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/slab.h> 17 #include <linux/module.h> 18 #include <linux/mutex.h> 19 #include <linux/uaccess.h> 20 #include <linux/bitops.h> 21 #include <linux/poll.h> 22 #include <linux/usb.h> 23 #include <linux/usb/cdc.h> 24 #include <asm/byteorder.h> 25 #include <asm/unaligned.h> 26 27 /* 28 * Version Information 29 */ 30 #define DRIVER_VERSION "v0.03" 31 #define DRIVER_AUTHOR "Oliver Neukum" 32 #define DRIVER_DESC "USB Abstract Control Model driver for USB WCM Device Management" 33 34 static const struct usb_device_id wdm_ids[] = { 35 { 36 .match_flags = USB_DEVICE_ID_MATCH_INT_CLASS | 37 USB_DEVICE_ID_MATCH_INT_SUBCLASS, 38 .bInterfaceClass = USB_CLASS_COMM, 39 .bInterfaceSubClass = USB_CDC_SUBCLASS_DMM 40 }, 41 { } 42 }; 43 44 MODULE_DEVICE_TABLE (usb, wdm_ids); 45 46 #define WDM_MINOR_BASE 176 47 48 49 #define WDM_IN_USE 1 50 #define WDM_DISCONNECTING 2 51 #define WDM_RESULT 3 52 #define WDM_READ 4 53 #define WDM_INT_STALL 5 54 #define WDM_POLL_RUNNING 6 55 #define WDM_RESPONDING 7 56 #define WDM_SUSPENDING 8 57 58 #define WDM_MAX 16 59 60 /* CDC-WMC r1.1 requires wMaxCommand to be "at least 256 decimal (0x100)" */ 61 #define WDM_DEFAULT_BUFSIZE 256 62 63 static DEFINE_MUTEX(wdm_mutex); 64 65 /* --- method tables --- */ 66 67 struct wdm_device { 68 u8 *inbuf; /* buffer for response */ 69 u8 *outbuf; /* buffer for command */ 70 u8 *sbuf; /* buffer for status */ 71 u8 *ubuf; /* buffer for copy to user space */ 72 73 struct urb *command; 74 struct urb *response; 75 struct urb *validity; 76 struct usb_interface *intf; 77 struct usb_ctrlrequest *orq; 78 struct usb_ctrlrequest *irq; 79 spinlock_t iuspin; 80 81 unsigned long flags; 82 u16 bufsize; 83 u16 wMaxCommand; 84 u16 wMaxPacketSize; 85 u16 bMaxPacketSize0; 86 __le16 inum; 87 int reslength; 88 int length; 89 int read; 90 int count; 91 dma_addr_t shandle; 92 dma_addr_t ihandle; 93 struct mutex wlock; 94 struct mutex rlock; 95 wait_queue_head_t wait; 96 struct work_struct rxwork; 97 int werr; 98 int rerr; 99 }; 100 101 static struct usb_driver wdm_driver; 102 103 /* --- callbacks --- */ 104 static void wdm_out_callback(struct urb *urb) 105 { 106 struct wdm_device *desc; 107 desc = urb->context; 108 spin_lock(&desc->iuspin); 109 desc->werr = urb->status; 110 spin_unlock(&desc->iuspin); 111 clear_bit(WDM_IN_USE, &desc->flags); 112 kfree(desc->outbuf); 113 wake_up(&desc->wait); 114 } 115 116 static void wdm_in_callback(struct urb *urb) 117 { 118 struct wdm_device *desc = urb->context; 119 int status = urb->status; 120 121 spin_lock(&desc->iuspin); 122 clear_bit(WDM_RESPONDING, &desc->flags); 123 124 if (status) { 125 switch (status) { 126 case -ENOENT: 127 dev_dbg(&desc->intf->dev, 128 "nonzero urb status received: -ENOENT"); 129 goto skip_error; 130 case -ECONNRESET: 131 dev_dbg(&desc->intf->dev, 132 "nonzero urb status received: -ECONNRESET"); 133 goto skip_error; 