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 /* Vodafone/Huawei K5005 (12d1:14c8) and similar modems */ 60 .match_flags = USB_DEVICE_ID_MATCH_VENDOR | 61 USB_DEVICE_ID_MATCH_INT_INFO, 62 .idVendor = HUAWEI_VENDOR_ID, 63 .bInterfaceClass = USB_CLASS_VENDOR_SPEC, 64 .bInterfaceSubClass = 1, 65 .bInterfaceProtocol = 57, /* NOTE: CDC ECM control interface! */ 66 }, 67 { } 68 }; 69 70 MODULE_DEVICE_TABLE (usb, wdm_ids); 71 72 #define WDM_MINOR_BASE 176 73 74 75 #define WDM_IN_USE 1 76 #define WDM_DISCONNECTING 2 77 #define WDM_RESULT 3 78 #define WDM_READ 4 79 #define WDM_INT_STALL 5 80 #define WDM_POLL_RUNNING 6 81 #define WDM_RESPONDING 7 82 #define WDM_SUSPENDING 8 83 #define WDM_RESETTING 9 84 85 #define WDM_MAX 16 86 87 /* CDC-WMC r1.1 requires wMaxCommand to be "at least 256 decimal (0x100)" */ 88 #define WDM_DEFAULT_BUFSIZE 256 89 90 static DEFINE_MUTEX(wdm_mutex); 91 static DEFINE_SPINLOCK(wdm_device_list_lock); 92 static LIST_HEAD(wdm_device_list); 93 94 /* --- method tables --- */ 95 96 struct wdm_device { 97 u8 *inbuf; /* buffer for response */ 98 u8 *outbuf; /* buffer for command */ 99 u8 *sbuf; /* buffer for status */ 100 u8 *ubuf; /* buffer for copy to user space */ 101 102 struct urb *command; 103 struct urb *response; 104 struct urb *validity; 105 struct usb_interface *intf; 106 struct usb_ctrlrequest *orq; 107 struct usb_ctrlrequest *irq; 108 spinlock_t iuspin; 109 110 unsigned long flags; 111 u16 bufsize; 112 u16 wMaxCommand; 113 u16 wMaxPacketSize; 114 __le16 inum; 115 int reslength; 116 int length; 117 int read; 118 int count; 119 dma_addr_t shandle; 120 dma_addr_t ihandle; 121 struct mutex wlock; 122 struct mutex rlock; 123 wait_queue_head_t wait; 124 struct work_struct rxwork; 125 int werr; 126 int rerr; 127 128 struct list_head device_list; 129 int (*manage_power)(struct usb_interface *, int); 130 }; 131 132 static struct usb_driver wdm_driver; 133 134 /* return intfdata if we own the interface, else look up intf in the list */ 135 static struct wdm_device *wdm_find_device(struct usb_interface *intf) 136 { 137 struct wdm_device *desc = NULL; 138 139 spin_lock(&wdm_device_list_lock); 140 list_for_each_entry(desc, &wdm_device_list, device_list) 141 if (desc->intf == intf) 142 break; 143 spin_unlock(&wdm_device_list_lock); 144 145 return desc; 146 } 147 148 static struct wdm_device *wdm_find_device_by_minor(int minor) 149 { 150 struct wdm_device *desc = NULL; 151 152 spin_lock(&wdm_device_list_lock); 153 list_for_each_entry(desc, &wdm_device_list, device_list) 154 if (desc->intf->minor == minor) 155 break; 156 spin_unlock(&wdm_device_list_lock); 157 158 return desc; 159 } 160 161 /* --- callbacks --- */ 162 static void wdm_out_callback(struct urb *urb) 163 { 164 struct wdm_device *desc; 165 desc = urb->context; 166 spin_lock(&desc->iuspin); 167 desc->werr = urb->status; 168 spin_unlock(&desc->iuspin); 169 kfree(desc->outbuf); 170 desc->outbuf = NULL; 171 clear_bit(WDM_IN_USE, &desc->flags); 172 wake_up(&desc->wait); 173 } 174 175 static void wdm_in_callback(struct urb *urb) 176 { 177 struct wdm_device *desc = urb->context; 178 int status = urb->status; 179 180 spin_lock(&desc->iuspin); 181 clear_bit(WDM_RESPONDING, &desc->flags); 182 183 if (status) { 184 switch (status) { 185 case -ENOENT: 186 