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#include <linux/poll.h> 36 37#include <linux/device.h> 38#include <linux/moduleparam.h> 39 40#include <linux/usb_gadgetfs.h> 41#include <linux/usb_gadget.h> 42 43 44/* 45 * The gadgetfs API maps each endpoint to a file descriptor so that you 46 * can use standard synchronous read/write calls for I/O. There's some 47 * O_NONBLOCK and O_ASYNC/FASYNC style i/o support. Example usermode 48 * drivers show how this works in practice. You can also use AIO to 49 * eliminate I/O gaps between requests, to help when streaming data. 50 * 51 * Key parts that must be USB-specific are protocols defining how the 52 * read/write operations relate to the hardware state machines. There 53 * are two types of files. One type is for the device, implementing ep0. 54 * The other type is for each IN or OUT endpoint. In both cases, the 55 * user mode driver must configure the hardware before using it. 56 * 57 * - First, dev_config() is called when /dev/gadget/$CHIP is configured 58 * (by writing configuration and device descriptors). Afterwards it 59 * may serve as a source of device events, used to handle all control 60 * requests other than basic enumeration. 61 * 62 * - Then, after a SET_CONFIGURATION control request, ep_config() is 63 * called when each /dev/gadget/ep* file is configured (by writing 64 * endpoint descriptors). Afterwards these files are used to write() 65 * IN data or to read() OUT data. To halt the endpoint, a "wrong 66 * direction" request is issued (like reading an IN endpoint). 67 * 68 * Unlike "usbfs" the only ioctl()s are for things that are rare, and maybe 69 * not possible on all hardware. For example, precise fault handling with 70 * respect to data left in endpoint fifos after aborted operations; or 71 * selective clearing of endpoint halts, to implement SET_INTERFACE. 72 */ 73 74#define DRIVER_DESC "USB Gadget filesystem" 75#define DRIVER_VERSION "24 Aug 2004" 76 77static const char driver_desc [] = DRIVER_DESC; 78static const char shortname [] = "gadgetfs"; 79 80MODULE_DESCRIPTION (DRIVER_DESC); 81MODULE_AUTHOR ("David Brownell"); 82MODULE_LICENSE ("GPL"); 83 84 85/*----------------------------------------------------------------------*/ 86 87#define GADGETFS_MAGIC 0xaee71ee7 88#define DMA_ADDR_INVALID (~(dma_addr_t)0) 89 90/* /dev/gadget/$CHIP represents ep0 and the whole device */ 91enum ep0_state { 92 /* DISBLED is the initial state. 93 */ 94 STATE_DEV_DISABLED = 0, 95 96 /* Only one open() of /dev/gadget/$CHIP; only one file tracks 97 * ep0/device i/o modes and binding to the controller. Driver 98 * must always write descriptors to initialize the device, then 99 * the device becomes UNCONNECTED until enumeration. 100 */ 101 STATE_DEV_OPENED, 102 103 /* From then on, ep0 fd is in either of two basic modes: 104 * - (UN)CONNECTED: read usb_gadgetfs_event(s) from it 105 * - SETUP: read/write will transfer control data and succeed; 106 * or if "wrong direction", performs protocol stall 107 */ 108 STATE_DEV_UNCONNECTED, 109 STATE_DEV_CONNECTED, 110 STATE_DEV_SETUP, 111 112 /* UNBOUND means the driver closed ep0, so the device won't be 113 * accessible again (DEV_DISABLED) until all fds are closed. 114 */ 115 STATE_DEV_UNBOUND, 116}; 117 118/* enough for the whole queue: most events invalidate others */ 119#define N_EVENT 5 120 121struct dev_data { 122 spinlock_t lock; 123 atomic_t count; 124 enum ep0_state state; /* P: lock */ 125 struct usb_gadgetfs_event event [N_EVENT]; 126 unsigned ev_next; 127 struct fasync_struct *fasync; 128 u8 current_config; 129 130 /* drivers reading ep0 MUST handle control requests (SETUP) 131 * reported that way; else the host will time out. 132 */ 133 unsigned usermode_setup : 1, 134 setup_in : 1, 135 setup_can_stall : 1, 136 setup_out_ready : 1, 137 setup_out_error : 1, 138 setup_abort : 1; 139 unsigned setup_wLength; 140 141 /* the rest is basically write-once */ 142 struct usb_config_descriptor *config, *hs_config; 143 struct usb_device_descriptor *dev; 144 struct usb_request *req; 145 struct usb_gadget *gadget; 146 struct list_head epfiles; 147 void *buf; 148 wait_queue_head_t wait; 149 struct super_block *sb; 150 struct dentry *dentry; 151 152 /* except this scratch i/o buffer for ep0 */ 153 u8 rbuf [256]; 154}; 155 156static inline void get_dev (struct dev_data *data) 157{ 158 atomic_inc (&data->count); 159} 160 161static void put_dev (struct dev_data *data) 162{ 163 if (likely (!atomic_dec_and_test (&data->count))) 164 return; 165 /* needs no more cleanup */ 166 BUG_ON (waitqueue_active (&data->wait)); 167 kfree (data); 168} 169 170static struct dev_data *dev_new (void) 171{ 172 struct dev_data *dev; 173 174 dev = kzalloc(sizeof(*dev), GFP_KERNEL); 175 if (!dev) 176 return NULL; 177 dev->state = STATE_DEV_DISABLED; 178 atomic_set (&dev->count, 1); 179 spin_lock_init (&dev->lock); 180 INIT_LIST_HEAD (&dev->epfiles); 181 init_waitqueue_head (&dev->wait); 182 return dev; 183} 184 185/*----------------------------------------------------------------------*/ 186 187/* other /dev/gadget/$ENDPOINT files represent endpoints */ 188enum ep_state { 189 STATE_EP_DISABLED = 0, 190 STATE_EP_READY, 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 kfree (data); 226} 227 228/*----------------------------------------------------------------------*/ 229 230/* most "how to use the hardware" policy choices are in userspace: 231 * mapping endpoint roles (which the driver needs) to the capabilities 232 * which the usb controller has. most of those capabilities are exposed 233 * implicitly, starting with the driver name and then endpoint names. 234 */ 235 236static const char *CHIP; 237 238/*----------------------------------------------------------------------*/ 239 240/* NOTE: don't use dev_printk calls before binding to the gadget 241 * at the end of ep0 configuration, or after unbind. 242 */ 243 244/* too wordy: dev_printk(level , &(d)->gadget->dev , fmt , ## args) */ 245#define xprintk(d,level,fmt,args...) \ 246 printk(level "%s: " fmt , shortname , ## args) 247 248#ifdef DEBUG 249#define DBG(dev,fmt,args...) \ 250 xprintk(dev , KERN_DEBUG , fmt , ## args) 251#else 252#define DBG(dev,fmt,args...) \ 253 do { } while (0) 254#endif /* DEBUG */ 255 256#ifdef VERBOSE 257#define VDEBUG DBG 258#else 259#define VDEBUG(dev,fmt,args...) \ 260 do { } while (0) 261#endif /* DEBUG */ 262 263#define ERROR(dev,fmt,args...) \ 264 xprintk(dev , KERN_ERR , fmt , ## args) 265#define WARN(dev,fmt,args...) \ 266 xprintk(dev , KERN_WARNING , fmt , ## args) 267#define INFO(dev,fmt,args...) \ 268 xprintk(dev , KERN_INFO , fmt , ## args) 269 270 271/*----------------------------------------------------------------------*/ 272 273/* SYNCHRONOUS ENDPOINT OPERATIONS (bulk/intr/iso) 274 * 275 * After opening, configure non-control endpoints. Then use normal 276 * stream read() and write() requests; and maybe ioctl() to get more 277 * precise FIFO status when recovering from cancellation. 278 */ 279 280static void epio_complete (struct usb_ep *ep, struct usb_request *req) 281{ 282 struct ep_data *epdata = ep->driver_data; 283 284 if (!req->context) 285 return; 286 if (req->status) 287 epdata->status = req->status; 288 else 289 epdata->status = req->actual; 290 complete ((struct completion *)req->context); 291} 292 293/* tasklock endpoint, returning when it's connected. 