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 37static 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 70MODULE_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 90static DEFINE_MUTEX(wdm_mutex); 91static DEFINE_SPINLOCK(wdm_device_list_lock); 92static LIST_HEAD(wdm_device_list); 93 94/* --- method tables --- */ 95 96struct 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 132static struct usb_driver wdm_driver; 133 134/* return intfdata if we own the interface, else look up intf in the list */ 135static 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 148static 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 --- */ 162static 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 175static 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; 212skip_error: 213 wake_up(&desc->wait); 214 215 set_bit(WDM_READ, &desc->flags); 216 spin_unlock(&desc->iuspin); 217} 218 219static 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) { 288sw: 289 rv = schedule_work(&desc->rxwork); 290 if (rv) 291 dev_err(&desc->intf->dev, 292 "Cannot schedule work\n"); 293 } 294 } 295exit: 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 304static 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 312static 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 319static 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 330static 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 goto outnp; 379 } 380 381 if (!(file->f_flags & O_NONBLOCK)) 382 r = wait_event_interruptible(desc->wait, !test_bit(WDM_IN_USE, 383 &desc->flags)); 384 else 385 if (test_bit(WDM_IN_USE, &desc->flags)) 386 r = -EAGAIN; 387 388 if (test_bit(WDM_RESETTING, &desc->flags)) 389 r = -EIO; 390 391 if (r < 0) { 392 kfree(buf); 393 goto out; 394 } 395 396 req = desc->orq; 397 usb_fill_control_urb( 398 desc->command, 399 interface_to_usbdev(desc->intf), 400 /* using common endpoint 0 */ 401 usb_sndctrlpipe(interface_to_usbdev(desc->intf), 0), 402 (unsigned char *)req, 403 buf, 404 count, 405 wdm_out_callback, 406 desc 407 ); 408 409 req->bRequestType = (USB_DIR_OUT | USB_TYPE_CLASS | 410 USB_RECIP_INTERFACE); 411 req->bRequest = USB_CDC_SEND_ENCAPSULATED_COMMAND; 412 req->wValue = 0; 413 req->wIndex = desc->inum; 414 req->wLength = cpu_to_le16(count); 415 set_bit(WDM_IN_USE, &desc->flags); 416 desc->outbuf = buf; 417 418 rv = usb_submit_urb(desc->command, GFP_KERNEL); 419 if (rv < 0) { 420 kfree(buf); 421 desc->outbuf = NULL; 422 clear_bit(WDM_IN_USE, &desc->flags); 423 dev_err(&desc->intf->dev, "Tx URB error: %d\n", rv); 424 } else { 425 dev_dbg(&desc->intf->dev, "Tx URB has been submitted index=%d", 426 req->wIndex); 427 } 428out: 429 usb_autopm_put_interface(desc->intf); 430outnp: 431 mutex_unlock(&desc->wlock); 432outnl: 433 return rv < 0 ? rv : count; 434} 435 436static ssize_t wdm_read 437(struct file *file, char __user *buffer, size_t count, loff_t *ppos) 438{ 439 int rv, cntr; 440 int i = 0; 441 struct wdm_device *desc = file->private_data; 442 443 444 rv = mutex_lock_interruptible(&desc->rlock); /*concurrent reads */ 445 if (rv < 0) 446 return -ERESTARTSYS; 447 448 cntr = ACCESS_ONCE(desc->length); 449 if (cntr == 0) { 450 desc->read = 0; 451retry: 452 if (test_bit(WDM_DISCONNECTING, &desc->flags)) { 453 rv = -ENODEV; 454 goto err; 455 } 456 i++; 457 if (file->f_flags & O_NONBLOCK) { 458 if (!test_bit(WDM_READ, &desc->flags)) { 459 rv = cntr ? cntr : -EAGAIN; 460 goto err; 461 } 462 rv = 0; 463 } else { 464 rv = wait_event_interruptible(desc->wait, 465 test_bit(WDM_READ, &desc->flags)); 466 } 467 468 /* may have happened while we slept */ 469 if (test_bit(WDM_DISCONNECTING, &desc->flags)) { 470 rv = -ENODEV; 471 goto err; 472 } 473 if (test_bit(WDM_RESETTING, &desc->flags)) { 474 rv = -EIO; 475 goto err; 476 } 477 usb_mark_last_busy(interface_to_usbdev(desc->intf)); 478 if (rv < 0) { 479 rv = -ERESTARTSYS; 480 goto err; 481 } 482 483 spin_lock_irq(&desc->iuspin); 484 485 if (desc->rerr) { /* read completed, error happened */ 486 desc->rerr = 0; 487 spin_unlock_irq(&desc->iuspin); 488 rv = -EIO; 489 goto err; 490 } 491 /* 492 * recheck whether we've lost the race 493 * against the completion handler 494 */ 495 if (!test_bit(WDM_READ, &desc->flags)) { /* lost race */ 496 spin_unlock_irq(&desc->iuspin); 497 goto retry; 498 } 499 if (!desc->reslength) { /* zero length read */ 500 dev_dbg(&desc->intf->dev, "%s: zero length - clearing WDM_READ\n", __func__); 501 clear_bit(WDM_READ, &desc->flags); 502 spin_unlock_irq(&desc->iuspin); 503 goto retry; 504 } 505 cntr = desc->length; 506 spin_unlock_irq(&desc->iuspin); 507 } 508 509 if (cntr > count) 510 cntr = count; 511 rv = copy_to_user(buffer, desc->ubuf, cntr); 512 if (rv > 0) { 513 rv = -EFAULT; 514 goto err; 515 } 516 517 spin_lock_irq(&desc->iuspin); 518 519 for (i = 0; i < desc->length - cntr; i++) 520 desc->ubuf[i] = desc->ubuf[i + cntr]; 521 522 desc->length -= cntr; 523 /* in case we had outstanding data */ 524 if (!desc->length) 525 clear_bit(WDM_READ, &desc->flags); 526 527 spin_unlock_irq(&desc->iuspin); 528 529 rv = cntr; 530 531err: 532 mutex_unlock(&desc->rlock); 533 return rv; 534} 535 536static int wdm_flush(struct file *file, fl_owner_t id) 537{ 538 struct wdm_device *desc = file->private_data; 539 540 wait_event(desc->wait, !test_bit(WDM_IN_USE, &desc->flags)); 541 542 /* cannot dereference desc->intf if WDM_DISCONNECTING */ 543 if (desc->werr < 0 && !test_bit(WDM_DISCONNECTING, &desc->flags)) 544 dev_err(&desc->intf->dev, "Error in flush path: %d\n", 545 desc->werr); 546 547 return usb_translate_errors(desc->werr); 548} 549 550static unsigned int wdm_poll(struct file *file, struct poll_table_struct *wait) 551{ 552 struct wdm_device *desc = file->private_data; 553 unsigned long flags; 554 unsigned int mask = 0; 555 556 spin_lock_irqsave(&desc->iuspin, flags); 557 if (test_bit(WDM_DISCONNECTING, &desc->flags)) { 558 mask = POLLHUP | POLLERR; 559 spin_unlock_irqrestore(&desc->iuspin, flags); 560 goto desc_out; 561 } 562 if (test_bit(WDM_READ, &desc->flags)) 563 mask = POLLIN | POLLRDNORM; 564 if (desc->rerr || desc->werr) 565 mask |= POLLERR; 566 if (!test_bit(WDM_IN_USE, &desc->flags)) 567 mask |= POLLOUT | POLLWRNORM; 568 spin_unlock_irqrestore(&desc->iuspin, flags); 569 570 poll_wait(file, &desc->wait, wait); 571 572desc_out: 573 return mask; 574} 575 576static int wdm_open(struct inode *inode, struct file *file) 577{ 578 int minor = iminor(inode); 579 int rv = -ENODEV; 580 