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 /* 436 * clear WDM_READ flag and possibly submit the read urb if resp_count 437 * is non-zero. 438 * 439 * Called with desc->iuspin locked 440 */ 441 static int clear_wdm_read_flag(struct wdm_device *desc) 442 { 443 int rv = 0; 444 445 clear_bit(WDM_READ, &desc->flags); 446 447 /* submit read urb only if the device is waiting for it */ 448 if (!desc->resp_count || !--desc->resp_count) 449 goto out; 450 451 set_bit(WDM_RESPONDING, &desc->flags); 452 spin_unlock_irq(&desc->iuspin); 453 rv = usb_submit_urb(desc->response, GFP_KERNEL); 454 spin_lock_irq(&desc->iuspin); 455 if (rv) { 456 dev_err(&desc->intf->dev, 457 "usb_submit_urb failed with result %d\n", rv); 458 459 /* make sure the next notification trigger a submit */ 460 clear_bit(WDM_RESPONDING, &desc->flags); 461 desc->resp_count = 0; 462 } 463 out: 464 return rv; 465 } 466 467 static ssize_t wdm_read 468 (struct file *file, char __user *buffer, size_t count, loff_t *ppos) 469 { 470 int rv, cntr; 471 int i = 0; 472 struct wdm_device *desc = file->private_data; 473 474 475 rv = mutex_lock_interruptible(&desc->rlock); /*concurrent reads */ 476 if (rv < 0) 477 return -ERESTARTSYS; 478 479 cntr = ACCESS_ONCE(desc->length); 480 if (cntr == 0) { 481 desc->read = 0; 482 retry: 483 if (test_bit(WDM_DISCONNECTING, &desc->flags)) { 484 rv = -ENODEV; 485 goto err; 486 } 487 if (test_bit(WDM_OVERFLOW, &desc->flags)) { 488 clear_bit(WDM_OVERFLOW, &desc->flags); 489 rv = -ENOBUFS; 490 goto err; 491 } 492 i++; 493 if (file->f_flags & O_NONBLOCK) { 494 if (!test_bit(WDM_READ, &desc->flags)) { 495 rv = cntr ? cntr : -EAGAIN; 496 goto err; 497 } 498 rv = 0; 499 } else { 500 rv = wait_event_interruptible(desc->wait, 501 test_bit(WDM_READ, &desc->flags)); 502 } 503 504 /* may have happened while we slept */ 505 if (test_bit(WDM_DISCONNECTING, &desc->flags)) { 506 rv = -ENODEV; 507 goto err; 508 } 509 if (test_bit(WDM_RESETTING, &desc->flags)) { 510 rv = -EIO; 511 goto err; 512 } 513 usb_mark_last_busy(interface_to_usbdev(desc->intf)); 514 if (rv < 0) { 515 rv = -ERESTARTSYS; 516 goto err; 517 } 518 519 spin_lock_irq(&desc->iuspin); 520 521 if (desc->rerr) { /* read completed, error happened */ 522 desc->rerr = 0; 523 spin_unlock_irq(&desc->iuspin); 524 rv = -EIO; 525 goto err; 526 } 527 /* 528 * recheck whether we've lost the race 529 * against the completion handler 530 */ 531 if (!test_bit(WDM_READ, &desc->flags)) { /* lost race */ 532 spin_unlock_irq(&desc->iuspin); 533 goto retry; 534 } 535 536 if (!desc->reslength) { /* zero length read */ 537 dev_dbg(&desc->intf->dev, "%s: zero length - clearing WDM_READ\n", __func__); 538 rv = clear_wdm_read_flag(desc); 539 spin_unlock_irq(&desc->iuspin); 540 if (rv < 0) 541 goto err; 542 goto retry; 543 } 544 cntr = desc->length; 545 spin_unlock_irq(&desc->iuspin); 546 } 547 548 if (cntr > count) 549 cntr = count; 550 rv = copy_to_user(buffer, desc->ubuf, cntr); 551 if (rv > 0) { 552 rv = -EFAULT; 553 goto err; 554 } 555 556 spin_lock_irq(&desc->iuspin); 557 558 for (i = 0; i < desc->length - cntr; i++) 559 