1 /* 2 * cdc-wdm.c 3 * 4 * This driver supports USB CDC WCM Device Management. 5 * 6 * Copyright (c) 2007-2009 Oliver Neukum 7 * 8 * Some code taken from cdc-acm.c 9 * 10 * Released under the GPLv2. 11 * 12 * Many thanks to Carl Nordbeck 13 */ 14 #include <linux/kernel.h> 15 #include <linux/errno.h> 16 #include <linux/ioctl.h> 17 #include <linux/slab.h> 18 #include <linux/module.h> 19 #include <linux/mutex.h> 20 #include <linux/uaccess.h> 21 #include <linux/bitops.h> 22 #include <linux/poll.h> 23 #include <linux/usb.h> 24 #include <linux/usb/cdc.h> 25 #include <asm/byteorder.h> 26 #include <asm/unaligned.h> 27 #include <linux/usb/cdc-wdm.h> 28 29 /* 30 * Version Information 31 */ 32 #define DRIVER_VERSION "v0.03" 33 #define DRIVER_AUTHOR "Oliver Neukum" 34 #define DRIVER_DESC "USB Abstract Control Model driver for USB WCM Device Management" 35 36 static const struct usb_device_id wdm_ids[] = { 37 { 38 .match_flags = USB_DEVICE_ID_MATCH_INT_CLASS | 39 USB_DEVICE_ID_MATCH_INT_SUBCLASS, 40 .bInterfaceClass = USB_CLASS_COMM, 41 .bInterfaceSubClass = USB_CDC_SUBCLASS_DMM 42 }, 43 { } 44 }; 45 46 MODULE_DEVICE_TABLE (usb, wdm_ids); 47 48 #define WDM_MINOR_BASE 176 49 50 51 #define WDM_IN_USE 1 52 #define WDM_DISCONNECTING 2 53 #define WDM_RESULT 3 54 #define WDM_READ 4 55 #define WDM_INT_STALL 5 56 #define WDM_POLL_RUNNING 6 57 #define WDM_RESPONDING 7 58 #define WDM_SUSPENDING 8 59 #define WDM_RESETTING 9 60 #define WDM_OVERFLOW 10 61 62 #define WDM_MAX 16 63 64 /* CDC-WMC r1.1 requires wMaxCommand to be "at least 256 decimal (0x100)" */ 65 #define WDM_DEFAULT_BUFSIZE 256 66 67 static DEFINE_MUTEX(wdm_mutex); 68 static DEFINE_SPINLOCK(wdm_device_list_lock); 69 static LIST_HEAD(wdm_device_list); 70 71 /* --- method tables --- */ 72 73 struct wdm_device { 74 u8 *inbuf; /* buffer for response */ 75 u8 *outbuf; /* buffer for command */ 76 u8 *sbuf; /* buffer for status */ 77 u8 *ubuf; /* buffer for copy to user space */ 78 79 struct urb *command; 80 struct urb *response; 81 struct urb *validity; 82 struct usb_interface *intf; 83 struct usb_ctrlrequest *orq; 84 struct usb_ctrlrequest *irq; 85 spinlock_t iuspin; 86 87 unsigned long flags; 88 u16 bufsize; 89 u16 wMaxCommand; 90 u16 wMaxPacketSize; 91 __le16 inum; 92 int reslength; 93 int length; 94 int read; 95 int count; 96 dma_addr_t shandle; 97 dma_addr_t ihandle; 98 struct mutex wlock; 99 struct mutex rlock; 100 wait_queue_head_t wait; 101 struct work_struct rxwork; 102 int werr; 103 int rerr; 104 105 struct list_head device_list; 106 int (*manage_power)(struct usb_interface *, int); 107 }; 108 109 static struct usb_driver wdm_driver; 110 111 /* return intfdata if we own the interface, else look up intf in the list */ 112 static struct wdm_device *wdm_find_device(struct usb_interface *intf) 113 { 114 struct wdm_device *desc; 115 116 spin_lock(&wdm_device_list_lock); 117 list_for_each_entry(desc, &wdm_device_list, device_list) 118 if (desc->intf == intf) 119 goto found; 120 desc = NULL; 121 found: 122 spin_unlock(&wdm_device_list_lock); 123 124 return desc; 125 } 126 127 static struct wdm_device *wdm_find_device_by_minor(int minor) 128 { 129 struct wdm_device *desc; 130 131 spin_lock(&wdm_device_list_lock); 132 list_for_each_entry(desc, &wdm_device_list, device_list) 133 if (desc->intf->minor == minor) 134 goto found; 135 desc = NULL; 136 found: 137 spin_unlock(&wdm_device_list_lock); 138 139 return desc; 140 } 141 142 /* --- callbacks --- */ 143 static void wdm_out_callback(struct urb *urb) 144 { 145 struct wdm_device *desc; 146 desc = urb->context; 147 spin_lock(&desc->iuspin); 148 desc->werr = urb->status; 149 spin_unlock(&desc->iuspin); 150 kfree(desc->outbuf); 151 desc->outbuf = NULL; 152 clear_bit(WDM_IN_USE, &desc->flags); 153 wake_up(&desc->wait); 154 } 155 156 static void wdm_in_callback(struct urb *urb) 157 { 158 struct wdm_device *desc = urb->context; 159 int status = urb->status; 160 int length = urb->actual_length; 161 162 spin_lock(&desc->iuspin); 163 clear_bit(WDM_RESPONDING, &desc->flags); 164 165 if (status) { 166 switch (status) { 167 case -ENOENT: 168 dev_dbg(&desc->intf->dev, 169 "nonzero urb status received: -ENOENT"); 170 goto skip_error; 171 case -ECONNRESET: 172 dev_dbg(&desc->intf->dev, 173 "nonzero urb status received: -ECONNRESET"); 174 goto skip_error; 175 case -ESHUTDOWN: 176 dev_dbg(&desc->intf->dev, 177 "nonzero urb status received: -ESHUTDOWN"); 178 goto skip_error; 179 case -EPIPE: 180 dev_err(&desc->intf->dev, 181 "nonzero urb status received: -EPIPE\n"); 182 break; 183 default: 184 dev_err(&desc->intf->dev, 185 "Unexpected error %d\n", status); 186 break; 187 } 188 } 189 190 desc->rerr = status; 191 if (length + desc->length > desc->wMaxCommand) { 192 /* The buffer would overflow */ 193 set_bit(WDM_OVERFLOW, &desc->flags); 194 } else { 195 /* we may already be in overflow */ 196 if (!test_bit(WDM_OVERFLOW, &desc->flags)) { 197 memmove(desc->ubuf + desc->length, desc->inbuf, length); 198 desc->length += length; 199 desc->reslength = length; 200 } 201 } 202 skip_error: 203 wake_up(&desc->wait); 204 205 set_bit(WDM_READ, &desc->flags); 206 spin_unlock(&desc->iuspin); 207 } 208 209 static void wdm_int_callback(struct urb *urb) 210 { 211 int rv = 0; 212 int responding; 213 int status = urb->status; 214 struct wdm_device *desc; 215 struct usb_cdc_notification *dr; 216 217 desc = urb->context; 218 dr = (struct usb_cdc_notification *)desc->sbuf; 219 220 if (status) { 221 switch (status) { 222 case -ESHUTDOWN: 223 case -ENOENT: 224 case -ECONNRESET: 225 return; /* unplug */ 226 case -EPIPE: 227 set_bit(WDM_INT_STALL, &desc->flags); 228 dev_err(&desc->intf->dev, "Stall on int endpoint\n"); 229 goto sw; /* halt is cleared in work */ 230 default: 231 dev_err(&desc->intf->dev, 232 "nonzero urb status received: %d\n", status); 233 break; 234 } 235 } 236 237 if (urb->actual_length < sizeof(struct usb_cdc_notification)) { 238 dev_err(&desc->intf->dev, "wdm_int_callback - %d bytes\n", 239 urb->actual_length); 240 goto exit; 241 } 242 243 switch (dr->bNotificationType) { 244 case USB_CDC_NOTIFY_RESPONSE_AVAILABLE: 245 dev_dbg(&desc->intf->dev, 246 "NOTIFY_RESPONSE_AVAILABLE received: index %d len %d", 247 dr->wIndex, dr->wLength); 248 break; 249 250 case USB_CDC_NOTIFY_NETWORK_CONNECTION: 251 252 dev_dbg(&desc->intf->dev, 253 "NOTIFY_NETWORK_CONNECTION %s network", 254 dr->wValue ? "connected to" : "disconnected from"); 255 goto exit; 256 default: 257 clear_bit(WDM_POLL_RUNNING, &desc->flags); 258 dev_err(&desc->intf->dev, 259 "unknown notification %d received: index %d len %d\n", 260 dr->bNotificationType, dr->wIndex, dr->wLength); 261 goto exit; 262 } 263 264 spin_lock(&desc->iuspin); 265 clear_bit(WDM_READ, &desc->flags); 266 responding = test_and_set_bit(WDM_RESPONDING, &desc->flags); 267 if (!responding && !test_bit(WDM_DISCONNECTING, &desc->flags) 268 && !test_bit(WDM_SUSPENDING, &desc->flags)) { 269 rv = usb_submit_urb(desc->response, GFP_ATOMIC); 270 dev_dbg(&desc->intf->dev, "%s: usb_submit_urb %d", 271 __func__, rv); 272 } 273 spin_unlock(&desc->iuspin); 