data->name, ep->name, sizeof (data->name) - 1); 1633 atomic_set (&data->count, 1); 1634 data->dev = dev; 1635 get_dev (dev); 1636 1637 data->ep = ep; 1638 ep->driver_data = data; 1639 1640 data->req = usb_ep_alloc_request (ep, GFP_KERNEL); 1641 if (!data->req) 1642 goto enomem1; 1643 1644 data->inode = gadgetfs_create_file (dev->sb, data->name, 1645 data, &ep_config_operations, 1646 &data->dentry); 1647 if (!data->inode) 1648 goto enomem2; 1649 list_add_tail (&data->epfiles, &dev->epfiles); 1650 } 1651 return 0; 1652 1653enomem2: 1654 usb_ep_free_request (ep, data->req); 1655enomem1: 1656 put_dev (dev); 1657 kfree (data); 1658enomem0: 1659 DBG (dev, "%s enomem\n", __func__); 1660 destroy_ep_files (dev); 1661 return -ENOMEM; 1662} 1663 1664static void 1665gadgetfs_unbind (struct usb_gadget *gadget) 1666{ 1667 struct dev_data *dev = get_gadget_data (gadget); 1668 1669 DBG (dev, "%s\n", __func__); 1670 1671 spin_lock_irq (&dev->lock); 1672 dev->state = STATE_DEV_UNBOUND; 1673 spin_unlock_irq (&dev->lock); 1674 1675 destroy_ep_files (dev); 1676 gadget->ep0->driver_data = NULL; 1677 set_gadget_data (gadget, NULL); 1678 1679 /* we've already been disconnected ... no i/o is active */ 1680 if (dev->req) 1681 usb_ep_free_request (gadget->ep0, dev->req); 1682 DBG (dev, "%s done\n", __func__); 1683 put_dev (dev); 1684} 1685 1686static struct dev_data *the_device; 1687 1688static int 1689gadgetfs_bind (struct usb_gadget *gadget) 1690{ 1691 struct dev_data *dev = the_device; 1692 1693 if (!dev) 1694 return -ESRCH; 1695 if (0 != strcmp (CHIP, gadget->name)) { 1696 pr_err("%s expected %s controller not %s\n", 1697 shortname, CHIP, gadget->name); 1698 return -ENODEV; 1699 } 1700 1701 set_gadget_data (gadget, dev); 1702 dev->gadget = gadget; 1703 gadget->ep0->driver_data = dev; 1704 1705 /* preallocate control response and buffer */ 1706 dev->req = usb_ep_alloc_request (gadget->ep0, GFP_KERNEL); 1707 if (!dev->req) 1708 goto enomem; 1709 dev->req->context = NULL; 1710 dev->req->complete = epio_complete; 1711 1712 if (activate_ep_files (dev) < 0) 1713 goto enomem; 1714 1715 INFO (dev, "bound to %s driver\n", gadget->name); 1716 spin_lock_irq(&dev->lock); 1717 dev->state = STATE_DEV_UNCONNECTED; 1718 spin_unlock_irq(&dev->lock); 1719 get_dev (dev); 1720 return 0; 1721 1722enomem: 1723 gadgetfs_unbind (gadget); 1724 return -ENOMEM; 1725} 1726 1727static void 1728gadgetfs_disconnect (struct usb_gadget *gadget) 1729{ 1730 struct dev_data *dev = get_gadget_data (gadget); 1731 unsigned long flags; 1732 1733 spin_lock_irqsave (&dev->lock, flags); 1734 if (dev->state == STATE_DEV_UNCONNECTED) 1735 goto exit; 1736 dev->state = STATE_DEV_UNCONNECTED; 1737 1738 INFO (dev, "disconnected\n"); 1739 next_event (dev, GADGETFS_DISCONNECT); 1740 ep0_readable (dev); 1741exit: 1742 spin_unlock_irqrestore (&dev->lock, flags); 1743} 1744 1745static void 1746gadgetfs_suspend (struct usb_gadget *gadget) 1747{ 1748 struct dev_data *dev = get_gadget_data (gadget); 1749 1750 INFO (dev, "suspended from state %d\n", dev->state); 1751 spin_lock (&dev->lock); 1752 switch (dev->state) { 1753 case STATE_DEV_SETUP: // VERY odd... host died?? 1754 case STATE_DEV_CONNECTED: 1755 case STATE_DEV_UNCONNECTED: 1756 next_event (dev, GADGETFS_SUSPEND); 1757 ep0_readable (dev); 1758 /* FALLTHROUGH */ 1759 default: 1760 break; 1761 } 1762 spin_unlock (&dev->lock); 1763} 1764 1765static struct usb_gadget_driver gadgetfs_driver = { 1766#ifdef CONFIG_USB_GADGET_DUALSPEED 1767 .max_speed = USB_SPEED_HIGH, 1768#else 1769 .max_speed = USB_SPEED_FULL, 1770#endif 1771 .function = (char *) driver_desc, 1772 .unbind = gadgetfs_unbind, 1773 .setup = gadgetfs_setup, 1774 .disconnect = gadgetfs_disconnect, 1775 .suspend = gadgetfs_suspend, 1776 1777 .driver = { 1778 .name = (char *) shortname, 1779 }, 1780}; 1781 1782/*----------------------------------------------------------------------*/ 1783 1784static void gadgetfs_nop(struct usb_gadget *arg) { } 1785 1786static int gadgetfs_probe (struct usb_gadget *gadget) 1787{ 1788 CHIP = gadget->name; 1789 return -EISNAM; 1790} 1791 1792static struct usb_gadget_driver probe_driver = { 1793 .max_speed = USB_SPEED_HIGH, 1794 .unbind = gadgetfs_nop, 1795 .setup = (void *)gadgetfs_nop, 1796 .disconnect = gadgetfs_nop, 1797 .driver = { 1798 .name = "nop", 1799 }, 1800}; 1801 1802 1803/* DEVICE INITIALIZATION 1804 * 1805 * fd = open ("/dev/gadget/$CHIP", O_RDWR) 1806 * status = write (fd, descriptors, sizeof descriptors) 1807 * 1808 * That write establishes the device configuration, so the kernel can 1809 * bind to the controller ... guaranteeing it can handle enumeration 1810 * at all necessary speeds. Descriptor order is: 1811 * 1812 * . message tag (u32, host order) ... for now, must be zero; it 1813 * would change to support features like multi-config devices 1814 * . full/low speed config ... all wTotalLength bytes (with interface, 1815 * class, altsetting, endpoint, and other descriptors) 1816 * . high speed config ... all descriptors, for high speed operation; 1817 * this one's optional except for high-speed hardware 1818 * . device descriptor 1819 * 1820 * Endpoints are not yet enabled. Drivers must wait until device 1821 * configuration and interface altsetting changes create 1822 * the need to configure (or unconfigure) them. 1823 * 1824 * After initialization, the device stays active for as long as that 1825 * $CHIP file is open. Events must then be read from that descriptor, 1826 * such as configuration notifications. 1827 */ 1828 1829static int is_valid_config (struct usb_config_descriptor *config) 1830{ 1831 return config->bDescriptorType == USB_DT_CONFIG 1832 && config->bLength == USB_DT_CONFIG_SIZE 1833 && config->bConfigurationValue != 0 1834 && (config->bmAttributes & USB_CONFIG_ATT_ONE) != 0 1835 && (config->bmAttributes & USB_CONFIG_ATT_WAKEUP) == 0; 1836 /* FIXME if gadget->is_otg, _must_ include an otg descriptor */ 1837 /* FIXME check lengths: walk to end */ 1838} 1839 1840static ssize_t 1841dev_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr) 1842{ 1843 struct dev_data *dev = fd->private_data; 1844 ssize_t value = len, length = len; 1845 unsigned total; 1846 u32 tag; 1847 char *kbuf; 1848 1849 if (len < (USB_DT_CONFIG_SIZE + USB_DT_DEVICE_SIZE + 4)) 1850 return -EINVAL; 1851 1852 /* we might need to change message format someday */ 1853 if (copy_from_user (&tag, buf, 4)) 1854 return -EFAULT; 1855 if (tag != 0) 1856 return -EINVAL; 1857 buf += 4; 1858 length -= 4; 1859 1860 kbuf = memdup_user(buf, length); 1861 if (IS_ERR(kbuf)) 1862 return PTR_ERR(kbuf); 1863 1864 spin_lock_irq (&dev->lock); 1865 value = -EINVAL; 1866 if (dev->buf) 1867 goto fail; 1868 dev->buf = kbuf; 1869 1870 /* full or low speed config */ 1871 dev->config = (void *) kbuf; 1872 total = le16_to_cpu(dev->config->wTotalLength); 1873 if (!is_valid_config (dev->config) || total >= length) 1874 goto fail; 1875 kbuf += total; 1876 length -= total; 1877 1878 /* optional high speed config */ 1879 if (kbuf [1] == USB_DT_CONFIG) { 1880 dev->hs_config = (void *) kbuf; 1881 total = le16_to_cpu(dev->hs_config->wTotalLength); 1882 if (!is_valid_config (dev->hs_config) || total >= length) 1883 goto fail; 1884 kbuf += total; 1885 length -= total; 1886 } 1887 1888 /* could support multiple configs, using another encoding! */ 1889 1890 /* device descriptor (tweaked for paranoia) */ 1891 if (length != USB_DT_DEVICE_SIZE) 1892 goto fail; 1893 dev->dev = (void *)kbuf; 1894 if (dev->dev->bLength != USB_DT_DEVICE_SIZE 1895 || dev->dev->bDescriptorType != USB_DT_DEVICE 1896 || dev->dev->bNumConfigurations != 1) 1897 goto fail; 1898 dev->dev->bNumConfigurations = 1; 1899 dev->dev->bcdUSB = cpu_to_le16 (0x0200); 1900 1901 /* triggers gadgetfs_bind(); then we can enumerate. */ 1902 spin_unlock_irq (&dev->lock); 1903 value = usb_gadget_probe_driver(&gadgetfs_driver, gadgetfs_bind); 1904 if (value != 0) { 1905 kfree (dev->buf); 1906 dev->buf = NULL; 1907 } else { 1908 /* at this point "good" hardware has for the first time 1909 * let the USB the host see us. alternatively, if users 1910 * unplug/replug that will clear all the error state. 1911 * 1912 * note: everything running before here was guaranteed 1913 * to choke driver model style diagnostics. from here 1914 * on, they can work ... except in cleanup paths that 1915 * kick in after the ep0 descriptor is closed. 1916 */ 1917 fd->f_op = &ep0_io_operations; 1918 value = len; 1919 } 1920 return value; 1921 1922fail: 1923 spin_unlock_irq (&dev->lock); 1924 pr_debug ("%s: %s fail %Zd, %p\n", shortname, __func__, value, dev); 1925 kfree (dev->buf); 1926 dev->buf = NULL; 1927 return value; 1928} 1929 1930static int 1931dev_open (struct inode *inode, struct file *fd) 1932{ 1933 struct dev_data *dev = inode->i_private; 1934 int value = -EBUSY; 1935 1936 spin_lock_irq(&dev->lock); 1937 if (dev->state == STATE_DEV_DISABLED) { 1938 dev->ev_next = 0; 1939 dev->state = STATE_DEV_OPENED; 1940 fd->private_data = dev; 1941 get_dev (dev); 1942 value = 0; 1943 } 1944 spin_unlock_irq(&dev->lock); 1945 return value; 1946} 1947 1948static const struct file_operations dev_init_operations = { 1949 .owner = THIS_MODULE, 1950 .llseek = no_llseek, 1951 1952 .open = dev_open, 1953 .write = dev_config, 1954 .fasync = ep0_fasync, 1955 .unlocked_ioctl = dev_ioctl, 1956 .release = dev_release, 1957}; 1958 1959/*----------------------------------------------------------------------*/ 1960 1961/* FILESYSTEM AND SUPERBLOCK OPERATIONS 1962 * 1963 * Mounting the filesystem creates a controller file, used first for 1964 * device configuration then later for event monitoring. 1965 */ 1966 1967 1968/* FIXME PAM etc could set this security policy without mount options 1969 * if epfiles inherited ownership and permissons from ep0 ... 1970 */ 1971 1972static unsigned default_uid; 1973static unsigned default_gid; 1974static unsigned default_perm = S_IRUSR | S_IWUSR; 1975 1976module_param (default_uid, uint, 0644); 1977module_param (default_gid, uint, 0644); 1978module_param (default_perm, uint, 0644); 1979 1980 1981static struct inode * 1982gadgetfs_make_inode (struct super_block *sb, 1983 void *data, const struct file_operations *fops, 1984 int mode) 1985{ 1986 struct inode *inode = new_inode (sb); 1987 1988 if (inode) { 1989 inode->i_ino = get_next_ino(); 1990 inode->i_mode = mode; 1991 inode->i_uid = default_uid; 1992 inode->i_gid = default_gid; 1993 inode->i_atime = inode->i_mtime = inode->i_ctime 1994 = CURRENT_TIME; 1995 inode->i_private = data; 1996 inode->i_fop = fops; 1997 } 1998 return inode; 1999} 2000 2001/* creates in fs root directory, so non-renamable and non-linkable. 