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 #include <linux/usb/cdc-wdm.h> 27 28 /* 29 * Version Information 30 */ 31 #define DRIVER_VERSION "v0.03" 32 #define DRIVER_AUTHOR "Oliver Neukum" 33 #define DRIVER_DESC "USB Abstract Control Model driver for USB WCM Device Management" 34 35 #define HUAWEI_VENDOR_ID 0x12D1 36 37 static const struct usb_device_id wdm_ids[] = { 38 { 39 .match_flags = USB_DEVICE_ID_MATCH_INT_CLASS | 40 USB_DEVICE_ID_MATCH_INT_SUBCLASS, 41 .bInterfaceClass = USB_CLASS_COMM, 42 .bInterfaceSubClass = USB_CDC_SUBCLASS_DMM 43 }, 44 { 45 /* 46 * Huawei E392, E398 and possibly other Qualcomm based modems 47 * embed the Qualcomm QMI protocol inside CDC on CDC ECM like 48 * control interfaces. Userspace access to this is required 49 * to configure the accompanying data interface 50 */ 51 .match_flags = USB_DEVICE_ID_MATCH_VENDOR | 52 USB_DEVICE_ID_MATCH_INT_INFO, 53 .idVendor = HUAWEI_VENDOR_ID, 54 .bInterfaceClass = USB_CLASS_VENDOR_SPEC, 55 .bInterfaceSubClass = 1, 56 .bInterfaceProtocol = 9, /* NOTE: CDC ECM control interface! */ 57 }, 58 { } 59 }; 60 61 MODULE_DEVICE_TABLE (usb, wdm_ids); 62 63 #define WDM_MINOR_BASE 176 64 65 66 #define WDM_IN_USE 1 67 #define WDM_DISCONNECTING 2 68 #define WDM_RESULT 3 69 #define WDM_READ 4 70 #define WDM_INT_STALL 5 71 #define WDM_POLL_RUNNING 6 72 #define WDM_RESPONDING 7 73 #define WDM_SUSPENDING 8 74 #define WDM_RESETTING 9 75 76 #define WDM_MAX 16 77 78 /* CDC-WMC r1.1 requires wMaxCommand to be "at least 256 decimal (0x100)" */ 79 #define WDM_DEFAULT_BUFSIZE 256 80 81 static DEFINE_MUTEX(wdm_mutex); 82 static DEFINE_SPINLOCK(wdm_device_list_lock); 83 static LIST_HEAD(wdm_device_list); 84 85 /* --- method tables --- */ 86 87 struct wdm_device { 88 u8 *inbuf; /* buffer for response */ 89 u8 *outbuf; /* buffer for command */ 90 u8 *sbuf; /* buffer for status */ 91 u8 *ubuf; /* buffer for copy to user space */ 92 93 struct urb *command; 94 struct urb *response; 95 struct urb *validity; 96 struct usb_interface *intf; 97 struct usb_ctrlrequest *orq; 98 struct usb_ctrlrequest *irq; 99 spinlock_t iuspin; 100 101 unsigned long flags; 102 u16 bufsize; 103 u16 wMaxCommand; 104 u16 wMaxPacketSize; 105 __le16 inum; 106 int reslength; 107 int length; 108 int read; 109 int count; 110 dma_addr_t shandle; 111 dma_addr_t ihandle; 112 struct mutex wlock; 113 struct mutex rlock; 114 wait_queue_head_t wait; 115 struct work_struct rxwork; 116 int werr; 117 int rerr; 118 119 struct list_head device_list; 120 int (*manage_power)(struct usb_interface *, int); 121 }; 122 123 static struct usb_driver wdm_driver; 124 125 /* return intfdata if we own the interface, else look up intf in the list */ 126 static struct wdm_device *wdm_find_device(struct usb_interface *intf) 127 { 128 struct wdm_device *desc = NULL; 129 130 spin_lock(&wdm_device_list_lock); 131 list_for_each_entry(desc, &wdm_device_list, device_list) 132 if (desc->intf == intf) 133 break; 134 spin_unlock(&wdm_device_list_lock); 135 136 return desc; 137 } 138 139 static struct wdm_device *wdm_find_device_by_minor(int minor) 140 { 141 struct wdm_device *desc = NULL; 142 143 spin_lock(&wdm_device_list_lock); 144 list_for_each_entry(desc, &wdm_device_list, device_list) 145 if (desc->intf->minor == minor) 146 break; 