134 case -ESHUTDOWN: 135 dev_dbg(&desc->intf->dev, 136 "nonzero urb status received: -ESHUTDOWN"); 137 goto skip_error; 138 case -EPIPE: 139 dev_err(&desc->intf->dev, 140 "nonzero urb status received: -EPIPE\n"); 141 break; 142 default: 143 dev_err(&desc->intf->dev, 144 "Unexpected error %d\n", status); 145 break; 146 } 147 } 148 149 desc->rerr = status; 150 desc->reslength = urb->actual_length; 151 memmove(desc->ubuf + desc->length, desc->inbuf, desc->reslength); 152 desc->length += desc->reslength; 153 skip_error: 154 wake_up(&desc->wait); 155 156 set_bit(WDM_READ, &desc->flags); 157 spin_unlock(&desc->iuspin); 158 } 159 160 static void wdm_int_callback(struct urb *urb) 161 { 162 int rv = 0; 163 int status = urb->status; 164 struct wdm_device *desc; 165 struct usb_ctrlrequest *req; 166 struct usb_cdc_notification *dr; 167 168 desc = urb->context; 169 req = desc->irq; 170 dr = (struct usb_cdc_notification *)desc->sbuf; 171 172 if (status) { 173 switch (status) { 174 case -ESHUTDOWN: 175 case -ENOENT: 176 case -ECONNRESET: 177 return; /* unplug */ 178 case -EPIPE: 179 set_bit(WDM_INT_STALL, &desc->flags); 180 dev_err(&desc->intf->dev, "Stall on int endpoint\n"); 181 goto sw; /* halt is cleared in work */ 182 default: 183 dev_err(&desc->intf->dev, 184 "nonzero urb status received: %d\n", status); 185 break; 186 } 187 } 188 189 if (urb->actual_length < sizeof(struct usb_cdc_notification)) { 190 dev_err(&desc->intf->dev, "wdm_int_callback - %d bytes\n", 191 urb->actual_length); 192 goto exit; 193 } 194 195 switch (dr->bNotificationType) { 196 case USB_CDC_NOTIFY_RESPONSE_AVAILABLE: 197 dev_dbg(&desc->intf->dev, 198 "NOTIFY_RESPONSE_AVAILABLE received: index %d len %d", 199 dr->wIndex, dr->wLength); 200 break; 201 202 case USB_CDC_NOTIFY_NETWORK_CONNECTION: 203 204 dev_dbg(&desc->intf->dev, 205 "NOTIFY_NETWORK_CONNECTION %s network", 206 dr->wValue ? "connected to" : "disconnected from"); 207 goto exit; 208 default: 209 clear_bit(WDM_POLL_RUNNING, &desc->flags); 210 dev_err(&desc->intf->dev, 211 "unknown notification %d received: index %d len %d\n", 212 dr->bNotificationType, dr->wIndex, dr->wLength); 213 goto exit; 214 } 215 216 req->bRequestType = (USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE); 217 req->bRequest = USB_CDC_GET_ENCAPSULATED_RESPONSE; 218 req->wValue = 0; 219 req->wIndex = desc->inum; 220 req->wLength = cpu_to_le16(desc->wMaxCommand); 221 222 usb_fill_control_urb( 223 desc->response, 224 interface_to_usbdev(desc->intf), 225 /* using common endpoint 0 */ 226 usb_rcvctrlpipe(interface_to_usbdev(desc->intf), 0), 227 (unsigned char *)req, 228 desc->inbuf, 229 desc->wMaxCommand, 230 wdm_in_callback, 231 desc 232 ); 233 desc->response->transfer_flags |= URB_NO_TRANSFER_DMA_MAP; 234 spin_lock(&desc->iuspin); 235 clear_bit(WDM_READ, &desc->flags); 236 set_bit(WDM_RESPONDING, &desc->flags); 237 if (!test_bit(WDM_DISCONNECTING, &desc->flags) 