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/ioctl.h> 17 #include <linux/slab.h> 18 #include <linux/module.h> 19 #include <linux/mutex.h> 20 #include <linux/uaccess.h> 21 #include <linux/bitops.h> 22 #include <linux/poll.h> 23 #include <linux/usb.h> 24 #include <linux/usb/cdc.h> 25 #include <asm/byteorder.h> 26 #include <asm/unaligned.h> 27 #include <linux/usb/cdc-wdm.h> 28 29 /* 30 * Version Information 31 */ 32 #define DRIVER_VERSION "v0.03" 33 #define DRIVER_AUTHOR "Oliver Neukum" 34 #define DRIVER_DESC "USB Abstract Control Model driver for USB WCM Device Management" 35 36 static const struct usb_device_id wdm_ids[] = { 37 { 38 .match_flags = USB_DEVICE_ID_MATCH_INT_CLASS | 39 USB_DEVICE_ID_MATCH_INT_SUBCLASS, 40 .bInterfaceClass = USB_CLASS_COMM, 41 .bInterfaceSubClass = USB_CDC_SUBCLASS_DMM 42 }, 43 { } 44 }; 45 46 MODULE_DEVICE_TABLE (usb, wdm_ids); 47 48 #define WDM_MINOR_BASE 176 49 50 51 #define WDM_IN_USE 1 52 #define WDM_DISCONNECTING 2 53 #define WDM_RESULT 3 54 #define WDM_READ 4 55 #define WDM_INT_STALL 5 56 #define WDM_POLL_RUNNING 6 57 #define WDM_RESPONDING 7 58 #define WDM_SUSPENDING 8 59 #define WDM_RESETTING 9 60 #define WDM_OVERFLOW 10 61 62 #define WDM_MAX 16 63 64 /* CDC-WMC r1.1 requires wMaxCommand to be "at least 256 decimal (0x100)" */ 65 #define WDM_DEFAULT_BUFSIZE 256 66 67 static DEFINE_MUTEX(wdm_mutex); 68 static DEFINE_SPINLOCK(wdm_device_list_lock); 69 static LIST_HEAD(wdm_device_list); 70 71 /* --- method tables --- */ 72 73 struct wdm_device { 74 u8 *inbuf; /* buffer for response */ 75 u8 *outbuf; /* buffer for command */ 76 u8 *sbuf; /* buffer for status */ 77 u8 *ubuf; /* buffer for copy to user space */ 78 79 struct urb *command; 80 struct urb *response; 81 struct urb *validity; 82 struct usb_interface *intf; 83 struct usb_ctrlrequest *orq; 84 struct usb_ctrlrequest *irq; 85 spinlock_t iuspin; 86 87 unsigned long flags; 88 u16 bufsize; 89 u16 wMaxCommand; 90 u16 wMaxPacketSize; 91 __le16 inum; 92 int reslength; 93 int length; 94 int read; 95 int count; 96 dma_addr_t shandle; 97 dma_addr_t ihandle; 98 struct mutex wlock; 99 struct mutex rlock; 100 wait_queue_head_t wait; 101 struct work_struct rxwork; 102 int werr; 103 int rerr; 104 int resp_count; 105 106 struct list_head device_list; 107 int (*manage_power)(struct usb_interface *, int); 108 }; 109 110 static struct usb_driver wdm_driver; 111 112 /* return intfdata if we own the interface, else look up intf in the list */ 113 static struct wdm_device *wdm_find_device(struct usb_interface *intf) 114 { 115 struct wdm_device *desc; 116 117 spin_lock(&wdm_device_list_lock); 118 list_for_each_entry(desc, &wdm_device_list, device_list) 119 if (desc->intf == intf) 120 goto found; 121 desc = NULL; 122 found: 123 spin_unlock(&wdm_device_list_lock); 124 125 return desc; 126 } 127 128 static struct wdm_device *wdm_find_device_by_minor(int minor) 129 { 130 struct wdm_device *desc; 131 132 spin_lock(&wdm_device_list_lock); 133 list_for_each_entry(desc, &wdm_device_list, device_list) 134 if (desc->intf->minor == minor) 135 goto found; 136 desc = NULL; 137 found: 138 spin_unlock(&wdm_device_list_lock); 139 140 return desc; 141 } 142 143 /* --- callbacks --- */ 144 static void wdm_out_callback(struct urb *urb) 145 { 146 struct wdm_device *desc; 147 desc = urb->context; 148 spin_lock(&desc->iuspin); 149 desc->werr = urb->status; 150 spin_unlock(&desc->iuspin); 151 kfree(desc->outbuf); 152 desc->outbuf = NULL; 153 clear_bit(WDM_IN_USE, &desc->flags); 154 wake_up(&desc->wait); 155 } 156 157 /* forward declaration */ 158 static int service_outstanding_interrupt(struct wdm_device *desc); 159 160 static void