desc->ubuf[i] = desc->ubuf[i + cntr]; 560 561 desc->length -= cntr; 562 /* in case we had outstanding data */ 563 if (!desc->length) 564 clear_wdm_read_flag(desc); 565 spin_unlock_irq(&desc->iuspin); 566 rv = cntr; 567 568 err: 569 mutex_unlock(&desc->rlock); 570 return rv; 571 } 572 573 static int wdm_flush(struct file *file, fl_owner_t id) 574 { 575 struct wdm_device *desc = file->private_data; 576 577 wait_event(desc->wait, !test_bit(WDM_IN_USE, &desc->flags)); 578 579 /* cannot dereference desc->intf if WDM_DISCONNECTING */ 580 if (desc->werr < 0 && !test_bit(WDM_DISCONNECTING, &desc->flags)) 581 dev_err(&desc->intf->dev, "Error in flush path: %d\n", 582 desc->werr); 583 584 return usb_translate_errors(desc->werr); 585 } 586 587 static unsigned int wdm_poll(struct file *file, struct poll_table_struct *wait) 588 { 589 struct wdm_device *desc = file->private_data; 590 unsigned long flags; 591 unsigned int mask = 0; 592 593 spin_lock_irqsave(&desc->iuspin, flags); 594 if (test_bit(WDM_DISCONNECTING, &desc->flags)) { 595 mask = POLLHUP | POLLERR; 596 spin_unlock_irqrestore(&desc->iuspin, flags); 597 goto desc_out; 598 } 599 if (test_bit(WDM_READ, &desc->flags)) 600 mask = POLLIN | POLLRDNORM; 601 if (desc->rerr || desc->werr) 602 mask |= POLLERR; 603 if (!test_bit(WDM_IN_USE, &desc->flags)) 604 mask |= POLLOUT | POLLWRNORM; 605 spin_unlock_irqrestore(&desc->iuspin, flags); 606 607 poll_wait(file, &desc->wait, wait); 608 609 desc_out: 610 return mask; 611 } 612 613 static int wdm_open(struct inode *inode, struct file *file) 614 { 615 int minor = iminor(inode); 616 int rv = -ENODEV; 617 struct usb_interface *intf; 618 struct wdm_device *desc; 619 620 mutex_lock(&wdm_mutex); 621 desc = wdm_find_device_by_minor(minor); 622 if (!desc) 623 goto out; 624 625 intf = desc->intf; 626 if (test_bit(WDM_DISCONNECTING, &desc->flags)) 627 goto out; 628 file->private_data = desc; 629 630 rv = usb_autopm_get_interface(desc->intf); 631 if (rv < 0) { 632 dev_err(&desc->intf->dev, "Error autopm - %d\n", rv); 633 goto out; 634 } 635 636 /* using write lock to protect desc->count */ 637 mutex_lock(&desc->wlock); 638 if (!desc->count++) { 639 desc->werr = 0; 640 desc->rerr = 0; 641 rv = usb_submit_urb(desc->validity, GFP_KERNEL); 642 if (rv < 0) { 643 desc->count--; 644 dev_err(&desc->intf->dev, 645 "Error submitting int urb - %d\n", rv); 646 rv = usb_translate_errors(rv); 647 } 648 } else { 649 rv = 0; 650 } 651 mutex_unlock(&desc->wlock); 652 if (desc->count == 1) 653 desc->manage_power(intf, 1); 654 usb_autopm_put_interface(desc->intf); 655 out: 656 mutex_unlock(&wdm_mutex); 657 return rv; 658 } 659 660 static int wdm_release(struct inode *inode, struct file *file) 661 { 662 struct wdm_device *desc = file->private_data; 663 664 mutex_lock(&wdm_mutex); 665 666 /* using write lock to protect desc->count */ 667 mutex_lock(&desc->wlock); 668 desc->count--; 669 mutex_unlock(&desc->wlock); 670 671 if (!desc->count) { 672 if (!test_bit(WDM_DISCONNECTING, &desc->flags)) { 673 dev_dbg(&desc->intf->dev, "wdm_release: cleanup"); 674 kill_urbs(desc); 675 spin_lock_irq(&desc->iuspin); 676 