274 if (rv < 0) { 275 clear_bit(WDM_RESPONDING, &desc->flags); 276 if (rv == -EPERM) 277 return; 278 if (rv == -ENOMEM) { 279 sw: 280 rv = schedule_work(&desc->rxwork); 281 if (rv) 282 dev_err(&desc->intf->dev, 283 "Cannot schedule work\n"); 284 } 285 } 286 exit: 287 rv = usb_submit_urb(urb, GFP_ATOMIC); 288 if (rv) 289 dev_err(&desc->intf->dev, 290 "%s - usb_submit_urb failed with result %d\n", 291 __func__, rv); 292 293 } 294 295 static void kill_urbs(struct wdm_device *desc) 296 { 297 /* the order here is essential */ 298 usb_kill_urb(desc->command); 299 usb_kill_urb(desc->validity); 300 usb_kill_urb(desc->response); 301 } 302 303 static void free_urbs(struct wdm_device *desc) 304 { 305 usb_free_urb(desc->validity); 306 usb_free_urb(desc->response); 307 usb_free_urb(desc->command); 308 } 309 310 static void cleanup(struct wdm_device *desc) 311 { 312 kfree(desc->sbuf); 313 kfree(desc->inbuf); 314 kfree(desc->orq); 315 kfree(desc->irq); 316 kfree(desc->ubuf); 317 free_urbs(desc); 318 kfree(desc); 319 } 320 321 static ssize_t wdm_write 322 (struct file *file, const char __user *buffer, size_t count, loff_t *ppos) 323 { 324 u8 *buf; 325 int rv = -EMSGSIZE, r, we; 326 struct wdm_device *desc = file->private_data; 327 struct usb_ctrlrequest *req; 328 329 if (count > desc->wMaxCommand) 330 count = desc->wMaxCommand; 331 332 spin_lock_irq(&desc->iuspin); 333 we = desc->werr; 334 desc->werr = 0; 335 spin_unlock_irq(&desc->iuspin); 336 if (we < 0) 337 return -EIO; 338 339 buf = kmalloc(count, GFP_KERNEL); 340 if (!buf) { 341 rv = -ENOMEM; 342 goto outnl; 343 } 344 345 r = copy_from_user(buf, buffer, count); 346 if (r > 0) { 347 kfree(buf); 348 rv = -EFAULT; 349 goto outnl; 350 } 351 352 /* concurrent writes and disconnect */ 353 r = mutex_lock_interruptible(&desc->wlock); 354 rv = -ERESTARTSYS; 355 if (r) { 356 kfree(buf); 357 goto outnl; 358 } 359 360 if (test_bit(WDM_DISCONNECTING, &desc->flags)) { 361 kfree(buf); 362 rv = -ENODEV; 363 goto outnp; 364 } 365 366 r = usb_autopm_get_interface(desc->intf); 367 if (r < 0) { 368 kfree(buf); 369 rv = usb_translate_errors(r); 370 goto outnp; 371 } 372 373 if (!(file->f_flags & O_NONBLOCK)) 374 r = wait_event_interruptible(desc->wait, !test_bit(WDM_IN_USE, 375 &desc->flags)); 376 else 377 if (test_bit(WDM_IN_USE, &desc->flags)) 378 r = -EAGAIN; 379 380 if (test_bit(WDM_RESETTING, &desc->flags)) 381 r = -EIO; 382 383 if (r < 0) { 384 kfree(buf); 385 rv = r; 386 goto out; 387 } 388 389 req = desc->orq; 390 usb_fill_control_urb( 391 desc->command, 392 interface_to_usbdev(desc->intf), 393 /* using common endpoint 0 */ 394 usb_sndctrlpipe(interface_to_usbdev(desc->intf), 0), 395 (unsigned char *)req, 396 buf, 397 count, 398 wdm_out_callback, 399 desc 400 ); 401 402 req->bRequestType = (USB_DIR_OUT | USB_TYPE_CLASS | 403 USB_RECIP_INTERFACE); 404 req->bRequest = USB_CDC_SEND_ENCAPSULATED_COMMAND; 405 req->wValue = 0; 406 req->wIndex = desc->inum; 407 req->wLength = cpu_to_le16(count); 408 set_bit(WDM_IN_USE, &desc->flags); 409 desc->outbuf = buf; 410 411 rv = usb_submit_urb(desc->command, GFP_KERNEL); 412 if (rv < 0) { 413 kfree(buf); 414 desc->outbuf = NULL; 415 clear_bit(WDM_IN_USE, &desc->flags); 416 dev_err(&desc->intf->dev, "Tx URB error: %d\n", rv); 417 rv = usb_translate_errors(rv); 418 } else { 419 dev_dbg(&desc->intf->dev, "Tx URB has been submitted index=%d", 420 req->wIndex); 421 } 422 out: 423 usb_autopm_put_interface(desc->intf); 424 outnp: 425 mutex_unlock(&desc->wlock); 426 outnl: 427 return rv < 0 ? rv : count; 