2002 * so inode and dentry are paired, until device reconfig. 2003 */ 2004static struct inode * 2005gadgetfs_create_file (struct super_block *sb, char const *name, 2006 void *data, const struct file_operations *fops, 2007 struct dentry **dentry_p) 2008{ 2009 struct dentry *dentry; 2010 struct inode *inode; 2011 2012 dentry = d_alloc_name(sb->s_root, name); 2013 if (!dentry) 2014 return NULL; 2015 2016 inode = gadgetfs_make_inode (sb, data, fops, 2017 S_IFREG | (default_perm & S_IRWXUGO)); 2018 if (!inode) { 2019 dput(dentry); 2020 return NULL; 2021 } 2022 d_add (dentry, inode); 2023 *dentry_p = dentry; 2024 return inode; 2025} 2026 2027static const struct super_operations gadget_fs_operations = { 2028 .statfs = simple_statfs, 2029 .drop_inode = generic_delete_inode, 2030}; 2031 2032static int 2033gadgetfs_fill_super (struct super_block *sb, void *opts, int silent) 2034{ 2035 struct inode *inode; 2036 struct dev_data *dev; 2037 2038 if (the_device) 2039 return -ESRCH; 2040 2041 /* fake probe to determine $CHIP */ 2042 (void) usb_gadget_probe_driver(&probe_driver, gadgetfs_probe); 2043 if (!CHIP) 2044 return -ENODEV; 2045 2046 /* superblock */ 2047 sb->s_blocksize = PAGE_CACHE_SIZE; 2048 sb->s_blocksize_bits = PAGE_CACHE_SHIFT; 2049 sb->s_magic = GADGETFS_MAGIC; 2050 sb->s_op = &gadget_fs_operations; 2051 sb->s_time_gran = 1; 2052 2053 /* root inode */ 2054 inode = gadgetfs_make_inode (sb, 2055 NULL, &simple_dir_operations, 2056 S_IFDIR | S_IRUGO | S_IXUGO); 2057 if (!inode) 2058 goto Enomem; 2059 inode->i_op = &simple_dir_inode_operations; 2060 if (!(sb->s_root = d_make_root (inode))) 2061 goto Enomem; 2062 2063 /* the ep0 file is named after the controller we expect; 2064 * user mode code can use it for sanity checks, like we do. 2065 */ 2066 dev = dev_new (); 2067 if (!dev) 2068 goto Enomem; 2069 2070 dev->sb = sb; 2071 if (!gadgetfs_create_file (sb, CHIP, 2072 dev, &dev_init_operations, 2073 &dev->dentry)) { 2074 put_dev(dev); 2075 goto Enomem; 2076 } 2077 2078 /* other endpoint files are available after hardware setup, 2079 * from binding to a controller. 2080 */ 2081 the_device = dev; 2082 return 0; 2083 2084Enomem: 2085 return -ENOMEM; 2086} 2087 2088/* "mount -t gadgetfs path /dev/gadget" ends up here */ 2089static struct dentry * 2090gadgetfs_mount (struct file_system_type *t, int flags, 2091 const char *path, void *opts) 2092{ 2093 return mount_single (t, flags, opts, gadgetfs_fill_super); 2094} 2095 2096static void 2097gadgetfs_kill_sb (struct super_block *sb) 2098{ 2099 kill_litter_super (sb); 2100 if (the_device) { 2101 put_dev (the_device); 2102 the_device = NULL; 2103 } 2104} 2105 2106/*----------------------------------------------------------------------*/ 2107 2108static struct file_system_type gadgetfs_type = { 2109 .owner = THIS_MODULE, 2110 .name = shortname, 2111 .mount = gadgetfs_mount, 2112 .kill_sb = gadgetfs_kill_sb, 2113}; 2114 2115/*----------------------------------------------------------------------*/ 2116 2117static int __init init (void) 2118{ 2119 int status; 2120 2121 status = register_filesystem (&gadgetfs_type); 2122 if (status == 0) 2123 pr_info ("%s: %s, version " DRIVER_VERSION "\n", 2124 shortname, driver_desc); 2125 return status; 2126} 2127module_init (init); 2128 2129static void __exit cleanup (void) 2130{ 2131 pr_debug ("unregister %s\n", shortname); 2132 unregister_filesystem (&gadgetfs_type); 2133} 2134module_exit (cleanup); 2135 2136