desc->resp_count = 0; 677 spin_unlock_irq(&desc->iuspin); 678 desc->manage_power(desc->intf, 0); 679 } else { 680 /* must avoid dev_printk here as desc->intf is invalid */ 681 pr_debug(KBUILD_MODNAME " %s: device gone - cleaning up\n", __func__); 682 cleanup(desc); 683 } 684 } 685 mutex_unlock(&wdm_mutex); 686 return 0; 687 } 688 689 static long wdm_ioctl(struct file *file, unsigned int cmd, unsigned long arg) 690 { 691 struct wdm_device *desc = file->private_data; 692 int rv = 0; 693 694 switch (cmd) { 695 case IOCTL_WDM_MAX_COMMAND: 696 if (copy_to_user((void __user *)arg, &desc->wMaxCommand, sizeof(desc->wMaxCommand))) 697 rv = -EFAULT; 698 break; 699 default: 700 rv = -ENOTTY; 701 } 702 return rv; 703 } 704 705 static const struct file_operations wdm_fops = { 706 .owner = THIS_MODULE, 707 .read = wdm_read, 708 .write = wdm_write, 709 .open = wdm_open, 710 .flush = wdm_flush, 711 .release = wdm_release, 712 .poll = wdm_poll, 713 .unlocked_ioctl = wdm_ioctl, 714 .compat_ioctl = wdm_ioctl, 715 .llseek = noop_llseek, 716 }; 717 718 static struct usb_class_driver wdm_class = { 719 .name = "cdc-wdm%d", 720 .fops = &wdm_fops, 721 .minor_base = WDM_MINOR_BASE, 722 }; 723 724 /* --- error handling --- */ 725 static void wdm_rxwork(struct work_struct *work) 726 { 727 struct wdm_device *desc = container_of(work, struct wdm_device, rxwork); 728 unsigned long flags; 729 int rv = 0; 730 int responding; 731 732 spin_lock_irqsave(&desc->iuspin, flags); 733 if (test_bit(WDM_DISCONNECTING, &desc->flags)) { 734 spin_unlock_irqrestore(&desc->iuspin, flags); 735 } else { 736 responding = test_and_set_bit(WDM_RESPONDING, &desc->flags); 737 spin_unlock_irqrestore(&desc->iuspin, flags); 738 if (!responding) 739 rv = usb_submit_urb(desc->response, GFP_KERNEL); 740 if (rv < 0 && rv != -EPERM) { 741 spin_lock_irqsave(&desc->iuspin, flags); 742 clear_bit(WDM_RESPONDING, &desc->flags); 743 if (!test_bit(WDM_DISCONNECTING, &desc->flags)) 744 schedule_work(&desc->rxwork); 745 spin_unlock_irqrestore(&desc->iuspin, flags); 746 } 747 } 748 } 749 750 /* --- hotplug --- */ 751 752 static int wdm_create(struct usb_interface *intf, struct usb_endpoint_descriptor *ep, 753 u16 bufsize, int (*manage_power)(struct usb_interface *, int)) 754 { 755 int rv = -ENOMEM; 756 struct wdm_device *desc; 757 758 desc = kzalloc(sizeof(struct wdm_device), GFP_KERNEL); 759 if (!desc) 760 goto out; 761 INIT_LIST_HEAD(&desc->device_list); 762 mutex_init(&desc->rlock); 763 mutex_init(&desc->wlock); 764 spin_lock_init(&desc->iuspin); 765 init_waitqueue_head(&desc->wait); 766 desc->wMaxCommand = bufsize; 767 /* this will be expanded and needed in hardware endianness */ 768 desc->inum = cpu_to_le16((u16)intf->cur_altsetting->desc.bInterfaceNumber); 769 desc->intf = intf; 770 INIT_WORK(&desc->rxwork, wdm_rxwork); 771 772 rv = -EINVAL; 773 if (!usb_endpoint_is_int_in(ep)) 774 goto err; 775 776 desc->wMaxPacketSize = usb_endpoint_maxp(ep); 777 778 desc->orq = kmalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL); 779 if (!desc->orq) 780 goto err; 781 desc->irq = kmalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL); 