dev_dbg(&desc->intf->dev, 187 "nonzero urb status received: -ENOENT"); 188 goto skip_error; 189 case -ECONNRESET: 190 dev_dbg(&desc->intf->dev, 191 "nonzero urb status received: -ECONNRESET"); 192 goto skip_error; 193 case -ESHUTDOWN: 194 dev_dbg(&desc->intf->dev, 195 "nonzero urb status received: -ESHUTDOWN"); 196 goto skip_error; 197 case -EPIPE: 198 dev_err(&desc->intf->dev, 199 "nonzero urb status received: -EPIPE\n"); 200 break; 201 default: 202 dev_err(&desc->intf->dev, 203 "Unexpected error %d\n", status); 204 break; 205 } 206 } 207 208 desc->rerr = status; 209 desc->reslength = urb->actual_length; 210 memmove(desc->ubuf + desc->length, desc->inbuf, desc->reslength); 211 desc->length += desc->reslength; 212 skip_error: 213 wake_up(&desc->wait); 214 215 set_bit(WDM_READ, &desc->flags); 216 spin_unlock(&desc->iuspin); 217 } 218 219 static void wdm_int_callback(struct urb *urb) 220 { 221 int rv = 0; 222 int status = urb->status; 223 struct wdm_device *desc; 224 struct usb_cdc_notification *dr; 225 226 desc = urb->context; 227 dr = (struct usb_cdc_notification *)desc->sbuf; 228 229 if (status) { 230 switch (status) { 231 case -ESHUTDOWN: 232 case -ENOENT: 233 case -ECONNRESET: 234 return; /* unplug */ 235 case -EPIPE: 236 set_bit(WDM_INT_STALL, &desc->flags); 237 dev_err(&desc->intf->dev, "Stall on int endpoint\n"); 238 goto sw; /* halt is cleared in work */ 239 default: 240 dev_err(&desc->intf->dev, 241 "nonzero urb status received: %d\n", status); 242 break; 243 } 244 } 245 246 if (urb->actual_length < sizeof(struct usb_cdc_notification)) { 247 dev_err(&desc->intf->dev, "wdm_int_callback - %d bytes\n", 248 urb->actual_length); 249 goto exit; 250 } 251 252 switch (dr->bNotificationType) { 253 case USB_CDC_NOTIFY_RESPONSE_AVAILABLE: 254 dev_dbg(&desc->intf->dev, 255 "NOTIFY_RESPONSE_AVAILABLE received: index %d len %d", 256 dr->wIndex, dr->wLength); 257 break; 258 259 case USB_CDC_NOTIFY_NETWORK_CONNECTION: 260 261 dev_dbg(&desc->intf->dev, 262 "NOTIFY_NETWORK_CONNECTION %s network", 263 dr->wValue ? "connected to" : "disconnected from"); 264 goto exit; 265 default: 266 clear_bit(WDM_POLL_RUNNING, &desc->flags); 267 dev_err(&desc->intf->dev, 268 "unknown notification %d received: index %d len %d\n", 269 dr->bNotificationType, dr->wIndex, dr->wLength); 270 goto exit; 271 } 272 273 spin_lock(&desc->iuspin); 274 clear_bit(WDM_READ, &desc->flags); 275 set_bit(WDM_RESPONDING, &desc->flags); 276 if (!test_bit(WDM_DISCONNECTING, &desc->flags) 277 && !test_bit(WDM_SUSPENDING, &desc->flags)) { 278 rv = usb_submit_urb(desc->response, GFP_ATOMIC); 279 dev_dbg(&desc->intf->dev, "%s: usb_submit_urb %d", 280 __func__, rv); 281 } 282 spin_unlock(&desc->iuspin); 283 if (rv < 0) { 284 clear_bit(WDM_RESPONDING, &desc->flags); 285 if (rv == -EPERM) 286 return; 287 if (rv == -ENOMEM) { 288 sw: 289 rv = schedule_work(&desc->rxwork); 290 if (rv) 291 dev_err(&desc->intf->dev, 292 "Cannot schedule work\n"); 293 } 294 } 295 exit: 296 rv = usb_submit_urb(urb, GFP_ATOMIC); 297 if (rv) 298 dev_err(&desc->intf->dev, 299 "%s - usb_submit_urb failed with result %d\n", 300 __func__, rv); 301 302 } 303 304 static void kill_urbs(struct wdm_device *desc) 305 { 306 /* the order here is essential */ 307 usb_kill_urb(desc->command); 308 usb_kill_urb(desc->validity); 309 