struct usb_interface *intf; 581 struct wdm_device *desc; 582 583 mutex_lock(&wdm_mutex); 584 desc = wdm_find_device_by_minor(minor); 585 if (!desc) 586 goto out; 587 588 intf = desc->intf; 589 if (test_bit(WDM_DISCONNECTING, &desc->flags)) 590 goto out; 591 file->private_data = desc; 592 593 rv = usb_autopm_get_interface(desc->intf); 594 if (rv < 0) { 595 dev_err(&desc->intf->dev, "Error autopm - %d\n", rv); 596 goto out; 597 } 598 599 /* using write lock to protect desc->count */ 600 mutex_lock(&desc->wlock); 601 if (!desc->count++) { 602 desc->werr = 0; 603 desc->rerr = 0; 604 rv = usb_submit_urb(desc->validity, GFP_KERNEL); 605 if (rv < 0) { 606 desc->count--; 607 dev_err(&desc->intf->dev, 608 "Error submitting int urb - %d\n", rv); 609 } 610 } else { 611 rv = 0; 612 } 613 mutex_unlock(&desc->wlock); 614 if (desc->count == 1) 615 desc->manage_power(intf, 1); 616 usb_autopm_put_interface(desc->intf); 617out: 618 mutex_unlock(&wdm_mutex); 619 return rv; 620} 621 622static int wdm_release(struct inode *inode, struct file *file) 623{ 624 struct wdm_device *desc = file->private_data; 625 626 mutex_lock(&wdm_mutex); 627 628 /* using write lock to protect desc->count */ 629 mutex_lock(&desc->wlock); 630 desc->count--; 631 mutex_unlock(&desc->wlock); 632 633 if (!desc->count) { 634 if (!test_bit(WDM_DISCONNECTING, &desc->flags)) { 635 dev_dbg(&desc->intf->dev, "wdm_release: cleanup"); 636 kill_urbs(desc); 637 desc->manage_power(desc->intf, 0); 638 } else { 639 /* must avoid dev_printk here as desc->intf is invalid */ 640 pr_debug(KBUILD_MODNAME " %s: device gone - cleaning up\n", __func__); 641 cleanup(desc); 642 } 643 } 644 mutex_unlock(&wdm_mutex); 645 return 0; 646} 647 648static const struct file_operations wdm_fops = { 649 .owner = THIS_MODULE, 650 .read = wdm_read, 651 .write = wdm_write, 652 .open = wdm_open, 653 .flush = wdm_flush, 654 .release = wdm_release, 655 .poll = wdm_poll, 656 .llseek = noop_llseek, 657}; 658 659static struct usb_class_driver wdm_class = { 660 .name = "cdc-wdm%d", 661 .fops = &wdm_fops, 662 .minor_base = WDM_MINOR_BASE, 663}; 664 665/* --- error handling --- */ 666static void wdm_rxwork(struct work_struct *work) 667{ 668 struct wdm_device *desc = container_of(work, struct wdm_device, rxwork); 669 unsigned long flags; 670 int rv; 671 672 spin_lock_irqsave(&desc->iuspin, flags); 673 if (test_bit(WDM_DISCONNECTING, &desc->flags)) { 674 spin_unlock_irqrestore(&desc->iuspin, flags); 675 } else { 676 spin_unlock_irqrestore(&desc->iuspin, flags); 677 rv = usb_submit_urb(desc->response, GFP_KERNEL); 678 if (rv < 0 && rv != -EPERM) { 679 spin_lock_irqsave(&desc->iuspin, flags); 680 if (!test_bit(WDM_DISCONNECTING, &desc->flags)) 681 schedule_work(&desc->rxwork); 682 spin_unlock_irqrestore(&desc->iuspin, flags); 683 } 684 } 685} 686 687/* --- hotplug --- */ 688 689static int wdm_create(struct usb_interface *intf, struct usb_endpoint_descriptor *ep, 690 u16 bufsize, int (*manage_power)(struct usb_interface *, int)) 691{ 692 int rv = -ENOMEM; 693 struct wdm_device *desc; 694 695 desc = kzalloc(sizeof(struct wdm_device), GFP_KERNEL); 696 if (!desc) 697 goto out; 698 INIT_LIST_HEAD(&desc->device_list); 699 mutex_init(&desc->rlock); 700 mutex_init(&desc->wlock); 