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 static void wdm_in_callback(struct urb *urb) 158 { 159 struct wdm_device *desc = urb->context; 160 int status = urb->status; 161 int length = urb->actual_length; 162 163 spin_lock(&desc->iuspin); 164 clear_bit(WDM_RESPONDING, &desc->flags); 165 166 if (status) { 167 switch (status) { 168 case -ENOENT: 169 dev_dbg(&desc->intf->dev, 170 "nonzero urb status received: -ENOENT"); 171 goto skip_error; 172 case -ECONNRESET: 173 dev_dbg(&desc->intf->dev, 174 "nonzero urb status received: -ECONNRESET"); 175 goto skip_error; 176 case -ESHUTDOWN: 177 dev_dbg(&desc->intf->dev, 178 "nonzero urb status received: -ESHUTDOWN"); 179 goto skip_error; 180 case -EPIPE: 181 dev_err(&desc->intf->dev, 182 "nonzero urb status received: -EPIPE\n"); 183 break; 184 default: 185 dev_err(&desc->intf->dev, 186 "Unexpected error %d\n", status); 187 break; 188 } 189 } 190 191 desc->rerr = status; 192 if (length + desc->length > desc->wMaxCommand) { 193 /* The buffer would overflow */ 194 set_bit(WDM_OVERFLOW, &desc->flags); 195 } else { 196 /* we may already be in overflow */ 197 if (!test_bit(WDM_OVERFLOW, &desc->flags)) { 198 memmove(desc->ubuf + desc->length, desc->inbuf, length); 199 desc->length += length; 200 desc->reslength = length; 201 } 202 } 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 responding; 214 int status = urb->status; 215 struct wdm_device *desc; 216 struct usb_cdc_notification *dr; 217 218 desc = urb->context; 219 dr = (struct usb_cdc_notification *)desc->sbuf; 220 221 if (status) { 222 switch (status) { 223 case -ESHUTDOWN: 224 case -ENOENT: 225 case -ECONNRESET: 226 return; /* unplug */ 227 case -EPIPE: 228 set_bit(WDM_INT_STALL, &desc->flags); 229 dev_err(&desc->intf->dev, "Stall on int endpoint\n"); 230 goto sw; /* halt is cleared in work */ 231 default: 232 dev_err(&desc->intf->dev, 233 "nonzero urb status received: %d\n", status); 234 break; 235 } 236 } 237 238 if (urb->actual_length < sizeof(struct usb_cdc_notification)) { 239 dev_err(&desc->intf->dev, "wdm_int_callback - %d bytes\n", 240 urb->actual_length); 241 goto exit; 242 } 243 244 switch (dr->bNotificationType) { 245 case USB_CDC_NOTIFY_RESPONSE_AVAILABLE: 246 dev_dbg(&desc->intf->dev, 247 "NOTIFY_RESPONSE_AVAILABLE received: index %d len %d", 248 dr->wIndex, dr->wLength); 249 break; 250 251 case USB_CDC_NOTIFY_NETWORK_CONNECTION: 252 253 dev_dbg(&desc->intf->dev, 254 "NOTIFY_NETWORK_CONNECTION %s network", 255 dr->wValue ? "connected to" : "disconnected from"); 256 goto exit; 257 case USB_CDC_NOTIFY_SPEED_CHANGE: 258 dev_dbg(&desc->intf->dev, "SPEED_CHANGE received (len %u)", 259 urb->actual_length); 260 goto exit; 261 default: 262 clear_bit(WDM_POLL_RUNNING, &desc->flags); 263 dev_err(&desc->intf->dev, 264 "unknown notification %d received: index %d len %d\n", 265 dr->bNotificationType, dr->wIndex, dr->wLength); 266 goto exit; 267 } 268 269 spin_lock(&desc->iuspin); 270 responding = test_and_set_bit(WDM_RESPONDING, &desc->flags); 271 if (!desc->resp_count++ && !responding 272 && !test_bit(WDM_DISCONNECTING, &desc->flags) 273 && !test_bit(WDM_SUSPENDING, &desc->flags)) { 274 rv = usb_submit_urb(desc->response, GFP_ATOMIC); 275 dev_dbg(&desc->intf->dev, "%s: usb_submit_urb %d", 276 __func__, rv); 277 } 278 spin_unlock(&desc->iuspin); 279 if (rv < 0) { 280 clear_bit(WDM_RESPONDING, &desc->flags); 281 if (rv == -EPERM) 282 return; 283 if (rv == -ENOMEM) { 284 sw: 285 rv = schedule_work(&desc->rxwork); 286 if (rv) 287 dev_err(&desc->intf->dev, 288 "Cannot schedule work\n"); 289 } 290 } 291 exit: 292 rv = usb_submit_urb(urb, GFP_ATOMIC); 293 if (rv) 294 dev_err(&desc->intf->dev, 295 "%s - usb_submit_urb failed with result %d\n", 296 __func__, rv); 297 298 } 299 300 static void kill_urbs(struct wdm_device *desc) 301 { 302 /* the order here is essential */ 303 usb_kill_urb(desc->command); 304 usb_kill_urb(desc->validity); 305 usb_kill_urb(desc->response); 306 } 307 308 static void free_urbs(struct wdm_device *desc) 309 { 310 usb_free_urb(desc->validity); 311 usb_free_urb(desc->response); 312 usb_free_urb(desc->command); 313 } 314 315 static void cleanup(struct wdm_device *desc) 316 { 317 kfree(desc->sbuf); 318 kfree(desc->inbuf); 319 kfree(desc->orq); 320 kfree(desc->irq); 321 kfree(desc->ubuf); 322 free_urbs(desc); 323 kfree(desc); 324 } 325 326 static ssize_t wdm_write 327 (struct file *file, const char __user *buffer, size_t count, loff_t *ppos) 328 { 329 u8 *buf; 330 int rv = -EMSGSIZE, r, we; 331 struct wdm_device *desc = file->private_data; 332 struct usb_ctrlrequest *req; 333 334 if (count > desc->wMaxCommand) 335 count = desc->wMaxCommand; 336 337 spin_lock_irq(&desc->iuspin); 338 we = desc->werr; 339 desc->werr = 0; 340 spin_unlock_irq(&desc->iuspin); 341 if (we < 0) 342 return -EIO; 343 344 buf = kmalloc(count, GFP_KERNEL); 345 if (!buf) { 346 rv = -ENOMEM; 347 goto outnl; 348 } 349 350 r = copy_from_user(buf, buffer, count); 351 if (r > 0) { 352 kfree(buf); 353 rv = -EFAULT; 354 goto outnl; 355 } 356 357 /* concurrent writes and disconnect */ 358 r = mutex_lock_interruptible(&desc->wlock); 359 rv = -ERESTARTSYS; 360 if (r) { 361 kfree(buf); 362 goto outnl; 363 } 364 365 if (test_bit(WDM_DISCONNECTING, &desc->flags)) { 366 kfree(buf); 367 rv = -ENODEV; 368 goto outnp; 369 } 370 371 r = usb_autopm_get_interface(desc->intf); 372 if (r < 0) { 373 kfree(buf); 374 rv = usb_translate_errors(r); 375 goto outnp; 376 } 377 378 if (!(file->f_flags & O_NONBLOCK)) 379 r = wait_event_interruptible(desc->wait, !test_bit(WDM_IN_USE, 380 &desc->flags)); 381 else 382 if (test_bit(WDM_IN_USE, &desc->flags)) 383 r = -EAGAIN; 384 385 if (test_bit(WDM_RESETTING, &desc->flags)) 386 r = -EIO; 387 388 if (r < 0) { 389 kfree(buf); 390 rv = r; 391 goto out; 392 } 393 394 req = desc->orq; 395 usb_fill_control_urb( 396 desc->command, 397 interface_to_usbdev(desc->intf), 398 /* using common endpoint 0 */ 399 usb_sndctrlpipe(interface_to_usbdev(desc->intf), 0), 400 (unsigned char *)req, 401 buf, 402 count, 403 wdm_out_callback, 404 desc 405 ); 406 407 req->bRequestType = (USB_DIR_OUT | USB_TYPE_CLASS | 408 USB_RECIP_INTERFACE); 409 req->bRequest = USB_CDC_SEND_ENCAPSULATED_COMMAND; 410 req->wValue = 0; 411 req->wIndex = desc->inum; 412 req->wLength = cpu_to_le16(count); 413 set_bit(WDM_IN_USE, &desc->flags); 414 