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 spin_unlock_irq(&desc->iuspin); 504 goto retry; 505 } 506 cntr = desc->length; 507 spin_unlock_irq(&desc->iuspin); 508 } 509 510 if (cntr > count) 511 cntr = count; 512 rv = copy_to_user(buffer, desc->ubuf, cntr); 513 if (rv > 0) { 514 rv = -EFAULT; 515 goto err; 516 } 517 518 spin_lock_irq(&desc->iuspin); 519 520 for (i = 0; i < desc->length - cntr; i++) 521 desc->ubuf[i] = desc->ubuf[i + cntr]; 522 523 desc->length -= cntr; 524 /* in case we had outstanding data */ 525 if (!desc->length) 526 clear_bit(WDM_READ, &desc->flags); 527 528 spin_unlock_irq(&desc->iuspin); 529 530 rv = cntr; 531 532 err: 533 mutex_unlock(&desc->rlock); 534 return rv; 535 } 536 537 static int wdm_flush(struct file *file, fl_owner_t id) 538 { 539 struct wdm_device *desc = file->private_data; 540 541 wait_event(desc->wait, !test_bit(WDM_IN_USE, &desc->flags)); 542 543 /* cannot dereference desc->intf if WDM_DISCONNECTING */ 544 if (desc->werr < 0 && !test_bit(WDM_DISCONNECTING, &desc->flags)) 545 dev_err(&desc->intf->dev, "Error in flush path: %d\n", 546 desc->werr); 547 548 return usb_translate_errors(desc->werr); 549 } 550 551 static unsigned int wdm_poll(struct file *file, struct poll_table_struct *wait) 552 { 553 struct wdm_device *desc = file->private_data; 554 unsigned long flags; 555 unsigned int mask = 0; 556 557 spin_lock_irqsave(&desc->iuspin, flags); 558 if (test_bit(WDM_DISCONNECTING, &desc->flags)) { 559 mask = POLLHUP | POLLERR; 560 spin_unlock_irqrestore(&desc->iuspin, flags); 561 goto desc_out; 562 } 563 if (test_bit(WDM_READ, &desc->flags)) 564 mask = POLLIN | POLLRDNORM; 565 if (desc->rerr || desc->werr) 566 mask |= POLLERR; 567 if (!test_bit(WDM_IN_USE, &desc->flags)) 568 mask |= POLLOUT | POLLWRNORM; 569 spin_unlock_irqrestore(&desc->iuspin, flags); 570 571 poll_wait(file, &desc->wait, wait); 572 573 desc_out: 574 return mask; 575 } 576 577 static int wdm_open(struct inode *inode, struct file *file) 578 { 579 int minor = iminor(inode); 580 int rv = -ENODEV; 581 struct usb_interface *intf; 582 struct wdm_device *desc; 583 584 mutex_lock(&wdm_mutex); 585 desc = wdm_find_device_by_minor(minor); 586 if (!desc) 587 goto out; 588 589 intf = desc->intf; 590 if (test_bit(WDM_DISCONNECTING, &desc->flags)) 591 goto out; 592 file->private_data = desc; 593 594 rv = usb_autopm_get_interface(desc->intf); 595 if (rv < 0) { 596 dev_err(&desc->intf->dev, "Error autopm - %d\n", rv); 597 goto out; 598 } 599 600 /* using write lock to protect desc->count */ 601 mutex_lock(&desc->wlock); 602 if (!desc->count++) { 603 desc->werr = 0; 604 desc->rerr = 0; 605 rv = usb_submit_urb(desc->validity, GFP_KERNEL); 606 if (rv < 0) { 607 desc->count--; 608 dev_err(&desc->intf->dev, 609 "Error submitting int urb - %d\n", rv); 610 rv = usb_translate_errors(rv); 611 } 612 } else { 613 rv = 0; 614 } 615 mutex_unlock(&desc->wlock); 616 if (desc->count == 1) 617 desc->manage_power(intf, 1); 618 usb_autopm_put_interface(desc->intf); 619 out: 620 mutex_unlock(&wdm_mutex); 621 