238 && !test_bit(WDM_SUSPENDING, &desc->flags)) { 239 rv = usb_submit_urb(desc->response, GFP_ATOMIC); 240 dev_dbg(&desc->intf->dev, "%s: usb_submit_urb %d", 241 __func__, rv); 242 } 243 spin_unlock(&desc->iuspin); 244 if (rv < 0) { 245 clear_bit(WDM_RESPONDING, &desc->flags); 246 if (rv == -EPERM) 247 return; 248 if (rv == -ENOMEM) { 249 sw: 250 rv = schedule_work(&desc->rxwork); 251 if (rv) 252 dev_err(&desc->intf->dev, 253 "Cannot schedule work\n"); 254 } 255 } 256 exit: 257 rv = usb_submit_urb(urb, GFP_ATOMIC); 258 if (rv) 259 dev_err(&desc->intf->dev, 260 "%s - usb_submit_urb failed with result %d\n", 261 __func__, rv); 262 263 } 264 265 static void kill_urbs(struct wdm_device *desc) 266 { 267 /* the order here is essential */ 268 usb_kill_urb(desc->command); 269 usb_kill_urb(desc->validity); 270 usb_kill_urb(desc->response); 271 } 272 273 static void free_urbs(struct wdm_device *desc) 274 { 275 usb_free_urb(desc->validity); 276 usb_free_urb(desc->response); 277 usb_free_urb(desc->command); 278 } 279 280 static void cleanup(struct wdm_device *desc) 281 { 282 usb_free_coherent(interface_to_usbdev(desc->intf), 283 desc->wMaxPacketSize, 284 desc->sbuf, 285 desc->validity->transfer_dma); 286 usb_free_coherent(interface_to_usbdev(desc->intf), 287 desc->bMaxPacketSize0, 288 desc->inbuf, 289 desc->response->transfer_dma); 290 kfree(desc->orq); 291 kfree(desc->irq); 292 kfree(desc->ubuf); 293 free_urbs(desc); 294 kfree(desc); 295 } 296 297 static ssize_t wdm_write 298 (struct file *file, const char __user *buffer, size_t count, loff_t *ppos) 299 { 300 u8 *buf; 301 int rv = -EMSGSIZE, r, we; 302 struct wdm_device *desc = file->private_data; 303 struct usb_ctrlrequest *req; 304 305 if (count > desc->wMaxCommand) 306 count = desc->wMaxCommand; 307 308 spin_lock_irq(&desc->iuspin); 309 we = desc->werr; 310 desc->werr = 0; 311 spin_unlock_irq(&desc->iuspin); 312 if (we < 0) 313 return -EIO; 314 315 desc->outbuf = buf = kmalloc(count, GFP_KERNEL); 316 if (!buf) { 317 rv = -ENOMEM; 318 goto outnl; 319 } 320 321 r = copy_from_user(buf, buffer, count); 322 if (r > 0) { 323 kfree(buf); 324 rv = -EFAULT; 325 goto outnl; 326 } 327 328 /* concurrent writes and disconnect */ 329 r = mutex_lock_interruptible(&desc->wlock); 330 rv = -ERESTARTSYS; 331 if (r) { 332 kfree(buf); 333 goto outnl; 334 } 335 336 if (test_bit(WDM_DISCONNECTING, &desc->flags)) { 337 kfree(buf); 338 rv = -ENODEV; 339 goto outnp; 340 } 341 342 r = usb_autopm_get_interface(desc->intf); 343 if (r < 0) { 344 kfree(buf); 345 goto outnp; 346 } 347 348 if (!