147 spin_unlock(&wdm_device_list_lock); 148 149 return desc; 150 } 151 152 /* --- callbacks --- */ 153 static void wdm_out_callback(struct urb *urb) 154 { 155 struct wdm_device *desc; 156 desc = urb->context; 157 spin_lock(&desc->iuspin); 158 desc->werr = urb->status; 159 spin_unlock(&desc->iuspin); 160 kfree(desc->outbuf); 161 desc->outbuf = NULL; 162 clear_bit(WDM_IN_USE, &desc->flags); 163 wake_up(&desc->wait); 164 } 165 166 static void wdm_in_callback(struct urb *urb) 167 { 168 struct wdm_device *desc = urb->context; 169 int status = urb->status; 170 171 spin_lock(&desc->iuspin); 172 clear_bit(WDM_RESPONDING, &desc->flags); 173 174 if (status) { 175 switch (status) { 176 case -ENOENT: 177 dev_dbg(&desc->intf->dev, 178 "nonzero urb status received: -ENOENT"); 179 goto skip_error; 180 case -ECONNRESET: 181 dev_dbg(&desc->intf->dev, 182 "nonzero urb status received: -ECONNRESET"); 183 goto skip_error; 184 case -ESHUTDOWN: 185 dev_dbg(&desc->intf->dev, 186 "nonzero urb status received: -ESHUTDOWN"); 187 goto skip_error; 188 case -EPIPE: 189 dev_err(&desc->intf->dev, 190 "nonzero urb status received: -EPIPE\n"); 191 break; 192 default: 193 dev_err(&desc->intf->dev, 194 "Unexpected error %d\n", status); 195 break; 196 } 197 } 198 199 desc->rerr = status; 200 desc->reslength = urb->actual_length; 201 memmove(desc->ubuf + desc->length, desc->inbuf, desc->reslength); 202 desc->length += desc->reslength; 203 skip_error: 204 wake_up(&desc->wait); 205 206 set_bit(WDM_READ, &desc->flags); 207 spin_unlock(&desc->iuspin); 208 } 209 210 static void wdm_int_callback(struct urb *urb) 211 { 212 int rv = 0; 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 set_bit(WDM_RESPONDING, &desc->flags); 267 if (!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 spin_lock(&wdm_device_list_lock); 313 list_del(&desc->device_list); 314 spin_unlock(&wdm_device_list_lock); 315 kfree(desc->sbuf); 316 kfree(desc->inbuf); 317 kfree(desc->orq); 318 kfree(desc->irq); 319 kfree(desc->ubuf); 320 free_urbs(desc); 321 kfree(desc); 322 } 323 324 static ssize_t wdm_write 325 (struct file *file, const char __user *buffer, size_t count, loff_t *ppos) 326 { 327 u8 *buf; 328 int rv = -EMSGSIZE, r, we; 329 struct wdm_device *desc = file->private_data; 330 struct usb_ctrlrequest *req; 331 332 if (count > desc->wMaxCommand) 333 count = desc->wMaxCommand; 334 335 spin_lock_irq(&desc->iuspin); 336 we = desc->werr; 337 desc->werr = 0; 338 spin_unlock_irq(&desc->iuspin); 339 if (we < 0) 340 return -EIO; 341 342 buf = kmalloc(count, GFP_KERNEL); 343 if (!buf) { 344 rv = -ENOMEM; 345 goto outnl; 346 } 347 348 r = copy_from_user(buf, buffer, count); 349 if (r > 0) { 350 kfree(buf); 351 rv = -EFAULT; 352 goto outnl; 353 } 354 355 /* concurrent writes and disconnect */ 356 r = mutex_lock_interruptible(&desc->wlock); 357 rv = -ERESTARTSYS; 358 if (r) { 359 kfree(buf); 360 goto outnl; 361 } 362 363 if (test_bit(WDM_DISCONNECTING, &desc->flags)) { 364 kfree(buf); 365 rv = -ENODEV; 366 goto outnp; 367 } 368 369 r = usb_autopm_get_interface(desc->intf); 370 if (r < 0) { 371 kfree(buf); 372 goto outnp; 373 } 374 375 if (!