desc->outbuf = buf; 415 416 rv = usb_submit_urb(desc->command, GFP_KERNEL); 417 if (rv < 0) { 418 kfree(buf); 419 desc->outbuf = NULL; 420 clear_bit(WDM_IN_USE, &desc->flags); 421 dev_err(&desc->intf->dev, "Tx URB error: %d\n", rv); 422 rv = usb_translate_errors(rv); 423 } else { 424 dev_dbg(&desc->intf->dev, "Tx URB has been submitted index=%d", 425 req->wIndex); 426 } 427 out: 428 usb_autopm_put_interface(desc->intf); 429 outnp: 430 mutex_unlock(&desc->wlock); 431 outnl: 432 return rv < 0 ? rv : count; 433 } 434 435 static ssize_t wdm_read 436 (struct file *file, char __user *buffer, size_t count, loff_t *ppos) 437 { 438 int rv, cntr; 439 int i = 0; 440 struct wdm_device *desc = file->private_data; 441 442 443 rv = mutex_lock_interruptible(&desc->rlock); /*concurrent reads */ 444 if (rv < 0) 445 return -ERESTARTSYS; 446 447 cntr = ACCESS_ONCE(desc->length); 448 if (cntr == 0) { 449 desc->read = 0; 450 retry: 451 if (test_bit(WDM_DISCONNECTING, &desc->flags)) { 452 rv = -ENODEV; 453 goto err; 454 } 455 if (test_bit(WDM_OVERFLOW, &desc->flags)) { 456 clear_bit(WDM_OVERFLOW, &desc->flags); 457 rv = -ENOBUFS; 458 goto err; 459 } 460 i++; 461 if (file->f_flags & O_NONBLOCK) { 462 if (!test_bit(WDM_READ, &desc->flags)) { 463 rv = cntr ? cntr : -EAGAIN; 464 goto err; 465 } 466 rv = 0; 467 } else { 468 rv = wait_event_interruptible(desc->wait, 469 test_bit(WDM_READ, &desc->flags)); 470 } 471 472 /* may have happened while we slept */ 473 if (test_bit(WDM_DISCONNECTING, &desc->flags)) { 474 rv = -ENODEV; 475 goto err; 476 } 477 if (test_bit(WDM_RESETTING, &desc->flags)) { 478 rv = -EIO; 479 goto err; 480 } 481 usb_mark_last_busy(interface_to_usbdev(desc->intf)); 482 if (rv < 0) { 483 rv = -ERESTARTSYS; 484 goto err; 485 } 486 487 spin_lock_irq(&desc->iuspin); 488 489 if (desc->rerr) { /* read completed, error happened */ 490 desc->rerr = 0; 491 spin_unlock_irq(&desc->iuspin); 492 rv = -EIO; 493 goto err; 494 } 495 /* 496 * recheck whether we've lost the race 497 * against the completion handler 498 */ 499 if (!test_bit(WDM_READ, &desc->flags)) { /* lost race */ 500 spin_unlock_irq(&desc->iuspin); 501 goto retry; 502 } 503 504 if (!desc->reslength) { /* zero length read */ 505 dev_dbg(&desc->intf->dev, "%s: zero length - clearing WDM_READ\n", __func__); 506 clear_bit(WDM_READ, &desc->flags); 507 spin_unlock_irq(&desc->iuspin); 508 goto retry; 509 } 510 cntr = desc->length; 511 spin_unlock_irq(&desc->iuspin); 512 } 513 514 if (cntr > count) 515 cntr = count; 516 rv = copy_to_user(buffer, desc->ubuf, cntr); 517 if (rv > 0) { 518 rv = -EFAULT; 519 goto err; 520 } 521 522 spin_lock_irq(&desc->iuspin); 523 524 for (i = 0; i < desc->length - cntr; i++) 525 desc->ubuf[i] = desc->ubuf[i + cntr]; 526 527 desc->length -= cntr; 528 /* in case we had outstanding data */ 529 if (!desc->length) { 530 clear_bit(WDM_READ, &desc->flags); 531 532 if (--desc->resp_count) { 533 set_bit(WDM_RESPONDING, &desc->flags); 534 spin_unlock_irq(&desc->iuspin); 535 536 rv = usb_submit_urb(desc->response, GFP_KERNEL); 537 if (rv) { 538 dev_err(&desc->intf->dev, 539 "%s: usb_submit_urb failed with result %d\n", 540 __func__, rv); 541 spin_lock_irq(&desc->iuspin); 