wdm_in_callback(struct urb *urb) 161 { 162 struct wdm_device *desc = urb->context; 163 int status = urb->status; 164 int length = urb->actual_length; 165 166 spin_lock(&desc->iuspin); 167 clear_bit(WDM_RESPONDING, &desc->flags); 168 169 if (status) { 170 switch (status) { 171 case -ENOENT: 172 dev_dbg(&desc->intf->dev, 173 "nonzero urb status received: -ENOENT\n"); 174 goto skip_error; 175 case -ECONNRESET: 176 dev_dbg(&desc->intf->dev, 177 "nonzero urb status received: -ECONNRESET\n"); 178 goto skip_error; 179 case -ESHUTDOWN: 180 dev_dbg(&desc->intf->dev, 181 "nonzero urb status received: -ESHUTDOWN\n"); 182 goto skip_error; 183 case -EPIPE: 184 dev_err(&desc->intf->dev, 185 "nonzero urb status received: -EPIPE\n"); 186 break; 187 default: 188 dev_err(&desc->intf->dev, 189 "Unexpected error %d\n", status); 190 break; 191 } 192 } 193 194 /* 195 * only set a new error if there is no previous error. 196 * Errors are only cleared during read/open 197 */ 198 if (desc->rerr == 0) 199 desc->rerr = status; 200 201 if (length + desc->length > desc->wMaxCommand) { 202 /* The buffer would overflow */ 203 set_bit(WDM_OVERFLOW, &desc->flags); 204 } else { 205 /* we may already be in overflow */ 206 if (!test_bit(WDM_OVERFLOW, &desc->flags)) { 207 memmove(desc->ubuf + desc->length, desc->inbuf, length); 208 desc->length += length; 209 desc->reslength = length; 210 } 211 } 212 skip_error: 213 set_bit(WDM_READ, &desc->flags); 214 wake_up(&desc->wait); 215 216 if (desc->rerr) { 217 /* 218 * Since there was an error, userspace may decide to not read 219 * any data after poll'ing. 220 * We should respond to further attempts from the device to send 221 * data, so that we can get unstuck. 222 */ 223 service_outstanding_interrupt(desc); 224 } 225 226 spin_unlock(&desc->iuspin); 227 } 228 229 static void wdm_int_callback(struct urb *urb) 230 { 231 int rv = 0; 232 int responding; 233 int status = urb->status; 234 struct wdm_device *desc; 235 struct usb_cdc_notification *dr; 236 237 desc = urb->context; 238 dr = (struct usb_cdc_notification *)desc->sbuf; 239 240 if (status) { 241 switch (status) { 242 case -ESHUTDOWN: 243 case -ENOENT: 244 case -ECONNRESET: 245 return; /* unplug */ 246 case -EPIPE: 247 set_bit(WDM_INT_STALL, &desc->flags); 248 dev_err(&desc->intf->dev, "Stall on int endpoint\n"); 249 goto sw; /* halt is cleared in work */ 250 default: 251 dev_err(&desc->intf->dev, 252 "nonzero urb status received: %d\n", status); 253 break; 254 } 255 } 256 257 if (urb->actual_length < sizeof(struct usb_cdc_notification)) { 258 dev_err(&desc->intf->dev, "wdm_int_callback - %d bytes\n", 259 urb->actual_length); 260 goto exit; 261 } 262 263 switch (dr->bNotificationType) { 264 case USB_CDC_NOTIFY_RESPONSE_AVAILABLE: 265 dev_dbg(&desc->intf->dev, 266 "NOTIFY_RESPONSE_AVAILABLE received: index %d len %d\n", 267 le16_to_cpu(dr->wIndex), le16_to_cpu(dr->wLength)); 268 break; 269 270 case USB_CDC_NOTIFY_NETWORK_CONNECTION: 271 272 dev_dbg(&desc->intf->dev, 273 "NOTIFY_NETWORK_CONNECTION %s network\n", 274 dr->wValue ? "connected to" : "disconnected from"); 275 goto exit; 276 case USB_CDC_NOTIFY_SPEED_CHANGE: 277 dev_dbg(&desc->intf->dev, "SPEED_CHANGE received (len %u)\n", 278 urb->actual_length); 279 goto exit; 280 default: 281 clear_bit(WDM_POLL_RUNNING, &desc->flags); 282 dev_err(&desc->intf->dev, 283 "unknown notification %d received: index %d len %d\n", 284 dr->bNotificationType, 285 le16_to_cpu(dr->wIndex), 286 le16_to_cpu(dr->wLength)); 287 goto exit; 288 } 289 290 spin_lock(&desc->iuspin); 291 responding = test_and_set_bit(WDM_RESPONDING, &desc->flags); 292 if (!desc->resp_count++ && !responding 293 && !test_bit(WDM_DISCONNECTING, &desc->flags) 