return rv; 622 } 623 624 static int wdm_release(struct inode *inode, struct file *file) 625 { 626 struct wdm_device *desc = file->private_data; 627 628 mutex_lock(&wdm_mutex); 629 630 /* using write lock to protect desc->count */ 631 mutex_lock(&desc->wlock); 632 desc->count--; 633 mutex_unlock(&desc->wlock); 634 635 if (!desc->count) { 636 if (!test_bit(WDM_DISCONNECTING, &desc->flags)) { 637 dev_dbg(&desc->intf->dev, "wdm_release: cleanup"); 638 kill_urbs(desc); 639 desc->manage_power(desc->intf, 0); 640 } else { 641 /* must avoid dev_printk here as desc->intf is invalid */ 642 pr_debug(KBUILD_MODNAME " %s: device gone - cleaning up\n", __func__); 643 cleanup(desc); 644 } 645 } 646 mutex_unlock(&wdm_mutex); 647 return 0; 648 } 649 650 static const struct file_operations wdm_fops = { 651 .owner = THIS_MODULE, 652 .read = wdm_read, 653 .write = wdm_write, 654 .open = wdm_open, 655 .flush = wdm_flush, 656 .release = wdm_release, 657 .poll = wdm_poll, 658 .llseek = noop_llseek, 659 }; 660 661 static struct usb_class_driver wdm_class = { 662 .name = "cdc-wdm%d", 663 .fops = &wdm_fops, 664 .minor_base = WDM_MINOR_BASE, 665 }; 666 667 /* --- error handling --- */ 668 static void wdm_rxwork(struct work_struct *work) 669 { 670 struct wdm_device *desc = container_of(work, struct wdm_device, rxwork); 671 unsigned long flags; 672 int rv; 673 674 spin_lock_irqsave(&desc->iuspin, flags); 675 if (test_bit(WDM_DISCONNECTING, &desc->flags)) { 676 spin_unlock_irqrestore(&desc->iuspin, flags); 677 } else { 678 spin_unlock_irqrestore(&desc->iuspin, flags); 679 rv = usb_submit_urb(desc->response, GFP_KERNEL); 680 if (rv < 0 && rv != -EPERM) { 681 spin_lock_irqsave(&desc->iuspin, flags); 682 if (!test_bit(WDM_DISCONNECTING, &desc->flags)) 683 schedule_work(&desc->rxwork); 684 spin_unlock_irqrestore(&desc->iuspin, flags); 685 } 686 } 687 } 688 689 /* --- hotplug --- */ 690 691 static int wdm_create(struct usb_interface *intf, struct usb_endpoint_descriptor *ep, 692 u16 bufsize, int (*manage_power)(struct usb_interface *, int)) 693 { 694 int rv = -ENOMEM; 695 struct wdm_device *desc; 696 697 desc = kzalloc(sizeof(struct wdm_device), GFP_KERNEL); 698 if (!desc) 699 goto out; 700 INIT_LIST_HEAD(&desc->device_list); 701 mutex_init(&desc->rlock); 702 mutex_init(&desc->wlock); 703 spin_lock_init(&desc->iuspin); 704 init_waitqueue_head(&desc->wait); 705 desc->wMaxCommand = bufsize; 706 /* this will be expanded and needed in hardware endianness */ 707 desc->inum = cpu_to_le16((u16)intf->cur_altsetting->desc.bInterfaceNumber); 708 desc->intf = intf; 709 INIT_WORK(&desc->rxwork, wdm_rxwork); 710 711 rv = -EINVAL; 712 if (!usb_endpoint_is_int_in(ep)) 713 goto err; 714 715 desc->wMaxPacketSize = usb_endpoint_maxp(ep); 716 717 desc->orq = kmalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL); 718 if (!desc->orq) 719 goto err; 720 desc->irq = kmalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL); 721 if (!desc->irq) 722 goto err; 723 724 desc->validity = usb_alloc_urb(0, GFP_KERNEL); 725 if (!desc->validity) 