294 * still need dev->lock to use epdata->ep. 295 */ 296static int 297get_ready_ep (unsigned f_flags, struct ep_data *epdata) 298{ 299 int val; 300 301 if (f_flags & O_NONBLOCK) { 302 if (down_trylock (&epdata->lock) != 0) 303 goto nonblock; 304 if (epdata->state != STATE_EP_ENABLED) { 305 up (&epdata->lock); 306nonblock: 307 val = -EAGAIN; 308 } else 309 val = 0; 310 return val; 311 } 312 313 if ((val = down_interruptible (&epdata->lock)) < 0) 314 return val; 315 316 switch (epdata->state) { 317 case STATE_EP_ENABLED: 318 break; 319 // case STATE_EP_DISABLED: /* "can't happen" */ 320 // case STATE_EP_READY: /* "can't happen" */ 321 default: /* error! */ 322 pr_debug ("%s: ep %p not available, state %d\n", 323 shortname, epdata, epdata->state); 324 // FALLTHROUGH 325 case STATE_EP_UNBOUND: /* clean disconnect */ 326 val = -ENODEV; 327 up (&epdata->lock); 328 } 329 return val; 330} 331 332static ssize_t 333ep_io (struct ep_data *epdata, void *buf, unsigned len) 334{ 335 DECLARE_COMPLETION_ONSTACK (done); 336 int value; 337 338 spin_lock_irq (&epdata->dev->lock); 339 if (likely (epdata->ep != NULL)) { 340 struct usb_request *req = epdata->req; 341 342 req->context = &done; 343 req->complete = epio_complete; 344 req->buf = buf; 345 req->length = len; 346 value = usb_ep_queue (epdata->ep, req, GFP_ATOMIC); 347 } else 348 value = -ENODEV; 349 spin_unlock_irq (&epdata->dev->lock); 350 351 if (likely (value == 0)) { 352 value = wait_event_interruptible (done.wait, done.done); 353 if (value != 0) { 354 spin_lock_irq (&epdata->dev->lock); 355 if (likely (epdata->ep != NULL)) { 356 DBG (epdata->dev, "%s i/o interrupted\n", 357 epdata->name); 358 usb_ep_dequeue (epdata->ep, epdata->req); 359 spin_unlock_irq (&epdata->dev->lock); 360 361 wait_event (done.wait, done.done); 362 if (epdata->status == -ECONNRESET) 363 epdata->status = -EINTR; 364 } else { 365 spin_unlock_irq (&epdata->dev->lock); 366 367 DBG (epdata->dev, "endpoint gone\n"); 368 epdata->status = -ENODEV; 369 } 370 } 371 return epdata->status; 372 } 373 return value; 374} 375 376 377/* handle a synchronous OUT bulk/intr/iso transfer */ 378static ssize_t 379ep_read (struct file *fd, char __user *buf, size_t len, loff_t *ptr) 380{ 381 struct ep_data *data = fd->private_data; 382 void *kbuf; 383 ssize_t value; 384 385 if ((value = get_ready_ep (fd->f_flags, data)) < 0) 386 return value; 387 388 /* halt any endpoint by doing a "wrong direction" i/o call */ 389 if (data->desc.bEndpointAddress & USB_DIR_IN) { 390 if ((data->desc.bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) 391 == USB_ENDPOINT_XFER_ISOC) 392 return -EINVAL; 393 DBG (data->dev, "%s halt\n", data->name); 394 spin_lock_irq (&data->dev->lock); 395 if (likely (data->ep != NULL)) 396 usb_ep_set_halt (data->ep); 397 spin_unlock_irq (&data->dev->lock); 398 up (&data->lock); 399 return -EBADMSG; 400 } 401 402 403 value = -ENOMEM; 404 kbuf = kmalloc (len, GFP_KERNEL); 405 if (unlikely (!kbuf)) 406 goto free1; 407 408 value = ep_io (data, kbuf, len); 409 VDEBUG (data->dev, "%s read %zu OUT, status %d\n", 410 data->name, len, (int) value); 411 if (value >= 0 && copy_to_user (buf, kbuf, value)) 412 value = -EFAULT; 413 414free1: 415 up (&data->lock); 416 kfree (kbuf); 417 return value; 418} 419 420/* handle a synchronous IN bulk/intr/iso transfer */ 421static ssize_t 422ep_write (struct file *fd, const char __user *buf, size_t len, loff_t *ptr) 423{ 424 struct ep_data *data = fd->private_data; 425 void *kbuf; 426 ssize_t value; 427 428 if ((value = get_ready_ep (fd->f_flags, data)) < 0) 429 return value; 430 431 /* halt any endpoint by doing a "wrong direction" i/o call */ 432 if (!(data->desc.bEndpointAddress & USB_DIR_IN)) { 433 if ((data->desc.bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) 434 == USB_ENDPOINT_XFER_ISOC) 435 return -EINVAL; 436 DBG (data->dev, "%s halt\n", data->name); 437 spin_lock_irq (&data->dev->lock); 438 if (likely (data->ep != NULL)) 439 usb_ep_set_halt (data->ep); 440 spin_unlock_irq (&data->dev->lock); 441 up (&data->lock); 442 return -EBADMSG; 443 } 444 445 446 value = -ENOMEM; 447 kbuf = kmalloc (len, GFP_KERNEL); 448 if (!kbuf) 449 goto free1; 450 if (copy_from_user (kbuf, buf, len)) { 451 value = -EFAULT; 452 goto free1; 453 } 454 455 value = ep_io (data, kbuf, len); 456 VDEBUG (data->dev, "%s write %zu IN, status %d\n", 457 data->name, len, (int) value); 458free1: 459 up (&data->lock); 460 kfree (kbuf); 461 return value; 462} 463 464static int 465ep_release (struct inode *inode, struct file *fd) 466{ 467 struct ep_data *data = fd->private_data; 468 int value; 469 470 if ((value = down_interruptible(&data->lock)) < 0) 471 return value; 472 473 /* clean up if this can be reopened */ 474 if (data->state != STATE_EP_UNBOUND) { 475 data->state = STATE_EP_DISABLED; 476 data->desc.bDescriptorType = 0; 477 data->hs_desc.bDescriptorType = 0; 478 usb_ep_disable(data->ep); 479 } 480 up (&data->lock); 481 put_ep (data); 482 return 0; 483} 484 485static int ep_ioctl (struct inode *inode, struct file *fd, 486 unsigned code, unsigned long value) 487{ 488 struct ep_data *data = fd->private_data; 489 int status; 490 491 if ((status = get_ready_ep (fd->f_flags, data)) < 0) 492 return status; 493 494 spin_lock_irq (&data->dev->lock); 495 if (likely (data->ep != NULL)) { 496 switch (code) { 497 case GADGETFS_FIFO_STATUS: 498 status = usb_ep_fifo_status (data->ep); 499 break; 500 case GADGETFS_FIFO_FLUSH: 501 usb_ep_fifo_flush (data->ep); 502 break; 503 case GADGETFS_CLEAR_HALT: 504 status = usb_ep_clear_halt (data->ep); 505 break; 506 default: 507 status = -ENOTTY; 508 } 509 } else 510 status = -ENODEV; 511 spin_unlock_irq (&data->dev->lock); 512 up (&data->lock); 513 return status; 514} 515 516/*----------------------------------------------------------------------*/ 517 518/* ASYNCHRONOUS ENDPOINT I/O OPERATIONS (bulk/intr/iso) */ 519 520struct kiocb_priv { 521 struct usb_request *req; 522 struct ep_data *epdata; 523 void *buf; 524 const struct iovec *iv; 525 unsigned long nr_segs; 526 unsigned actual; 527}; 528 529static int ep_aio_cancel(struct kiocb *iocb, struct io_event *e) 530{ 531 struct kiocb_priv *priv = iocb->private; 532 struct ep_data *epdata; 533 int value; 534 535 local_irq_disable(); 536 epdata = priv->epdata; 537 // spin_lock(&epdata->dev->lock); 538 kiocbSetCancelled(iocb); 539 if (likely(epdata && epdata->ep && priv->req)) 540 value = usb_ep_dequeue (epdata->ep, priv->req); 541 else 542 value = -EINVAL; 543 // spin_unlock(&epdata->dev->lock); 544 local_irq_enable(); 545 546 aio_put_req(iocb); 547 return value; 548} 549 550static ssize_t ep_aio_read_retry(struct kiocb *iocb) 551{ 552 struct kiocb_priv *priv = iocb->private; 553 ssize_t len, total; 554 void *to_copy; 555 int i; 556 557 /* we "retry" to get the right mm context for this: */ 558 559 /* copy stuff into user buffers */ 560 total = priv->actual; 561 len = 0; 562 to_copy = priv->buf; 563 for (i=0; i < priv->nr_segs; i++) { 564 ssize_t this = min((ssize_t)(priv->iv[i].iov_len), total); 565 566 if (copy_to_user(priv->iv[i].iov_base, to_copy, this)) { 567 if (len == 0) 568 len = -EFAULT; 569 break; 570 } 571 572 total -= this; 573 len += this; 574 to_copy += this; 575 if (total == 0) 576 break; 577 } 578 kfree(priv->buf); 579 kfree(priv); 580 return len; 581} 582 583static void ep_aio_complete(struct usb_ep *ep, struct usb_request *req) 584{ 585 struct kiocb *iocb = req->context; 586 struct kiocb_priv *priv = iocb->private; 587 struct ep_data *epdata = priv->epdata; 588 589 /* lock against disconnect (and ideally, cancel) */ 590 spin_lock(&epdata->dev->lock); 591 priv->req = NULL; 592 priv->epdata = NULL; 593 594 /* if this was a write or a read returning no data then we 595 * don't need to copy anything to userspace, so we can 596 * complete the aio request immediately. 