usb_kill_urb(desc->response); 310 } 311 312 static void free_urbs(struct wdm_device *desc) 313 { 314 usb_free_urb(desc->validity); 315 usb_free_urb(desc->response); 316 usb_free_urb(desc->command); 317 } 318 319 static void cleanup(struct wdm_device *desc) 320 { 321 kfree(desc->sbuf); 322 kfree(desc->inbuf); 323 kfree(desc->orq); 324 kfree(desc->irq); 325 kfree(desc->ubuf); 326 free_urbs(desc); 327 kfree(desc); 328 } 329 330 static ssize_t wdm_write 331 (struct file *file, const char __user *buffer, size_t count, loff_t *ppos) 332 { 333 u8 *buf; 334 int rv = -EMSGSIZE, r, we; 335 struct wdm_device *desc = file->private_data; 336 struct usb_ctrlrequest *req; 337 338 if (count > desc->wMaxCommand) 339 count = desc->wMaxCommand; 340 341 spin_lock_irq(&desc->iuspin); 342 we = desc->werr; 343 desc->werr = 0; 344 spin_unlock_irq(&desc->iuspin); 345 if (we < 0) 346 return -EIO; 347 348 buf = kmalloc(count, GFP_KERNEL); 349 if (!buf) { 350 rv = -ENOMEM; 351 goto outnl; 352 } 353 354 r = copy_from_user(buf, buffer, count); 355 if (r > 0) { 356 kfree(buf); 357 rv = -EFAULT; 358 goto outnl; 359 } 360 361 /* concurrent writes and disconnect */ 362 r = mutex_lock_interruptible(&desc->wlock); 363 rv = -ERESTARTSYS; 364 if (r) { 365 kfree(buf); 366 goto outnl; 367 } 368 369 if (test_bit(WDM_DISCONNECTING, &desc->flags)) { 370 kfree(buf); 371 rv = -ENODEV; 372 goto outnp; 373 } 374 375 r = usb_autopm_get_interface(desc->intf); 376 if (r < 0) { 377 kfree(buf); 378 rv = usb_translate_errors(r); 379 goto outnp; 380 } 381 382 if (!(file->f_flags & O_NONBLOCK)) 383 r = wait_event_interruptible(desc->wait, !test_bit(WDM_IN_USE, 384 &desc->flags)); 385 else 386 if (test_bit(WDM_IN_USE, &desc->flags)) 387 r = -EAGAIN; 388 389 if (test_bit(WDM_RESETTING, &desc->flags)) 390 r = -EIO; 391 392 if (r < 0) { 393 kfree(buf); 394 rv = r; 395 goto out; 396 } 397 398 req = desc->orq; 399 usb_fill_control_urb( 400 desc->command, 401 interface_to_usbdev(desc->intf), 402 /* using common endpoint 0 */ 403 usb_sndctrlpipe(interface_to_usbdev(desc->intf), 0), 404 (unsigned char *)req, 405 buf, 406 count, 407 wdm_out_callback, 408 desc 409 ); 410 411 req->bRequestType = (USB_DIR_OUT | USB_TYPE_CLASS | 412 USB_RECIP_INTERFACE); 413 req->bRequest = USB_CDC_SEND_ENCAPSULATED_COMMAND; 414 req->wValue = 0; 415 req->wIndex = desc->inum; 416 req->wLength = cpu_to_le16(count); 417 set_bit(WDM_IN_USE, &desc->flags); 418 desc->outbuf = buf; 419 420 rv = usb_submit_urb(desc->command, GFP_KERNEL); 421 if (rv < 0) { 422 kfree(buf); 423 desc->outbuf = NULL; 424 clear_bit(WDM_IN_USE, &desc->flags); 425 dev_err(&desc->intf->dev, "Tx URB error: %d\n", rv); 426 rv = usb_translate_errors(rv); 427 } else { 428 dev_dbg(&desc->intf->dev, "Tx URB has been submitted index=%d", 429 req->wIndex); 430 } 431 out: 432 usb_autopm_put_interface(desc->intf); 433 outnp: 434 mutex_unlock(&desc->wlock); 435 outnl: 436 return rv < 0 ? rv : count; 437 } 438 439 static ssize_t wdm_read 440 (struct file *file, char __user *buffer, size_t count, loff_t *ppos) 441 { 442 int rv, cntr; 443 int i = 0; 444 struct wdm_device *desc = file->private_data; 445 446 447 rv = mutex_lock_interruptible(&desc->rlock); /*concurrent reads */ 448 if (rv < 0) 449 return -ERESTARTSYS; 450 451 cntr = ACCESS_ONCE(desc->length); 452 if (cntr == 0) { 453 desc->read = 0; 454 retry: 455 if (test_bit(WDM_DISCONNECTING, &desc->flags)) { 456 rv = -ENODEV; 457 goto err; 458 } 459 i++; 460 if (file->f_flags & O_NONBLOCK) { 461 if (!test_bit(WDM_READ, &desc->flags)) { 462 rv = cntr ? cntr : -EAGAIN; 463 goto err; 464 } 465 rv = 0; 466 } else { 467 rv = wait_event_interruptible(desc->wait, 468 test_bit(WDM_READ, &desc->flags)); 469 } 470 471 /* may have happened while we slept */ 472 if (test_bit(WDM_DISCONNECTING, &desc->flags)) { 473 rv = -ENODEV; 474 goto err; 475 } 476 if (test_bit(WDM_RESETTING, &desc->flags)) { 477 rv = -EIO; 478 goto err; 479 } 480 usb_mark_last_busy(interface_to_usbdev(desc->intf)); 481 if (rv < 0) { 482 rv = -ERESTARTSYS; 483 goto err; 484 } 485 486 spin_lock_irq(&desc->iuspin); 487 488 if (desc->rerr) { /* read completed, error happened */ 489 desc->rerr = 0; 490 spin_unlock_irq(&desc->iuspin); 491 rv = -EIO; 492 goto err; 493 } 494 /* 495 * recheck whether we've lost the race 496 * against the completion handler 497 */ 498 if (!test_bit(WDM_READ, &desc->flags)) { /* lost race */ 499 spin_unlock_irq(&desc->iuspin); 500 goto retry; 501 } 502 if (!desc->reslength) { /* zero length read */ 503 dev_dbg(&desc->intf->dev, "%s: zero length - clearing WDM_READ\n", __func__); 504 clear_bit(WDM_READ, &desc->flags); 505 spin_unlock_irq(&desc->iuspin); 506 goto retry; 507 } 508 cntr = desc->length; 509 spin_unlock_irq(&desc->iuspin); 510 } 511 512 if (cntr > count) 513 cntr = count; 514 rv = copy_to_user(buffer, desc->ubuf, cntr); 515 if (rv > 0) { 516 rv = -EFAULT; 517 goto err; 518 } 519 520 spin_lock_irq(&desc->iuspin); 521 522 for (i = 0; i < desc->length - cntr; i++) 523 desc->ubuf[i] = desc->ubuf[i + cntr]; 524 525 desc->length -= cntr; 526 /* in case we had outstanding data */ 527 if (!desc->length) 528 clear_bit(WDM_READ, &desc->flags); 529 530 spin_unlock_irq(&desc->iuspin); 531 532 rv = cntr; 533 534 err: 535 mutex_unlock(&desc->rlock); 536 return rv; 537 } 538 539 static int wdm_flush(struct file *file, fl_owner_t id) 540 { 541 struct wdm_device *desc = file->private_data; 542 543 wait_event(desc->wait, !test_bit(WDM_IN_USE, &desc->flags)); 544 545 /* cannot dereference desc->intf if WDM_DISCONNECTING */ 546 if (desc->werr < 0 && !test_bit(WDM_DISCONNECTING, &desc->flags)) 547 dev_err(&desc->intf->dev, "Error in flush path: %d\n", 548 desc->werr); 549 550 return usb_translate_errors(desc->werr); 551 } 552 553 static unsigned int wdm_poll(struct file *file, struct poll_table_struct *wait) 554 { 555 struct wdm_device *desc = file->private_data; 556 unsigned long flags; 557 unsigned int mask = 0; 558 559 spin_lock_irqsave(&desc->iuspin, flags); 560 if (test_bit(WDM_DISCONNECTING, &desc->flags)) { 561 mask = POLLHUP | POLLERR; 562 spin_unlock_irqrestore(&desc->iuspin, flags); 563 goto desc_out; 564 } 565 if (test_bit(WDM_READ, &desc->flags)) 566 mask = POLLIN | POLLRDNORM; 567 if (desc->rerr || desc->werr) 568 mask |= POLLERR; 569 if (!test_bit(WDM_IN_USE, &desc->flags)) 570 mask |= POLLOUT | POLLWRNORM; 571 spin_unlock_irqrestore(&desc->iuspin, flags); 572 573 poll_wait(file, &desc->wait, wait); 574 575 desc_out: 576 return mask; 577 } 578 579 static int wdm_open(struct inode *inode, struct file *file) 580 { 581 int minor = iminor(inode); 582 int rv = -ENODEV; 583 struct usb_interface *intf; 584 struct wdm_device *desc; 585 586 mutex_lock(&wdm_mutex); 587 desc = wdm_find_device_by_minor(minor); 588 if (!desc) 589 goto out; 590 591 intf = desc->intf; 592 if (test_bit(WDM_DISCONNECTING, &desc->flags)) 593 goto out; 594 file->private_data = desc; 595 596 rv = usb_autopm_get_interface(desc->intf); 597 if (rv < 0) { 598 dev_err(&desc->intf->dev, "Error autopm - %d\n", rv); 599 goto out; 600 } 601 602 /* using write lock to protect desc->count */ 603 mutex_lock(&desc->wlock); 604 if (!desc->count++) { 605 desc->werr = 0; 606 desc->rerr = 0; 607 rv = usb_submit_urb(desc->validity, GFP_KERNEL); 608 if (rv < 0) { 609 desc->count--; 610 dev_err(&desc->intf->dev, 611 "Error submitting int urb - %d\n", rv); 612 rv = usb_translate_errors(rv); 613 } 614 } else { 615 rv = 0; 616 } 617 mutex_unlock(&desc->wlock); 618 if (desc->count == 1) 619 desc->manage_power(intf, 1); 620 usb_autopm_put_interface(desc->intf); 621 out: 622 mutex_unlock(&wdm_mutex); 623 return rv; 624 } 625 626 static int wdm_release(struct inode *inode, struct file *file) 627 { 628 struct wdm_device *desc = file->private_data; 629 630 mutex_lock(&wdm_mutex); 631 632 /* using write lock to protect desc->count */ 633 mutex_lock(&desc->wlock); 634 desc->count--; 635 mutex_unlock(&desc->wlock); 636 637 if (!desc->count) { 638 if (!test_bit(WDM_DISCONNECTING, &desc->flags)) { 639 dev_dbg(&desc->intf->dev, "wdm_release: cleanup"); 640 kill_urbs(desc); 641 desc->manage_power(desc->intf, 0); 642 } else { 643 /* must avoid dev_printk here as desc->intf is invalid */ 644 pr_debug(KBUILD_MODNAME " %s: device gone - cleaning up\n", __func__); 645 cleanup(desc); 646 } 647 } 648 mutex_unlock(&wdm_mutex); 649 return 0; 650 } 651 652 static const struct file_operations wdm_fops = { 653 .owner = THIS_MODULE, 654 .read = wdm_read, 655 .write = wdm_write, 656 .open = wdm_open, 657 .flush = wdm_flush, 658 .release = wdm_release, 659 .poll = wdm_poll, 660 .llseek = noop_llseek, 661 }; 662 663 static struct usb_class_driver wdm_class = { 664 .name = "cdc-wdm%d", 665 .fops = &wdm_fops, 666 .minor_base = WDM_MINOR_BASE, 667 }; 668 669 /* --- error handling --- */ 670 static void wdm_rxwork(struct work_struct *work) 671 { 672 struct wdm_device *desc = container_of(work, struct wdm_device, rxwork); 673 unsigned long flags; 674 int rv; 675 676 spin_lock_irqsave(&desc->iuspin, flags); 677 if (test_bit(WDM_DISCONNECTING, &desc->flags)) { 678 spin_unlock_irqrestore(&desc->iuspin, flags); 679 } else { 680 spin_unlock_irqrestore(&desc->iuspin, flags); 681 rv = usb_submit_urb(desc->response, GFP_KERNEL); 682 if (rv < 0 && rv != -EPERM) { 683 spin_lock_irqsave(&desc->iuspin, flags); 684 if (!test_bit(WDM_DISCONNECTING, &desc->flags)) 685 schedule_work(&desc->rxwork); 686 spin_unlock_irqrestore(&desc->iuspin, flags); 687 } 688 } 689 } 690 691 /* --- hotplug --- */ 692 693 static int wdm_create(struct usb_interface *intf, struct usb_endpoint_descriptor *ep, 694 u16 bufsize, int (*manage_power)(struct usb_interface *, int)) 695 { 696 int rv = -ENOMEM; 697 struct wdm_device *desc; 698 699 desc = kzalloc(sizeof(struct wdm_device), GFP_KERNEL); 700 if (!desc) 701 goto out; 702 INIT_LIST_HEAD(&desc->device_list); 703 mutex_init(&desc->rlock); 704 mutex_init(&desc->wlock); 