294 && !test_bit(WDM_SUSPENDING, &desc->flags)) { 295 rv = usb_submit_urb(desc->response, GFP_ATOMIC); 296 dev_dbg(&desc->intf->dev, "submit response URB %d\n", rv); 297 } 298 spin_unlock(&desc->iuspin); 299 if (rv < 0) { 300 clear_bit(WDM_RESPONDING, &desc->flags); 301 if (rv == -EPERM) 302 return; 303 if (rv == -ENOMEM) { 304 sw: 305 rv = schedule_work(&desc->rxwork); 306 if (rv) 307 dev_err(&desc->intf->dev, 308 "Cannot schedule work\n"); 309 } 310 } 311 exit: 312 rv = usb_submit_urb(urb, GFP_ATOMIC); 313 if (rv) 314 dev_err(&desc->intf->dev, 315 "%s - usb_submit_urb failed with result %d\n", 316 __func__, rv); 317 318 } 319 320 static void kill_urbs(struct wdm_device *desc) 321 { 322 /* the order here is essential */ 323 usb_kill_urb(desc->command); 324 usb_kill_urb(desc->validity); 325 usb_kill_urb(desc->response); 326 } 327 328 static void free_urbs(struct wdm_device *desc) 329 { 330 usb_free_urb(desc->validity); 331 usb_free_urb(desc->response); 332 usb_free_urb(desc->command); 333 } 334 335 static void cleanup(struct wdm_device *desc) 336 { 337 kfree(desc->sbuf); 338 kfree(desc->inbuf); 339 kfree(desc->orq); 340 kfree(desc->irq); 341 kfree(desc->ubuf); 342 free_urbs(desc); 343 kfree(desc); 344 } 345 346 static ssize_t wdm_write 347 (struct file *file, const char __user *buffer, size_t count, loff_t *ppos) 348 { 349 u8 *buf; 350 int rv = -EMSGSIZE, r, we; 351 struct wdm_device *desc = file->private_data; 352 struct usb_ctrlrequest *req; 353 354 if (count > desc->wMaxCommand) 355 count = desc->wMaxCommand; 356 357 spin_lock_irq(&desc->iuspin); 358 we = desc->werr; 359 desc->werr = 0; 360 spin_unlock_irq(&desc->iuspin); 361 if (we < 0) 362 return usb_translate_errors(we); 363 364 buf = memdup_user(buffer, count); 365 if (IS_ERR(buf)) 366 return PTR_ERR(buf); 367 368 /* concurrent writes and disconnect */ 369 r = mutex_lock_interruptible(&desc->wlock); 370 rv = -ERESTARTSYS; 371 if (r) 372 goto out_free_mem; 373 374 if (test_bit(WDM_DISCONNECTING, &desc->flags)) { 375 rv = -ENODEV; 376 goto out_free_mem_lock; 377 } 378 379 r = usb_autopm_get_interface(desc->intf); 380 if (r < 0) { 381 rv = usb_translate_errors(r); 382 goto out_free_mem_lock; 383 } 384 385 if (!(file->f_flags & O_NONBLOCK)) 386 r = wait_event_interruptible(desc->wait, !test_bit(WDM_IN_USE, 387 &desc->flags)); 388 else 389 if (test_bit(WDM_IN_USE, &desc->flags)) 390 r = -EAGAIN; 391 392 if (test_bit(WDM_RESETTING, &desc->flags)) 393 r = -EIO; 394 395 if (r < 0) { 396 rv = r; 397 goto out_free_mem_pm; 398 } 399 400 req = desc->orq; 401 usb_fill_control_urb( 402 desc->command, 403 interface_to_usbdev(desc->intf), 404 /* using common endpoint 0 */ 405 usb_sndctrlpipe(interface_to_usbdev(desc->intf), 0), 406 (unsigned char *)req, 407 buf, 408 count, 409 wdm_out_callback, 410 desc 411 ); 412 413 req->bRequestType = (USB_DIR_OUT | USB_TYPE_CLASS | 414 USB_RECIP_INTERFACE); 415 req->bRequest = USB_CDC_SEND_ENCAPSULATED_COMMAND; 416 req->wValue = 0; 417 req->wIndex = desc->inum; /* already converted */ 418 req->wLength = cpu_to_le16(count); 419 set_bit(WDM_IN_USE, &desc->flags); 420 desc->outbuf = buf; 421 422 rv = usb_submit_urb(desc->command, GFP_KERNEL); 423 if (rv < 0) { 424 desc->outbuf = NULL; 425 clear_bit(WDM_IN_USE, &desc->flags); 426 dev_err(&desc->intf->dev, "Tx URB error: %d\n", rv); 427 rv = usb_translate_errors(rv); 428 goto out_free_mem_pm; 429 } else { 430 dev_dbg(&desc->intf->dev, "Tx URB has been submitted index=%d\n", 431 le16_to_cpu(req->wIndex)); 432 } 433 434 usb_autopm_put_interface(desc->intf); 435 mutex_unlock(&desc->wlock); 436 return count; 437 438 out_free_mem_pm: 439 usb_autopm_put_interface(desc->intf); 440 out_free_mem_lock: 441 mutex_unlock(&desc->wlock); 442 out_free_mem: 443 kfree(buf); 444 return rv; 445 } 446 447 /* 448 * Submit the read urb if resp_count is non-zero. 449 * 450 * Called with desc->iuspin locked 451 */ 452 static int service_outstanding_interrupt(struct wdm_device *desc) 453 { 454 int rv = 0; 455 456 /* submit read urb only if the device is waiting for it */ 457 if (!desc->resp_count || !