597 */ 598 if (priv->iv == NULL || unlikely(req->actual == 0)) { 599 kfree(req->buf); 600 kfree(priv); 601 iocb->private = NULL; 602 /* aio_complete() reports bytes-transferred _and_ faults */ 603 aio_complete(iocb, req->actual ? req->actual : req->status, 604 req->status); 605 } else { 606 /* retry() won't report both; so we hide some faults */ 607 if (unlikely(0 != req->status)) 608 DBG(epdata->dev, "%s fault %d len %d\n", 609 ep->name, req->status, req->actual); 610 611 priv->buf = req->buf; 612 priv->actual = req->actual; 613 kick_iocb(iocb); 614 } 615 spin_unlock(&epdata->dev->lock); 616 617 usb_ep_free_request(ep, req); 618 put_ep(epdata); 619} 620 621static ssize_t 622ep_aio_rwtail( 623 struct kiocb *iocb, 624 char *buf, 625 size_t len, 626 struct ep_data *epdata, 627 const struct iovec *iv, 628 unsigned long nr_segs 629) 630{ 631 struct kiocb_priv *priv; 632 struct usb_request *req; 633 ssize_t value; 634 635 priv = kmalloc(sizeof *priv, GFP_KERNEL); 636 if (!priv) { 637 value = -ENOMEM; 638fail: 639 kfree(buf); 640 return value; 641 } 642 iocb->private = priv; 643 priv->iv = iv; 644 priv->nr_segs = nr_segs; 645 646 value = get_ready_ep(iocb->ki_filp->f_flags, epdata); 647 if (unlikely(value < 0)) { 648 kfree(priv); 649 goto fail; 650 } 651 652 iocb->ki_cancel = ep_aio_cancel; 653 get_ep(epdata); 654 priv->epdata = epdata; 655 priv->actual = 0; 656 657 /* each kiocb is coupled to one usb_request, but we can't 658 * allocate or submit those if the host disconnected. 659 */ 660 spin_lock_irq(&epdata->dev->lock); 661 if (likely(epdata->ep)) { 662 req = usb_ep_alloc_request(epdata->ep, GFP_ATOMIC); 663 if (likely(req)) { 664 priv->req = req; 665 req->buf = buf; 666 req->length = len; 667 req->complete = ep_aio_complete; 668 req->context = iocb; 669 value = usb_ep_queue(epdata->ep, req, GFP_ATOMIC); 670 if (unlikely(0 != value)) 671 usb_ep_free_request(epdata->ep, req); 672 } else 673 value = -EAGAIN; 674 } else 675 value = -ENODEV; 676 spin_unlock_irq(&epdata->dev->lock); 677 678 up(&epdata->lock); 679 680 if (unlikely(value)) { 681 kfree(priv); 682 put_ep(epdata); 683 } else 684 value = (iv ? -EIOCBRETRY : -EIOCBQUEUED); 685 return value; 686} 687 688static ssize_t 689ep_aio_read(struct kiocb *iocb, const struct iovec *iov, 690 unsigned long nr_segs, loff_t o) 691{ 692 struct ep_data *epdata = iocb->ki_filp->private_data; 693 char *buf; 694 695 if (unlikely(epdata->desc.bEndpointAddress & USB_DIR_IN)) 696 return -EINVAL; 697 698 buf = kmalloc(iocb->ki_left, GFP_KERNEL); 699 if (unlikely(!buf)) 700 return -ENOMEM; 701 702 iocb->ki_retry = ep_aio_read_retry; 703 return ep_aio_rwtail(iocb, buf, iocb->ki_left, epdata, iov, nr_segs); 704} 705 706static ssize_t 707ep_aio_write(struct kiocb *iocb, const struct iovec *iov, 708 unsigned long nr_segs, loff_t o) 709{ 710 struct ep_data *epdata = iocb->ki_filp->private_data; 711 char *buf; 712 size_t len = 0; 713 int i = 0; 714 715 if (unlikely(!(epdata->desc.bEndpointAddress & USB_DIR_IN))) 716 return -EINVAL; 717 718 buf = kmalloc(iocb->ki_left, GFP_KERNEL); 719 if (unlikely(!buf)) 720 return -ENOMEM; 721 722 for (i=0; i < nr_segs; i++) { 723 if (unlikely(copy_from_user(&buf[len], iov[i].iov_base, 724 iov[i].iov_len) != 0)) { 725 kfree(buf); 726 return -EFAULT; 727 } 728 len += iov[i].iov_len; 729 } 730 return ep_aio_rwtail(iocb, buf, len, epdata, NULL, 0); 731} 732 733/*----------------------------------------------------------------------*/ 734 735/* used after endpoint configuration */ 736static const struct file_operations ep_io_operations = { 737 .owner = THIS_MODULE, 738 .llseek = no_llseek, 739 740 .read = ep_read, 741 .write = ep_write, 742 .ioctl = ep_ioctl, 743 .release = ep_release, 744 745 .aio_read = ep_aio_read, 746 .aio_write = ep_aio_write, 747}; 748 749/* ENDPOINT INITIALIZATION 750 * 751 * fd = open ("/dev/gadget/$ENDPOINT", O_RDWR) 752 * status = write (fd, descriptors, sizeof descriptors) 753 * 754 * That write establishes the endpoint configuration, configuring 755 * the controller to process bulk, interrupt, or isochronous transfers 756 * at the right maxpacket size, and so on. 757 * 758 * The descriptors are message type 1, identified by a host order u32 759 * at the beginning of what's written. Descriptor order is: full/low 760 * speed descriptor, then optional high speed descriptor. 761 */ 762static ssize_t 763ep_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr) 764{ 765 struct ep_data *data = fd->private_data; 766 struct usb_ep *ep; 767 u32 tag; 768 int value, length = len; 769 770 if ((value = down_interruptible (&data->lock)) < 0) 771 return value; 772 773 if (data->state != STATE_EP_READY) { 774 value = -EL2HLT; 775 goto fail; 776 } 777 778 value = len; 779 if (len < USB_DT_ENDPOINT_SIZE + 4) 780 goto fail0; 781 782 /* we might need to change message format someday */ 783 if (copy_from_user (&tag, buf, 4)) { 784 goto fail1; 785 } 786 if (tag != 1) { 787 DBG(data->dev, "config %s, bad tag %d\n", data->name, tag); 788 goto fail0; 789 } 790 buf += 4; 791 len -= 4; 792 793 /* NOTE: audio endpoint extensions not accepted here; 794 * just don't include the extra bytes. 795 */ 796 797 /* full/low speed descriptor, then high speed */ 798 if (copy_from_user (&data->desc, buf, USB_DT_ENDPOINT_SIZE)) { 799 goto fail1; 800 } 801 if (data->desc.bLength != USB_DT_ENDPOINT_SIZE 802 || data->desc.bDescriptorType != USB_DT_ENDPOINT) 803 goto fail0; 804 if (len != USB_DT_ENDPOINT_SIZE) { 805 if (len != 2 * USB_DT_ENDPOINT_SIZE) 806 goto fail0; 807 if (copy_from_user (&data->hs_desc, buf + USB_DT_ENDPOINT_SIZE, 808 USB_DT_ENDPOINT_SIZE)) { 809 goto fail1; 810 } 811 if (data->hs_desc.bLength != USB_DT_ENDPOINT_SIZE 812 || data->hs_desc.bDescriptorType 813 != USB_DT_ENDPOINT) { 814 DBG(data->dev, "config %s, bad hs length or type\n", 815 data->name); 816 goto fail0; 817 } 818 } 819 820 spin_lock_irq (&data->dev->lock); 821 if (data->dev->state == STATE_DEV_UNBOUND) { 822 value = -ENOENT; 823 goto gone; 824 } else if ((ep = data->ep) == NULL) { 825 value = -ENODEV; 826 goto gone; 827 } 828 switch (data->dev->gadget->speed) { 829 case USB_SPEED_LOW: 830 case USB_SPEED_FULL: 831 value = usb_ep_enable (ep, &data->desc); 832 if (value == 0) 833 data->state = STATE_EP_ENABLED; 834 break; 835#ifdef CONFIG_USB_GADGET_DUALSPEED 836 case USB_SPEED_HIGH: 837 /* fails if caller didn't provide that descriptor... */ 