726 goto err; 727 728 desc->response = usb_alloc_urb(0, GFP_KERNEL); 729 if (!desc->response) 730 goto err; 731 732 desc->command = usb_alloc_urb(0, GFP_KERNEL); 733 if (!desc->command) 734 goto err; 735 736 desc->ubuf = kmalloc(desc->wMaxCommand, GFP_KERNEL); 737 if (!desc->ubuf) 738 goto err; 739 740 desc->sbuf = kmalloc(desc->wMaxPacketSize, GFP_KERNEL); 741 if (!desc->sbuf) 742 goto err; 743 744 desc->inbuf = kmalloc(desc->wMaxCommand, GFP_KERNEL); 745 if (!desc->inbuf) 746 goto err; 747 748 usb_fill_int_urb( 749 desc->validity, 750 interface_to_usbdev(intf), 751 usb_rcvintpipe(interface_to_usbdev(intf), ep->bEndpointAddress), 752 desc->sbuf, 753 desc->wMaxPacketSize, 754 wdm_int_callback, 755 desc, 756 ep->bInterval 757 ); 758 759 desc->irq->bRequestType = (USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE); 760 desc->irq->bRequest = USB_CDC_GET_ENCAPSULATED_RESPONSE; 761 desc->irq->wValue = 0; 762 desc->irq->wIndex = desc->inum; 763 desc->irq->wLength = cpu_to_le16(desc->wMaxCommand); 764 765 usb_fill_control_urb( 766 desc->response, 767 interface_to_usbdev(intf), 768 /* using common endpoint 0 */ 769 usb_rcvctrlpipe(interface_to_usbdev(desc->intf), 0), 770 (unsigned char *)desc->irq, 771 desc->inbuf, 772 desc->wMaxCommand, 773 wdm_in_callback, 774 desc 775 ); 776 777 desc->manage_power = manage_power; 778 779 spin_lock(&wdm_device_list_lock); 780 list_add(&desc->device_list, &wdm_device_list); 781 spin_unlock(&wdm_device_list_lock); 782 783 rv = usb_register_dev(intf, &wdm_class); 784 if (rv < 0) 785 goto err; 786 else 787 dev_info(&intf->dev, "%s: USB WDM device\n", dev_name(intf->usb_dev)); 788 out: 789 return rv; 790 err: 791 spin_lock(&wdm_device_list_lock); 792 list_del(&desc->device_list); 793 spin_unlock(&wdm_device_list_lock); 794 cleanup(desc); 795 return rv; 796 } 797 798 static int wdm_manage_power(struct usb_interface *intf, int on) 799 { 800 /* need autopm_get/put here to ensure the usbcore sees the new value */ 801 int rv = usb_autopm_get_interface(intf); 802 if (rv < 0) 803 goto err; 804 805 intf->needs_remote_wakeup = on; 806 usb_autopm_put_interface(intf); 807 err: 808 return rv; 809 } 810 811 static int wdm_probe(struct usb_interface *intf, const struct usb_device_id *id) 812 { 813 int rv = -EINVAL; 814 struct usb_host_interface *iface; 815 struct usb_endpoint_descriptor *ep; 816 struct usb_cdc_dmm_desc *dmhd; 817 u8 *buffer = intf->altsetting->extra; 818 int buflen = intf->altsetting->extralen; 819 u16 maxcom = WDM_DEFAULT_BUFSIZE; 820 821 if (!buffer) 822 goto err; 823 while (buflen > 2) { 824 if (buffer[1] != USB_DT_CS_INTERFACE) { 825 dev_err(&intf->dev, "skipping garbage\n"); 826 goto next_desc; 827 } 828 829 switch (buffer[2]) { 830 case USB_CDC_HEADER_TYPE: 831 break; 832 case USB_CDC_DMM_TYPE: 833 dmhd = (struct usb_cdc_dmm_desc *)buffer; 834 maxcom = le16_to_cpu(dmhd->wMaxCommand); 835 dev_dbg(&intf->dev, 836 "Finding maximum buffer length: %d", maxcom); 837 break; 838 default: 839 dev_err(&intf->dev, 840 "Ignoring extra header, type %d, length %d\n", 841 buffer[2], buffer[0]); 842 break; 843 } 844 next_desc: 845 buflen -= buffer[0]; 846 buffer += buffer[0]; 847 } 848 849 iface = intf->cur_altsetting; 850 if (iface->desc.bNumEndpoints != 1) 851 goto err; 852 ep = &iface->endpoint[0].desc; 853 854 rv = wdm_create(intf, ep, maxcom, &wdm_manage_power); 855 856 err: 857 return rv; 858 } 859 860 /** 861 * usb_cdc_wdm_register - register a WDM subdriver 862 * @intf: usb interface the subdriver will associate with 863 * @ep: interrupt endpoint to monitor for notifications 864 * @bufsize: maximum message size to support for read/write 865 * 866 * Create WDM usb class character device and associate it with intf 867 * without binding, allowing another driver to manage the interface. 868 * 869 * The subdriver will manage the given interrupt endpoint exclusively 870 * and will issue control requests referring to the given intf. It 871 * will otherwise avoid interferring, and in particular not do 872 * usb_set_intfdata/usb_get_intfdata on intf. 873 * 874 * The return value is a pointer to the subdriver's struct usb_driver. 875 * The registering driver is responsible for calling this subdriver's 876 * disconnect, suspend, resume, pre_reset and post_reset methods from 877 * its own. 878 */ 879 struct usb_driver *usb_cdc_wdm_register(struct usb_interface *intf, 880 struct usb_endpoint_descriptor *ep, 881 int bufsize, 882 int (*manage_power)(struct usb_interface *, int)) 883 { 884 int rv = -EINVAL; 885 886 rv = wdm_create(intf, ep, bufsize, manage_power); 887 if (rv < 0) 888 goto err; 889 890 return &wdm_driver; 891 err: 892 return ERR_PTR(rv); 893 } 894 EXPORT_SYMBOL(usb_cdc_wdm_register); 895 896 static void wdm_disconnect(struct usb_interface *intf) 897 { 898 struct wdm_device *desc; 899 unsigned long flags; 900 901 usb_deregister_dev(intf, &wdm_class); 902 desc = wdm_find_device(intf); 903 mutex_lock(&wdm_mutex); 904 905 /* the spinlock makes sure no new urbs are generated in the callbacks */ 906 spin_lock_irqsave(&desc->iuspin, flags); 907 set_bit(WDM_DISCONNECTING, &desc->flags); 908 set_bit(WDM_READ, &desc->flags); 909 /* to terminate pending flushes */ 910 clear_bit(WDM_IN_USE, &desc->flags); 911 spin_unlock_irqrestore(&desc->iuspin, flags); 912 wake_up_all(&desc->wait); 913 mutex_lock(&desc->rlock); 914 mutex_lock(&desc->wlock); 915 kill_urbs(desc); 916 cancel_work_sync(&desc->rxwork); 917 mutex_unlock(&desc->wlock); 918 mutex_unlock(&desc->rlock); 919 920 /* the desc->intf pointer used as list key is now invalid */ 921 spin_lock(&wdm_device_list_lock); 922 list_del(&desc->device_list); 923 spin_unlock(&wdm_device_list_lock); 924 925 if (!desc->count) 926 cleanup(desc); 927 else 928 dev_dbg(&intf->dev, "%s: %d open files - postponing cleanup\n", __func__, desc->count); 929 mutex_unlock(&wdm_mutex); 930 } 931 932 #ifdef CONFIG_PM 933 static int wdm_suspend(struct usb_interface *intf, pm_message_t message) 934 { 935 struct wdm_device *desc = wdm_find_device(intf); 936 int rv = 0; 937 938 dev_dbg(&desc->intf->dev, "wdm%d_suspend\n", intf->minor); 