782 if (!desc->irq) 783 goto err; 784 785 desc->validity = usb_alloc_urb(0, GFP_KERNEL); 786 if (!desc->validity) 787 goto err; 788 789 desc->response = usb_alloc_urb(0, GFP_KERNEL); 790 if (!desc->response) 791 goto err; 792 793 desc->command = usb_alloc_urb(0, GFP_KERNEL); 794 if (!desc->command) 795 goto err; 796 797 desc->ubuf = kmalloc(desc->wMaxCommand, GFP_KERNEL); 798 if (!desc->ubuf) 799 goto err; 800 801 desc->sbuf = kmalloc(desc->wMaxPacketSize, GFP_KERNEL); 802 if (!desc->sbuf) 803 goto err; 804 805 desc->inbuf = kmalloc(desc->wMaxCommand, GFP_KERNEL); 806 if (!desc->inbuf) 807 goto err; 808 809 usb_fill_int_urb( 810 desc->validity, 811 interface_to_usbdev(intf), 812 usb_rcvintpipe(interface_to_usbdev(intf), ep->bEndpointAddress), 813 desc->sbuf, 814 desc->wMaxPacketSize, 815 wdm_int_callback, 816 desc, 817 ep->bInterval 818 ); 819 820 desc->irq->bRequestType = (USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE); 821 desc->irq->bRequest = USB_CDC_GET_ENCAPSULATED_RESPONSE; 822 desc->irq->wValue = 0; 823 desc->irq->wIndex = desc->inum; 824 desc->irq->wLength = cpu_to_le16(desc->wMaxCommand); 825 826 usb_fill_control_urb( 827 desc->response, 828 interface_to_usbdev(intf), 829 /* using common endpoint 0 */ 830 usb_rcvctrlpipe(interface_to_usbdev(desc->intf), 0), 831 (unsigned char *)desc->irq, 832 desc->inbuf, 833 desc->wMaxCommand, 834 wdm_in_callback, 835 desc 836 ); 837 838 desc->manage_power = manage_power; 839 840 spin_lock(&wdm_device_list_lock); 841 list_add(&desc->device_list, &wdm_device_list); 842 spin_unlock(&wdm_device_list_lock); 843 844 rv = usb_register_dev(intf, &wdm_class); 845 if (rv < 0) 846 goto err; 847 else 848 dev_info(&intf->dev, "%s: USB WDM device\n", dev_name(intf->usb_dev)); 849 out: 850 return rv; 851 err: 852 spin_lock(&wdm_device_list_lock); 853 list_del(&desc->device_list); 854 spin_unlock(&wdm_device_list_lock); 855 cleanup(desc); 856 return rv; 857 } 858 859 static int wdm_manage_power(struct usb_interface *intf, int on) 860 { 861 /* need autopm_get/put here to ensure the usbcore sees the new value */ 862 int rv = usb_autopm_get_interface(intf); 863 864 intf->needs_remote_wakeup = on; 865 if (!rv) 866 usb_autopm_put_interface(intf); 867 return 0; 868 } 869 870 static int wdm_probe(struct usb_interface *intf, const struct usb_device_id *id) 871 { 872 int rv = -EINVAL; 873 struct usb_host_interface *iface; 874 struct usb_endpoint_descriptor *ep; 875 struct usb_cdc_dmm_desc *dmhd; 876 u8 *buffer = intf->altsetting->extra; 877 int buflen = intf->altsetting->extralen; 878 u16 maxcom = WDM_DEFAULT_BUFSIZE; 879 880 if (!buffer) 881 goto err; 882 while (buflen > 2) { 883 if (buffer[1] != USB_DT_CS_INTERFACE) { 884 dev_err(&intf->dev, "skipping garbage\n"); 885 goto next_desc; 886 } 887 888 switch (buffer[2]) { 889 case USB_CDC_HEADER_TYPE: 890 break; 891 case USB_CDC_DMM_TYPE: 892 dmhd = (struct usb_cdc_dmm_desc *)buffer; 893 maxcom = le16_to_cpu(dmhd->wMaxCommand); 894 dev_dbg(&intf->dev, 895 "Finding maximum buffer length: %d", maxcom); 896 break; 897 default: 898 dev_err(&intf->dev, 899 "Ignoring