542 clear_bit(WDM_RESPONDING, &desc->flags); 543 spin_unlock_irq(&desc->iuspin); 544 545 if (rv == -ENOMEM) { 546 rv = schedule_work(&desc->rxwork); 547 if (rv) 548 dev_err(&desc->intf->dev, "Cannot schedule work\n"); 549 } else { 550 spin_lock_irq(&desc->iuspin); 551 desc->resp_count = 0; 552 spin_unlock_irq(&desc->iuspin); 553 } 554 } 555 } else 556 spin_unlock_irq(&desc->iuspin); 557 } else 558 spin_unlock_irq(&desc->iuspin); 559 560 rv = cntr; 561 562 err: 563 mutex_unlock(&desc->rlock); 564 return rv; 565 } 566 567 static int wdm_flush(struct file *file, fl_owner_t id) 568 { 569 struct wdm_device *desc = file->private_data; 570 571 wait_event(desc->wait, !test_bit(WDM_IN_USE, &desc->flags)); 572 573 /* cannot dereference desc->intf if WDM_DISCONNECTING */ 574 if (desc->werr < 0 && !test_bit(WDM_DISCONNECTING, &desc->flags)) 575 dev_err(&desc->intf->dev, "Error in flush path: %d\n", 576 desc->werr); 577 578 return usb_translate_errors(desc->werr); 579 } 580 581 static unsigned int wdm_poll(struct file *file, struct poll_table_struct *wait) 582 { 583 struct wdm_device *desc = file->private_data; 584 unsigned long flags; 585 unsigned int mask = 0; 586 587 spin_lock_irqsave(&desc->iuspin, flags); 588 if (test_bit(WDM_DISCONNECTING, &desc->flags)) { 589 mask = POLLHUP | POLLERR; 590 spin_unlock_irqrestore(&desc->iuspin, flags); 591 goto desc_out; 592 } 593 if (test_bit(WDM_READ, &desc->flags)) 594 mask = POLLIN | POLLRDNORM; 595 if (desc->rerr || desc->werr) 596 mask |= POLLERR; 597 if (!test_bit(WDM_IN_USE, &desc->flags)) 598 mask |= POLLOUT | POLLWRNORM; 599 spin_unlock_irqrestore(&desc->iuspin, flags); 600 601 poll_wait(file, &desc->wait, wait); 602 603 desc_out: 604 return mask; 605 } 606 607 static int wdm_open(struct inode *inode, struct file *file) 608 { 609 int minor = iminor(inode); 610 int rv = -ENODEV; 611 struct usb_interface *intf; 612 struct wdm_device *desc; 613 614 mutex_lock(&wdm_mutex); 615 desc = wdm_find_device_by_minor(minor); 616 if (!desc) 617 goto out; 618 619 intf = desc->intf; 620 if (test_bit(WDM_DISCONNECTING, &desc->flags)) 621 goto out; 622 file->private_data = desc; 623 624 rv = usb_autopm_get_interface(desc->intf); 625 if (rv < 0) { 626 dev_err(&desc->intf->dev, "Error autopm - %d\n", rv); 627 goto out; 628 } 629 630 /* using write lock to protect desc->count */ 631 mutex_lock(&desc->wlock); 632 if (!desc->count++) { 633 desc->werr = 0; 634 desc->rerr = 0; 635 rv = usb_submit_urb(desc->validity, GFP_KERNEL); 636 if (rv < 0) { 637 desc->count--; 638 dev_err(&desc->intf->dev, 639 "Error submitting int urb - %d\n", rv); 640 rv = usb_translate_errors(rv); 641 } 642 } else { 643 rv = 0; 644 } 645 mutex_unlock(&desc->wlock); 646 if (desc->count == 1) 647 desc->manage_power(intf, 1); 648 usb_autopm_put_interface(desc->intf); 649 out: 650 mutex_unlock(&wdm_mutex); 651 return rv; 652 } 653 654 static int wdm_release(struct inode *inode, struct file *file) 655 { 656 struct wdm_device *desc = file->private_data; 657 658 mutex_lock(&wdm_mutex); 659 660 /* using write lock to protect desc->count */ 661 mutex_lock(&desc->wlock); 662 desc->count--; 663 mutex_unlock(&desc->wlock); 