939 940 /* if this is an autosuspend the caller does the locking */ 941 if (!PMSG_IS_AUTO(message)) { 942 mutex_lock(&desc->rlock); 943 mutex_lock(&desc->wlock); 944 } 945 spin_lock_irq(&desc->iuspin); 946 947 if (PMSG_IS_AUTO(message) && 948 (test_bit(WDM_IN_USE, &desc->flags) 949 || test_bit(WDM_RESPONDING, &desc->flags))) { 950 spin_unlock_irq(&desc->iuspin); 951 rv = -EBUSY; 952 } else { 953 954 set_bit(WDM_SUSPENDING, &desc->flags); 955 spin_unlock_irq(&desc->iuspin); 956 /* callback submits work - order is essential */ 957 kill_urbs(desc); 958 cancel_work_sync(&desc->rxwork); 959 } 960 if (!PMSG_IS_AUTO(message)) { 961 mutex_unlock(&desc->wlock); 962 mutex_unlock(&desc->rlock); 963 } 964 965 return rv; 966 } 967 #endif 968 969 static int recover_from_urb_loss(struct wdm_device *desc) 970 { 971 int rv = 0; 972 973 if (desc->count) { 974 rv = usb_submit_urb(desc->validity, GFP_NOIO); 975 if (rv < 0) 976 dev_err(&desc->intf->dev, 977 "Error resume submitting int urb - %d\n", rv); 978 } 979 return rv; 980 } 981 982 #ifdef CONFIG_PM 983 static int wdm_resume(struct usb_interface *intf) 984 { 985 struct wdm_device *desc = wdm_find_device(intf); 986 int rv; 987 988 dev_dbg(&desc->intf->dev, "wdm%d_resume\n", intf->minor); 989 990 clear_bit(WDM_SUSPENDING, &desc->flags); 991 rv = recover_from_urb_loss(desc); 992 993 return rv; 994 } 995 #endif 996 997 static int wdm_pre_reset(struct usb_interface *intf) 998 { 999 struct wdm_device *desc = wdm_find_device(intf); 1000 1001 /* 1002 * we notify everybody using poll of 1003 * an exceptional situation 1004 * must be done before recovery lest a spontaneous 1005 * message from the device is lost 1006 */ 1007 spin_lock_irq(&desc->iuspin); 1008 set_bit(WDM_RESETTING, &desc->flags); /* inform read/write */ 1009 set_bit(WDM_READ, &desc->flags); /* unblock read */ 1010 clear_bit(WDM_IN_USE, &desc->flags); /* unblock write */ 1011 desc->rerr = -EINTR; 1012 spin_unlock_irq(&desc->iuspin); 1013 wake_up_all(&desc->wait); 1014 mutex_lock(&desc->rlock); 1015 mutex_lock(&desc->wlock); 1016 kill_urbs(desc); 1017 cancel_work_sync(&desc->rxwork); 1018 return 0; 1019 } 1020 1021 static int wdm_post_reset(struct usb_interface *intf) 1022 { 1023 struct wdm_device *desc = wdm_find_device(intf); 1024 int rv; 1025 1026 clear_bit(WDM_RESETTING, &desc->flags); 1027 rv = recover_from_urb_loss(desc); 1028 mutex_unlock(&desc->wlock); 1029 mutex_unlock(&desc->rlock); 1030 return 0; 1031 } 1032 1033 static struct usb_driver wdm_driver = { 1034 .name = "cdc_wdm", 1035 .probe = wdm_probe, 1036 .disconnect = wdm_disconnect, 1037 #ifdef CONFIG_PM 1038 .suspend = wdm_suspend, 1039 .resume = wdm_resume, 1040 .reset_resume = wdm_resume, 1041 #endif 1042 .pre_reset = wdm_pre_reset, 1043 .post_reset = wdm_post_reset, 1044 .id_table = wdm_ids, 1045 .supports_autosuspend = 1, 1046 .disable_hub_initiated_lpm = 1, 1047 }; 1048 1049 module_usb_driver(wdm_driver); 1050 1051 MODULE_AUTHOR(DRIVER_AUTHOR); 1052 MODULE_DESCRIPTION(DRIVER_DESC); 1053 MODULE_LICENSE("GPL"); 1054