(file->f_flags & O_NONBLOCK)) 349 r = wait_event_interruptible(desc->wait, !test_bit(WDM_IN_USE, 350 &desc->flags)); 351 else 352 if (test_bit(WDM_IN_USE, &desc->flags)) 353 r = -EAGAIN; 354 if (r < 0) { 355 kfree(buf); 356 goto out; 357 } 358 359 req = desc->orq; 360 usb_fill_control_urb( 361 desc->command, 362 interface_to_usbdev(desc->intf), 363 /* using common endpoint 0 */ 364 usb_sndctrlpipe(interface_to_usbdev(desc->intf), 0), 365 (unsigned char *)req, 366 buf, 367 count, 368 wdm_out_callback, 369 desc 370 ); 371 372 req->bRequestType = (USB_DIR_OUT | USB_TYPE_CLASS | 373 USB_RECIP_INTERFACE); 374 req->bRequest = USB_CDC_SEND_ENCAPSULATED_COMMAND; 375 req->wValue = 0; 376 req->wIndex = desc->inum; 377 req->wLength = cpu_to_le16(count); 378 set_bit(WDM_IN_USE, &desc->flags); 379 380 rv = usb_submit_urb(desc->command, GFP_KERNEL); 381 if (rv < 0) { 382 kfree(buf); 383 clear_bit(WDM_IN_USE, &desc->flags); 384 dev_err(&desc->intf->dev, "Tx URB error: %d\n", rv); 385 } else { 386 dev_dbg(&desc->intf->dev, "Tx URB has been submitted index=%d", 387 req->wIndex); 388 } 389 out: 390 usb_autopm_put_interface(desc->intf); 391 outnp: 392 mutex_unlock(&desc->wlock); 393 outnl: 394 return rv < 0 ? rv : count; 395 } 396 397 static ssize_t wdm_read 398 (struct file *file, char __user *buffer, size_t count, loff_t *ppos) 399 { 400 int rv, cntr = 0; 401 int i = 0; 402 struct wdm_device *desc = file->private_data; 403 404 405 rv = mutex_lock_interruptible(&desc->rlock); /*concurrent reads */ 406 if (rv < 0) 407 return -ERESTARTSYS; 408 409 if (desc->length == 0) { 410 desc->read = 0; 411 retry: 412 if (test_bit(WDM_DISCONNECTING, &desc->flags)) { 413 rv = -ENODEV; 414 goto err; 415 } 416 i++; 417 if (file->f_flags & O_NONBLOCK) { 418 if (!test_bit(WDM_READ, &desc->flags)) { 419 rv = cntr ? cntr : -EAGAIN; 420 goto err; 421 } 422 rv = 0; 423 } else { 424 rv = wait_event_interruptible(desc->wait, 425 test_bit(WDM_READ, &desc->flags)); 426 } 427 428 /* may have happened while we slept */ 429 if (test_bit(WDM_DISCONNECTING, &desc->flags)) { 430 rv = -ENODEV; 431 goto err; 432 } 433 usb_mark_last_busy(interface_to_usbdev(desc->intf)); 434 if (rv < 0) { 435 rv = -ERESTARTSYS; 436 goto err; 437 } 438 439 spin_lock_irq(&desc->iuspin); 440 441 if (desc->rerr) { /* read completed, error happened */ 442 desc->rerr = 0; 443 spin_unlock_irq(&desc->iuspin); 444 rv = -EIO; 445 goto err; 446 } 447 /* 448 * recheck whether we've lost the race 449 * against the completion handler 450 */ 451 if (!test_bit(WDM_READ, &desc->flags)) { /* lost race */ 452 spin_unlock_irq(&desc->iuspin); 453 goto retry; 454 } 455 if (!desc->reslength) { /* zero length read */ 456 spin_unlock_irq(&desc->iuspin); 457 goto retry; 458 } 459 clear_bit(WDM_READ, &desc->flags); 460 spin_unlock_irq(&desc->iuspin); 461 } 462 463 cntr = count > desc->length ? desc->length : count; 464 rv = copy_to_user(buffer, desc->ubuf, cntr); 465 if (rv > 0) { 466 rv = -EFAULT; 467 goto err; 468 } 469 470 for (i = 0; i < desc->length - cntr; i++) 471 desc->ubuf[i] = desc->ubuf[i + cntr]; 472 473 spin_lock_irq(&desc->iuspin); 474 desc->length -= cntr; 475 spin_unlock_irq(&desc->iuspin); 476 /* in case we had outstanding data */ 477 if (!desc->length) 478 