701 spin_lock_init(&desc->iuspin); 702 init_waitqueue_head(&desc->wait); 703 desc->wMaxCommand = bufsize; 704 /* this will be expanded and needed in hardware endianness */ 705 desc->inum = cpu_to_le16((u16)intf->cur_altsetting->desc.bInterfaceNumber); 706 desc->intf = intf; 707 INIT_WORK(&desc->rxwork, wdm_rxwork); 708 709 rv = -EINVAL; 710 if (!usb_endpoint_is_int_in(ep)) 711 goto err; 712 713 desc->wMaxPacketSize = usb_endpoint_maxp(ep); 714 715 desc->orq = kmalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL); 716 if (!desc->orq) 717 goto err; 718 desc->irq = kmalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL); 719 if (!desc->irq) 720 goto err; 721 722 desc->validity = usb_alloc_urb(0, GFP_KERNEL); 723 if (!desc->validity) 724 goto err; 725 726 desc->response = usb_alloc_urb(0, GFP_KERNEL); 727 if (!desc->response) 728 goto err; 729 730 desc->command = usb_alloc_urb(0, GFP_KERNEL); 731 if (!desc->command) 732 goto err; 733 734 desc->ubuf = kmalloc(desc->wMaxCommand, GFP_KERNEL); 735 if (!desc->ubuf) 736 goto err; 737 738 desc->sbuf = kmalloc(desc->wMaxPacketSize, GFP_KERNEL); 739 if (!desc->sbuf) 740 goto err; 741 742 desc->inbuf = kmalloc(desc->wMaxCommand, GFP_KERNEL); 743 if (!desc->inbuf) 744 goto err; 745 746 usb_fill_int_urb( 747 desc->validity, 748 interface_to_usbdev(intf), 749 usb_rcvintpipe(interface_to_usbdev(intf), ep->bEndpointAddress), 750 desc->sbuf, 751 desc->wMaxPacketSize, 752 wdm_int_callback, 753 desc, 754 ep->bInterval 755 ); 756 757 desc->irq->bRequestType = (USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE); 758 desc->irq->bRequest = USB_CDC_GET_ENCAPSULATED_RESPONSE; 759 desc->irq->wValue = 0; 760 desc->irq->wIndex = desc->inum; 761 desc->irq->wLength = cpu_to_le16(desc->wMaxCommand); 762 763 usb_fill_control_urb( 764 desc->response, 765 interface_to_usbdev(intf), 766 /* using common endpoint 0 */ 767 usb_rcvctrlpipe(interface_to_usbdev(desc->intf), 0), 768 (unsigned char *)desc->irq, 769 desc->inbuf, 770 desc->wMaxCommand, 771 wdm_in_callback, 772 desc 773 ); 774 775 desc->manage_power = manage_power; 776 777 spin_lock(&wdm_device_list_lock); 778 list_add(&desc->device_list, &wdm_device_list); 779 spin_unlock(&wdm_device_list_lock); 780 781 rv = usb_register_dev(intf, &wdm_class); 782 if (rv < 0) 783 goto err; 784 else 785 dev_info(&intf->dev, "%s: USB WDM device\n", dev_name(intf->usb_dev)); 786out: 787 return rv; 788err: 789 spin_lock(&wdm_device_list_lock); 790 list_del(&desc->device_list); 791 spin_unlock(&wdm_device_list_lock); 792 cleanup(desc); 793 return rv; 794} 795 796static int wdm_manage_power(struct usb_interface *intf, int on) 797{ 798 /* need autopm_get/put here to ensure the usbcore sees the new value */ 799 int rv = usb_autopm_get_interface(intf); 800 if (rv < 0) 801 goto err; 802 803 intf->needs_remote_wakeup = on; 804 usb_autopm_put_interface(intf); 805err: 806 return rv; 807} 808 809static int wdm_probe(struct usb_interface *intf, const struct usb_device_id *id) 810{ 811 int rv = -EINVAL; 812 struct usb_host_interface *iface; 813 struct usb_endpoint_descriptor *ep; 814 struct usb_cdc_dmm_desc *dmhd; 815 u8 *buffer = intf->altsetting->extra; 816 int buflen = intf->altsetting->extralen; 817 u16 