(file->f_flags & O_NONBLOCK)) 376 r = wait_event_interruptible(desc->wait, !test_bit(WDM_IN_USE, 377 &desc->flags)); 378 else 379 if (test_bit(WDM_IN_USE, &desc->flags)) 380 r = -EAGAIN; 381 382 if (test_bit(WDM_RESETTING, &desc->flags)) 383 r = -EIO; 384 385 if (r < 0) { 386 kfree(buf); 387 goto out; 388 } 389 390 req = desc->orq; 391 usb_fill_control_urb( 392 desc->command, 393 interface_to_usbdev(desc->intf), 394 /* using common endpoint 0 */ 395 usb_sndctrlpipe(interface_to_usbdev(desc->intf), 0), 396 (unsigned char *)req, 397 buf, 398 count, 399 wdm_out_callback, 400 desc 401 ); 402 403 req->bRequestType = (USB_DIR_OUT | USB_TYPE_CLASS | 404 USB_RECIP_INTERFACE); 405 req->bRequest = USB_CDC_SEND_ENCAPSULATED_COMMAND; 406 req->wValue = 0; 407 req->wIndex = desc->inum; 408 req->wLength = cpu_to_le16(count); 409 set_bit(WDM_IN_USE, &desc->flags); 410 desc->outbuf = buf; 411 412 rv = usb_submit_urb(desc->command, GFP_KERNEL); 413 if (rv < 0) { 414 kfree(buf); 415 desc->outbuf = NULL; 416 clear_bit(WDM_IN_USE, &desc->flags); 417 dev_err(&desc->intf->dev, "Tx URB error: %d\n", 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 i++; 451 if (file->f_flags & O_NONBLOCK) { 452 if (!test_bit(WDM_READ, &desc->flags)) { 453 rv = cntr ? cntr : -EAGAIN; 454 goto err; 455 } 456 rv = 0; 457 } else { 458 rv = wait_event_interruptible(desc->wait, 459 test_bit(WDM_READ, &desc->flags)); 460 } 461 462 /* may have happened while we slept */ 463 if (test_bit(WDM_DISCONNECTING, &desc->flags)) { 464 rv = -ENODEV; 465 goto err; 466 } 467 if (test_bit(WDM_RESETTING, &desc->flags)) { 468 rv = -EIO; 469 goto err; 470 } 471 usb_mark_last_busy(interface_to_usbdev(desc->intf)); 472 if (rv < 0) { 473 rv = -ERESTARTSYS; 474 goto err; 475 } 476 477 spin_lock_irq(&desc->iuspin); 478 479 if (desc->rerr) { /* read completed, error happened */ 480 desc->rerr = 0; 481 spin_unlock_irq(&desc->iuspin); 482 rv = -EIO; 483 goto err; 484 } 485 /* 486 * recheck whether we've lost the race 487 * against the completion handler 488 */ 489 if (!test_bit(WDM_READ, &desc->flags)) { /* lost race */ 490 spin_unlock_irq(&desc->iuspin); 491 goto retry; 492 } 493 if (!desc->reslength) { /* zero length read */ 494 spin_unlock_irq(&desc->iuspin); 495 goto retry; 496 } 497 cntr = desc->length; 498 spin_unlock_irq(&desc->iuspin); 499 } 500 501 if (cntr > count) 502 cntr = count; 503 rv = copy_to_user(buffer, desc->ubuf, cntr); 504 if (rv > 0) { 505 rv = -EFAULT; 506 goto err; 507 } 508 509 spin_lock_irq(&desc->iuspin); 510 511 for (i = 0; i < desc->length - cntr; i++) 512 desc->ubuf[i] = desc->ubuf[i + cntr]; 513 514 desc->length -= cntr; 515 /* in case we had outstanding data */ 516 if (!desc->length) 517 clear_bit(WDM_READ, &desc->flags); 518 519 spin_unlock_irq(&desc->iuspin); 520 521 rv = cntr; 522 523 err: 524 mutex_unlock(&desc->rlock); 525 return rv; 526 } 527 528 static int wdm_flush(struct file *file, fl_owner_t id) 529 { 530 struct wdm_device *desc = file->private_data; 531 532 wait_event(desc->wait, !test_bit(WDM_IN_USE, &desc->flags)); 533 if (desc->werr < 0) 534 dev_err(&desc->intf->dev, "Error in flush path: %d\n", 535 desc->werr); 536 537 return desc->werr; 538 } 539 540 static unsigned int wdm_poll(struct file *file, struct poll_table_struct *wait) 541 { 542 struct wdm_device *desc = file->private_data; 543 unsigned long flags; 544 unsigned int mask = 0; 545 546 spin_lock_irqsave(&desc->iuspin, flags); 