664 665 if (!desc->count) { 666 if (!test_bit(WDM_DISCONNECTING, &desc->flags)) { 667 dev_dbg(&desc->intf->dev, "wdm_release: cleanup"); 668 kill_urbs(desc); 669 spin_lock_irq(&desc->iuspin); 670 desc->resp_count = 0; 671 spin_unlock_irq(&desc->iuspin); 672 desc->manage_power(desc->intf, 0); 673 } else { 674 /* must avoid dev_printk here as desc->intf is invalid */ 675 pr_debug(KBUILD_MODNAME " %s: device gone - cleaning up\n", __func__); 676 cleanup(desc); 677 } 678 } 679 mutex_unlock(&wdm_mutex); 680 return 0; 681 } 682 683 static long wdm_ioctl(struct file *file, unsigned int cmd, unsigned long arg) 684 { 685 struct wdm_device *desc = file->private_data; 686 int rv = 0; 687 688 switch (cmd) { 689 case IOCTL_WDM_MAX_COMMAND: 690 if (copy_to_user((void __user *)arg, &desc->wMaxCommand, sizeof(desc->wMaxCommand))) 691 rv = -EFAULT; 692 break; 693 default: 694 rv = -ENOTTY; 695 } 696 return rv; 697 } 698 699 static const struct file_operations wdm_fops = { 700 .owner = THIS_MODULE, 701 .read = wdm_read, 702 .write = wdm_write, 703 .open = wdm_open, 704 .flush = wdm_flush, 705 .release = wdm_release, 706 .poll = wdm_poll, 707 .unlocked_ioctl = wdm_ioctl, 708 .compat_ioctl = wdm_ioctl, 709 .llseek = noop_llseek, 710 }; 711 712 static struct usb_class_driver wdm_class = { 713 .name = "cdc-wdm%d", 714 .fops = &wdm_fops, 715 .minor_base = WDM_MINOR_BASE, 716 }; 717 718 /* --- error handling --- */ 719 static void wdm_rxwork(struct work_struct *work) 720 { 721 struct wdm_device *desc = container_of(work, struct wdm_device, rxwork); 722 unsigned long flags; 723 int rv = 0; 724 int responding; 725 726 spin_lock_irqsave(&desc->iuspin, flags); 727 if (test_bit(WDM_DISCONNECTING, &desc->flags)) { 728 spin_unlock_irqrestore(&desc->iuspin, flags); 729 } else { 730 responding = test_and_set_bit(WDM_RESPONDING, &desc->flags); 731 spin_unlock_irqrestore(&desc->iuspin, flags); 732 if (!responding) 733 rv = usb_submit_urb(desc->response, GFP_KERNEL); 734 if (rv < 0 && rv != -EPERM) { 735 spin_lock_irqsave(&desc->iuspin, flags); 736 clear_bit(WDM_RESPONDING, &desc->flags); 737 if (!test_bit(WDM_DISCONNECTING, &desc->flags)) 738 schedule_work(&desc->rxwork); 739 spin_unlock_irqrestore(&desc->iuspin, flags); 740 } 741 } 742 } 743 744 /* --- hotplug --- */ 745 746 static int wdm_create(struct usb_interface *intf, struct usb_endpoint_descriptor *ep, 747 u16 bufsize, int (*manage_power)(struct usb_interface *, int)) 748 { 749 int rv = -ENOMEM; 750 struct wdm_device *desc; 751 752 desc = kzalloc(sizeof(struct wdm_device), GFP_KERNEL); 753 if (!desc) 754 goto out; 755 INIT_LIST_HEAD(&desc->device_list); 756 mutex_init(&desc->rlock); 757 mutex_init(&desc->wlock); 758 spin_lock_init(&desc->iuspin); 759 init_waitqueue_head(&desc->wait); 760 desc->wMaxCommand = bufsize; 761 /* this will be expanded and needed in hardware endianness */ 762 desc->inum = cpu_to_le16((u16)intf->cur_altsetting->desc.bInterfaceNumber); 763 desc->intf = intf; 764 INIT_WORK(&desc->rxwork, wdm_rxwork); 765 766 rv = -EINVAL; 767 if (!usb_endpoint_is_int_in(ep)) 768 goto err; 769 770 desc->wMaxPacketSize = usb_endpoint_maxp(ep); 771 772 desc->orq = kmalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL); 773 if (!desc->orq) 774 goto err; 775 desc->irq = kmalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL); 776 if (!desc->irq) 777 goto err; 778 779 desc->validity = usb_alloc_urb(0, GFP_KERNEL); 780 if (!desc->validity) 781 goto err; 782 783 desc->response = usb_alloc_urb(0, GFP_KERNEL); 784 if (!desc->response) 785 goto err; 786 787 desc->command = usb_alloc_urb(0, GFP_KERNEL); 788 if (!desc->command) 789 goto err; 790 791 desc->ubuf = kmalloc(desc->wMaxCommand, GFP_KERNEL); 792 if (!desc->ubuf) 793 goto err; 794 795 desc->sbuf = kmalloc(desc->wMaxPacketSize, GFP_KERNEL); 796 if (!desc->sbuf) 797 goto err; 798 799 desc->inbuf = kmalloc(desc->wMaxCommand, GFP_KERNEL); 800 if (!desc->inbuf) 801 goto err; 802 803 usb_fill_int_urb( 804 desc->validity, 805 interface_to_usbdev(intf), 806 usb_rcvintpipe(interface_to_usbdev(intf), ep->bEndpointAddress), 807 desc->sbuf, 808 desc->wMaxPacketSize, 809 wdm_int_callback, 810 desc, 811 ep->bInterval 812 ); 813 814 desc->irq->bRequestType = (USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE); 815 desc->irq->bRequest = USB_CDC_GET_ENCAPSULATED_RESPONSE; 816 desc->irq->wValue = 0; 817 desc->irq->wIndex = desc->inum; 818 desc->irq->wLength = cpu_to_le16(desc->wMaxCommand); 819 820 usb_fill_control_urb( 821 desc->response, 822 interface_to_usbdev(intf), 823 /* using common endpoint 0 */ 824 usb_rcvctrlpipe(interface_to_usbdev(desc->intf), 0), 825 (unsigned char *)desc->irq, 826 desc->inbuf, 827 desc->wMaxCommand, 828 wdm_in_callback, 829 desc 830 ); 831 832 desc->manage_power = manage_power; 833 834 spin_lock(&wdm_device_list_lock); 835 list_add(&desc->device_list, &wdm_device_list); 836 spin_unlock(&wdm_device_list_lock); 837 838 rv = usb_register_dev(intf, &wdm_class); 839 if (rv < 0) 840 goto err; 841 else 842 dev_info(&intf->dev, "%s: USB WDM device\n", dev_name(intf->usb_dev)); 843 out: 844 return rv; 845 err: 846 spin_lock(&wdm_device_list_lock); 847 list_del(&desc->device_list); 848 spin_unlock(&wdm_device_list_lock); 849 cleanup(desc); 850 return rv; 851 } 852 853 static int wdm_manage_power(struct usb_interface *intf, int on) 854 { 855 /* need autopm_get/put here to ensure the usbcore sees the new value */ 856 int rv = usb_autopm_get_interface(intf); 857 if (rv < 0) 858 goto err; 859 860 intf->needs_remote_wakeup = on; 861 usb_autopm_put_interface(intf); 862 err: 863 return rv; 864 } 865 866 static int wdm_probe(struct usb_interface *intf, const struct usb_device_id *id) 867 { 868 int rv = -EINVAL; 869 struct usb_host_interface *iface; 870 struct usb_endpoint_descriptor *ep; 871 struct usb_cdc_dmm_desc *dmhd; 872 u8 *buffer = intf->altsetting->extra; 873 int buflen = intf->altsetting->extralen; 874 u16 maxcom = WDM_DEFAULT_BUFSIZE; 875 876 if (!buffer) 877 goto err; 878 while (buflen > 2) { 879 if (buffer[1] != USB_DT_CS_INTERFACE) { 880 dev_err(&intf->dev, "skipping garbage\n"); 881 goto next_desc; 882 } 883 884 switch (buffer[2]) { 885 case USB_CDC_HEADER_TYPE: 886 break; 887 case USB_CDC_DMM_TYPE: 888 dmhd = (struct usb_cdc_dmm_desc *)buffer; 889 maxcom = le16_to_cpu(dmhd->wMaxCommand); 890 dev_dbg(&intf->dev, 