428 } 429 430 static ssize_t wdm_read 431 (struct file *file, char __user *buffer, size_t count, loff_t *ppos) 432 { 433 int rv, cntr; 434 int i = 0; 435 struct wdm_device *desc = file->private_data; 436 437 438 rv = mutex_lock_interruptible(&desc->rlock); /*concurrent reads */ 439 if (rv < 0) 440 return -ERESTARTSYS; 441 442 cntr = ACCESS_ONCE(desc->length); 443 if (cntr == 0) { 444 desc->read = 0; 445 retry: 446 if (test_bit(WDM_DISCONNECTING, &desc->flags)) { 447 rv = -ENODEV; 448 goto err; 449 } 450 if (test_bit(WDM_OVERFLOW, &desc->flags)) { 451 clear_bit(WDM_OVERFLOW, &desc->flags); 452 rv = -ENOBUFS; 453 goto err; 454 } 455 i++; 456 if (file->f_flags & O_NONBLOCK) { 457 if (!test_bit(WDM_READ, &desc->flags)) { 458 rv = cntr ? cntr : -EAGAIN; 459 goto err; 460 } 461 rv = 0; 462 } else { 463 rv = wait_event_interruptible(desc->wait, 464 test_bit(WDM_READ, &desc->flags)); 465 } 466 467 /* may have happened while we slept */ 468 if (test_bit(WDM_DISCONNECTING, &desc->flags)) { 469 rv = -ENODEV; 470 goto err; 471 } 472 if (test_bit(WDM_RESETTING, &desc->flags)) { 473 rv = -EIO; 474 goto err; 475 } 476 usb_mark_last_busy(interface_to_usbdev(desc->intf)); 477 if (rv < 0) { 478 rv = -ERESTARTSYS; 479 goto err; 480 } 481 482 spin_lock_irq(&desc->iuspin); 483 484 if (desc->rerr) { /* read completed, error happened */ 485 desc->rerr = 0; 486 spin_unlock_irq(&desc->iuspin); 487 rv = -EIO; 488 goto err; 489 } 490 /* 491 * recheck whether we've lost the race 492 * against the completion handler 493 */ 494 if (!test_bit(WDM_READ, &desc->flags)) { /* lost race */ 495 spin_unlock_irq(&desc->iuspin); 496 goto retry; 497 } 498 499 if (!desc->reslength) { /* zero length read */ 500 dev_dbg(&desc->intf->dev, "%s: zero length - clearing WDM_READ\n", __func__); 501 clear_bit(WDM_READ, &desc->flags); 502 spin_unlock_irq(&desc->iuspin); 503 goto retry; 504 } 505 cntr = desc->length; 506 spin_unlock_irq(&desc->iuspin); 507 } 508 509 if (cntr > count) 510 cntr = count; 511 rv = copy_to_user(buffer, desc->ubuf, cntr); 512 if (rv > 0) { 513 rv = -EFAULT; 514 goto err; 515 } 516 517 spin_lock_irq(&desc->iuspin); 518 519 for (i = 0; i < desc->length - cntr; i++) 520 desc->ubuf[i] = desc->ubuf[i + cntr]; 521 522 desc->length -= cntr; 523 /* in case we had outstanding data */ 524 if (!desc->length) 525 clear_bit(WDM_READ, &desc->flags); 526 527 spin_unlock_irq(&desc->iuspin); 528 529 rv = cntr; 530 531 err: 532 mutex_unlock(&desc->rlock); 533 return rv; 534 } 535 536 static int wdm_flush(struct file *file, fl_owner_t id) 537 { 538 struct wdm_device *desc = file->private_data; 539 540 wait_event(desc->wait, !test_bit(WDM_IN_USE, &desc->flags)); 541 542 /* cannot dereference desc->intf if WDM_DISCONNECTING */ 543 if (desc->werr < 0 && !test_bit(WDM_DISCONNECTING, &desc->flags)) 544 dev_err(&desc->intf->dev, "Error in flush path: %d\n", 545 desc->werr); 546 547 return usb_translate_errors(desc->werr); 548 } 549 550 static unsigned int wdm_poll(struct file *file, struct poll_table_struct *wait) 551 { 552 struct wdm_device *desc = file->private_data; 553 unsigned long flags; 554 unsigned int mask = 0; 555 556 spin_lock_irqsave(&desc->iuspin, flags); 557 if (test_bit(WDM_DISCONNECTING, &desc->flags)) { 558 mask = POLLHUP | POLLERR; 559 spin_unlock_irqrestore(&desc->iuspin, flags); 560 goto desc_out; 561 } 562 if (test_bit(WDM_READ, &desc->flags)) 563 mask = POLLIN | POLLRDNORM; 564 if (desc->rerr || desc->werr) 565 mask |= POLLERR; 566 if (!test_bit(WDM_IN_USE, &desc->flags)) 567 mask |= POLLOUT | POLLWRNORM; 568 spin_unlock_irqrestore(&desc->iuspin, flags); 569 570 poll_wait(file, &desc->wait, wait); 571 572 desc_out: 573 return mask; 574 } 575 576 static int wdm_open(struct inode *inode, struct file *file) 577 { 578 int minor = iminor(inode); 579 int rv = -ENODEV; 580 struct usb_interface *intf; 581 struct wdm_device *desc; 582 583 mutex_lock(&wdm_mutex); 584 desc = wdm_find_device_by_minor(minor); 585 if (!desc) 586 goto out; 587 588 intf = desc->intf; 589 if (test_bit(WDM_DISCONNECTING, &desc->flags)) 590 goto out; 591 file->private_data = desc; 592 593 rv = usb_autopm_get_interface(desc->intf); 594 if (rv < 0) { 595 dev_err(&desc->intf->dev, "Error autopm - %d\n", rv); 596 goto out; 597 } 598 599 /* using write lock to protect desc->count */ 600 mutex_lock(&desc->wlock); 601 if (!desc->count++) { 602 desc->werr = 0; 603 desc->rerr = 0; 604 rv = usb_submit_urb(desc->validity, GFP_KERNEL); 605 if (rv < 0) { 606 desc->count--; 607 dev_err(&desc->intf->dev, 608 "Error submitting int urb - %d\n", rv); 609 rv = usb_translate_errors(rv); 610 } 611 } else { 612 rv = 0; 613 } 614 mutex_unlock(&desc->wlock); 615 if (desc->count == 1) 616 desc->manage_power(intf, 1); 617 usb_autopm_put_interface(desc->intf); 618 out: 619 mutex_unlock(&wdm_mutex); 620 return rv; 621 } 622 623 static int wdm_release(struct inode *inode, struct file *file) 624 { 625 struct wdm_device *desc = file->private_data; 626 627 mutex_lock(&wdm_mutex); 628 629 /* using write lock to protect desc->count */ 630 mutex_lock(&desc->wlock); 631 desc->count--; 632 mutex_unlock(&desc->wlock); 633 634 if (!desc->count) { 635 if (!test_bit(WDM_DISCONNECTING, &desc->flags)) { 636 dev_dbg(&desc->intf->dev, "wdm_release: cleanup"); 637 kill_urbs(desc); 638 desc->manage_power(desc->intf, 0); 639 } else { 640 /* must avoid dev_printk here as desc->intf is invalid */ 641 pr_debug(KBUILD_MODNAME " %s: device gone - cleaning up\n", __func__); 642 cleanup(desc); 643 } 644 } 645 mutex_unlock(&wdm_mutex); 646 return 0; 647 } 648 649 static long wdm_ioctl(struct file *file, unsigned int cmd, unsigned long arg) 650 { 651 struct wdm_device *desc = file->private_data; 652 int rv = 0; 653 654 switch (cmd) { 655 case IOCTL_WDM_MAX_COMMAND: 656 if (copy_to_user((void __user *)arg, &desc->wMaxCommand, sizeof(desc->wMaxCommand))) 657 rv = -EFAULT; 658 break; 659 default: 660 rv = -ENOTTY; 661 } 662 return rv; 663 } 664 665 static const struct file_operations wdm_fops = { 666 .owner = THIS_MODULE, 667 .read = wdm_read, 668 .write = wdm_write, 669 .open = wdm_open, 670 .flush = wdm_flush, 671 .release = wdm_release, 672 .poll = wdm_poll, 673 .unlocked_ioctl = wdm_ioctl, 674 .compat_ioctl = wdm_ioctl, 675 .llseek = noop_llseek, 676 }; 677 678 static struct usb_class_driver wdm_class = { 679 .name = "cdc-wdm%d", 680 .fops = &wdm_fops, 681 .minor_base = WDM_MINOR_BASE, 682 }; 683 684 /* --- error handling --- */ 685 static void wdm_rxwork(struct work_struct *work) 686 { 687 struct wdm_device *desc = container_of(work, struct wdm_device, rxwork); 688 unsigned long flags; 689 int rv = 0; 690 int responding; 691 692 spin_lock_irqsave(&desc->iuspin, flags); 693 if (test_bit(WDM_DISCONNECTING, &desc->flags)) { 694 spin_unlock_irqrestore(&desc->iuspin, flags); 695 } else { 696 responding = test_and_set_bit(WDM_RESPONDING, &desc->flags); 697 spin_unlock_irqrestore(&desc->iuspin, flags); 698 if (!responding) 699 rv = usb_submit_urb(desc->response, GFP_KERNEL); 700 if (rv < 0 && rv != -EPERM) { 701 spin_lock_irqsave(&desc->iuspin, flags); 