547 if (test_bit(WDM_DISCONNECTING, &desc->flags)) { 548 mask = POLLERR; 549 spin_unlock_irqrestore(&desc->iuspin, flags); 550 goto desc_out; 551 } 552 if (test_bit(WDM_READ, &desc->flags)) 553 mask = POLLIN | POLLRDNORM; 554 if (desc->rerr || desc->werr) 555 mask |= POLLERR; 556 if (!test_bit(WDM_IN_USE, &desc->flags)) 557 mask |= POLLOUT | POLLWRNORM; 558 spin_unlock_irqrestore(&desc->iuspin, flags); 559 560 poll_wait(file, &desc->wait, wait); 561 562 desc_out: 563 return mask; 564 } 565 566 static int wdm_open(struct inode *inode, struct file *file) 567 { 568 int minor = iminor(inode); 569 int rv = -ENODEV; 570 struct usb_interface *intf; 571 struct wdm_device *desc; 572 573 mutex_lock(&wdm_mutex); 574 desc = wdm_find_device_by_minor(minor); 575 if (!desc) 576 goto out; 577 578 intf = desc->intf; 579 if (test_bit(WDM_DISCONNECTING, &desc->flags)) 580 goto out; 581 file->private_data = desc; 582 583 rv = usb_autopm_get_interface(desc->intf); 584 if (rv < 0) { 585 dev_err(&desc->intf->dev, "Error autopm - %d\n", rv); 586 goto out; 587 } 588 589 /* using write lock to protect desc->count */ 590 mutex_lock(&desc->wlock); 591 if (!desc->count++) { 592 desc->werr = 0; 593 desc->rerr = 0; 594 rv = usb_submit_urb(desc->validity, GFP_KERNEL); 595 if (rv < 0) { 596 desc->count--; 597 dev_err(&desc->intf->dev, 598 "Error submitting int urb - %d\n", rv); 599 } 600 } else { 601 rv = 0; 602 } 603 mutex_unlock(&desc->wlock); 604 if (desc->count == 1) 605 desc->manage_power(intf, 1); 606 usb_autopm_put_interface(desc->intf); 607 out: 608 mutex_unlock(&wdm_mutex); 609 return rv; 610 } 611 612 static int wdm_release(struct inode *inode, struct file *file) 613 { 614 struct wdm_device *desc = file->private_data; 615 616 mutex_lock(&wdm_mutex); 617 618 /* using write lock to protect desc->count */ 619 mutex_lock(&desc->wlock); 620 desc->count--; 621 mutex_unlock(&desc->wlock); 622 623 if (!desc->count) { 624 dev_dbg(&desc->intf->dev, "wdm_release: cleanup"); 625 kill_urbs(desc); 626 if (!test_bit(WDM_DISCONNECTING, &desc->flags)) 627 desc->manage_power(desc->intf, 0); 628 } 629 mutex_unlock(&wdm_mutex); 630 return 0; 631 } 632 633 static const struct file_operations wdm_fops = { 634 .owner = THIS_MODULE, 635 .read = wdm_read, 636 .write = wdm_write, 637 .open = wdm_open, 638 .flush = wdm_flush, 639 .release = wdm_release, 640 .poll = wdm_poll, 641 .llseek = noop_llseek, 642 }; 643 644 static struct usb_class_driver wdm_class = { 645 .name = "cdc-wdm%d", 646 .fops = &wdm_fops, 647 .minor_base = WDM_MINOR_BASE, 648 }; 649 650 /* --- error handling --- */ 651 static void wdm_rxwork(struct work_struct *work) 652 { 653 struct wdm_device *desc = container_of(work, struct wdm_device, rxwork); 654 unsigned long flags; 655 int rv; 656 657 spin_lock_irqsave(&desc->iuspin, flags); 658 if (test_bit(WDM_DISCONNECTING, &desc->flags)) { 659 spin_unlock_irqrestore(&desc->iuspin, flags); 660 } else { 661 spin_unlock_irqrestore(&desc->iuspin, flags); 662 rv = usb_submit_urb(desc->response, GFP_KERNEL); 663 if (rv < 0 && rv != -EPERM) { 664 spin_lock_irqsave(&desc->iuspin, flags); 665 if (!test_bit(WDM_DISCONNECTING, &desc->flags)) 666 schedule_work(&desc->rxwork); 667 spin_unlock_irqrestore(&desc->iuspin, flags); 668 } 669 } 670 } 671 672 /* --- hotplug --- */ 673 674 static int wdm_create(struct usb_interface *intf, struct usb_endpoint_descriptor *ep, 675 u16 bufsize, int (*manage_power)(struct usb_interface *, int)) 676 { 677 int rv = -ENOMEM; 678 struct wdm_device *desc; 679 680 desc = kzalloc(sizeof(struct wdm_device), GFP_KERNEL); 681 if (!desc) 682 goto out; 683 INIT_LIST_HEAD(&desc->device_list); 684 mutex_init(&desc->rlock); 685 mutex_init(&desc->wlock); 686 spin_lock_init(&desc->iuspin); 687 init_waitqueue_head(&desc->wait); 688 desc->wMaxCommand = bufsize; 689 /* this will be expanded and needed in hardware endianness */ 690 desc->inum = cpu_to_le16((u16)intf->cur_altsetting->desc.bInterfaceNumber); 691 desc->intf = intf; 692 INIT_WORK(&desc->rxwork, wdm_rxwork); 693 694 rv = -EINVAL; 695 if (!usb_endpoint_is_int_in(ep)) 696 goto err; 697 698 desc->wMaxPacketSize = usb_endpoint_maxp(ep); 699 700 desc->orq = kmalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL); 701 if (!desc->orq) 702 goto err; 703 desc->irq = kmalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL); 704 if (!desc->irq) 705 goto err; 706 707 desc->validity = usb_alloc_urb(0, GFP_KERNEL); 708 if (!desc->validity) 709 goto err; 710 711 desc->response = usb_alloc_urb(0, GFP_KERNEL); 712 if (!desc->response) 713 goto err; 714 715 desc->command = usb_alloc_urb(0, GFP_KERNEL); 716 if (!desc->command) 717 goto err; 718 719 desc->ubuf = kmalloc(desc->wMaxCommand, GFP_KERNEL); 720 if (!desc->ubuf) 721 goto err; 722 723 desc->sbuf = kmalloc(desc->wMaxPacketSize, GFP_KERNEL); 724 if (!desc->sbuf) 725 goto err; 726 727 desc->inbuf = kmalloc(desc->wMaxCommand, GFP_KERNEL); 728 if (!desc->inbuf) 729 goto err; 730 731 usb_fill_int_urb( 732 desc->validity, 733 interface_to_usbdev(intf), 734 usb_rcvintpipe(interface_to_usbdev(intf), ep->bEndpointAddress), 735 desc->sbuf, 736 desc->wMaxPacketSize, 737 wdm_int_callback, 738 desc, 739 ep->bInterval 740 ); 741 742 desc->irq->bRequestType = (USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE); 743 desc->irq->bRequest = USB_CDC_GET_ENCAPSULATED_RESPONSE; 744 desc->irq->wValue = 0; 745 desc->irq->wIndex = desc->inum; 746 desc->irq->wLength = cpu_to_le16(desc->wMaxCommand); 747 748 usb_fill_control_urb( 749 desc->response, 750 interface_to_usbdev(intf), 751 /* using common endpoint 0 */ 752 usb_rcvctrlpipe(interface_to_usbdev(desc->intf), 0), 753 (unsigned char *)desc->irq, 754 desc->inbuf, 755 desc->wMaxCommand, 756 wdm_in_callback, 757 desc 758 ); 759 760 desc->manage_power = manage_power; 761 762 spin_lock(&wdm_device_list_lock); 763 list_add(&desc->device_list, &wdm_device_list); 764 spin_unlock(&wdm_device_list_lock); 765 766 rv = usb_register_dev(intf, &wdm_class); 767 if (rv < 0) 768 goto err; 769 else 770 dev_info(&intf->dev, "%s: USB WDM device\n", dev_name(intf->usb_dev)); 771 out: 772 return rv; 773 err: 774 cleanup(desc); 775 return rv; 776 } 777 778 static int wdm_manage_power(struct usb_interface *intf, int on) 779 { 780 /* need autopm_get/put here to ensure the usbcore sees the new value */ 781 int rv = usb_autopm_get_interface(intf); 782 if (rv < 0) 783 goto err; 784 785 intf->needs_remote_wakeup = on; 786 usb_autopm_put_interface(intf); 787 err: 788 return rv; 789 } 790 791 static int wdm_probe(struct usb_interface *intf, const