--desc->resp_count) 458 goto out; 459 460 set_bit(WDM_RESPONDING, &desc->flags); 461 spin_unlock_irq(&desc->iuspin); 462 rv = usb_submit_urb(desc->response, GFP_KERNEL); 463 spin_lock_irq(&desc->iuspin); 464 if (rv) { 465 dev_err(&desc->intf->dev, 466 "usb_submit_urb failed with result %d\n", rv); 467 468 /* make sure the next notification trigger a submit */ 469 clear_bit(WDM_RESPONDING, &desc->flags); 470 desc->resp_count = 0; 471 } 472 out: 473 return rv; 474 } 475 476 static ssize_t wdm_read 477 (struct file *file, char __user *buffer, size_t count, loff_t *ppos) 478 { 479 int rv, cntr; 480 int i = 0; 481 struct wdm_device *desc = file->private_data; 482 483 484 rv = mutex_lock_interruptible(&desc->rlock); /*concurrent reads */ 485 if (rv < 0) 486 return -ERESTARTSYS; 487 488 cntr = ACCESS_ONCE(desc->length); 489 if (cntr == 0) { 490 desc->read = 0; 491 retry: 492 if (test_bit(WDM_DISCONNECTING, &desc->flags)) { 493 rv = -ENODEV; 494 goto err; 495 } 496 if (test_bit(WDM_OVERFLOW, &desc->flags)) { 497 clear_bit(WDM_OVERFLOW, &desc->flags); 498 rv = -ENOBUFS; 499 goto err; 500 } 501 i++; 502 if (file->f_flags & O_NONBLOCK) { 503 if (!test_bit(WDM_READ, &desc->flags)) { 504 rv = -EAGAIN; 505 goto err; 506 } 507 rv = 0; 508 } else { 509 rv = wait_event_interruptible(desc->wait, 510 test_bit(WDM_READ, &desc->flags)); 511 } 512 513 /* may have happened while we slept */ 514 if (test_bit(WDM_DISCONNECTING, &desc->flags)) { 515 rv = -ENODEV; 516 goto err; 517 } 518 if (test_bit(WDM_RESETTING, &desc->flags)) { 519 rv = -EIO; 520 goto err; 521 } 522 usb_mark_last_busy(interface_to_usbdev(desc->intf)); 523 if (rv < 0) { 524 rv = -ERESTARTSYS; 525 goto err; 526 } 527 528 spin_lock_irq(&desc->iuspin); 529 530 if (desc->rerr) { /* read completed, error happened */ 531 rv = usb_translate_errors(desc->rerr); 532 desc->rerr = 0; 533 spin_unlock_irq(&desc->iuspin); 534 goto err; 535 } 536 /* 537 * recheck whether we've lost the race 538 * against the completion handler 539 */ 540 if (!test_bit(WDM_READ, &desc->flags)) { /* lost race */ 541 spin_unlock_irq(&desc->iuspin); 542 goto retry; 543 } 544 545 if (!desc->reslength) { /* zero length read */ 546 dev_dbg(&desc->intf->dev, "zero length - clearing WDM_READ\n"); 547 clear_bit(WDM_READ, &desc->flags); 548 rv = service_outstanding_interrupt(desc); 549 spin_unlock_irq(&desc->iuspin); 550 if (rv < 0) 551 goto err; 552 goto retry; 553 } 554 cntr = desc->length; 555 spin_unlock_irq(&desc->iuspin); 556 } 557 558 if (cntr > count) 559 cntr = count; 560 rv = copy_to_user(buffer, desc->ubuf, cntr); 561 if (rv > 0) { 562 rv = -EFAULT; 563 goto err; 564 } 565 566 spin_lock_irq(&desc->iuspin); 567 568 for (i = 0; i < desc->length - cntr; i++) 569 desc->ubuf[i] = desc->ubuf[i + cntr]; 570 571 desc->length -= cntr; 572 /* in case we had outstanding data */ 573 if (!desc->length) { 574 clear_bit(WDM_READ, &desc->flags); 575 service_outstanding_interrupt(desc); 576 } 577 spin_unlock_irq(&desc->iuspin); 578 rv = cntr; 579 580 err: 581 mutex_unlock(&desc->rlock); 582 return rv; 583 } 584 585 static int wdm_flush(struct file *file, fl_owner_t id) 586 { 587 struct wdm_device *desc = file->private_data; 588 589 wait_event(desc->wait, !test_bit(WDM_IN_USE, &desc->flags)); 