705 spin_lock_init(&desc->iuspin); 706 init_waitqueue_head(&desc->wait); 707 desc->wMaxCommand = bufsize; 708 /* this will be expanded and needed in hardware endianness */ 709 desc->inum = cpu_to_le16((u16)intf->cur_altsetting->desc.bInterfaceNumber); 710 desc->intf = intf; 711 INIT_WORK(&desc->rxwork, wdm_rxwork); 712 713 rv = -EINVAL; 714 if (!usb_endpoint_is_int_in(ep)) 715 goto err; 716 717 desc->wMaxPacketSize = usb_endpoint_maxp(ep); 718 719 desc->orq = kmalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL); 720 if (!desc->orq) 721 goto err; 722 desc->irq = kmalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL); 723 if (!desc->irq) 724 goto err; 725 726 desc->validity = usb_alloc_urb(0, GFP_KERNEL); 727 if (!desc->validity) 728 goto err; 729 730 desc->response = usb_alloc_urb(0, GFP_KERNEL); 731 if (!desc->response) 732 goto err; 733 734 desc->command = usb_alloc_urb(0, GFP_KERNEL); 735 if (!desc->command) 736 goto err; 737 738 desc->ubuf = kmalloc(desc->wMaxCommand, GFP_KERNEL); 739 if (!desc->ubuf) 740 goto err; 741 742 desc->sbuf = kmalloc(desc->wMaxPacketSize, GFP_KERNEL); 743 if (!desc->sbuf) 744 goto err; 745 746 desc->inbuf = kmalloc(desc->wMaxCommand, GFP_KERNEL); 747 if (!desc->inbuf) 748 goto err; 749 750 usb_fill_int_urb( 751 desc->validity, 752 interface_to_usbdev(intf), 753 usb_rcvintpipe(interface_to_usbdev(intf), ep->bEndpointAddress), 754 desc->sbuf, 755 desc->wMaxPacketSize, 756 wdm_int_callback, 757 desc, 758 ep->bInterval 759 ); 760 761 desc->irq->bRequestType = (USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE); 762 desc->irq->bRequest = USB_CDC_GET_ENCAPSULATED_RESPONSE; 763 desc->irq->wValue = 0; 764 desc->irq->wIndex = desc->inum; 765 desc->irq->wLength = cpu_to_le16(desc->wMaxCommand); 766 767 usb_fill_control_urb( 768 desc->response, 769 interface_to_usbdev(intf), 770 /* using common endpoint 0 */ 771 usb_rcvctrlpipe(interface_to_usbdev(desc->intf), 0), 772 (unsigned char *)desc->irq, 773 desc->inbuf, 774 desc->wMaxCommand, 775 wdm_in_callback, 776 desc 777 ); 778 779 desc->manage_power = manage_power; 780 781 spin_lock(&wdm_device_list_lock); 782 list_add(&desc->device_list, &wdm_device_list); 783 spin_unlock(&wdm_device_list_lock); 784 785 rv = usb_register_dev(intf, &wdm_class); 786 if (rv < 0) 787 goto err; 788 else 789 dev_info(&intf->dev, "%s: USB WDM device\n", dev_name(intf->usb_dev)); 790 out: 791 return rv; 792 err: 793 spin_lock(&wdm_device_list_lock); 794 list_del(&desc->device_list); 795 spin_unlock(&wdm_device_list_lock); 796 cleanup(desc); 797 return rv; 798 } 799 800 static int wdm_manage_power(struct usb_interface *intf, int on) 801 { 802 /* need autopm_get/put here to ensure the usbcore sees the new value */ 803 int rv = usb_autopm_get_interface(intf); 804 if (rv < 0) 805 goto err; 806 807 intf->needs_remote_wakeup = on; 808 usb_autopm_put_interface(intf); 809 err: 810 return rv; 811 } 812 813 static int wdm_probe(struct usb_interface *intf, const struct usb_device_id *id) 814 { 815 int rv = -EINVAL; 816 struct usb_host_interface *iface; 817 struct usb_endpoint_descriptor *ep; 818 struct usb_cdc_dmm_desc *dmhd; 819 u8 *buffer = intf->altsetting->extra; 820 int buflen = intf->altsetting->extralen; 821 u16 maxcom = WDM_DEFAULT_BUFSIZE; 822 823 if (!buffer) 824 