891 "Finding maximum buffer length: %d", maxcom); 892 break; 893 default: 894 dev_err(&intf->dev, 895 "Ignoring extra header, type %d, length %d\n", 896 buffer[2], buffer[0]); 897 break; 898 } 899 next_desc: 900 buflen -= buffer[0]; 901 buffer += buffer[0]; 902 } 903 904 iface = intf->cur_altsetting; 905 if (iface->desc.bNumEndpoints != 1) 906 goto err; 907 ep = &iface->endpoint[0].desc; 908 909 rv = wdm_create(intf, ep, maxcom, &wdm_manage_power); 910 911 err: 912 return rv; 913 } 914 915 /** 916 * usb_cdc_wdm_register - register a WDM subdriver 917 * @intf: usb interface the subdriver will associate with 918 * @ep: interrupt endpoint to monitor for notifications 919 * @bufsize: maximum message size to support for read/write 920 * 921 * Create WDM usb class character device and associate it with intf 922 * without binding, allowing another driver to manage the interface. 923 * 924 * The subdriver will manage the given interrupt endpoint exclusively 925 * and will issue control requests referring to the given intf. It 926 * will otherwise avoid interferring, and in particular not do 927 * usb_set_intfdata/usb_get_intfdata on intf. 928 * 929 * The return value is a pointer to the subdriver's struct usb_driver. 930 * The registering driver is responsible for calling this subdriver's 931 * disconnect, suspend, resume, pre_reset and post_reset methods from 932 * its own. 933 */ 934 struct usb_driver *usb_cdc_wdm_register(struct usb_interface *intf, 935 struct usb_endpoint_descriptor *ep, 936 int bufsize, 937 int (*manage_power)(struct usb_interface *, int)) 938 { 939 int rv = -EINVAL; 940 941 rv = wdm_create(intf, ep, bufsize, manage_power); 942 if (rv < 0) 943 goto err; 944 945 return &wdm_driver; 946 err: 947 return ERR_PTR(rv); 948 } 949 EXPORT_SYMBOL(usb_cdc_wdm_register); 950 951 static void wdm_disconnect(struct usb_interface *intf) 952 { 953 struct wdm_device *desc; 954 unsigned long flags; 955 956 usb_deregister_dev(intf, &wdm_class); 957 desc = wdm_find_device(intf); 958 mutex_lock(&wdm_mutex); 959 960 /* the spinlock makes sure no new urbs are generated in the callbacks */ 961 spin_lock_irqsave(&desc->iuspin, flags); 962 set_bit(WDM_DISCONNECTING, &desc->flags); 963 set_bit(WDM_READ, &desc->flags); 964 /* to terminate pending flushes */ 965 clear_bit(WDM_IN_USE, &desc->flags); 966 spin_unlock_irqrestore(&desc->iuspin, flags); 967 wake_up_all(&desc->wait); 968 mutex_lock(&desc->rlock); 969 mutex_lock(&desc->wlock); 970 kill_urbs(desc); 971 cancel_work_sync(&desc->rxwork); 972 mutex_unlock(&desc->wlock); 973 mutex_unlock(&desc->rlock); 974 975 /* the desc->intf pointer used as list key is now invalid */ 976 spin_lock(&wdm_device_list_lock); 977 list_del(&desc->device_list); 978 spin_unlock(&wdm_device_list_lock); 979 980 if (!desc->count) 981 cleanup(desc); 982 else 983 dev_dbg(&intf->dev, "%s: %d open files - postponing cleanup\n", __func__, desc->count); 984 mutex_unlock(&wdm_mutex); 985 } 986 987 #ifdef CONFIG_PM 988 static int wdm_suspend(struct usb_interface *intf, pm_message_t message) 989 { 990 struct wdm_device *desc = wdm_find_device(intf); 991 int rv = 0; 992 993 