590 591 /* cannot dereference desc->intf if WDM_DISCONNECTING */ 592 if (desc->werr < 0 && !test_bit(WDM_DISCONNECTING, &desc->flags)) 593 dev_err(&desc->intf->dev, "Error in flush path: %d\n", 594 desc->werr); 595 596 return usb_translate_errors(desc->werr); 597 } 598 599 static unsigned int wdm_poll(struct file *file, struct poll_table_struct *wait) 600 { 601 struct wdm_device *desc = file->private_data; 602 unsigned long flags; 603 unsigned int mask = 0; 604 605 spin_lock_irqsave(&desc->iuspin, flags); 606 if (test_bit(WDM_DISCONNECTING, &desc->flags)) { 607 mask = POLLHUP | POLLERR; 608 spin_unlock_irqrestore(&desc->iuspin, flags); 609 goto desc_out; 610 } 611 if (test_bit(WDM_READ, &desc->flags)) 612 mask = POLLIN | POLLRDNORM; 613 if (desc->rerr || desc->werr) 614 mask |= POLLERR; 615 if (!test_bit(WDM_IN_USE, &desc->flags)) 616 mask |= POLLOUT | POLLWRNORM; 617 spin_unlock_irqrestore(&desc->iuspin, flags); 618 619 poll_wait(file, &desc->wait, wait); 620 621 desc_out: 622 return mask; 623 } 624 625 static int wdm_open(struct inode *inode, struct file *file) 626 { 627 int minor = iminor(inode); 628 int rv = -ENODEV; 629 struct usb_interface *intf; 630 struct wdm_device *desc; 631 632 mutex_lock(&wdm_mutex); 633 desc = wdm_find_device_by_minor(minor); 634 if (!desc) 635 goto out; 636 637 intf = desc->intf; 638 if (test_bit(WDM_DISCONNECTING, &desc->flags)) 639 goto out; 640 file->private_data = desc; 641 642 rv = usb_autopm_get_interface(desc->intf); 643 if (rv < 0) { 644 dev_err(&desc->intf->dev, "Error autopm - %d\n", rv); 645 goto out; 646 } 647 648 /* using write lock to protect desc->count */ 649 mutex_lock(&desc->wlock); 650 if (!desc->count++) { 651 desc->werr = 0; 652 desc->rerr = 0; 653 rv = usb_submit_urb(desc->validity, GFP_KERNEL); 654 if (rv < 0) { 655 desc->count--; 656 dev_err(&desc->intf->dev, 657 "Error submitting int urb - %d\n", rv); 658 rv = usb_translate_errors(rv); 659 } 660 } else { 661 rv = 0; 662 } 663 mutex_unlock(&desc->wlock); 664 if (desc->count == 1) 665 desc->manage_power(intf, 1); 666 usb_autopm_put_interface(desc->intf); 667 out: 668 mutex_unlock(&wdm_mutex); 669 return rv; 670 } 671 672 static int wdm_release(struct inode *inode, struct file *file) 673 { 674 struct wdm_device *desc = file->private_data; 675 676 mutex_lock(&wdm_mutex); 677 678 /* using write lock to protect desc->count */ 679 mutex_lock(&desc->wlock); 680 desc->count--; 681 mutex_unlock(&desc->wlock); 682 683 if (!desc->count) { 684 if (!test_bit(WDM_DISCONNECTING, &desc->flags)) { 685 dev_dbg(&desc->intf->dev, "wdm_release: cleanup\n"); 686 kill_urbs(desc); 687 spin_lock_irq(&desc->iuspin); 688 desc->resp_count = 0; 689 spin_unlock_irq(&desc->iuspin); 690 desc->manage_power(desc->intf, 0); 691 } else { 692 /* must avoid dev_printk here as desc->intf is invalid */ 693 pr_debug(KBUILD_MODNAME " %s: device gone - cleaning up\n", __func__); 694 cleanup(desc); 695 } 696 } 697 mutex_unlock(&wdm_mutex); 698 return 0; 699 } 700 701 static long wdm_ioctl(struct file *file, unsigned int cmd, unsigned long arg) 702 { 703 struct wdm_device *desc = file->private_data; 704 int rv = 0; 705 706 switch (cmd) { 707 case IOCTL_WDM_MAX_COMMAND: 708 if (copy_to_user((void __user *)arg, &desc->wMaxCommand, sizeof(desc->wMaxCommand))) 709 rv = -EFAULT; 710 break; 711 default: 712 rv = -ENOTTY; 713 } 714 return rv; 715 } 716 717 static const struct file_operations wdm_fops = { 718 .owner = THIS_MODULE, 719 .read = wdm_read, 720 .write = wdm_write, 721 .open = wdm_open, 722 .flush = wdm_flush, 723 .release = wdm_release, 724 .poll = wdm_poll, 725 .unlocked_ioctl = wdm_ioctl, 726 .compat_ioctl = wdm_ioctl, 727 .llseek = noop_llseek, 728 }; 729 730 static struct usb_class_driver wdm_class = { 731 .name = "cdc-wdm%d", 732 .fops = &wdm_fops, 733 .minor_base = WDM_MINOR_BASE, 734 }; 735 736 /* --- error handling --- */ 737 static void wdm_rxwork(struct work_struct *work) 738 { 739 struct wdm_device *desc = container_of(work, struct wdm_device, rxwork); 740 unsigned long flags; 741 int rv = 0; 742 int responding; 743 744 spin_lock_irqsave(&desc->iuspin, flags); 745 if (test_bit(WDM_DISCONNECTING, &desc->flags)) { 746 spin_unlock_irqrestore(&desc->iuspin, flags); 747 } else { 748 responding = test_and_set_bit(WDM_RESPONDING, &desc->flags); 749 spin_unlock_irqrestore(&desc->iuspin, flags); 750 if (!responding) 751 rv = usb_submit_urb(desc->response, GFP_KERNEL); 752 if (rv < 0 && rv != -EPERM) { 753 spin_lock_irqsave(&desc->iuspin, flags); 754 clear_bit(WDM_RESPONDING, &desc->flags); 755 if (!test_bit(WDM_DISCONNECTING, &desc->flags)) 756 schedule_work(&desc->rxwork); 757 spin_unlock_irqrestore(&desc->iuspin, flags); 758 } 759 } 760 } 761 762 /* --- hotplug --- */ 763 764 static int wdm_create(struct usb_interface *intf, struct usb_endpoint_descriptor *ep, 765 u16 bufsize, int (*manage_power)(struct usb_interface *, int)) 766 { 767 int rv = -ENOMEM; 768 struct wdm_device *desc; 769 770 desc = kzalloc(sizeof(struct wdm_device), GFP_KERNEL); 771 if (!desc) 772 goto out; 773 INIT_LIST_HEAD(&desc->device_list); 774 mutex_init(&desc->rlock); 775 mutex_init(&desc->wlock); 776 spin_lock_init(&desc->iuspin); 777 init_waitqueue_head(&desc->wait); 778 desc->wMaxCommand = bufsize; 779 /* this will be expanded and needed in hardware endianness */ 780 desc->inum = cpu_to_le16((u16)intf->cur_altsetting->desc.bInterfaceNumber); 781 desc->intf = intf; 782 INIT_WORK(&desc->rxwork, wdm_rxwork); 783 784 rv = -EINVAL; 785 if (!usb_endpoint_is_int_in(ep)) 786 goto err; 787 788 desc->wMaxPacketSize = usb_endpoint_maxp(ep); 789 790 desc->orq = kmalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL); 791 if (!desc->orq) 792 goto err; 793 desc->irq = kmalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL); 794 if (!desc->irq) 795 goto err; 796 797 desc->validity = usb_alloc_urb(0, GFP_KERNEL); 798 if (!desc->validity) 799 goto err; 800 801 desc->response = usb_alloc_urb(0, GFP_KERNEL); 802 if (!desc->response) 803 goto err; 804 805 desc->command = usb_alloc_urb(0, GFP_KERNEL); 806 if (!desc->command) 807 goto err; 808 809 desc->ubuf = kmalloc(desc->wMaxCommand, GFP_KERNEL); 810 if (!desc->ubuf) 811 goto err; 812 813 desc->sbuf = kmalloc(desc->wMaxPacketSize, GFP_KERNEL); 814 if (!desc->sbuf) 815 goto err; 816 817 desc->inbuf = kmalloc(desc->wMaxCommand, GFP_KERNEL); 818 if (!desc->inbuf) 819 goto err; 820 821 usb_fill_int_urb( 822 desc->validity, 823 interface_to_usbdev(intf), 824 usb_rcvintpipe(interface_to_usbdev(intf), ep->bEndpointAddress), 825 desc->sbuf, 826 desc->wMaxPacketSize, 827 wdm_int_callback, 828 desc, 829 ep->bInterval 830 ); 831 832 desc->irq->bRequestType = (USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE); 833 desc->irq->bRequest = USB_CDC_GET_ENCAPSULATED_RESPONSE; 834 desc->irq->wValue = 0; 835 desc->irq->wIndex = desc->inum; /* already converted */ 836 desc->irq->wLength = cpu_to_le16(desc->wMaxCommand); 837 838 usb_fill_control_urb( 839 desc->response, 840 interface_to_usbdev(intf), 841 /* using common endpoint 0 */ 842 usb_rcvctrlpipe(interface_to_usbdev(desc->intf), 0), 843 (unsigned char *)desc->irq, 844 desc->inbuf, 845 desc->wMaxCommand, 846 wdm_in_callback, 847 desc 848 ); 849 850 desc->manage_power = manage_power; 851 852 spin_lock(&wdm_device_list_lock); 853 