extra header, type %d, length %d\n", 900 buffer[2], buffer[0]); 901 break; 902 } 903 next_desc: 904 buflen -= buffer[0]; 905 buffer += buffer[0]; 906 } 907 908 iface = intf->cur_altsetting; 909 if (iface->desc.bNumEndpoints != 1) 910 goto err; 911 ep = &iface->endpoint[0].desc; 912 913 rv = wdm_create(intf, ep, maxcom, &wdm_manage_power); 914 915 err: 916 return rv; 917 } 918 919 /** 920 * usb_cdc_wdm_register - register a WDM subdriver 921 * @intf: usb interface the subdriver will associate with 922 * @ep: interrupt endpoint to monitor for notifications 923 * @bufsize: maximum message size to support for read/write 924 * 925 * Create WDM usb class character device and associate it with intf 926 * without binding, allowing another driver to manage the interface. 927 * 928 * The subdriver will manage the given interrupt endpoint exclusively 929 * and will issue control requests referring to the given intf. It 930 * will otherwise avoid interferring, and in particular not do 931 * usb_set_intfdata/usb_get_intfdata on intf. 932 * 933 * The return value is a pointer to the subdriver's struct usb_driver. 934 * The registering driver is responsible for calling this subdriver's 935 * disconnect, suspend, resume, pre_reset and post_reset methods from 936 * its own. 937 */ 938 struct usb_driver *usb_cdc_wdm_register(struct usb_interface *intf, 939 struct usb_endpoint_descriptor *ep, 940 int bufsize, 941 int (*manage_power)(struct usb_interface *, int)) 942 { 943 int rv = -EINVAL; 944 945 rv = wdm_create(intf, ep, bufsize, manage_power); 946 if (rv < 0) 947 goto err; 948 949 return &wdm_driver; 950 err: 951 return ERR_PTR(rv); 952 } 953 EXPORT_SYMBOL(usb_cdc_wdm_register); 954 955 static void wdm_disconnect(struct usb_interface *intf) 956 { 957 struct wdm_device *desc; 958 unsigned long flags; 959 960 usb_deregister_dev(intf, &wdm_class); 961 desc = wdm_find_device(intf); 962 mutex_lock(&wdm_mutex); 963 964 /* the spinlock makes sure no new urbs are generated in the callbacks */ 965 spin_lock_irqsave(&desc->iuspin, flags); 966 set_bit(WDM_DISCONNECTING, &desc->flags); 967 set_bit(WDM_READ, &desc->flags); 968 /* to terminate pending flushes */ 969 clear_bit(WDM_IN_USE, &desc->flags); 970 spin_unlock_irqrestore(&desc->iuspin, flags); 971 wake_up_all(&desc->wait); 972 mutex_lock(&desc->rlock); 973 mutex_lock(&desc->wlock); 974 kill_urbs(desc); 975 cancel_work_sync(&desc->rxwork); 976 mutex_unlock(&desc->wlock); 977 mutex_unlock(&desc->rlock); 978 979 /* the desc->intf pointer used as list key is now invalid */ 980 spin_lock(&wdm_device_list_lock); 981 list_del(&desc->device_list); 982 spin_unlock(&wdm_device_list_lock); 983 984 if (!desc->count) 985 cleanup(desc); 986 else 987 dev_dbg(&intf->dev, "%s: %d open files - postponing cleanup\n", __func__, desc->count); 988 mutex_unlock(&wdm_mutex); 989 } 990 991 #ifdef CONFIG_PM 992 static int wdm_suspend(struct usb_interface *intf, pm_message_t message) 993 { 994 struct wdm_device *desc = wdm_find_device(intf); 995 int rv = 0; 996 997 dev_dbg(&desc->intf->dev, "wdm%d_suspend\n", intf->minor); 998 999 /* if this is