maxcom = WDM_DEFAULT_BUFSIZE; 818 819 if (!buffer) 820 goto err; 821 while (buflen > 2) { 822 if (buffer[1] != USB_DT_CS_INTERFACE) { 823 dev_err(&intf->dev, "skipping garbage\n"); 824 goto next_desc; 825 } 826 827 switch (buffer[2]) { 828 case USB_CDC_HEADER_TYPE: 829 break; 830 case USB_CDC_DMM_TYPE: 831 dmhd = (struct usb_cdc_dmm_desc *)buffer; 832 maxcom = le16_to_cpu(dmhd->wMaxCommand); 833 dev_dbg(&intf->dev, 834 "Finding maximum buffer length: %d", maxcom); 835 break; 836 default: 837 dev_err(&intf->dev, 838 "Ignoring extra header, type %d, length %d\n", 839 buffer[2], buffer[0]); 840 break; 841 } 842next_desc: 843 buflen -= buffer[0]; 844 buffer += buffer[0]; 845 } 846 847 iface = intf->cur_altsetting; 848 if (iface->desc.bNumEndpoints != 1) 849 goto err; 850 ep = &iface->endpoint[0].desc; 851 852 rv = wdm_create(intf, ep, maxcom, &wdm_manage_power); 853 854err: 855 return rv; 856} 857 858/** 859 * usb_cdc_wdm_register - register a WDM subdriver 860 * @intf: usb interface the subdriver will associate with 861 * @ep: interrupt endpoint to monitor for notifications 862 * @bufsize: maximum message size to support for read/write 863 * 864 * Create WDM usb class character device and associate it with intf 865 * without binding, allowing another driver to manage the interface. 866 * 867 * The subdriver will manage the given interrupt endpoint exclusively 868 * and will issue control requests referring to the given intf. It 869 * will otherwise avoid interferring, and in particular not do 870 * usb_set_intfdata/usb_get_intfdata on intf. 871 * 872 * The return value is a pointer to the subdriver's struct usb_driver. 873 * The registering driver is responsible for calling this subdriver's 874 * disconnect, suspend, resume, pre_reset and post_reset methods from 875 * its own. 876 */ 877struct usb_driver *usb_cdc_wdm_register(struct usb_interface *intf, 878 struct usb_endpoint_descriptor *ep, 879 int bufsize, 880 int (*manage_power)(struct usb_interface *, int)) 881{ 882 int rv = -EINVAL; 883 884 rv = wdm_create(intf, ep, bufsize, manage_power); 885 if (rv < 0) 886 goto err; 887 888 return &wdm_driver; 889err: 890 return ERR_PTR(rv); 891} 892EXPORT_SYMBOL(usb_cdc_wdm_register); 893 894static void wdm_disconnect(struct usb_interface *intf) 895{ 896 struct wdm_device *desc; 897 unsigned long flags; 898 899 usb_deregister_dev(intf, &wdm_class); 900 desc = wdm_find_device(intf); 901 mutex_lock(&wdm_mutex); 902 903 /* the spinlock makes sure no new urbs are generated in the callbacks */ 904 spin_lock_irqsave(&desc->iuspin, flags); 905 set_bit(WDM_DISCONNECTING, &desc->flags); 906 set_bit(WDM_READ, &desc->flags); 907 /* to terminate pending flushes */ 908 clear_bit(WDM_IN_USE, &desc->flags); 909 spin_unlock_irqrestore(&desc->iuspin, flags); 910 wake_up_all(&desc->wait); 911 mutex_lock(&desc->rlock); 912 mutex_lock(&desc->wlock); 913 kill_urbs(desc); 914 cancel_work_sync(&desc->rxwork); 915 mutex_unlock(&desc->wlock); 916 mutex_unlock(&desc->rlock); 917 918 /* the desc->intf pointer used as list key is now invalid */ 919 spin_lock(&wdm_device_list_lock); 920 list_del(&desc->device_list); 921 spin_unlock(&wdm_device_list_lock); 922 923 if (!desc->count) 924 cleanup(desc); 925 