struct usb_device_id *id) 792 { 793 int rv = -EINVAL; 794 struct usb_host_interface *iface; 795 struct usb_endpoint_descriptor *ep; 796 struct usb_cdc_dmm_desc *dmhd; 797 u8 *buffer = intf->altsetting->extra; 798 int buflen = intf->altsetting->extralen; 799 u16 maxcom = WDM_DEFAULT_BUFSIZE; 800 801 if (!buffer) 802 goto err; 803 while (buflen > 2) { 804 if (buffer[1] != USB_DT_CS_INTERFACE) { 805 dev_err(&intf->dev, "skipping garbage\n"); 806 goto next_desc; 807 } 808 809 switch (buffer[2]) { 810 case USB_CDC_HEADER_TYPE: 811 break; 812 case USB_CDC_DMM_TYPE: 813 dmhd = (struct usb_cdc_dmm_desc *)buffer; 814 maxcom = le16_to_cpu(dmhd->wMaxCommand); 815 dev_dbg(&intf->dev, 816 "Finding maximum buffer length: %d", maxcom); 817 break; 818 default: 819 dev_err(&intf->dev, 820 "Ignoring extra header, type %d, length %d\n", 821 buffer[2], buffer[0]); 822 break; 823 } 824 next_desc: 825 buflen -= buffer[0]; 826 buffer += buffer[0]; 827 } 828 829 iface = intf->cur_altsetting; 830 if (iface->desc.bNumEndpoints != 1) 831 goto err; 832 ep = &iface->endpoint[0].desc; 833 834 rv = wdm_create(intf, ep, maxcom, &wdm_manage_power); 835 836 err: 837 return rv; 838 } 839 840 /** 841 * usb_cdc_wdm_register - register a WDM subdriver 842 * @intf: usb interface the subdriver will associate with 843 * @ep: interrupt endpoint to monitor for notifications 844 * @bufsize: maximum message size to support for read/write 845 * 846 * Create WDM usb class character device and associate it with intf 847 * without binding, allowing another driver to manage the interface. 848 * 849 * The subdriver will manage the given interrupt endpoint exclusively 850 * and will issue control requests referring to the given intf. It 851 * will otherwise avoid interferring, and in particular not do 852 * usb_set_intfdata/usb_get_intfdata on intf. 853 * 854 * The return value is a pointer to the subdriver's struct usb_driver. 855 * The registering driver is responsible for calling this subdriver's 856 * disconnect, suspend, resume, pre_reset and post_reset methods from 857 * its own. 858 */ 859 struct usb_driver *usb_cdc_wdm_register(struct usb_interface *intf, 860 struct usb_endpoint_descriptor *ep, 861 int bufsize, 862 int (*manage_power)(struct usb_interface *, int)) 863 { 864 int rv = -EINVAL; 865 866 rv = wdm_create(intf, ep, bufsize, manage_power); 867 if (rv < 0) 868 goto err; 869 870 return &wdm_driver; 871 err: 872 return ERR_PTR(rv); 873 } 874 EXPORT_SYMBOL(usb_cdc_wdm_register); 875 876 static void wdm_disconnect(struct usb_interface *intf) 877 { 878 struct wdm_device *desc; 879 unsigned long flags; 880 881 usb_deregister_dev(intf, &wdm_class); 882 desc = wdm_find_device(intf); 883 mutex_lock(&wdm_mutex); 884 885 /* the spinlock makes sure no new urbs are generated in the callbacks */ 886 spin_lock_irqsave(&desc->iuspin, flags); 887 set_bit(WDM_DISCONNECTING, &desc->flags); 888 set_bit(WDM_READ, &desc->flags); 889 /* to terminate pending flushes */ 890 clear_bit(WDM_IN_USE, &desc->flags); 891 spin_unlock_irqrestore(&desc->iuspin, flags); 892 wake_up_all(&desc->wait); 893 mutex_lock(&desc->rlock); 894 mutex_lock(&desc->wlock); 895 kill_urbs(desc); 896 cancel_work_sync(&desc->rxwork); 897 mutex_unlock(&desc->wlock); 898 mutex_unlock(&desc->rlock); 899 if (!desc->count) 900 cleanup(desc); 901 mutex_unlock(&wdm_mutex); 902 } 903 904 #ifdef CONFIG_PM 905 static int wdm_suspend(struct usb_interface *intf, pm_message_t message) 906 { 907 struct wdm_device *desc = wdm_find_device(intf); 908 int rv = 0; 909 910 dev_dbg(&desc->intf->dev, "wdm%d_suspend\n", intf->minor); 911 912 /* if this is an autosuspend the caller does the locking */ 913 if (!PMSG_IS_AUTO(message)) { 914 mutex_lock(&desc->rlock); 915 mutex_lock(&desc->wlock); 916 } 917 spin_lock_irq(&desc->iuspin); 918 919 if (PMSG_IS_AUTO(message) && 920 (test_bit(WDM_IN_USE, &desc->flags) 921 || test_bit(WDM_RESPONDING, &desc->flags))) { 922 spin_unlock_irq(&desc->iuspin); 923 rv = -EBUSY; 924 } else { 925 926 set_bit(WDM_SUSPENDING, &desc->flags); 927 spin_unlock_irq(&desc->iuspin); 928 /* callback submits work - order is essential */ 929 kill_urbs(desc); 930 cancel_work_sync(&desc->rxwork); 931 } 932 if (!PMSG_IS_AUTO(message)) { 933 mutex_unlock(&desc->wlock); 934 mutex_unlock(&desc->rlock); 935 } 936 937 return rv; 938 } 939 #endif 940 941 static int recover_from_urb_loss(struct wdm_device *desc) 942 { 943 int rv = 0; 944 945 if (desc->count) { 946 rv = usb_submit_urb(desc->validity, GFP_NOIO); 947 if (rv < 0) 948 dev_err(&desc->intf->dev, 949 "Error resume submitting int urb - %d\n", rv); 950 } 951 return rv; 952 } 953 954 #ifdef CONFIG_PM 955 static int wdm_resume(struct usb_interface *intf) 956 { 957 struct wdm_device *desc = wdm_find_device(intf); 958 int rv; 959 960 dev_dbg(&desc->intf->dev, "wdm%d_resume\n", intf->minor); 961 962 clear_bit(WDM_SUSPENDING, &desc->flags); 963 rv = recover_from_urb_loss(desc); 964 965 return rv; 966 } 967 #endif 968 969 static int wdm_pre_reset(struct usb_interface *intf) 970 { 971 struct wdm_device *desc = wdm_find_device(intf); 972 973 /* 974 * we notify everybody using poll of 975 * an exceptional situation 976 * must be done before recovery lest a spontaneous 977 * message from the device is lost 978 */ 979 spin_lock_irq(&desc->iuspin); 980 set_bit(WDM_RESETTING, &desc->flags); /* inform read/write */ 981 set_bit(WDM_READ, &desc->flags); /* unblock read */ 982 clear_bit(WDM_IN_USE, &desc->flags); /* unblock write */ 983 desc->rerr = -EINTR; 984 spin_unlock_irq(&desc->iuspin); 985 wake_up_all(&desc->wait); 986 mutex_lock(&desc->rlock); 987 mutex_lock(&desc->wlock); 988 kill_urbs(desc); 989 cancel_work_sync(&desc->rxwork); 990 return 0; 991 } 992 993 static int wdm_post_reset(struct usb_interface *intf) 994 { 995 struct wdm_device *desc = wdm_find_device(intf); 996 int rv; 997 998 clear_bit(WDM_RESETTING, &desc->flags); 999 rv = recover_from_urb_loss(desc); 1000 mutex_unlock(&desc->wlock); 1001 mutex_unlock(&desc->rlock); 1002 return 0; 1003 } 1004 1005 static struct usb_driver wdm_driver = { 1006 .name = "cdc_wdm", 1007 .probe = wdm_probe, 1008 .disconnect = wdm_disconnect, 1009 #ifdef CONFIG_PM 1010 .suspend = wdm_suspend, 1011 .resume = wdm_resume, 1012 .reset_resume = wdm_resume, 1013 #endif 1014 .pre_reset = wdm_pre_reset, 1015 .post_reset = wdm_post_reset, 1016 .id_table = wdm_ids, 1017 .supports_autosuspend = 1, 1018 }; 1019 1020 module_usb_driver(wdm_driver); 1021 1022 MODULE_AUTHOR(DRIVER_AUTHOR); 1023 MODULE_DESCRIPTION(DRIVER_DESC); 1024 MODULE_LICENSE("GPL"); 1025