clear_bit(WDM_READ, &desc->flags); 479 rv = cntr; 480 481 err: 482 mutex_unlock(&desc->rlock); 483 return rv; 484 } 485 486 static int wdm_flush(struct file *file, fl_owner_t id) 487 { 488 struct wdm_device *desc = file->private_data; 489 490 wait_event(desc->wait, !test_bit(WDM_IN_USE, &desc->flags)); 491 if (desc->werr < 0) 492 dev_err(&desc->intf->dev, "Error in flush path: %d\n", 493 desc->werr); 494 495 return desc->werr; 496 } 497 498 static unsigned int wdm_poll(struct file *file, struct poll_table_struct *wait) 499 { 500 struct wdm_device *desc = file->private_data; 501 unsigned long flags; 502 unsigned int mask = 0; 503 504 spin_lock_irqsave(&desc->iuspin, flags); 505 if (test_bit(WDM_DISCONNECTING, &desc->flags)) { 506 mask = POLLERR; 507 spin_unlock_irqrestore(&desc->iuspin, flags); 508 goto desc_out; 509 } 510 if (test_bit(WDM_READ, &desc->flags)) 511 mask = POLLIN | POLLRDNORM; 512 if (desc->rerr || desc->werr) 513 mask |= POLLERR; 514 if (!test_bit(WDM_IN_USE, &desc->flags)) 515 mask |= POLLOUT | POLLWRNORM; 516 spin_unlock_irqrestore(&desc->iuspin, flags); 517 518 poll_wait(file, &desc->wait, wait); 519 520 desc_out: 521 return mask; 522 } 523 524 static int wdm_open(struct inode *inode, struct file *file) 525 { 526 int minor = iminor(inode); 527 int rv = -ENODEV; 528 struct usb_interface *intf; 529 struct wdm_device *desc; 530 531 mutex_lock(&wdm_mutex); 532 intf = usb_find_interface(&wdm_driver, minor); 533 if (!intf) 534 goto out; 535 536 desc = usb_get_intfdata(intf); 537 if (test_bit(WDM_DISCONNECTING, &desc->flags)) 538 goto out; 539 file->private_data = desc; 540 541 rv = usb_autopm_get_interface(desc->intf); 542 if (rv < 0) { 543 dev_err(&desc->intf->dev, "Error autopm - %d\n", rv); 544 goto out; 545 } 546 intf->needs_remote_wakeup = 1; 547 548 /* using write lock to protect desc->count */ 549 mutex_lock(&desc->wlock); 550 if (!desc->count++) { 551 desc->werr = 0; 552 desc->rerr = 0; 553 rv = usb_submit_urb(desc->validity, GFP_KERNEL); 554 if (rv < 0) { 555 desc->count--; 556 dev_err(&desc->intf->dev, 557 "Error submitting int urb - %d\n", rv); 558 } 559 } else { 560 rv = 0; 561 } 562 mutex_unlock(&desc->wlock); 563 usb_autopm_put_interface(desc->intf); 564 out: 565 mutex_unlock(&wdm_mutex); 566 return rv; 567 } 568 569 static int wdm_release(struct inode *inode, struct file *file) 570 { 571 struct wdm_device *desc = file->private_data; 572 573 mutex_lock(&wdm_mutex); 574 575 /* using write lock to protect desc->count */ 576 mutex_lock(&desc->wlock); 577 desc->count--; 578 mutex_unlock(&desc->wlock); 579 580 if (!desc->count) { 581 dev_dbg(&desc->intf->dev, "wdm_release: cleanup"); 582 kill_urbs(desc); 583 if (!test_bit(WDM_DISCONNECTING, &desc->flags)) 584 desc->intf->needs_remote_wakeup = 0; 585 } 586 mutex_unlock(&wdm_mutex); 587 return 0; 588 } 589 590 static const struct file_operations wdm_fops = { 591 .owner = THIS_MODULE, 592 .read = wdm_read, 593 .write = wdm_write, 594 .open = wdm_open, 595 .flush = wdm_flush, 596 .release = wdm_release, 597 .poll = wdm_poll, 598 .llseek = noop_llseek, 599 }; 600 601 static struct usb_class_driver wdm_class = { 602 .name = "cdc-wdm%d", 603 .fops = &wdm_fops, 604 .minor_base = WDM_MINOR_BASE, 605 }; 606 607 /* --- error handling --- */ 608 static void wdm_rxwork(struct work_struct *work) 609 { 610 struct wdm_device *desc = container_of(work, struct wdm_device, rxwork); 611 unsigned long flags; 612 int rv; 613 614 spin_lock_irqsave(&desc->iuspin, flags); 615 if (test_bit(WDM_DISCONNECTING, &desc->flags)) { 616 spin_unlock_irqrestore(&desc->iuspin, flags); 617 } else { 618 spin_unlock_irqrestore(&desc->iuspin, flags); 619 rv = usb_submit_urb(desc->response, GFP_KERNEL); 620 if (rv < 0 && rv != -EPERM) { 621 spin_lock_irqsave(&desc->iuspin, flags); 622 if (!test_bit(WDM_DISCONNECTING, &desc->flags)) 623 schedule_work(&desc->rxwork); 624 spin_unlock_irqrestore(&desc->iuspin, flags); 625 } 626 } 627 } 628 629 /* --- hotplug --- */ 630 631 static int wdm_probe(struct usb_interface *intf, const struct usb_device_id *id) 632 { 633 int rv = -EINVAL; 634 struct usb_device *udev = interface_to_usbdev(intf); 635 struct wdm_device *desc; 636 struct usb_host_interface *iface; 637 struct usb_endpoint_descriptor *ep; 638 struct usb_cdc_dmm_desc *dmhd; 639 u8 *buffer = intf->altsetting->extra; 640 int buflen = intf->altsetting->extralen; 641 u16 maxcom = WDM_DEFAULT_BUFSIZE; 642 643 if (!buffer) 644 goto out; 645 646 while (buflen > 2) { 647 if (buffer [1] != USB_DT_CS_INTERFACE) { 648 dev_err(&intf->dev, "skipping garbage\n"); 649 goto next_desc; 650 } 651 652 switch (buffer [2]) { 653 case USB_CDC_HEADER_TYPE: 654 break; 655 case USB_CDC_DMM_TYPE: 656 dmhd = (struct usb_cdc_dmm_desc *)buffer; 657 maxcom = le16_to_cpu(dmhd->wMaxCommand); 658 dev_dbg(&intf->dev, 659 "Finding maximum buffer length: %d", maxcom); 660 break; 661 default: 662 dev_err(&intf->dev, 663 "Ignoring extra header, type %d, length %d\n", 664 buffer[2], buffer[0]); 665 break; 666 } 667 next_desc: 668 buflen -= buffer[0]; 669 buffer += buffer[0]; 670 } 671 672 rv = -ENOMEM; 673 desc = kzalloc(sizeof(struct wdm_device), GFP_KERNEL); 674 if (!desc) 675 goto out; 676 mutex_init(&desc->rlock); 677 mutex_init(&desc->wlock); 678 spin_lock_init(&desc->iuspin); 679 init_waitqueue_head(&desc->wait); 680 desc->wMaxCommand = maxcom; 681 /* this will be expanded and needed in hardware endianness */ 682 desc->inum = cpu_to_le16((u16)intf->cur_altsetting->desc.bInterfaceNumber); 683 desc->intf = intf; 684 INIT_WORK(&desc->rxwork, wdm_rxwork); 685 686 rv = -EINVAL; 687 iface = intf->cur_altsetting; 688 if (iface->desc.bNumEndpoints != 1) 689 goto err; 690 ep = &iface->endpoint[0].desc; 691 if (!ep || !usb_endpoint_is_int_in(ep)) 692 goto err; 693 694 desc->wMaxPacketSize = usb_endpoint_maxp(ep); 695 