goto err; 825 while (buflen > 2) { 826 if (buffer[1] != USB_DT_CS_INTERFACE) { 827 dev_err(&intf->dev, "skipping garbage\n"); 828 goto next_desc; 829 } 830 831 switch (buffer[2]) { 832 case USB_CDC_HEADER_TYPE: 833 break; 834 case USB_CDC_DMM_TYPE: 835 dmhd = (struct usb_cdc_dmm_desc *)buffer; 836 maxcom = le16_to_cpu(dmhd->wMaxCommand); 837 dev_dbg(&intf->dev, 838 "Finding maximum buffer length: %d", maxcom); 839 break; 840 default: 841 dev_err(&intf->dev, 842 "Ignoring extra header, type %d, length %d\n", 843 buffer[2], buffer[0]); 844 break; 845 } 846 next_desc: 847 buflen -= buffer[0]; 848 buffer += buffer[0]; 849 } 850 851 iface = intf->cur_altsetting; 852 if (iface->desc.bNumEndpoints != 1) 853 goto err; 854 ep = &iface->endpoint[0].desc; 855 856 rv = wdm_create(intf, ep, maxcom, &wdm_manage_power); 857 858 err: 859 return rv; 860 } 861 862 /** 863 * usb_cdc_wdm_register - register a WDM subdriver 864 * @intf: usb interface the subdriver will associate with 865 * @ep: interrupt endpoint to monitor for notifications 866 * @bufsize: maximum message size to support for read/write 867 * 868 * Create WDM usb class character device and associate it with intf 869 * without binding, allowing another driver to manage the interface. 870 * 871 * The subdriver will manage the given interrupt endpoint exclusively 872 * and will issue control requests referring to the given intf. It 873 * will otherwise avoid interferring, and in particular not do 874 * usb_set_intfdata/usb_get_intfdata on intf. 875 * 876 * The return value is a pointer to the subdriver's struct usb_driver. 877 * The registering driver is responsible for calling this subdriver's 878 * disconnect, suspend, resume, pre_reset and post_reset methods from 879 * its own. 880 */ 881 struct usb_driver *usb_cdc_wdm_register(struct usb_interface *intf, 882 struct usb_endpoint_descriptor *ep, 883 int bufsize, 884 int (*manage_power)(struct usb_interface *, int)) 885 { 886 int rv = -EINVAL; 887 888 rv = wdm_create(intf, ep, bufsize, manage_power); 889 if (rv < 0) 890 goto err; 891 892 return &wdm_driver; 893 err: 894 return ERR_PTR(rv); 895 } 896 EXPORT_SYMBOL(usb_cdc_wdm_register); 897 898 static void wdm_disconnect(struct usb_interface *intf) 899 { 900 struct wdm_device *desc; 901 unsigned long flags; 902 903 usb_deregister_dev(intf, &wdm_class); 904 desc = wdm_find_device(intf); 905 mutex_lock(&wdm_mutex); 906 907 /* the spinlock makes sure no new urbs are generated in the callbacks */ 908 spin_lock_irqsave(&desc->iuspin, flags); 909 set_bit(WDM_DISCONNECTING, &desc->flags); 910 set_bit(WDM_READ, &desc->flags); 911 /* to terminate pending flushes */ 912 clear_bit(WDM_IN_USE, &desc->flags); 913 spin_unlock_irqrestore(&desc->iuspin, flags); 914 wake_up_all(&desc->wait); 915 mutex_lock(&desc->rlock); 916 mutex_lock(&desc->wlock); 917 kill_urbs(desc); 918 cancel_work_sync(&desc->rxwork); 919 mutex_unlock(&desc->wlock); 920 mutex_unlock(&desc->rlock); 921 922 /* the desc->intf pointer used as list key is now invalid */ 923 spin_lock(&wdm_device_list_lock); 924 list_del(&desc->device_list); 925 spin_unlock(&wdm_device_list_lock); 926 927 if (!desc->count) 928 cleanup(desc); 929 else 930 dev_dbg(&intf->dev, "%s: %d open files - postponing cleanup\n", __func__, desc->count); 931 