mutex_unlock(&wdm_mutex); 926} 927 928#ifdef CONFIG_PM 929static int wdm_suspend(struct usb_interface *intf, pm_message_t message) 930{ 931 struct wdm_device *desc = wdm_find_device(intf); 932 int rv = 0; 933 934 dev_dbg(&desc->intf->dev, "wdm%d_suspend\n", intf->minor); 935 936 /* if this is an autosuspend the caller does the locking */ 937 if (!PMSG_IS_AUTO(message)) { 938 mutex_lock(&desc->rlock); 939 mutex_lock(&desc->wlock); 940 } 941 spin_lock_irq(&desc->iuspin); 942 943 if (PMSG_IS_AUTO(message) && 944 (test_bit(WDM_IN_USE, &desc->flags) 945 || test_bit(WDM_RESPONDING, &desc->flags))) { 946 spin_unlock_irq(&desc->iuspin); 947 rv = -EBUSY; 948 } else { 949 950 set_bit(WDM_SUSPENDING, &desc->flags); 951 spin_unlock_irq(&desc->iuspin); 952 /* callback submits work - order is essential */ 953 kill_urbs(desc); 954 cancel_work_sync(&desc->rxwork); 955 } 956 if (!PMSG_IS_AUTO(message)) { 957 mutex_unlock(&desc->wlock); 958 mutex_unlock(&desc->rlock); 959 } 960 961 return rv; 962} 963#endif 964 965static int recover_from_urb_loss(struct wdm_device *desc) 966{ 967 int rv = 0; 968 969 if (desc->count) { 970 rv = usb_submit_urb(desc->validity, GFP_NOIO); 971 if (rv < 0) 972 dev_err(&desc->intf->dev, 973 "Error resume submitting int urb - %d\n", rv); 974 } 975 return rv; 976} 977 978#ifdef CONFIG_PM 979static int wdm_resume(struct usb_interface *intf) 980{ 981 struct wdm_device *desc = wdm_find_device(intf); 982 int rv; 983 984 dev_dbg(&desc->intf->dev, "wdm%d_resume\n", intf->minor); 985 986 clear_bit(WDM_SUSPENDING, &desc->flags); 987 rv = recover_from_urb_loss(desc); 988 989 return rv; 990} 991#endif 992 993static int wdm_pre_reset(struct usb_interface *intf) 994{ 995 struct wdm_device *desc = wdm_find_device(intf); 996 997 /* 998 * we notify everybody using poll of 999 * an exceptional situation 1000 * must be done before recovery lest a spontaneous 1001 * message from the device is lost 1002 */ 1003 spin_lock_irq(&desc->iuspin); 1004 set_bit(WDM_RESETTING, &desc->flags); /* inform read/write */ 1005 set_bit(WDM_READ, &desc->flags); /* unblock read */ 1006 clear_bit(WDM_IN_USE, &desc->flags); /* unblock write */ 1007 desc->rerr = -EINTR; 1008 spin_unlock_irq(&desc->iuspin); 1009 wake_up_all(&desc->wait); 1010 mutex_lock(&desc->rlock); 1011 mutex_lock(&desc->wlock); 1012 kill_urbs(desc); 1013 cancel_work_sync(&desc->rxwork); 1014 return 0; 1015} 1016 1017static int wdm_post_reset(struct usb_interface *intf) 1018{ 1019 struct wdm_device *desc = wdm_find_device(intf); 1020 int rv; 1021 1022 clear_bit(WDM_RESETTING, &desc->flags); 1023 rv = recover_from_urb_loss(desc); 1024 mutex_unlock(&desc->wlock); 1025 mutex_unlock(&desc->rlock); 1026 return 0; 1027} 1028 1029static struct usb_driver wdm_driver = { 1030 .name = "cdc_wdm", 1031 .probe = wdm_probe, 1032 .disconnect = wdm_disconnect, 1033#ifdef CONFIG_PM 1034 .suspend = wdm_suspend, 1035 .resume = wdm_resume, 1036 .reset_resume = wdm_resume, 1037#endif 1038 .pre_reset = wdm_pre_reset, 1039 .post_reset = wdm_post_reset, 1040 .id_table = wdm_ids, 1041 .supports_autosuspend = 1, 1042}; 1043 1044module_usb_driver(wdm_driver); 1045 1046MODULE_AUTHOR(DRIVER_AUTHOR); 1047MODULE_DESCRIPTION(DRIVER_DESC); 1048MODULE_LICENSE("GPL"); 1049