838 value = usb_ep_enable (ep, &data->hs_desc); 839 if (value == 0) 840 data->state = STATE_EP_ENABLED; 841 break; 842#endif 843 default: 844 DBG(data->dev, "unconnected, %s init abandoned\n", 845 data->name); 846 value = -EINVAL; 847 } 848 if (value == 0) { 849 fd->f_op = &ep_io_operations; 850 value = length; 851 } 852gone: 853 spin_unlock_irq (&data->dev->lock); 854 if (value < 0) { 855fail: 856 data->desc.bDescriptorType = 0; 857 data->hs_desc.bDescriptorType = 0; 858 } 859 up (&data->lock); 860 return value; 861fail0: 862 value = -EINVAL; 863 goto fail; 864fail1: 865 value = -EFAULT; 866 goto fail; 867} 868 869static int 870ep_open (struct inode *inode, struct file *fd) 871{ 872 struct ep_data *data = inode->i_private; 873 int value = -EBUSY; 874 875 if (down_interruptible (&data->lock) != 0) 876 return -EINTR; 877 spin_lock_irq (&data->dev->lock); 878 if (data->dev->state == STATE_DEV_UNBOUND) 879 value = -ENOENT; 880 else if (data->state == STATE_EP_DISABLED) { 881 value = 0; 882 data->state = STATE_EP_READY; 883 get_ep (data); 884 fd->private_data = data; 885 VDEBUG (data->dev, "%s ready\n", data->name); 886 } else 887 DBG (data->dev, "%s state %d\n", 888 data->name, data->state); 889 spin_unlock_irq (&data->dev->lock); 890 up (&data->lock); 891 return value; 892} 893 894/* used before endpoint configuration */ 895static const struct file_operations ep_config_operations = { 896 .owner = THIS_MODULE, 897 .llseek = no_llseek, 898 899 .open = ep_open, 900 .write = ep_config, 901 .release = ep_release, 902}; 903 904/*----------------------------------------------------------------------*/ 905 906/* EP0 IMPLEMENTATION can be partly in userspace. 907 * 908 * Drivers that use this facility receive various events, including 909 * control requests the kernel doesn't handle. Drivers that don't 910 * use this facility may be too simple-minded for real applications. 911 */ 912 913static inline void ep0_readable (struct dev_data *dev) 914{ 915 wake_up (&dev->wait); 916 kill_fasync (&dev->fasync, SIGIO, POLL_IN); 917} 918 919static void clean_req (struct usb_ep *ep, struct usb_request *req) 920{ 921 struct dev_data *dev = ep->driver_data; 922 923 if (req->buf != dev->rbuf) { 924 usb_ep_free_buffer (ep, req->buf, req->dma, req->length); 925 req->buf = dev->rbuf; 926 req->dma = DMA_ADDR_INVALID; 927 } 928 req->complete = epio_complete; 929 dev->setup_out_ready = 0; 930} 931 932static void ep0_complete (struct usb_ep *ep, struct usb_request *req) 933{ 934 struct dev_data *dev = ep->driver_data; 935 unsigned long flags; 936 int free = 1; 937 938 /* for control OUT, data must still get to userspace */ 939 spin_lock_irqsave(&dev->lock, flags); 940 if (!dev->setup_in) { 941 dev->setup_out_error = (req->status != 0); 942 if (!dev->setup_out_error) 943 free = 0; 944 dev->setup_out_ready = 1; 945 ep0_readable (dev); 946 } 947 948 /* clean up as appropriate */ 949 if (free && req->buf != &dev->rbuf) 950 clean_req (ep, req); 951 req->complete = epio_complete; 952 spin_unlock_irqrestore(&dev->lock, flags); 953} 954 955static int setup_req (struct usb_ep *ep, struct usb_request *req, u16 len) 956{ 957 struct dev_data *dev = ep->driver_data; 958 959 if (dev->setup_out_ready) { 960 DBG (dev, "ep0 request busy!\n"); 961 return -EBUSY; 962 } 963 if (len > sizeof (dev->rbuf)) 964 req->buf = usb_ep_alloc_buffer (ep, len, &req->dma, GFP_ATOMIC); 965 if (req->buf == 0) { 966 req->buf = dev->rbuf; 967 return -ENOMEM; 968 } 969 req->complete = ep0_complete; 970 req->length = len; 971 req->zero = 0; 972 return 0; 973} 974 975static ssize_t 976ep0_read (struct file *fd, char __user *buf, size_t len, loff_t *ptr) 977{ 978 struct dev_data *dev = fd->private_data; 979 ssize_t retval; 980 enum ep0_state state; 981 982 spin_lock_irq (&dev->lock); 983 984 /* report fd mode change before acting on it */ 985 if (dev->setup_abort) { 986 dev->setup_abort = 0; 987 retval = -EIDRM; 988 goto done; 989 } 990 991 /* control DATA stage */ 992 if ((state = dev->state) == STATE_DEV_SETUP) { 993 994 if (dev->setup_in) { /* stall IN */ 995 VDEBUG(dev, "ep0in stall\n"); 996 (void) usb_ep_set_halt (dev->gadget->ep0); 997 retval = -EL2HLT; 998 dev->state = STATE_DEV_CONNECTED; 999 1000 } else if (len == 0) { /* ack SET_CONFIGURATION etc */ 1001 struct usb_ep *ep = dev->gadget->ep0; 1002 struct usb_request *req = dev->req; 1003 1004 if ((retval = setup_req (ep, req, 0)) == 0) 1005 retval = usb_ep_queue (ep, req, GFP_ATOMIC); 1006 dev->state = STATE_DEV_CONNECTED; 1007 1008 /* assume that was SET_CONFIGURATION */ 1009 if (dev->current_config) { 1010 unsigned power; 1011#ifdef CONFIG_USB_GADGET_DUALSPEED 1012 if (dev->gadget->speed == USB_SPEED_HIGH) 1013 power = dev->hs_config->bMaxPower; 1014 else 1015#endif 1016 power = dev->config->bMaxPower; 1017 usb_gadget_vbus_draw(dev->gadget, 2 * power); 1018 } 1019 1020 } else { /* collect OUT data */ 1021 if ((fd->f_flags & O_NONBLOCK) != 0 1022 && !dev->setup_out_ready) { 1023 retval = -EAGAIN; 1024 goto done; 1025 } 1026 spin_unlock_irq (&dev->lock); 1027 retval = wait_event_interruptible (dev->wait, 1028 dev->setup_out_ready != 0); 1029 1030 spin_lock_irq (&dev->lock); 1031 if (retval) 1032 goto done; 1033 1034 if (dev->state != STATE_DEV_SETUP) { 1035 retval = -ECANCELED; 1036 goto done; 1037 } 1038 dev->state = STATE_DEV_CONNECTED; 1039 1040 if (dev->setup_out_error) 1041 retval = -EIO; 1042 else { 1043 len = min (len, (size_t)dev->req->actual); 1044 if (copy_to_user (buf, dev->req->buf, len)) 1045 retval = -EFAULT; 1046 clean_req (dev->gadget->ep0, dev->req); 1047 /* NOTE userspace can't yet choose to stall */ 1048 } 1049 } 1050 goto done; 1051 } 1052 1053 /* else normal: return event data */ 1054 if (len < sizeof dev->event [0]) { 1055 retval = -EINVAL; 1056 goto done; 1057 } 1058 len -= len % sizeof (struct usb_gadgetfs_event); 1059 dev->usermode_setup = 1; 1060 1061scan: 1062 /* return queued events right away */ 1063 if (dev->ev_next != 0) { 1064 unsigned i, n; 1065 1066 n = len / sizeof (struct usb_gadgetfs_event); 1067 if (dev->ev_next < n) 1068 n = dev->ev_next; 1069 1070 /* ep0 i/o has special semantics during STATE_DEV_SETUP */ 1071 for (i = 0; i < n; i++) { 1072 if (dev->event [i].type == GADGETFS_SETUP) { 1073 dev->state = STATE_DEV_SETUP; 1074 n = i + 1; 1075 break; 1076 } 1077 } 1078 spin_unlock_irq (&dev->lock); 1079 len = n * sizeof (struct usb_gadgetfs_event); 1080 if (copy_to_user (buf, &dev->event, len)) 1081 retval = -EFAULT; 1082 else 1083 retval = len; 1084 if (len > 0) { 1085 /* NOTE this doesn't guard against broken drivers; 1086 * concurrent ep0 readers may lose events. 