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 kfree(desc->sbuf); 313 kfree(desc->inbuf); 314 kfree(desc->orq); 315 kfree(desc->irq); 316 kfree(desc->ubuf); 317 free_urbs(desc); 318 kfree(desc); 319 } 320 321 static ssize_t wdm_write 322 (struct file *file, const char __user *buffer, size_t count, loff_t *ppos) 323 { 324 u8 *buf; 325 int rv = -EMSGSIZE, r, we; 326 struct wdm_device *desc = file->private_data; 327 struct usb_ctrlrequest *req; 328 329 if (count > desc->wMaxCommand) 330 count = desc->wMaxCommand; 331 332 spin_lock_irq(&desc->iuspin); 333 we = desc->werr; 334 desc->werr = 0; 335 spin_unlock_irq(&desc->iuspin); 336 if (we < 0) 337 return -EIO; 338 339 buf = kmalloc(count, GFP_KERNEL); 340 if (!buf) { 341 rv = -ENOMEM; 342 goto outnl; 343 } 344 345 r = copy_from_user(buf, buffer, count); 346 if (r > 0) { 347 kfree(buf); 348 rv = -EFAULT; 349 goto outnl; 350 } 351 352 /* concurrent writes and disconnect */ 353 r = mutex_lock_interruptible(&desc->wlock); 354 rv = -ERESTARTSYS; 355 if (r) { 356 kfree(buf); 357 goto outnl; 358 } 359 360 if (test_bit(WDM_DISCONNECTING, &desc->flags)) { 361 kfree(buf); 362 rv = -ENODEV; 363 goto outnp; 364 } 365 366 r = usb_autopm_get_interface(desc->intf); 367 if (r < 0) { 368 kfree(buf); 369 rv = usb_translate_errors(r); 370 goto outnp; 371 } 372 373 if (!(file->f_flags & O_NONBLOCK)) 374 r = wait_event_interruptible(desc->wait, !test_bit(WDM_IN_USE, 375 &desc->flags)); 376 else 377 if (test_bit(WDM_IN_USE, &desc->flags)) 378 r = -EAGAIN; 379 380 if (test_bit(WDM_RESETTING, &desc->flags)) 381 r = -EIO; 382 383 if (r < 0) { 384 kfree(buf); 385 rv = r; 386 goto out; 387 } 388 389 req = desc->orq; 390 usb_fill_control_urb( 391 desc->command, 392 interface_to_usbdev(desc->intf), 393 /* using common endpoint 0 */ 394 usb_sndctrlpipe(interface_to_usbdev(desc->intf), 0), 395 (unsigned char *)req, 396 buf, 397 count, 398 wdm_out_callback, 399 desc 400 ); 401 402 req->bRequestType = (USB_DIR_OUT | USB_TYPE_CLASS | 403 USB_RECIP_INTERFACE); 404 req->bRequest = USB_CDC_SEND_ENCAPSULATED_COMMAND; 405 req->wValue = 0; 406 req->wIndex = desc->inum; 407 req->wLength = cpu_to_le16(count); 408 set_bit(WDM_IN_USE, &desc->flags); 409 desc->outbuf = buf; 410 411 rv = usb_submit_urb(desc->command, GFP_KERNEL); 412 if (rv < 0) { 413 kfree(buf); 414 desc->outbuf = NULL; 415 clear_bit(WDM_IN_USE, &desc->flags); 416 dev_err(&desc->intf->dev, "Tx URB error: %d\n", rv); 417 rv = usb_translate_errors(rv); 418 } else { 419 dev_dbg(&desc->intf->dev, "Tx URB has been submitted index=%d", 420 req->wIndex); 421 } 422 out: 423 usb_autopm_put_interface(desc->intf); 424 outnp: 425 mutex_unlock(&desc->wlock); 426 outnl: 427 return rv < 0 ? rv : count; 428 } 429 430 static ssize_t wdm_read 431 (struct file *file, char __user *buffer, size_t count, loff_t *ppos) 432 { 433 int rv, cntr; 434 int i = 0; 435 struct wdm_device *desc = file->private_data; 436 437 438 rv = mutex_lock_interruptible(&desc->rlock); /*concurrent reads */ 439 if (rv < 0) 440 return -ERESTARTSYS; 441 442 cntr = ACCESS_ONCE(desc->length); 443 if (cntr == 0) { 444 desc->read = 0; 445 retry: 446 if (test_bit(WDM_DISCONNECTING, &desc->flags)) { 447 rv = -ENODEV; 448 goto err; 449 } 450 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)); 533 534 /* cannot dereference desc->intf if WDM_DISCONNECTING */ 535 if (desc->werr < 0 && !test_bit(WDM_DISCONNECTING, &desc->flags)) 536 dev_err(&desc->intf->dev, "Error in flush path: %d\n", 537 desc->werr); 538 539 return usb_translate_errors(desc->werr); 540 } 541 542 static unsigned int wdm_poll(struct file *file, struct poll_table_struct *wait) 543 { 544 struct wdm_device *desc = file->private_data; 545 unsigned long flags; 546 unsigned int mask = 0; 547 548 spin_lock_irqsave(&desc->iuspin, flags); 549 if (test_bit(WDM_DISCONNECTING, &desc->flags)) { 550 mask = POLLHUP | POLLERR; 551 spin_unlock_irqrestore(&desc->iuspin, flags); 552 goto desc_out; 553 } 554 if (test_bit(WDM_READ, &desc->flags)) 555 mask = POLLIN | POLLRDNORM; 556 if (desc->rerr || desc->werr) 557 mask |= POLLERR; 558 if (!test_bit(WDM_IN_USE, &desc->flags)) 559 mask |= POLLOUT | POLLWRNORM; 560 spin_unlock_irqrestore(&desc->iuspin, flags); 561 562 poll_wait(file, &desc->wait, wait); 563 564 desc_out: 565 return mask; 566 } 567 568 static int wdm_open(struct inode *inode, struct file *file) 569 { 570 int minor = iminor(inode); 571 int rv = -ENODEV; 572 struct usb_interface *intf; 573 struct wdm_device *desc; 574 575 mutex_lock(&wdm_mutex); 576 desc = wdm_find_device_by_minor(minor); 577 if (!desc) 578 goto out; 579 580 intf = desc->intf; 581 if (test_bit(WDM_DISCONNECTING, &desc->flags)) 582 goto out; 583 file->private_data = desc; 584 585 rv = usb_autopm_get_interface(desc->intf); 586 if (rv < 0) { 587 dev_err(&desc->intf->dev, "Error autopm - %d\n", rv); 588 goto out; 589 } 590 591 /* using write lock to protect desc->count */ 592 mutex_lock(&desc->wlock); 593 if (!desc->count++) { 594 desc->werr = 0; 595 desc->rerr = 0; 596 rv = usb_submit_urb(desc->validity, GFP_KERNEL); 597 if (rv < 0) { 598 desc->count--; 599 dev_err(&desc->intf->dev, 600 "Error submitting int urb - %d\n", rv); 601 rv = usb_translate_errors(rv); 602 } 603 } else { 604 rv = 0; 605 } 606 mutex_unlock(&desc->wlock); 607 if (desc->count == 1) 608 desc->manage_power(intf, 1); 609 usb_autopm_put_interface(desc->intf); 610 out: 611 mutex_unlock(&wdm_mutex); 612 return rv; 613 } 614 615 static int wdm_release(struct inode *inode, struct file *file) 616 { 617 struct wdm_device *desc = file->private_data; 618 619 mutex_lock(&wdm_mutex); 620 621 /* using write lock to protect desc->count */ 622 mutex_lock(&desc->wlock); 623 desc->count--; 624 mutex_unlock(&desc->wlock); 625 626 if (!desc->count) { 627 if (!test_bit(WDM_DISCONNECTING, &desc->flags)) { 628 dev_dbg(&desc->intf->dev, "wdm_release: cleanup"); 629 kill_urbs(desc); 630 desc->manage_power(desc->intf, 0); 631 } else { 632 /* must avoid dev_printk here as desc->intf is invalid */ 633 pr_debug(KBUILD_MODNAME " %s: device gone - cleaning up\n", __func__); 634 cleanup(desc); 635 } 636 } 637 mutex_unlock(&wdm_mutex); 638 return 0; 639 } 640 641 static const struct file_operations wdm_fops = { 642 .owner = THIS_MODULE, 643 .read = wdm_read, 644 .write = wdm_write, 645 .open = wdm_open, 646 .flush = wdm_flush, 647 .release = wdm_release, 648 .poll = wdm_poll, 649 .llseek = noop_llseek, 650 }; 651 652 static struct usb_class_driver wdm_class = { 653 .name = "cdc-wdm%d", 654 .fops = &wdm_fops, 655 .minor_base = WDM_MINOR_BASE, 656 }; 657 658 /* --- error handling --- */ 659 static void wdm_rxwork(struct work_struct *work) 660 { 661 struct wdm_device *desc = container_of(work, struct wdm_device, rxwork); 662 unsigned long flags; 663 int rv; 664 665 spin_lock_irqsave(&desc->iuspin, flags); 666 if (test_bit(WDM_DISCONNECTING, &desc->flags)) { 667 spin_unlock_irqrestore(&desc->iuspin, flags); 668 } else { 669 spin_unlock_irqrestore(&desc->iuspin, flags); 670 rv = usb_submit_urb(desc->response, GFP_KERNEL); 671 if (rv < 0 && rv != -EPERM) { 672 spin_lock_irqsave(&desc->iuspin, flags); 673 if (!test_bit(WDM_DISCONNECTING, &desc->flags)) 674 schedule_work(&desc->rxwork); 675 spin_unlock_irqrestore(&desc->iuspin, flags); 676 } 677 } 678 } 679 680 /* --- hotplug --- */ 681 682 static int wdm_create(struct usb_interface *intf, struct usb_endpoint_descriptor *ep, 683 u16 bufsize, int (*manage_power)(struct usb_interface *, int)) 684 { 685 int rv = -ENOMEM; 686 struct wdm_device *desc; 687 688 desc = kzalloc(sizeof(struct wdm_device), GFP_KERNEL); 689 if (!desc) 690 goto out; 691 INIT_LIST_HEAD(&desc->device_list); 692 mutex_init(&desc->rlock); 693 mutex_init(&desc->wlock); 694 spin_lock_init(&desc->iuspin); 695 init_waitqueue_head(&desc->wait); 696 desc->wMaxCommand = bufsize; 697 /* this will be expanded and needed in hardware endianness */ 698 desc->inum = cpu_to_le16((u16)intf->cur_altsetting->desc.bInterfaceNumber); 699 desc->intf = intf; 700 INIT_WORK(&desc->rxwork, wdm_rxwork); 701 702 rv = -EINVAL; 703 if (!usb_endpoint_is_int_in(ep)) 704 goto err; 705 706 desc->wMaxPacketSize = usb_endpoint_maxp(ep); 707 708 desc->orq = kmalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL); 709 if (!desc->orq) 710 goto err; 711 desc->irq = kmalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL); 712 if (!desc->irq) 713 goto err; 714 715 desc->validity = usb_alloc_urb(0, GFP_KERNEL); 716 if (!desc->validity) 717 goto err; 718 719 desc->response = usb_alloc_urb(0, GFP_KERNEL); 720 if (!desc->response) 721 goto err; 722 723 desc->command = usb_alloc_urb(0, GFP_KERNEL); 724 if (!desc->command) 725 goto err; 726 727 desc->ubuf = kmalloc(desc->wMaxCommand, GFP_KERNEL); 728 if (!desc->ubuf) 729 goto err; 730 731 desc->sbuf = kmalloc(desc->wMaxPacketSize, GFP_KERNEL); 732 if (!desc->sbuf) 733 goto err; 734 735 desc->inbuf = kmalloc(desc->wMaxCommand, GFP_KERNEL); 736 if (!desc->inbuf) 737 goto err; 738 739 usb_fill_int_urb( 740 desc->validity, 741 interface_to_usbdev(intf), 742 usb_rcvintpipe(interface_to_usbdev(intf), ep->bEndpointAddress), 743 desc->sbuf, 744 desc->wMaxPacketSize, 745 wdm_int_callback, 746 desc, 747 ep->bInterval 748 ); 749 750 desc->irq->bRequestType = (USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE); 751 desc->irq->bRequest = USB_CDC_GET_ENCAPSULATED_RESPONSE; 752 desc->irq->wValue = 0; 753 desc->irq->wIndex = desc->inum; 754 desc->irq->wLength = cpu_to_le16(desc->wMaxCommand); 755 756 usb_fill_control_urb( 757 desc->response, 758 interface_to_usbdev(intf), 759 /* using common endpoint 0 */ 760 usb_rcvctrlpipe(interface_to_usbdev(desc->intf), 0), 761 (unsigned char *)desc->irq, 762 desc->inbuf, 763 desc->wMaxCommand, 764 wdm_in_callback, 765 desc 766 ); 767 768 desc->manage_power = manage_power; 769 770 spin_lock(&wdm_device_list_lock); 771 list_add(&desc->device_list, &wdm_device_list); 772 spin_unlock(&wdm_device_list_lock); 773 774 rv = usb_register_dev(intf, &wdm_class); 775 if (rv < 0) 776 goto err; 777 else 778 dev_info(&intf->dev, "%s: USB WDM device\n", dev_name(intf->usb_dev)); 779 out: 780 return rv; 781 err: 782 spin_lock(&wdm_device_list_lock); 783 list_del(&desc->device_list); 784 spin_unlock(&wdm_device_list_lock); 785 cleanup(desc); 786 return rv; 787 } 788 789 static int wdm_manage_power(struct usb_interface *intf, int on) 790 { 791 /* need autopm_get/put here to ensure the usbcore sees the new value */ 792 int rv = usb_autopm_get_interface(intf); 793 if (rv < 0) 794 goto err; 795 796 intf->needs_remote_wakeup = on; 797 usb_autopm_put_interface(intf); 798 err: 799 return rv; 800 } 801 802 static int wdm_probe(struct usb_interface *intf, const struct usb_device_id *id) 803 { 804 int rv = -EINVAL; 805 struct usb_host_interface *iface; 806 struct usb_endpoint_descriptor *ep; 807 struct usb_cdc_dmm_desc *dmhd; 808 u8 *buffer = intf->altsetting->extra; 809 int buflen = intf->altsetting->extralen; 810 u16 maxcom = WDM_DEFAULT_BUFSIZE; 811 812 if (!buffer) 813 goto err; 814 while (buflen > 2) { 815 if (buffer[1] != USB_DT_CS_INTERFACE) { 816 dev_err(&intf->dev, "skipping garbage\n"); 817 goto next_desc; 818 } 819 820 switch (buffer[2]) { 821 case USB_CDC_HEADER_TYPE: 822 break; 823 case USB_CDC_DMM_TYPE: 824 dmhd = (struct usb_cdc_dmm_desc *)buffer; 825 maxcom = le16_to_cpu(dmhd->wMaxCommand); 826 dev_dbg(&intf->dev, 827 "Finding maximum buffer length: %d", maxcom); 828 break; 829 default: 830 dev_err(&intf->dev, 831 "Ignoring extra header, type %d, length %d\n", 832 buffer[2], buffer[0]); 833 break; 834 } 835 next_desc: 836 buflen -= buffer[0]; 837 buffer += buffer[0]; 838 } 839 840 iface = intf->cur_altsetting; 841 if (iface->desc.bNumEndpoints != 1) 842 goto err; 