desc->bMaxPacketSize0 = udev->descriptor.bMaxPacketSize0; 696 697 desc->orq = kmalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL); 698 if (!desc->orq) 699 goto err; 700 desc->irq = kmalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL); 701 if (!desc->irq) 702 goto err; 703 704 desc->validity = usb_alloc_urb(0, GFP_KERNEL); 705 if (!desc->validity) 706 goto err; 707 708 desc->response = usb_alloc_urb(0, GFP_KERNEL); 709 if (!desc->response) 710 goto err; 711 712 desc->command = usb_alloc_urb(0, GFP_KERNEL); 713 if (!desc->command) 714 goto err; 715 716 desc->ubuf = kmalloc(desc->wMaxCommand, GFP_KERNEL); 717 if (!desc->ubuf) 718 goto err; 719 720 desc->sbuf = usb_alloc_coherent(interface_to_usbdev(intf), 721 desc->wMaxPacketSize, 722 GFP_KERNEL, 723 &desc->validity->transfer_dma); 724 if (!desc->sbuf) 725 goto err; 726 727 desc->inbuf = usb_alloc_coherent(interface_to_usbdev(intf), 728 desc->wMaxCommand, 729 GFP_KERNEL, 730 &desc->response->transfer_dma); 731 if (!desc->inbuf) 732 goto err2; 733 734 usb_fill_int_urb( 735 desc->validity, 736 interface_to_usbdev(intf), 737 usb_rcvintpipe(interface_to_usbdev(intf), ep->bEndpointAddress), 738 desc->sbuf, 739 desc->wMaxPacketSize, 740 wdm_int_callback, 741 desc, 742 ep->bInterval 743 ); 744 desc->validity->transfer_flags |= URB_NO_TRANSFER_DMA_MAP; 745 746 usb_set_intfdata(intf, desc); 747 rv = usb_register_dev(intf, &wdm_class); 748 if (rv < 0) 749 goto err3; 750 else 751 dev_info(&intf->dev, "cdc-wdm%d: USB WDM device\n", 752 intf->minor - WDM_MINOR_BASE); 753 out: 754 return rv; 755 err3: 756 usb_set_intfdata(intf, NULL); 757 usb_free_coherent(interface_to_usbdev(desc->intf), 758 desc->bMaxPacketSize0, 759 desc->inbuf, 760 desc->response->transfer_dma); 761 err2: 762 usb_free_coherent(interface_to_usbdev(desc->intf), 763 desc->wMaxPacketSize, 764 desc->sbuf, 765 desc->validity->transfer_dma); 766 err: 767 free_urbs(desc); 768 kfree(desc->ubuf); 769 kfree(desc->orq); 770 kfree(desc->irq); 771 kfree(desc); 772 return rv; 773 } 774 775 static void wdm_disconnect(struct usb_interface *intf) 776 { 777 struct wdm_device *desc; 778 unsigned long flags; 779 780 usb_deregister_dev(intf, &wdm_class); 781 mutex_lock(&wdm_mutex); 782 desc = usb_get_intfdata(intf); 783 784 /* the spinlock makes sure no new urbs are generated in the callbacks */ 785 spin_lock_irqsave(&desc->iuspin, flags); 786 set_bit(WDM_DISCONNECTING, &desc->flags); 787 set_bit(WDM_READ, &desc->flags); 788 /* to terminate pending flushes */ 789 clear_bit(WDM_IN_USE, &desc->flags); 790 spin_unlock_irqrestore(&desc->iuspin, flags); 791 wake_up_all(&desc->wait); 792 mutex_lock(&desc->rlock); 793 mutex_lock(&desc->wlock); 794 kill_urbs(desc); 795 cancel_work_sync(&desc->rxwork); 796 mutex_unlock(&desc->wlock); 797 mutex_unlock(&desc->rlock); 798 if (!desc->count) 799 cleanup(desc); 800 mutex_unlock(&wdm_mutex); 801 } 802 803 #ifdef CONFIG_PM 