1087 */ 1088 spin_lock_irq (&dev->lock); 1089 if (dev->ev_next > n) { 1090 memmove(&dev->event[0], &dev->event[n], 1091 sizeof (struct usb_gadgetfs_event) 1092 * (dev->ev_next - n)); 1093 } 1094 dev->ev_next -= n; 1095 spin_unlock_irq (&dev->lock); 1096 } 1097 return retval; 1098 } 1099 if (fd->f_flags & O_NONBLOCK) { 1100 retval = -EAGAIN; 1101 goto done; 1102 } 1103 1104 switch (state) { 1105 default: 1106 DBG (dev, "fail %s, state %d\n", __FUNCTION__, state); 1107 retval = -ESRCH; 1108 break; 1109 case STATE_DEV_UNCONNECTED: 1110 case STATE_DEV_CONNECTED: 1111 spin_unlock_irq (&dev->lock); 1112 DBG (dev, "%s wait\n", __FUNCTION__); 1113 1114 /* wait for events */ 1115 retval = wait_event_interruptible (dev->wait, 1116 dev->ev_next != 0); 1117 if (retval < 0) 1118 return retval; 1119 spin_lock_irq (&dev->lock); 1120 goto scan; 1121 } 1122 1123done: 1124 spin_unlock_irq (&dev->lock); 1125 return retval; 1126} 1127 1128static struct usb_gadgetfs_event * 1129next_event (struct dev_data *dev, enum usb_gadgetfs_event_type type) 1130{ 1131 struct usb_gadgetfs_event *event; 1132 unsigned i; 1133 1134 switch (type) { 1135 /* these events purge the queue */ 1136 case GADGETFS_DISCONNECT: 1137 if (dev->state == STATE_DEV_SETUP) 1138 dev->setup_abort = 1; 1139 // FALL THROUGH 1140 case GADGETFS_CONNECT: 1141 dev->ev_next = 0; 1142 break; 1143 case GADGETFS_SETUP: /* previous request timed out */ 1144 case GADGETFS_SUSPEND: /* same effect */ 1145 /* these events can't be repeated */ 1146 for (i = 0; i != dev->ev_next; i++) { 1147 if (dev->event [i].type != type) 1148 continue; 1149 DBG(dev, "discard old event[%d] %d\n", i, type); 1150 dev->ev_next--; 1151 if (i == dev->ev_next) 1152 break; 1153 /* indices start at zero, for simplicity */ 1154 memmove (&dev->event [i], &dev->event [i + 1], 1155 sizeof (struct usb_gadgetfs_event) 1156 * (dev->ev_next - i)); 1157 } 1158 break; 1159 default: 1160 BUG (); 1161 } 1162 VDEBUG(dev, "event[%d] = %d\n", dev->ev_next, type); 1163 event = &dev->event [dev->ev_next++]; 1164 BUG_ON (dev->ev_next > N_EVENT); 1165 memset (event, 0, sizeof *event); 1166 event->type = type; 1167 return event; 1168} 1169 1170static ssize_t 1171ep0_write (struct file *fd, const char __user *buf, size_t len, loff_t *ptr) 1172{ 1173 struct dev_data *dev = fd->private_data; 1174 ssize_t retval = -ESRCH; 1175 1176 spin_lock_irq (&dev->lock); 1177 1178 /* report fd mode change before acting on it */ 1179 if (dev->setup_abort) { 1180 dev->setup_abort = 0; 1181 retval = -EIDRM; 1182 1183 /* data and/or status stage for control request */ 1184 } else if (dev->state == STATE_DEV_SETUP) { 1185 1186 /* IN DATA+STATUS caller makes len <= wLength */ 1187 if (dev->setup_in) { 1188 retval = setup_req (dev->gadget->ep0, dev->req, len); 1189 if (retval == 0) { 1190 dev->state = STATE_DEV_CONNECTED; 1191 spin_unlock_irq (&dev->lock); 1192 if (copy_from_user (dev->req->buf, buf, len)) 1193 retval = -EFAULT; 1194 else { 1195 if (len < dev->setup_wLength) 1196 dev->req->zero = 1; 1197 retval = usb_ep_queue ( 1198 dev->gadget->ep0, dev->req, 1199 GFP_KERNEL); 1200 } 1201 if (retval < 0) { 1202 spin_lock_irq (&dev->lock); 1203 clean_req (dev->gadget->ep0, dev->req); 1204 spin_unlock_irq (&dev->lock); 1205 } else 1206 retval = len; 1207 1208 return retval; 1209 } 1210 1211 /* can stall some OUT transfers */ 1212 } else if (dev->setup_can_stall) { 1213 VDEBUG(dev, "ep0out stall\n"); 1214 (void) usb_ep_set_halt (dev->gadget->ep0); 1215 retval = -EL2HLT; 1216 dev->state = STATE_DEV_CONNECTED; 1217 } else { 1218 DBG(dev, "bogus ep0out stall!\n"); 1219 } 1220 } else 1221 DBG (dev, "fail %s, state %d\n", __FUNCTION__, dev->state); 1222 1223 spin_unlock_irq (&dev->lock); 1224 return retval; 1225} 1226 1227static int 1228ep0_fasync (int f, struct file *fd, int on) 1229{ 1230 struct dev_data *dev = fd->private_data; 1231 // caller must F_SETOWN before signal delivery happens 1232 VDEBUG (dev, "%s %s\n", __FUNCTION__, on ? "on" : "off"); 1233 return fasync_helper (f, fd, on, &dev->fasync); 1234} 1235 1236static struct usb_gadget_driver gadgetfs_driver; 1237 1238static int 1239dev_release (struct inode *inode, struct file *fd) 1240{ 1241 struct dev_data *dev = fd->private_data; 1242 1243 /* closing ep0 === shutdown all */ 1244 1245 usb_gadget_unregister_driver (&gadgetfs_driver); 1246 1247 /* at this point "good" hardware has disconnected the 1248 * device from USB; the host won't see it any more. 1249 * alternatively, all host requests will time out. 1250 */ 1251 1252 fasync_helper (-1, fd, 0, &dev->fasync); 1253 kfree (dev->buf); 1254 dev->buf = NULL; 1255 put_dev (dev); 1256 1257 /* other endpoints were all decoupled from this device */ 1258 spin_lock_irq(&dev->lock); 1259 dev->state = STATE_DEV_DISABLED; 1260 spin_unlock_irq(&dev->lock); 1261 return 0; 1262} 1263 1264static unsigned int 1265ep0_poll (struct file *fd, poll_table *wait) 1266{ 1267 struct dev_data *dev = fd->private_data; 1268 int mask = 0; 1269 1270 poll_wait(fd, &dev->wait, wait); 1271 1272 spin_lock_irq (&dev->lock); 1273 1274 /* report fd mode change before acting on it */ 1275 if (dev->setup_abort) { 1276 dev->setup_abort = 0; 1277 mask = POLLHUP; 1278 goto out; 1279 } 1280 1281 if (dev->state == STATE_DEV_SETUP) { 1282 if (dev->setup_in || dev->setup_can_stall) 1283 mask = POLLOUT; 1284 } else { 1285 if (dev->ev_next != 0) 1286 mask = POLLIN; 1287 } 1288out: 1289 spin_unlock_irq(&dev->lock); 1290 return mask; 1291} 1292 1293static int dev_ioctl (struct inode *inode, struct file *fd, 1294 unsigned code, unsigned long value) 1295{ 1296 struct dev_data *dev = fd->private_data; 1297 struct usb_gadget *gadget = dev->gadget; 1298 1299 if (gadget->ops->ioctl) 1300 return gadget->ops->ioctl (gadget, code, value); 1301 return -ENOTTY; 1302} 1303 1304/* used after device configuration */ 1305static const struct file_operations ep0_io_operations = { 1306 .owner = THIS_MODULE, 1307 .llseek = no_llseek, 1308 1309 .read = ep0_read, 1310 .write = ep0_write, 1311 .fasync = ep0_fasync, 1312 .poll = ep0_poll, 1313 .ioctl = dev_ioctl, 1314 .release = dev_release, 1315}; 1316 1317/*----------------------------------------------------------------------*/ 1318 1319/* The in-kernel gadget driver handles most ep0 issues, in particular 1320 * enumerating the single configuration (as provided from user space). 1321 * 1322 * Unrecognized ep0 requests may be handled in user space. 1323 */ 1324 1325#ifdef CONFIG_USB_GADGET_DUALSPEED 1326static void make_qualifier (struct dev_data *dev) 1327{ 1328 struct usb_qualifier_descriptor qual; 1329 struct usb_device_descriptor *desc; 1330 1331 qual.bLength = sizeof qual; 1332 qual.bDescriptorType = USB_DT_DEVICE_QUALIFIER; 1333 qual.bcdUSB = __constant_cpu_to_le16 (0x0200); 1334 1335 desc = dev->dev; 1336 qual.bDeviceClass = desc->bDeviceClass; 1337 qual.bDeviceSubClass = desc->bDeviceSubClass; 1338 qual.bDeviceProtocol = desc->bDeviceProtocol; 1339 1340 /* assumes ep0 uses the same value for both speeds ... */ 1341 qual.bMaxPacketSize0 = desc->bMaxPacketSize0; 1342 1343 qual.bNumConfigurations = 1; 1344 qual.bRESERVED = 0; 1345 1346 memcpy (dev->rbuf, &qual, sizeof qual); 1347} 1348#endif 1349 1350static int 1351config_buf (struct dev_data *dev, u8 type, unsigned index) 1352{ 1353 int len; 1354#ifdef CONFIG_USB_GADGET_DUALSPEED 1355 int hs; 1356#endif 1357 1358 /* only one configuration */ 1359 if (index > 0) 1360 return -EINVAL; 1361 1362#ifdef CONFIG_USB_GADGET_DUALSPEED 1363 hs = (dev->gadget->speed == USB_SPEED_HIGH); 1364 if (type == USB_DT_OTHER_SPEED_CONFIG) 1365 hs = !hs; 1366 if (hs) { 1367 dev->req->buf = dev->hs_config; 1368 len = le16_to_cpu(dev->hs_config->wTotalLength); 1369 } else 1370#endif 1371 { 1372 dev->req->buf = dev->config; 1373 len = le16_to_cpu(dev->config->wTotalLength); 1374 } 1375 ((u8 *)dev->req->buf) [1] = type; 1376 return len; 1377} 1378 1379static int 1380gadgetfs_setup (struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl) 1381{ 1382 struct dev_data *dev = get_gadget_data (gadget); 1383 struct usb_request *req = dev->req; 1384 int value = -EOPNOTSUPP; 1385 struct usb_gadgetfs_event *event; 1386 u16 w_value = le16_to_cpu(ctrl->wValue); 1387 u16 w_length = le16_to_cpu(ctrl->wLength); 1388 1389 spin_lock (&dev->lock); 1390 dev->setup_abort = 0; 1391 if (dev->state == STATE_DEV_UNCONNECTED) { 1392#ifdef CONFIG_USB_GADGET_DUALSPEED 1393 if (gadget->speed == USB_SPEED_HIGH && dev->hs_config == 0) { 1394 spin_unlock(&dev->lock); 1395 ERROR (dev, "no high speed config??