702 clear_bit(WDM_RESPONDING, &desc->flags); 703 if (!test_bit(WDM_DISCONNECTING, &desc->flags)) 704 schedule_work(&desc->rxwork); 705 spin_unlock_irqrestore(&desc->iuspin, flags); 706 } 707 } 708 } 709 710 /* --- hotplug --- */ 711 712 static int wdm_create(struct usb_interface *intf, struct usb_endpoint_descriptor *ep, 713 u16 bufsize, int (*manage_power)(struct usb_interface *, int)) 714 { 715 int rv = -ENOMEM; 716 struct wdm_device *desc; 717 718 desc = kzalloc(sizeof(struct wdm_device), GFP_KERNEL); 719 if (!desc) 720 goto out; 721 INIT_LIST_HEAD(&desc->device_list); 722 mutex_init(&desc->rlock); 723 mutex_init(&desc->wlock); 724 spin_lock_init(&desc->iuspin); 725 init_waitqueue_head(&desc->wait); 726 desc->wMaxCommand = bufsize; 727 /* this will be expanded and needed in hardware endianness */ 728 desc->inum = cpu_to_le16((u16)intf->cur_altsetting->desc.bInterfaceNumber); 729 desc->intf = intf; 730 INIT_WORK(&desc->rxwork, wdm_rxwork); 731 732 rv = -EINVAL; 733 if (!usb_endpoint_is_int_in(ep)) 734 goto err; 735 736 desc->wMaxPacketSize = usb_endpoint_maxp(ep); 737 738 desc->orq = kmalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL); 739 if (!desc->orq) 740 goto err; 741 desc->irq = kmalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL); 742 if (!desc->irq) 743 goto err; 744 745 desc->validity = usb_alloc_urb(0, GFP_KERNEL); 746 if (!desc->validity) 747 goto err; 748 749 desc->response = usb_alloc_urb(0, GFP_KERNEL); 750 if (!desc->response) 751 goto err; 752 753 desc->command = usb_alloc_urb(0, GFP_KERNEL); 754 if (!desc->command) 755 goto err; 756 757 desc->ubuf = kmalloc(desc->wMaxCommand, GFP_KERNEL); 758 if (!desc->ubuf) 759 goto err; 760 761 desc->sbuf = kmalloc(desc->wMaxPacketSize, GFP_KERNEL); 762 if (!desc->sbuf) 763 goto err; 764 765 desc->inbuf = kmalloc(desc->wMaxCommand, GFP_KERNEL); 766 if (!desc->inbuf) 767 goto err; 768 769 usb_fill_int_urb( 770 desc->validity, 771 interface_to_usbdev(intf), 772 usb_rcvintpipe(interface_to_usbdev(intf), ep->bEndpointAddress), 773 desc->sbuf, 774 desc->wMaxPacketSize, 775 wdm_int_callback, 776 desc, 777 ep->bInterval 778 ); 779 780 desc->irq->bRequestType = (USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE); 781 desc->irq->bRequest = USB_CDC_GET_ENCAPSULATED_RESPONSE; 782 desc->irq->wValue = 0; 783 desc->irq->wIndex = desc->inum; 784 desc->irq->wLength = cpu_to_le16(desc->wMaxCommand); 785 786 usb_fill_control_urb( 787 desc->response, 788 interface_to_usbdev(intf), 789 /* using common endpoint 0 */ 790 usb_rcvctrlpipe(interface_to_usbdev(desc->intf), 0), 791 (unsigned char *)desc->irq, 792 desc->inbuf, 793 desc->wMaxCommand, 794 wdm_in_callback, 795 desc 796 ); 797 798 desc->manage_power = manage_power; 799 800 spin_lock(&wdm_device_list_lock); 801 list_add(&desc->device_list, &wdm_device_list); 802 spin_unlock(&wdm_device_list_lock); 803 804 rv = usb_register_dev(intf, &wdm_class); 805 if (rv < 0) 806 goto err; 807 else 808 dev_info(&intf->dev, "%s: USB WDM device\n", dev_name(intf->usb_dev)); 809 out: 810 return rv; 811 err: 812 spin_lock(&wdm_device_list_lock); 813 list_del(&desc->device_list); 814 spin_unlock(&wdm_device_list_lock); 815 cleanup(desc); 816 return rv; 817 } 818 819 static int wdm_manage_power(struct usb_interface *intf, int on) 820 { 821 /* need autopm_get/put here to ensure the usbcore sees the new value */ 822 int rv = usb_autopm_get_interface(intf); 823 if (rv < 0) 824 goto err; 825 826 intf->needs_remote_wakeup = on; 827 usb_autopm_put_interface(intf); 828 