804 static int wdm_suspend(struct usb_interface *intf, pm_message_t message) 805 { 806 struct wdm_device *desc = usb_get_intfdata(intf); 807 int rv = 0; 808 809 dev_dbg(&desc->intf->dev, "wdm%d_suspend\n", intf->minor); 810 811 /* if this is an autosuspend the caller does the locking */ 812 if (!PMSG_IS_AUTO(message)) { 813 mutex_lock(&desc->rlock); 814 mutex_lock(&desc->wlock); 815 } 816 spin_lock_irq(&desc->iuspin); 817 818 if (PMSG_IS_AUTO(message) && 819 (test_bit(WDM_IN_USE, &desc->flags) 820 || test_bit(WDM_RESPONDING, &desc->flags))) { 821 spin_unlock_irq(&desc->iuspin); 822 rv = -EBUSY; 823 } else { 824 825 set_bit(WDM_SUSPENDING, &desc->flags); 826 spin_unlock_irq(&desc->iuspin); 827 /* callback submits work - order is essential */ 828 kill_urbs(desc); 829 cancel_work_sync(&desc->rxwork); 830 } 831 if (!PMSG_IS_AUTO(message)) { 832 mutex_unlock(&desc->wlock); 833 mutex_unlock(&desc->rlock); 834 } 835 836 return rv; 837 } 838 #endif 839 840 static int recover_from_urb_loss(struct wdm_device *desc) 841 { 842 int rv = 0; 843 844 if (desc->count) { 845 rv = usb_submit_urb(desc->validity, GFP_NOIO); 846 if (rv < 0) 847 dev_err(&desc->intf->dev, 848 "Error resume submitting int urb - %d\n", rv); 849 } 850 return rv; 851 } 852 853 #ifdef CONFIG_PM 854 static int wdm_resume(struct usb_interface *intf) 855 { 856 struct wdm_device *desc = usb_get_intfdata(intf); 857 int rv; 858 859 dev_dbg(&desc->intf->dev, "wdm%d_resume\n", intf->minor); 860 861 clear_bit(WDM_SUSPENDING, &desc->flags); 862 rv = recover_from_urb_loss(desc); 863 864 return rv; 865 } 866 #endif 867 868 static int wdm_pre_reset(struct usb_interface *intf) 869 { 870 struct wdm_device *desc = usb_get_intfdata(intf); 871 872 mutex_lock(&desc->rlock); 873 mutex_lock(&desc->wlock); 874 kill_urbs(desc); 875 876 /* 877 * we notify everybody using poll of 878 * an exceptional situation 879 * must be done before recovery lest a spontaneous 880 * message from the device is lost 881 */ 882 spin_lock_irq(&desc->iuspin); 883 desc->rerr = -EINTR; 884 spin_unlock_irq(&desc->iuspin); 885 wake_up_all(&desc->wait); 886 return 0; 887 } 888 889 static int wdm_post_reset(struct usb_interface *intf) 890 { 891 struct wdm_device *desc = usb_get_intfdata(intf); 892 int rv; 893 894 rv = recover_from_urb_loss(desc); 895 mutex_unlock(&desc->wlock); 896 mutex_unlock(&desc->rlock); 897 return 0; 898 } 899 900 static struct usb_driver wdm_driver = { 901 .name = "cdc_wdm", 902 .probe = wdm_probe, 903 .disconnect = wdm_disconnect, 904 #ifdef CONFIG_PM 905 .suspend = wdm_suspend, 906 .resume = wdm_resume, 907 .reset_resume = wdm_resume, 908 #endif 909 .pre_reset = wdm_pre_reset, 910 .post_reset = wdm_post_reset, 911 .id_table = wdm_ids, 912 .supports_autosuspend = 1, 913 }; 914 915 module_usb_driver(wdm_driver); 916 917 MODULE_AUTHOR(DRIVER_AUTHOR); 918 MODULE_DESCRIPTION(DRIVER_DESC); 919 MODULE_LICENSE("GPL"); 920