\n"); 1396 return -EINVAL; 1397 } 1398#endif /* CONFIG_USB_GADGET_DUALSPEED */ 1399 1400 dev->state = STATE_DEV_CONNECTED; 1401 dev->dev->bMaxPacketSize0 = gadget->ep0->maxpacket; 1402 1403 INFO (dev, "connected\n"); 1404 event = next_event (dev, GADGETFS_CONNECT); 1405 event->u.speed = gadget->speed; 1406 ep0_readable (dev); 1407 1408 /* host may have given up waiting for response. we can miss control 1409 * requests handled lower down (device/endpoint status and features); 1410 * then ep0_{read,write} will report the wrong status. controller 1411 * driver will have aborted pending i/o. 1412 */ 1413 } else if (dev->state == STATE_DEV_SETUP) 1414 dev->setup_abort = 1; 1415 1416 req->buf = dev->rbuf; 1417 req->dma = DMA_ADDR_INVALID; 1418 req->context = NULL; 1419 value = -EOPNOTSUPP; 1420 switch (ctrl->bRequest) { 1421 1422 case USB_REQ_GET_DESCRIPTOR: 1423 if (ctrl->bRequestType != USB_DIR_IN) 1424 goto unrecognized; 1425 switch (w_value >> 8) { 1426 1427 case USB_DT_DEVICE: 1428 value = min (w_length, (u16) sizeof *dev->dev); 1429 req->buf = dev->dev; 1430 break; 1431#ifdef CONFIG_USB_GADGET_DUALSPEED 1432 case USB_DT_DEVICE_QUALIFIER: 1433 if (!dev->hs_config) 1434 break; 1435 value = min (w_length, (u16) 1436 sizeof (struct usb_qualifier_descriptor)); 1437 make_qualifier (dev); 1438 break; 1439 case USB_DT_OTHER_SPEED_CONFIG: 1440 // FALLTHROUGH 1441#endif 1442 case USB_DT_CONFIG: 1443 value = config_buf (dev, 1444 w_value >> 8, 1445 w_value & 0xff); 1446 if (value >= 0) 1447 value = min (w_length, (u16) value); 1448 break; 1449 case USB_DT_STRING: 1450 goto unrecognized; 1451 1452 default: // all others are errors 1453 break; 1454 } 1455 break; 1456 1457 /* currently one config, two speeds */ 1458 case USB_REQ_SET_CONFIGURATION: 1459 if (ctrl->bRequestType != 0) 1460 break; 1461 if (0 == (u8) w_value) { 1462 value = 0; 1463 dev->current_config = 0; 1464 usb_gadget_vbus_draw(gadget, 8 /* mA */ ); 1465 // user mode expected to disable endpoints 1466 } else { 1467 u8 config, power; 1468#ifdef CONFIG_USB_GADGET_DUALSPEED 1469 if (gadget->speed == USB_SPEED_HIGH) { 1470 config = dev->hs_config->bConfigurationValue; 1471 power = dev->hs_config->bMaxPower; 1472 } else 1473#endif 1474 { 1475 config = dev->config->bConfigurationValue; 1476 power = dev->config->bMaxPower; 1477 } 1478 1479 if (config == (u8) w_value) { 1480 value = 0; 1481 dev->current_config = config; 1482 usb_gadget_vbus_draw(gadget, 2 * power); 1483 } 1484 } 1485 1486 /* report SET_CONFIGURATION like any other control request, 1487 * except that usermode may not stall this. the next 1488 * request mustn't be allowed start until this finishes: 1489 * endpoints and threads set up, etc. 1490 * 1491 * NOTE: older PXA hardware (before PXA 255: without UDCCFR) 1492 * has bad/racey automagic that prevents synchronizing here. 1493 * even kernel mode drivers often miss them. 1494 */ 1495 if (value == 0) { 1496 INFO (dev, "configuration #%d\n", dev->current_config); 1497 if (dev->usermode_setup) { 1498 dev->setup_can_stall = 0; 1499 goto delegate; 1500 } 1501 } 1502 break; 1503 1504#ifndef CONFIG_USB_GADGETFS_PXA2XX 1505 /* PXA automagically handles this request too */ 1506 case USB_REQ_GET_CONFIGURATION: 1507 if (ctrl->bRequestType != 0x80) 1508 break; 1509 *(u8 *)req->buf = dev->current_config; 1510 value = min (w_length, (u16) 1); 1511 break; 1512#endif 1513 1514 default: 1515unrecognized: 1516 VDEBUG (dev, "%s req%02x.%02x v%04x i%04x l%d\n", 1517 dev->usermode_setup ? "delegate" : "fail", 1518 ctrl->bRequestType, ctrl->bRequest, 1519 w_value, le16_to_cpu(ctrl->wIndex), w_length); 1520 1521 /* if there's an ep0 reader, don't stall */ 1522 if (dev->usermode_setup) { 1523 dev->setup_can_stall = 1; 1524delegate: 1525 dev->setup_in = (ctrl->bRequestType & USB_DIR_IN) 1526 ? 1 : 0; 1527 dev->setup_wLength = w_length; 1528 dev->setup_out_ready = 0; 1529 dev->setup_out_error = 0; 1530 value = 0; 1531 1532 /* read DATA stage for OUT right away */ 1533 if (unlikely (!dev->setup_in && w_length)) { 1534 value = setup_req (gadget->ep0, dev->req, 1535 w_length); 1536 if (value < 0) 1537 break; 1538 value = usb_ep_queue (gadget->ep0, dev->req, 1539 GFP_ATOMIC); 1540 if (value < 0) { 1541 clean_req (gadget->ep0, dev->req); 1542 break; 1543 } 1544 1545 /* we can't currently stall these */ 1546 dev->setup_can_stall = 0; 1547 } 1548 1549 /* state changes when reader collects event */ 1550 event = next_event (dev, GADGETFS_SETUP); 1551 event->u.setup = *ctrl; 1552 ep0_readable (dev); 1553 spin_unlock (&dev->lock); 1554 return 0; 1555 } 1556 } 1557 1558 /* proceed with data transfer and status phases? */ 1559 if (value >= 0 && dev->state != STATE_DEV_SETUP) { 1560 req->length = value; 1561 req->zero = value < w_length; 1562 value = usb_ep_queue (gadget->ep0, req, GFP_ATOMIC); 1563 if (value < 0) { 1564 DBG (dev, "ep_queue --> %d\n", value); 1565 req->status = 0; 1566 } 1567 } 1568 1569 /* device stalls when value < 0 */ 1570 spin_unlock (&dev->lock); 1571 return value; 1572} 1573 1574static void destroy_ep_files (struct dev_data *dev) 1575{ 1576 struct list_head *entry, *tmp; 1577 1578 DBG (dev, "%s %d\n", __FUNCTION__, dev->state); 1579 1580 /* dev->state must prevent interference */ 1581restart: 1582 spin_lock_irq (&dev->lock); 1583 list_for_each_safe (entry, tmp, &dev->epfiles) { 1584 struct ep_data *ep; 1585 struct inode *parent; 1586 struct dentry *dentry; 1587 1588 /* break link to FS */ 1589 ep = list_entry (entry, struct ep_data, epfiles); 1590 list_del_init (&ep->epfiles); 1591 dentry = ep->dentry; 1592 ep->dentry = NULL; 1593 parent = dentry->d_parent->d_inode; 1594 1595 /* break link to controller */ 1596 if (ep->state == STATE_EP_ENABLED) 1597 (void) usb_ep_disable (ep->ep); 1598 ep->state = STATE_EP_UNBOUND; 1599 usb_ep_free_request (ep->ep, ep->req); 1600 ep->ep = NULL; 1601 wake_up (&ep->wait); 1602 put_ep (ep); 1603 1604 spin_unlock_irq (&dev->lock); 1605 1606 /* break link to dcache */ 1607 mutex_lock (&parent->i_mutex); 1608 d_delete (dentry); 1609 dput (dentry); 1610 mutex_unlock (&parent->i_mutex); 1611 1612 /* fds may still be open */ 1613 goto restart; 1614 } 1615 spin_unlock_irq (&dev->lock); 1616} 1617 1618 1619static struct inode * 1620gadgetfs_create_file (struct super_block *sb, char const *name, 1621 void *data, const struct file_operations *fops, 1622 struct dentry **dentry_p); 1623 1624static int activate_ep_files (struct dev_data *dev) 