err: 829 return rv; 830 } 831 832 static int wdm_probe(struct usb_interface *intf, const struct usb_device_id *id) 833 { 834 int rv = -EINVAL; 835 struct usb_host_interface *iface; 836 struct usb_endpoint_descriptor *ep; 837 struct usb_cdc_dmm_desc *dmhd; 838 u8 *buffer = intf->altsetting->extra; 839 int buflen = intf->altsetting->extralen; 840 u16 maxcom = WDM_DEFAULT_BUFSIZE; 841 842 if (!buffer) 843 goto err; 844 while (buflen > 2) { 845 if (buffer[1] != USB_DT_CS_INTERFACE) { 846 dev_err(&intf->dev, "skipping garbage\n"); 847 goto next_desc; 848 } 849 850 switch (buffer[2]) { 851 case USB_CDC_HEADER_TYPE: 852 break; 853 case USB_CDC_DMM_TYPE: 854 dmhd = (struct usb_cdc_dmm_desc *)buffer; 855 maxcom = le16_to_cpu(dmhd->wMaxCommand); 856 dev_dbg(&intf->dev, 857 "Finding maximum buffer length: %d", maxcom); 858 break; 859 default: 860 dev_err(&intf->dev, 861 "Ignoring extra header, type %d, length %d\n", 862 buffer[2], buffer[0]); 863 break; 864 } 865 next_desc: 866 buflen -= buffer[0]; 867 buffer += buffer[0]; 868 } 869 870 iface = intf->cur_altsetting; 871 if (iface->desc.bNumEndpoints != 1) 872 goto err; 873 ep = &iface->endpoint[0].desc; 874 875 rv = wdm_create(intf, ep, maxcom, &wdm_manage_power); 876 877 err: 878 return rv; 879 } 880 881 /** 882 * usb_cdc_wdm_register - register a WDM subdriver 883 * @intf: usb interface the subdriver will associate with 884 * @ep: interrupt endpoint to monitor for notifications 885 * @bufsize: maximum message size to support for read/write 886 * 887 * Create WDM usb class character device and associate it with intf 888 * without binding, allowing another driver to manage the interface. 889 * 890 * The subdriver will manage the given interrupt endpoint exclusively 891 * and will issue control requests referring to the given intf. It 892 * will otherwise avoid interferring, and in particular not do 893 * usb_set_intfdata/usb_get_intfdata on intf. 894 * 895 * The return value is a pointer to the subdriver's struct usb_driver. 896 * The registering driver is responsible for calling this subdriver's 897 * disconnect, suspend, resume, pre_reset and post_reset methods from 898 * its own. 899 */ 900 struct usb_driver *usb_cdc_wdm_register(struct usb_interface *intf, 901 struct usb_endpoint_descriptor *ep, 902 int bufsize, 903 int (*manage_power)(struct usb_interface *, int)) 904 { 905 int rv = -EINVAL; 906 907 rv = wdm_create(intf, ep, bufsize, manage_power); 908 if (rv < 0) 909 goto err; 910 911 return &wdm_driver; 912 err: 913 return ERR_PTR(rv); 914 } 915 EXPORT_SYMBOL(usb_cdc_wdm_register); 916 917 static void wdm_disconnect(struct usb_interface *intf) 918 { 919 struct wdm_device *desc; 920 unsigned long flags; 921 922 usb_deregister_dev(intf, &wdm_class); 923 desc = wdm_find_device(intf); 924 mutex_lock(&wdm_mutex); 925 926 /* the spinlock makes sure no new urbs are generated in the callbacks */ 927 spin_lock_irqsave(&desc->iuspin, flags); 928 set_bit(WDM_DISCONNECTING, &desc->flags); 929 set_bit(WDM_READ, &desc->flags); 930 /* to terminate pending flushes */ 931 clear_bit(WDM_IN_USE, &desc->flags); 932 spin_unlock_irqrestore(&desc->iuspin, flags); 933 wake_up_all(&desc->wait); 934 mutex_lock(&desc->rlock); 935 mutex_lock(&desc->wlock); 936 kill_urbs(desc); 937 cancel_work_sync(&desc->rxwork); 938 mutex_unlock(&desc->wlock); 939 mutex_unlock(&desc->rlock); 940 941 /* the desc->intf pointer used as list key is now invalid */ 942 spin_lock(&wdm_device_list_lock); 943 list_del(&desc->device_list); 944 spin_unlock(&wdm_device_list_lock); 