843 ep = &iface->endpoint[0].desc; 844 845 rv = wdm_create(intf, ep, maxcom, &wdm_manage_power); 846 847 err: 848 return rv; 849 } 850 851 /** 852 * usb_cdc_wdm_register - register a WDM subdriver 853 * @intf: usb interface the subdriver will associate with 854 * @ep: interrupt endpoint to monitor for notifications 855 * @bufsize: maximum message size to support for read/write 856 * 857 * Create WDM usb class character device and associate it with intf 858 * without binding, allowing another driver to manage the interface. 859 * 860 * The subdriver will manage the given interrupt endpoint exclusively 861 * and will issue control requests referring to the given intf. It 862 * will otherwise avoid interferring, and in particular not do 863 * usb_set_intfdata/usb_get_intfdata on intf. 864 * 865 * The return value is a pointer to the subdriver's struct usb_driver. 866 * The registering driver is responsible for calling this subdriver's 867 * disconnect, suspend, resume, pre_reset and post_reset methods from 868 * its own. 869 */ 870 struct usb_driver *usb_cdc_wdm_register(struct usb_interface *intf, 871 struct usb_endpoint_descriptor *ep, 872 int bufsize, 873 int (*manage_power)(struct usb_interface *, int)) 874 { 875 int rv = -EINVAL; 876 877 rv = wdm_create(intf, ep, bufsize, manage_power); 878 if (rv < 0) 879 goto err; 880 881 return &wdm_driver; 882 err: 883 return ERR_PTR(rv); 884 } 885 EXPORT_SYMBOL(usb_cdc_wdm_register); 886 887 static void wdm_disconnect(struct usb_interface *intf) 888 { 889 struct wdm_device *desc; 890 unsigned long flags; 891 892 usb_deregister_dev(intf, &wdm_class); 893 desc = wdm_find_device(intf); 894 mutex_lock(&wdm_mutex); 895 896 /* the spinlock makes sure no new urbs are generated in the callbacks */ 897 spin_lock_irqsave(&desc->iuspin, flags); 898 set_bit(WDM_DISCONNECTING, &desc->flags); 899 set_bit(WDM_READ, &desc->flags); 900 /* to terminate pending flushes */ 901 clear_bit(WDM_IN_USE, &desc->flags); 902 spin_unlock_irqrestore(&desc->iuspin, flags); 903 wake_up_all(&desc->wait); 904 mutex_lock(&desc->rlock); 905 mutex_lock(&desc->wlock); 906 kill_urbs(desc); 907 cancel_work_sync(&desc->rxwork); 908 mutex_unlock(&desc->wlock); 909 mutex_unlock(&desc->rlock); 910 911 /* the desc->intf pointer used as list key is now invalid */ 912 spin_lock(&wdm_device_list_lock); 913 list_del(&desc->device_list); 914 spin_unlock(&wdm_device_list_lock); 915 916 if (!desc->count) 917 cleanup(desc); 918 else 919 dev_dbg(&intf->dev, "%s: %d open files - postponing cleanup\n", __func__, desc->count); 920 mutex_unlock(&wdm_mutex); 921 } 922 923 #ifdef CONFIG_PM 924 static int wdm_suspend(struct usb_interface *intf, pm_message_t message) 925 { 926 struct wdm_device *desc = wdm_find_device(intf); 927 int rv = 0; 928 929 dev_dbg(&desc->intf->dev, "wdm%d_suspend\n", intf->minor); 930 931 /* if this is an autosuspend the caller does the locking */ 932 if (!PMSG_IS_AUTO(message)) { 