mutex_unlock(&wdm_mutex); 932 } 933 934 #ifdef CONFIG_PM 935 static int wdm_suspend(struct usb_interface *intf, pm_message_t message) 936 { 937 struct wdm_device *desc = wdm_find_device(intf); 938 int rv = 0; 939 940 dev_dbg(&desc->intf->dev, "wdm%d_suspend\n", intf->minor); 941 942 /* if this is an autosuspend the caller does the locking */ 943 if (!PMSG_IS_AUTO(message)) { 944 mutex_lock(&desc->rlock); 945 mutex_lock(&desc->wlock); 946 } 947 spin_lock_irq(&desc->iuspin); 948 949 if (PMSG_IS_AUTO(message) && 950 (test_bit(WDM_IN_USE, &desc->flags) 951 || test_bit(WDM_RESPONDING, &desc->flags))) { 952 spin_unlock_irq(&desc->iuspin); 953 rv = -EBUSY; 954 } else { 955 956 set_bit(WDM_SUSPENDING, &desc->flags); 957 spin_unlock_irq(&desc->iuspin); 958 /* callback submits work - order is essential */ 959 kill_urbs(desc); 960 cancel_work_sync(&desc->rxwork); 961 } 962 if (!PMSG_IS_AUTO(message)) { 963 mutex_unlock(&desc->wlock); 964 mutex_unlock(&desc->rlock); 965 } 966 967 return rv; 968 } 969 #endif 970 971 static int recover_from_urb_loss(struct wdm_device *desc) 972 { 973 int rv = 0; 974 975 if (desc->count) { 976 rv = usb_submit_urb(desc->validity, GFP_NOIO); 977 if (rv < 0) 978 dev_err(&desc->intf->dev, 979 "Error resume submitting int urb - %d\n", rv); 980 } 981 return rv; 982 } 983 984 #ifdef CONFIG_PM 985 static int wdm_resume(struct usb_interface *intf) 986 { 987 struct wdm_device *desc = wdm_find_device(intf); 988 int rv; 989 990 dev_dbg(&desc->intf->dev, "wdm%d_resume\n", intf->minor); 991 992 clear_bit(WDM_SUSPENDING, &desc->flags); 993 rv = recover_from_urb_loss(desc); 994 995 return rv; 996 } 997 #endif 998 999 static int wdm_pre_reset(struct usb_interface *intf) 1000 { 1001 struct wdm_device *desc = wdm_find_device(intf); 1002 1003 /* 1004 * we notify everybody using poll of 1005 * an exceptional situation 1006 * must be done before recovery lest a spontaneous 1007 * message from the device is lost 1008 */ 1009 spin_lock_irq(&desc->iuspin); 1010 set_bit(WDM_RESETTING, &desc->flags); /* inform read/write */ 1011 set_bit(WDM_READ, &desc->flags); /* unblock read */ 1012 clear_bit(WDM_IN_USE, &desc->flags); /* unblock write */ 1013 desc->rerr = -EINTR; 1014 spin_unlock_irq(&desc->iuspin); 1015 wake_up_all(&desc->wait); 1016 mutex_lock(&desc->rlock); 1017 mutex_lock(&desc->wlock); 1018 kill_urbs(desc); 1019 cancel_work_sync(&desc->rxwork); 1020 return 0; 1021 } 1022 1023 static int wdm_post_reset(struct usb_interface *intf) 1024 { 1025 struct wdm_device *desc = wdm_find_device(intf); 1026 int rv; 1027 1028 clear_bit(WDM_RESETTING, &desc->flags); 1029 rv = recover_from_urb_loss(desc); 1030 mutex_unlock(&desc->wlock); 1031 mutex_unlock(&desc->rlock); 1032 return 0; 1033 } 1034 1035 static struct usb_driver wdm_driver = { 1036 .name = "cdc_wdm", 1037 .probe = wdm_probe, 1038 .disconnect = wdm_disconnect, 1039 #ifdef CONFIG_PM 1040 .suspend = wdm_suspend, 1041 .resume = wdm_resume, 1042 .reset_resume = wdm_resume, 1043 #endif 1044 .pre_reset = wdm_pre_reset, 1045 .post_reset = wdm_post_reset, 1046 .id_table = wdm_ids, 1047 .supports_autosuspend = 1, 1048 .disable_hub_initiated_lpm = 1, 1049 }; 1050 1051 module_usb_driver(wdm_driver); 1052 1053 MODULE_AUTHOR(DRIVER_AUTHOR); 1054 MODULE_DESCRIPTION(DRIVER_DESC); 1055 MODULE_LICENSE("GPL"); 1056