list_add(&desc->device_list, &wdm_device_list); 854 spin_unlock(&wdm_device_list_lock); 855 856 rv = usb_register_dev(intf, &wdm_class); 857 if (rv < 0) 858 goto err; 859 else 860 dev_info(&intf->dev, "%s: USB WDM device\n", dev_name(intf->usb_dev)); 861 out: 862 return rv; 863 err: 864 spin_lock(&wdm_device_list_lock); 865 list_del(&desc->device_list); 866 spin_unlock(&wdm_device_list_lock); 867 cleanup(desc); 868 return rv; 869 } 870 871 static int wdm_manage_power(struct usb_interface *intf, int on) 872 { 873 /* need autopm_get/put here to ensure the usbcore sees the new value */ 874 int rv = usb_autopm_get_interface(intf); 875 876 intf->needs_remote_wakeup = on; 877 if (!rv) 878 usb_autopm_put_interface(intf); 879 return 0; 880 } 881 882 static int wdm_probe(struct usb_interface *intf, const struct usb_device_id *id) 883 { 884 int rv = -EINVAL; 885 struct usb_host_interface *iface; 886 struct usb_endpoint_descriptor *ep; 887 struct usb_cdc_parsed_header hdr; 888 u8 *buffer = intf->altsetting->extra; 889 int buflen = intf->altsetting->extralen; 890 u16 maxcom = WDM_DEFAULT_BUFSIZE; 891 892 if (!buffer) 893 goto err; 894 895 cdc_parse_cdc_header(&hdr, intf, buffer, buflen); 896 897 if (hdr.usb_cdc_dmm_desc) 898 maxcom = le16_to_cpu(hdr.usb_cdc_dmm_desc->wMaxCommand); 899 900 iface = intf->cur_altsetting; 901 if (iface->desc.bNumEndpoints != 1) 902 goto err; 903 ep = &iface->endpoint[0].desc; 904 905 rv = wdm_create(intf, ep, maxcom, &wdm_manage_power); 906 907 err: 908 return rv; 909 } 910 911 /** 912 * usb_cdc_wdm_register - register a WDM subdriver 913 * @intf: usb interface the subdriver will associate with 914 * @ep: interrupt endpoint to monitor for notifications 915 * @bufsize: maximum message size to support for read/write 916 * 917 * Create WDM usb class character device and associate it with intf 918 * without binding, allowing another driver to manage the interface. 919 * 920 * The subdriver will manage the given interrupt endpoint exclusively 921 * and will issue control requests referring to the given intf. It 922 * will otherwise avoid interferring, and in particular not do 923 * usb_set_intfdata/usb_get_intfdata on intf. 924 * 925 * The return value is a pointer to the subdriver's struct usb_driver. 926 * The registering driver is responsible for calling this subdriver's 927 * disconnect, suspend, resume, pre_reset and post_reset methods from 928 * its own. 929 */ 930 struct usb_driver *usb_cdc_wdm_register(struct usb_interface *intf, 931 struct usb_endpoint_descriptor *ep, 932 int bufsize, 933 int (*manage_power)(struct usb_interface *, int)) 934 { 935 int rv = -EINVAL; 936 937 rv = wdm_create(intf, ep, bufsize, manage_power); 938 if (rv < 0) 939 goto err; 940 941 return &wdm_driver; 942 err: 943 return ERR_PTR(rv); 944 } 945 EXPORT_SYMBOL(usb_cdc_wdm_register); 946 947 static void wdm_disconnect(struct usb_interface *intf) 948 { 949 struct wdm_device *desc; 950 unsigned long flags; 951 952 usb_deregister_dev(intf, &wdm_class); 953 desc = wdm_find_device(intf); 954 mutex_lock(&wdm_mutex); 955 956 /* the spinlock makes sure no new urbs are generated in the callbacks */ 957 spin_lock_irqsave(&desc->iuspin, flags); 958 set_bit(WDM_DISCONNECTING, &desc->flags); 959 set_bit(WDM_READ, &desc->flags); 960 /* to terminate pending flushes */ 961 clear_bit(WDM_IN_USE, &desc->flags); 962 spin_unlock_irqrestore(&desc->iuspin, flags); 963 wake_up_all(&desc->wait); 964 mutex_lock(&desc->rlock); 965 mutex_lock(&desc->wlock); 966 kill_urbs(desc); 967 cancel_work_sync(&desc->rxwork); 968 mutex_unlock(&desc->wlock); 969 mutex_unlock(&desc->rlock); 970 971 /* the desc->intf pointer used as list key is