dev_dbg(&desc->intf->dev, "wdm%d_suspend\n", intf->minor); 994 995 /* if this is an autosuspend the caller does the locking */ 996 if (!PMSG_IS_AUTO(message)) { 997 mutex_lock(&desc->rlock); 998 mutex_lock(&desc->wlock); 999 } 1000 spin_lock_irq(&desc->iuspin); 1001 1002 if (PMSG_IS_AUTO(message) && 1003 (test_bit(WDM_IN_USE, &desc->flags) 1004 || test_bit(WDM_RESPONDING, &desc->flags))) { 1005 spin_unlock_irq(&desc->iuspin); 1006 rv = -EBUSY; 1007 } else { 1008 1009 set_bit(WDM_SUSPENDING, &desc->flags); 1010 spin_unlock_irq(&desc->iuspin); 1011 /* callback submits work - order is essential */ 1012 kill_urbs(desc); 1013 cancel_work_sync(&desc->rxwork); 1014 } 1015 if (!PMSG_IS_AUTO(message)) { 1016 mutex_unlock(&desc->wlock); 1017 mutex_unlock(&desc->rlock); 1018 } 1019 1020 return rv; 1021 } 1022 #endif 1023 1024 static int recover_from_urb_loss(struct wdm_device *desc) 1025 { 1026 int rv = 0; 1027 1028 if (desc->count) { 1029 rv = usb_submit_urb(desc->validity, GFP_NOIO); 1030 if (rv < 0) 1031 dev_err(&desc->intf->dev, 1032 "Error resume submitting int urb - %d\n", rv); 1033 } 1034 return rv; 1035 } 1036 1037 #ifdef CONFIG_PM 1038 static int wdm_resume(struct usb_interface *intf) 1039 { 1040 struct wdm_device *desc = wdm_find_device(intf); 1041 int rv; 1042 1043 dev_dbg(&desc->intf->dev, "wdm%d_resume\n", intf->minor); 1044 1045 clear_bit(WDM_SUSPENDING, &desc->flags); 1046 rv = recover_from_urb_loss(desc); 1047 1048 return rv; 1049 } 1050 #endif 1051 1052 static int wdm_pre_reset(struct usb_interface *intf) 1053 { 1054 struct wdm_device *desc = wdm_find_device(intf); 1055 1056 /* 1057 * we notify everybody using poll of 1058 * an exceptional situation 1059 * must be done before recovery lest a spontaneous 1060 * message from the device is lost 1061 */ 1062 spin_lock_irq(&desc->iuspin); 1063 set_bit(WDM_RESETTING, &desc->flags); /* inform read/write */ 1064 set_bit(WDM_READ, &desc->flags); /* unblock read */ 1065 clear_bit(WDM_IN_USE, &desc->flags); /* unblock write */ 1066 desc->rerr = -EINTR; 1067 spin_unlock_irq(&desc->iuspin); 1068 wake_up_all(&desc->wait); 1069 mutex_lock(&desc->rlock); 1070 mutex_lock(&desc->wlock); 1071 kill_urbs(desc); 1072 cancel_work_sync(&desc->rxwork); 1073 return 0; 1074 } 1075 1076 static int wdm_post_reset(struct usb_interface *intf) 1077 { 1078 struct wdm_device *desc = wdm_find_device(intf); 1079 int rv; 1080 1081 clear_bit(WDM_OVERFLOW, &desc->flags); 1082 clear_bit(WDM_RESETTING, &desc->flags); 1083 rv = recover_from_urb_loss(desc); 1084 mutex_unlock(&desc->wlock); 1085 mutex_unlock(&desc->rlock); 1086 return 0; 1087 } 1088 1089 static struct usb_driver wdm_driver = { 1090 .name = "cdc_wdm", 1091 .probe = wdm_probe, 1092 .disconnect = wdm_disconnect, 1093 #ifdef CONFIG_PM 1094 .suspend = wdm_suspend, 1095 .resume = wdm_resume, 1096 .reset_resume = wdm_resume, 1097 #endif 1098 .pre_reset = wdm_pre_reset, 1099 .post_reset = wdm_post_reset, 1100 .id_table = wdm_ids, 1101 .supports_autosuspend = 1, 1102 .disable_hub_initiated_lpm = 1, 1103 }; 1104 1105 module_usb_driver(wdm_driver); 1106 1107 MODULE_AUTHOR(DRIVER_AUTHOR); 1108 MODULE_DESCRIPTION(DRIVER_DESC); 1109 MODULE_LICENSE("GPL"); 1110