933 mutex_lock(&desc->rlock); 934 mutex_lock(&desc->wlock); 935 } 936 spin_lock_irq(&desc->iuspin); 937 938 if (PMSG_IS_AUTO(message) && 939 (test_bit(WDM_IN_USE, &desc->flags) 940 || test_bit(WDM_RESPONDING, &desc->flags))) { 941 spin_unlock_irq(&desc->iuspin); 942 rv = -EBUSY; 943 } else { 944 945 set_bit(WDM_SUSPENDING, &desc->flags); 946 spin_unlock_irq(&desc->iuspin); 947 /* callback submits work - order is essential */ 948 kill_urbs(desc); 949 cancel_work_sync(&desc->rxwork); 950 } 951 if (!PMSG_IS_AUTO(message)) { 952 mutex_unlock(&desc->wlock); 953 mutex_unlock(&desc->rlock); 954 } 955 956 return rv; 957 } 958 #endif 959 960 static int recover_from_urb_loss(struct wdm_device *desc) 961 { 962 int rv = 0; 963 964 if (desc->count) { 965 rv = usb_submit_urb(desc->validity, GFP_NOIO); 966 if (rv < 0) 967 dev_err(&desc->intf->dev, 968 "Error resume submitting int urb - %d\n", rv); 969 } 970 return rv; 971 } 972 973 #ifdef CONFIG_PM 974 static int wdm_resume(struct usb_interface *intf) 975 { 976 struct wdm_device *desc = wdm_find_device(intf); 977 int rv; 978 979 dev_dbg(&desc->intf->dev, "wdm%d_resume\n", intf->minor); 980 981 clear_bit(WDM_SUSPENDING, &desc->flags); 982 rv = recover_from_urb_loss(desc); 983 984 return rv; 985 } 986 #endif 987 988 static int wdm_pre_reset(struct usb_interface *intf) 989 { 990 struct wdm_device *desc = wdm_find_device(intf); 991 992 /* 993 * we notify everybody using poll of 994 * an exceptional situation 995 * must be done before recovery lest a spontaneous 996 * message from the device is lost 997 */ 998 spin_lock_irq(&desc->iuspin); 999 set_bit(WDM_RESETTING, &desc->flags); /* inform read/write */ 1000 set_bit(WDM_READ, &desc->flags); /* unblock read */ 1001 clear_bit(WDM_IN_USE, &desc->flags); /* unblock write */ 1002 desc->rerr = -EINTR; 1003 spin_unlock_irq(&desc->iuspin); 1004 wake_up_all(&desc->wait); 1005 mutex_lock(&desc->rlock); 1006 mutex_lock(&desc->wlock); 1007 kill_urbs(desc); 1008 cancel_work_sync(&desc->rxwork); 1009 return 0; 1010 } 1011 1012 static int wdm_post_reset(struct usb_interface *intf) 1013 { 1014 struct wdm_device *desc = wdm_find_device(intf); 1015 int rv; 1016 1017 clear_bit(WDM_RESETTING, &desc->flags); 1018 rv = recover_from_urb_loss(desc); 1019 mutex_unlock(&desc->wlock); 1020 mutex_unlock(&desc->rlock); 1021 return 0; 1022 } 1023 1024 static struct usb_driver wdm_driver = { 1025 .name = "cdc_wdm", 1026 .probe = wdm_probe, 1027 .disconnect = wdm_disconnect, 1028 #ifdef CONFIG_PM 1029 .suspend = wdm_suspend, 1030 .resume = wdm_resume, 1031 .reset_resume = wdm_resume, 1032 #endif 1033 .pre_reset = wdm_pre_reset, 1034 .post_reset = wdm_post_reset, 1035 .id_table = wdm_ids, 1036 .supports_autosuspend = 1, 1037 .disable_hub_initiated_lpm = 1, 1038 }; 1039 1040 module_usb_driver(wdm_driver); 1041 1042 MODULE_AUTHOR(DRIVER_AUTHOR); 1043 MODULE_DESCRIPTION(DRIVER_DESC); 1044 MODULE_LICENSE("GPL"); 1045