now invalid */ 972 spin_lock(&wdm_device_list_lock); 973 list_del(&desc->device_list); 974 spin_unlock(&wdm_device_list_lock); 975 976 if (!desc->count) 977 cleanup(desc); 978 else 979 dev_dbg(&intf->dev, "%d open files - postponing cleanup\n", desc->count); 980 mutex_unlock(&wdm_mutex); 981 } 982 983 #ifdef CONFIG_PM 984 static int wdm_suspend(struct usb_interface *intf, pm_message_t message) 985 { 986 struct wdm_device *desc = wdm_find_device(intf); 987 int rv = 0; 988 989 dev_dbg(&desc->intf->dev, "wdm%d_suspend\n", intf->minor); 990 991 /* if this is an autosuspend the caller does the locking */ 992 if (!PMSG_IS_AUTO(message)) { 993 mutex_lock(&desc->rlock); 994 mutex_lock(&desc->wlock); 995 } 996 spin_lock_irq(&desc->iuspin); 997 998 if (PMSG_IS_AUTO(message) && 999 (test_bit(WDM_IN_USE, &desc->flags) 1000 || test_bit(WDM_RESPONDING, &desc->flags))) { 1001 spin_unlock_irq(&desc->iuspin); 1002 rv = -EBUSY; 1003 } else { 1004 1005 set_bit(WDM_SUSPENDING, &desc->flags); 1006 spin_unlock_irq(&desc->iuspin); 1007 /* callback submits work - order is essential */ 1008 kill_urbs(desc); 1009 cancel_work_sync(&desc->rxwork); 1010 } 1011 if (!PMSG_IS_AUTO(message)) { 1012 mutex_unlock(&desc->wlock); 1013 mutex_unlock(&desc->rlock); 1014 } 1015 1016 return rv; 1017 } 1018 #endif 1019 1020 static int recover_from_urb_loss(struct wdm_device *desc) 1021 { 1022 int rv = 0; 1023 1024 if (desc->count) { 1025 rv = usb_submit_urb(desc->validity, GFP_NOIO); 1026 if (rv < 0) 1027 dev_err(&desc->intf->dev, 1028 "Error resume submitting int urb - %d\n", rv); 1029 } 1030 return rv; 1031 } 1032 1033 #ifdef CONFIG_PM 1034 static int wdm_resume(struct usb_interface *intf) 1035 { 1036 struct wdm_device *desc = wdm_find_device(intf); 1037 int rv; 1038 1039 dev_dbg(&desc->intf->dev, "wdm%d_resume\n", intf->minor); 1040 1041 clear_bit(WDM_SUSPENDING, &desc->flags); 1042 rv = recover_from_urb_loss(desc); 1043 1044 return rv; 1045 } 1046 #endif 1047 1048 static int wdm_pre_reset(struct usb_interface *intf) 1049 { 1050 struct wdm_device *desc = wdm_find_device(intf); 1051 1052 /* 1053 * we notify everybody using poll of 1054 * an exceptional situation 1055 * must be done before recovery lest a spontaneous 1056 * message from the device is lost 1057 */ 1058 spin_lock_irq(&desc->iuspin); 1059 set_bit(WDM_RESETTING, &desc->flags); /* inform read/write */ 1060 set_bit(WDM_READ, &desc->flags); /* unblock read */ 1061 clear_bit(WDM_IN_USE, &desc->flags); /* unblock write */ 1062 desc->rerr = -EINTR; 1063 spin_unlock_irq(&desc->iuspin); 1064 wake_up_all(&desc->wait); 1065 mutex_lock(&desc->rlock); 1066 mutex_lock(&desc->wlock); 1067 kill_urbs(desc); 1068 cancel_work_sync(&desc->rxwork); 1069 return 0; 1070 } 1071 1072 static int wdm_post_reset(struct usb_interface *intf) 1073 { 1074 struct wdm_device *desc = wdm_find_device(intf); 1075 int rv; 1076 1077 clear_bit(WDM_OVERFLOW, &desc->flags); 1078 clear_bit(WDM_RESETTING, &desc->flags); 1079 rv = recover_from_urb_loss(desc); 1080 mutex_unlock(&desc->wlock); 1081 mutex_unlock(&desc->rlock); 1082 return 0; 1083 } 1084 1085 static struct usb_driver wdm_driver = { 1086 .name = "cdc_wdm", 1087 .probe = wdm_probe, 1088 .disconnect = wdm_disconnect, 1089 #ifdef CONFIG_PM 1090 .suspend = wdm_suspend, 1091 .resume = wdm_resume, 1092 .reset_resume = wdm_resume, 1093 #endif 1094 .pre_reset = wdm_pre_reset, 1095 .post_reset = wdm_post_reset, 1096 .id_table = wdm_ids, 1097 .supports_autosuspend = 1, 1098 .disable_hub_initiated_lpm = 1, 1099 }; 1100 1101 module_usb_driver(wdm_driver); 1102 1103 MODULE_AUTHOR(DRIVER_AUTHOR); 1104 MODULE_DESCRIPTION(DRIVER_DESC); 1105 MODULE_LICENSE("GPL"); 1106