an autosuspend the caller does the locking */ 1000 if (!PMSG_IS_AUTO(message)) { 1001 mutex_lock(&desc->rlock); 1002 mutex_lock(&desc->wlock); 1003 } 1004 spin_lock_irq(&desc->iuspin); 1005 1006 if (PMSG_IS_AUTO(message) && 1007 (test_bit(WDM_IN_USE, &desc->flags) 1008 || test_bit(WDM_RESPONDING, &desc->flags))) { 1009 spin_unlock_irq(&desc->iuspin); 1010 rv = -EBUSY; 1011 } else { 1012 1013 set_bit(WDM_SUSPENDING, &desc->flags); 1014 spin_unlock_irq(&desc->iuspin); 1015 /* callback submits work - order is essential */ 1016 kill_urbs(desc); 1017 cancel_work_sync(&desc->rxwork); 1018 } 1019 if (!PMSG_IS_AUTO(message)) { 1020 mutex_unlock(&desc->wlock); 1021 mutex_unlock(&desc->rlock); 1022 } 1023 1024 return rv; 1025 } 1026 #endif 1027 1028 static int recover_from_urb_loss(struct wdm_device *desc) 1029 { 1030 int rv = 0; 1031 1032 if (desc->count) { 1033 rv = usb_submit_urb(desc->validity, GFP_NOIO); 1034 if (rv < 0) 1035 dev_err(&desc->intf->dev, 1036 "Error resume submitting int urb - %d\n", rv); 1037 } 1038 return rv; 1039 } 1040 1041 #ifdef CONFIG_PM 1042 static int wdm_resume(struct usb_interface *intf) 1043 { 1044 struct wdm_device *desc = wdm_find_device(intf); 1045 int rv; 1046 1047 dev_dbg(&desc->intf->dev, "wdm%d_resume\n", intf->minor); 1048 1049 clear_bit(WDM_SUSPENDING, &desc->flags); 1050 rv = recover_from_urb_loss(desc); 1051 1052 return rv; 1053 } 1054 #endif 1055 1056 static int wdm_pre_reset(struct usb_interface *intf) 1057 { 1058 struct wdm_device *desc = wdm_find_device(intf); 1059 1060 /* 1061 * we notify everybody using poll of 1062 * an exceptional situation 1063 * must be done before recovery lest a spontaneous 1064 * message from the device is lost 1065 */ 1066 spin_lock_irq(&desc->iuspin); 1067 set_bit(WDM_RESETTING, &desc->flags); /* inform read/write */ 1068 set_bit(WDM_READ, &desc->flags); /* unblock read */ 1069 clear_bit(WDM_IN_USE, &desc->flags); /* unblock write */ 1070 desc->rerr = -EINTR; 1071 spin_unlock_irq(&desc->iuspin); 1072 wake_up_all(&desc->wait); 1073 mutex_lock(&desc->rlock); 1074 mutex_lock(&desc->wlock); 1075 kill_urbs(desc); 1076 cancel_work_sync(&desc->rxwork); 1077 return 0; 1078 } 1079 1080 static int wdm_post_reset(struct usb_interface *intf) 1081 { 1082 struct wdm_device *desc = wdm_find_device(intf); 1083 int rv; 1084 1085 clear_bit(WDM_OVERFLOW, &desc->flags); 1086 clear_bit(WDM_RESETTING, &desc->flags); 1087 rv = recover_from_urb_loss(desc); 1088 mutex_unlock(&desc->wlock); 1089 mutex_unlock(&desc->rlock); 1090 return 0; 1091 } 1092 1093 static struct usb_driver wdm_driver = { 1094 .name = "cdc_wdm", 1095 .probe = wdm_probe, 1096 .disconnect = wdm_disconnect, 1097 #ifdef CONFIG_PM 1098 .suspend = wdm_suspend, 1099 .resume = wdm_resume, 1100 .reset_resume = wdm_resume, 1101 #endif 1102 .pre_reset = wdm_pre_reset, 1103 .post_reset = wdm_post_reset, 1104 .id_table = wdm_ids, 1105 .supports_autosuspend = 1, 1106 .disable_hub_initiated_lpm = 1, 1107 }; 1108 1109 module_usb_driver(wdm_driver); 1110 1111 MODULE_AUTHOR(DRIVER_AUTHOR); 1112 MODULE_DESCRIPTION(DRIVER_DESC); 1113 MODULE_LICENSE("GPL"); 1114