945 946 if (!desc->count) 947 cleanup(desc); 948 else 949 dev_dbg(&intf->dev, "%s: %d open files - postponing cleanup\n", __func__, desc->count); 950 mutex_unlock(&wdm_mutex); 951 } 952 953 #ifdef CONFIG_PM 954 static int wdm_suspend(struct usb_interface *intf, pm_message_t message) 955 { 956 struct wdm_device *desc = wdm_find_device(intf); 957 int rv = 0; 958 959 dev_dbg(&desc->intf->dev, "wdm%d_suspend\n", intf->minor); 960 961 /* if this is an autosuspend the caller does the locking */ 962 if (!PMSG_IS_AUTO(message)) { 963 mutex_lock(&desc->rlock); 964 mutex_lock(&desc->wlock); 965 } 966 spin_lock_irq(&desc->iuspin); 967 968 if (PMSG_IS_AUTO(message) && 969 (test_bit(WDM_IN_USE, &desc->flags) 970 || test_bit(WDM_RESPONDING, &desc->flags))) { 971 spin_unlock_irq(&desc->iuspin); 972 rv = -EBUSY; 973 } else { 974 975 set_bit(WDM_SUSPENDING, &desc->flags); 976 spin_unlock_irq(&desc->iuspin); 977 /* callback submits work - order is essential */ 978 kill_urbs(desc); 979 cancel_work_sync(&desc->rxwork); 980 } 981 if (!PMSG_IS_AUTO(message)) { 982 mutex_unlock(&desc->wlock); 983 mutex_unlock(&desc->rlock); 984 } 985 986 return rv; 987 } 988 #endif 989 990 static int recover_from_urb_loss(struct wdm_device *desc) 991 { 992 int rv = 0; 993 994 if (desc->count) { 995 rv = usb_submit_urb(desc->validity, GFP_NOIO); 996 if (rv < 0) 997 dev_err(&desc->intf->dev, 998 "Error resume submitting int urb - %d\n", rv); 999 } 1000 return rv; 1001 } 1002 1003 #ifdef CONFIG_PM 1004 static int wdm_resume(struct usb_interface *intf) 1005 { 1006 struct wdm_device *desc = wdm_find_device(intf); 1007 int rv; 1008 1009 dev_dbg(&desc->intf->dev, "wdm%d_resume\n", intf->minor); 1010 1011 clear_bit(WDM_SUSPENDING, &desc->flags); 1012 rv = recover_from_urb_loss(desc); 1013 1014 return rv; 1015 } 1016 #endif 1017 1018 static int wdm_pre_reset(struct usb_interface *intf) 1019 { 1020 struct wdm_device *desc = wdm_find_device(intf); 1021 1022 /* 1023 * we notify everybody using poll of 1024 * an exceptional situation 1025 * must be done before recovery lest a spontaneous 1026 * message from the device is lost 1027 */ 1028 spin_lock_irq(&desc->iuspin); 1029 set_bit(WDM_RESETTING, &desc->flags); /* inform read/write */ 1030 set_bit(WDM_READ, &desc->flags); /* unblock read */ 1031 clear_bit(WDM_IN_USE, &desc->flags); /* unblock write */ 1032 desc->rerr = -EINTR; 1033 spin_unlock_irq(&desc->iuspin); 1034 wake_up_all(&desc->wait); 1035 mutex_lock(&desc->rlock); 1036 mutex_lock(&desc->wlock); 1037 kill_urbs(desc); 1038 cancel_work_sync(&desc->rxwork); 1039 return 0; 1040 } 1041 1042 static int wdm_post_reset(struct usb_interface *intf) 1043 { 1044 struct wdm_device *desc = wdm_find_device(intf); 1045 int rv; 1046 1047 clear_bit(WDM_OVERFLOW, &desc->flags); 1048 clear_bit(WDM_RESETTING, &desc->flags); 1049 rv = recover_from_urb_loss(desc); 1050 mutex_unlock(&desc->wlock); 1051 mutex_unlock(&desc->rlock); 1052 return 0; 1053 } 1054 1055 static struct usb_driver wdm_driver = { 1056 .name = "cdc_wdm", 1057 .probe = wdm_probe, 1058 .disconnect = wdm_disconnect, 1059 #ifdef CONFIG_PM 1060 .suspend = wdm_suspend, 1061 .resume = wdm_resume, 1062 .reset_resume = wdm_resume, 1063 #endif 1064 .pre_reset = wdm_pre_reset, 1065 .post_reset = wdm_post_reset, 1066 .id_table = wdm_ids, 1067 .supports_autosuspend = 1, 1068 .disable_hub_initiated_lpm = 1, 1069 }; 1070 1071 module_usb_driver(wdm_driver); 1072 1073 MODULE_AUTHOR(DRIVER_AUTHOR); 1074 MODULE_DESCRIPTION(DRIVER_DESC); 1075 MODULE_LICENSE("GPL"); 1076