1625{ 1626 struct usb_ep *ep; 1627 struct ep_data *data; 1628 1629 gadget_for_each_ep (ep, dev->gadget) { 1630 1631 data = kzalloc(sizeof(*data), GFP_KERNEL); 1632 if (!data) 1633 goto enomem0; 1634 data->state = STATE_EP_DISABLED; 1635 init_MUTEX (&data->lock); 1636 init_waitqueue_head (&data->wait); 1637 1638 strncpy (data->name, ep->name, sizeof (data->name) - 1); 1639 atomic_set (&data->count, 1); 1640 data->dev = dev; 1641 get_dev (dev); 1642 1643 data->ep = ep; 1644 ep->driver_data = data; 1645 1646 data->req = usb_ep_alloc_request (ep, GFP_KERNEL); 1647 if (!data->req) 1648 goto enomem1; 1649 1650 data->inode = gadgetfs_create_file (dev->sb, data->name, 1651 data, &ep_config_operations, 1652 &data->dentry); 1653 if (!data->inode) 1654 goto enomem2; 1655 list_add_tail (&data->epfiles, &dev->epfiles); 1656 } 1657 return 0; 1658 1659enomem2: 1660 usb_ep_free_request (ep, data->req); 1661enomem1: 1662 put_dev (dev); 1663 kfree (data); 1664enomem0: 1665 DBG (dev, "%s enomem\n", __FUNCTION__); 1666 destroy_ep_files (dev); 1667 return -ENOMEM; 1668} 1669 1670static void 1671gadgetfs_unbind (struct usb_gadget *gadget) 1672{ 1673 struct dev_data *dev = get_gadget_data (gadget); 1674 1675 DBG (dev, "%s\n", __FUNCTION__); 1676 1677 spin_lock_irq (&dev->lock); 1678 dev->state = STATE_DEV_UNBOUND; 1679 spin_unlock_irq (&dev->lock); 1680 1681 destroy_ep_files (dev); 1682 gadget->ep0->driver_data = NULL; 1683 set_gadget_data (gadget, NULL); 1684 1685 /* we've already been disconnected ... no i/o is active */ 1686 if (dev->req) 1687 usb_ep_free_request (gadget->ep0, dev->req); 1688 DBG (dev, "%s done\n", __FUNCTION__); 1689 put_dev (dev); 1690} 1691 1692static struct dev_data *the_device; 1693 1694static int 1695gadgetfs_bind (struct usb_gadget *gadget) 1696{ 1697 struct dev_data *dev = the_device; 1698 1699 if (!dev) 1700 return -ESRCH; 1701 if (0 != strcmp (CHIP, gadget->name)) { 1702 printk (KERN_ERR "%s expected %s controller not %s\n", 1703 shortname, CHIP, gadget->name); 1704 return -ENODEV; 1705 } 1706 1707 set_gadget_data (gadget, dev); 1708 dev->gadget = gadget; 1709 gadget->ep0->driver_data = dev; 1710 dev->dev->bMaxPacketSize0 = gadget->ep0->maxpacket; 1711 1712 /* preallocate control response and buffer */ 1713 dev->req = usb_ep_alloc_request (gadget->ep0, GFP_KERNEL); 1714 if (!dev->req) 1715 goto enomem; 1716 dev->req->context = NULL; 1717 dev->req->complete = epio_complete; 1718 1719 if (activate_ep_files (dev) < 0) 1720 goto enomem; 1721 1722 INFO (dev, "bound to %s driver\n", gadget->name); 1723 spin_lock_irq(&dev->lock); 1724 dev->state = STATE_DEV_UNCONNECTED; 1725 spin_unlock_irq(&dev->lock); 1726 get_dev (dev); 1727 return 0; 1728 1729enomem: 1730 gadgetfs_unbind (gadget); 1731 return -ENOMEM; 1732} 1733 1734static void 1735gadgetfs_disconnect (struct usb_gadget *gadget) 1736{ 1737 struct dev_data *dev = get_gadget_data (gadget); 1738 1739 spin_lock (&dev->lock); 1740 if (dev->state == STATE_DEV_UNCONNECTED) 1741 goto exit; 1742 dev->state = STATE_DEV_UNCONNECTED; 1743 1744 INFO (dev, "disconnected\n"); 1745 next_event (dev, GADGETFS_DISCONNECT); 1746 ep0_readable (dev); 1747exit: 1748 spin_unlock (&dev->lock); 1749} 1750 1751static void 1752gadgetfs_suspend (struct usb_gadget *gadget) 1753{ 1754 struct dev_data *dev = get_gadget_data (gadget); 1755 1756 INFO (dev, "suspended from state %d\n", dev->state); 1757 spin_lock (&dev->lock); 1758 switch (dev->state) { 1759 case STATE_DEV_SETUP: // VERY odd... host died?? 1760 case STATE_DEV_CONNECTED: 1761 case STATE_DEV_UNCONNECTED: 1762 next_event (dev, GADGETFS_SUSPEND); 1763 ep0_readable (dev); 1764 /* FALLTHROUGH */ 1765 default: 1766 break; 1767 } 1768 spin_unlock (&dev->lock); 1769} 1770 1771static struct usb_gadget_driver gadgetfs_driver = { 1772#ifdef CONFIG_USB_GADGET_DUALSPEED 1773 .speed = USB_SPEED_HIGH, 1774#else 1775 .speed = USB_SPEED_FULL, 1776#endif 1777 .function = (char *) driver_desc, 1778 .bind = gadgetfs_bind, 1779 .unbind = gadgetfs_unbind, 1780 .setup = gadgetfs_setup, 1781 .disconnect = gadgetfs_disconnect, 1782 .suspend = gadgetfs_suspend, 1783 1784 .driver = { 1785 .name = (char *) shortname, 1786 }, 1787}; 1788 1789/*----------------------------------------------------------------------*/ 1790 1791static void gadgetfs_nop(struct usb_gadget *arg) { } 1792 1793static int gadgetfs_probe (struct usb_gadget *gadget) 1794{ 1795 CHIP = gadget->name; 1796 return -EISNAM; 1797} 1798 1799static struct usb_gadget_driver probe_driver = { 1800 .speed = USB_SPEED_HIGH, 1801 .bind = gadgetfs_probe, 1802 .unbind = gadgetfs_nop, 1803 .setup = (void *)gadgetfs_nop, 1804 .disconnect = gadgetfs_nop, 1805 .driver = { 1806 .name = "nop", 1807 }, 1808}; 1809 1810 1811/* DEVICE INITIALIZATION 1812 * 1813 * fd = open ("/dev/gadget/$CHIP", O_RDWR) 1814 * status = write (fd, descriptors, sizeof descriptors) 1815 * 1816 * That write establishes the device configuration, so the kernel can 1817 * bind to the controller ... guaranteeing it can handle enumeration 1818 * at all necessary speeds. Descriptor order is: 1819 * 1820 * . message tag (u32, host order) ... for now, must be zero; it 1821 * would change to support features like multi-config devices 1822 * . full/low speed config ... all wTotalLength bytes (with interface, 1823 * class, altsetting, endpoint, and other descriptors) 1824 * . high speed config ... all descriptors, for high speed operation; 1825 * this one's optional except for high-speed hardware 1826 * . device descriptor 1827 * 1828 * Endpoints are not yet enabled. Drivers must wait until device 1829 * configuration and interface altsetting changes create 1830 * the need to configure (or unconfigure) them. 1831 * 1832 * After initialization, the device stays active for as long as that 1833 * $CHIP file is open. Events must then be read from that descriptor, 1834 * such as configuration notifications. 1835 */ 1836 1837static int is_valid_config (struct usb_config_descriptor *config) 1838{ 1839 return config->bDescriptorType == USB_DT_CONFIG 1840 && config->bLength == USB_DT_CONFIG_SIZE 1841 && config->bConfigurationValue != 0 1842 && (config->bmAttributes & USB_CONFIG_ATT_ONE) != 0 1843 && (config->bmAttributes & USB_CONFIG_ATT_WAKEUP) == 0; 1844} 1845 1846static ssize_t 1847dev_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr) 1848{ 1849 struct dev_data *dev = fd->private_data; 1850 ssize_t value = len, length = len; 1851 unsigned total; 1852 u32 tag; 1853 char *kbuf; 1854 1855 if (len < (USB_DT_CONFIG_SIZE + USB_DT_DEVICE_SIZE + 4)) 1856 return -EINVAL; 1857 1858 /* we might need to change message format someday */ 1859 if (copy_from_user (&tag, buf, 4)) 1860 return -EFAULT; 1861 if (tag != 0) 1862 return -EINVAL; 1863 buf += 4; 1864 length -= 4; 1865 1866 kbuf = kmalloc (length, GFP_KERNEL); 1867 if (!kbuf) 1868 return -ENOMEM; 1869 if (copy_from_user (kbuf, buf, length)) { 1870 kfree (kbuf); 1871 return -EFAULT; 1872 } 1873 1874 spin_lock_irq (&dev->lock); 1875 value = -EINVAL; 1876 if (dev->buf) 1877 goto fail; 1878 dev->buf = kbuf; 1879 1880 /* full or low speed config */ 1881 dev->config = (void *) kbuf; 1882 total = le16_to_cpu(dev->config->wTotalLength); 1883 if (!is_valid_config (dev->config) || total >= length) 1884 goto fail; 1885 kbuf += total; 1886 length -= total; 1887 1888 /* optional high speed config */ 1889 if (kbuf [1] == USB_DT_CONFIG) { 1890 dev->hs_config = (void *) kbuf; 1891 total = le16_to_cpu(dev->hs_config->wTotalLength); 1892 if (!is_valid_config (dev->hs_config) || total >= length) 1893 goto fail; 1894 kbuf += total; 1895 length -= total; 1896 } 1897 1898 /* could support multiple configs, using another encoding! */ 1899 1900 /* device descriptor (tweaked for paranoia) */ 1901 if (length != USB_DT_DEVICE_SIZE) 1902 goto fail; 1903 dev->dev = (void *)kbuf; 1904 if (dev->dev->bLength != USB_DT_DEVICE_SIZE 1905 || dev->dev->bDescriptorType != USB_DT_DEVICE 1906 || dev->dev->bNumConfigurations != 1) 1907 goto fail; 1908 dev->dev->bNumConfigurations = 1; 1909 dev->dev->bcdUSB = __constant_cpu_to_le16 (0x0200); 1910 1911 /* triggers gadgetfs_bind(); then we can enumerate. */ 1912 spin_unlock_irq (&dev->lock); 1913 value = usb_gadget_register_driver (&gadgetfs_driver); 1914 if (value != 0) { 1915 kfree (dev->buf); 1916 dev->buf = NULL; 1917 } else { 1918 /* at this point "good" hardware has for the first time 1919 * let the USB the host see us. alternatively, if users 1920 * unplug/replug that will clear all the error state. 1921 * 1922 * note: everything running before here was guaranteed 1923 * to choke driver model style diagnostics. from here 1924 * on, they can work ... except in cleanup paths that 1925 * kick in after the ep0 descriptor is closed. 1926 */ 1927 fd->f_op = &ep0_io_operations; 1928 value = len; 1929 } 1930 return value; 1931 1932fail: 1933 spin_unlock_irq (&dev->lock); 1934 pr_debug ("%s: %s fail %Zd, %p\n", shortname, __FUNCTION__, value, dev); 1935 kfree (dev->buf); 1936 dev->buf = NULL; 1937 return value; 1938} 1939 1940static int 1941dev_open (struct inode *inode, struct file *fd) 1942{ 1943 struct dev_data *dev = inode->i_private; 1944 int value = -EBUSY; 1945 1946 spin_lock_irq(&dev->lock); 1947 if (dev->state == STATE_DEV_DISABLED) { 1948 dev->ev_next = 0; 1949 dev->state = STATE_DEV_OPENED; 1950 fd->private_data = dev; 1951 get_dev (dev); 1952 value = 0; 1953 } 1954 spin_unlock_irq(&dev->lock); 1955 return value; 1956} 1957 1958static const struct file_operations dev_init_operations = { 1959 .owner = THIS_MODULE, 1960 .llseek = no_llseek, 1961 1962 .open = dev_open, 1963 .write = dev_config, 1964 .fasync = ep0_fasync, 1965 .ioctl = dev_ioctl, 1966 .release = dev_release, 1967}; 1968 1969/*----------------------------------------------------------------------*/ 1970 1971/* FILESYSTEM AND SUPERBLOCK OPERATIONS 1972 * 1973 * Mounting the filesystem creates a controller file, used first for 1974 * device configuration then later for event monitoring. 1975 */ 1976 1977 1978 1979static unsigned default_uid; 1980static unsigned default_gid; 1981static unsigned default_perm = S_IRUSR | S_IWUSR; 1982 1983module_param (default_uid, uint, 0644); 1984module_param (default_gid, uint, 0644); 1985module_param (default_perm, uint, 0644); 1986 1987 1988static struct inode * 1989gadgetfs_make_inode (struct super_block *sb, 1990 void *data, const struct file_operations *fops, 1991 int mode) 1992{ 1993 struct inode *inode = new_inode (sb); 1994 1995 if (inode) { 1996 inode->i_mode = mode; 1997 inode->i_uid = default_uid; 1998 inode->i_gid = default_gid; 1999 inode->i_blocks = 0; 2000 inode->i_atime = inode->i_mtime = inode->i_ctime 2001 = CURRENT_TIME; 2002 inode->i_private = data; 2003 inode->i_fop = fops; 2004 } 2005 return inode; 2006} 2007 2008/* creates in fs root directory, so non-renamable and non-linkable. 2009 * so inode and dentry are paired, until device reconfig. 2010 */ 2011static struct inode * 2012gadgetfs_create_file (struct super_block *sb, char const *name, 2013 void *data, const struct file_operations *fops, 2014 struct dentry **dentry_p) 2015{ 2016 struct dentry *dentry; 2017 struct inode *inode; 2018 2019 dentry = d_alloc_name(sb->s_root, name); 2020 if (!dentry) 2021 return NULL; 2022 2023 inode = gadgetfs_make_inode (sb, data, fops, 2024 S_IFREG | (default_perm & S_IRWXUGO)); 2025 if (!inode) { 2026 dput(dentry); 2027 return NULL; 2028 } 2029 d_add (dentry, inode); 2030 *dentry_p = dentry; 2031 return inode; 2032} 2033 2034static struct super_operations gadget_fs_operations = { 2035 .statfs = simple_statfs, 2036 .drop_inode = generic_delete_inode, 2037}; 2038 2039static int 2040gadgetfs_fill_super (struct super_block *sb, void *opts, int silent) 2041{ 2042 struct inode *inode; 2043 struct dentry *d; 2044 struct dev_data *dev; 2045 2046 if (the_device) 2047 return -ESRCH; 2048 2049 /* fake probe to determine $CHIP */ 2050 (void) usb_gadget_register_driver (&probe_driver); 2051 if (!CHIP) 2052 return -ENODEV; 2053 2054 /* superblock */ 2055 sb->s_blocksize = PAGE_CACHE_SIZE; 2056 sb->s_blocksize_bits = PAGE_CACHE_SHIFT; 2057 sb->s_magic = GADGETFS_MAGIC; 2058 sb->s_op = &gadget_fs_operations; 2059 sb->s_time_gran = 1; 2060 2061 /* root inode */ 2062 inode = gadgetfs_make_inode (sb, 2063 NULL, &simple_dir_operations, 2064 S_IFDIR | S_IRUGO | S_IXUGO); 2065 if (!inode) 2066 goto enomem0; 2067 inode->i_op = &simple_dir_inode_operations; 2068 if (!(d = d_alloc_root (inode))) 2069 goto enomem1; 2070 sb->s_root = d; 2071 2072 /* the ep0 file is named after the controller we expect; 2073 * user mode code can use it for sanity checks, like we do. 2074 */ 2075 dev = dev_new (); 2076 if (!dev) 2077 goto enomem2; 2078 2079 dev->sb = sb; 2080 if (!gadgetfs_create_file (sb, CHIP, 2081 dev, &dev_init_operations, 2082 &dev->dentry)) 2083 goto enomem3; 2084 2085 /* other endpoint files are available after hardware setup, 2086 * from binding to a controller. 2087 */ 2088 the_device = dev; 2089 return 0; 2090 2091enomem3: 2092 put_dev (dev); 2093enomem2: 2094 dput (d); 2095enomem1: 2096 iput (inode); 2097enomem0: 2098 return -ENOMEM; 2099} 2100 2101/* "mount -t gadgetfs path /dev/gadget" ends up here */ 2102static int 2103gadgetfs_get_sb (struct file_system_type *t, int flags, 2104 const char *path, void *opts, struct vfsmount *mnt) 2105{ 2106 return get_sb_single (t, flags, opts, gadgetfs_fill_super, mnt); 2107} 2108 2109static void 2110gadgetfs_kill_sb (struct super_block *sb) 2111{ 2112 kill_litter_super (sb); 2113 if (the_device) { 2114 put_dev (the_device); 2115 the_device = NULL; 2116 } 2117} 2118 2119/*----------------------------------------------------------------------*/ 2120 2121static struct file_system_type gadgetfs_type = { 2122 .owner = THIS_MODULE, 2123 .name = shortname, 2124 .get_sb = gadgetfs_get_sb, 2125 .kill_sb = gadgetfs_kill_sb, 2126}; 2127 2128/*----------------------------------------------------------------------*/ 2129 2130static int __init init (void) 2131{ 2132 int status; 2133 2134 status = register_filesystem (&gadgetfs_type); 2135 if (status == 0) 2136 pr_info ("%s: %s, version " DRIVER_VERSION "\n", 2137 shortname, driver_desc); 2138 return status; 2139} 2140module_init (init); 2141 2142static void __exit cleanup (void) 2143{ 2144 pr_debug ("unregister %s\n", shortname); 2145 unregister_filesystem (&gadgetfs_type); 2146} 2147module_exit (cleanup); 2148