1/* 2 * drivers/usb/driver.c - most of the driver model stuff for usb 3 * 4 * (C) Copyright 2005 Greg Kroah-Hartman <gregkh@suse.de> 5 * 6 * based on drivers/usb/usb.c which had the following copyrights: 7 * (C) Copyright Linus Torvalds 1999 8 * (C) Copyright Johannes Erdfelt 1999-2001 9 * (C) Copyright Andreas Gal 1999 10 * (C) Copyright Gregory P. Smith 1999 11 * (C) Copyright Deti Fliegl 1999 (new USB architecture) 12 * (C) Copyright Randy Dunlap 2000 13 * (C) Copyright David Brownell 2000-2004 14 * (C) Copyright Yggdrasil Computing, Inc. 2000 15 * (usb_device_id matching changes by Adam J. Richter) 16 * (C) Copyright Greg Kroah-Hartman 2002-2003 17 * 18 * NOTE! This is not actually a driver at all, rather this is 19 * just a collection of helper routines that implement the 20 * matching, probing, releasing, suspending and resuming for 21 * real drivers. 22 * 23 */ 24 25#include <linux/device.h> 26#include <linux/usb.h> 27#include <linux/workqueue.h> 28#include "hcd.h" 29#include "usb.h" 30 31#ifdef CONFIG_HOTPLUG 32 33/* 34 * Adds a new dynamic USBdevice ID to this driver, 35 * and cause the driver to probe for all devices again. 36 */ 37ssize_t usb_store_new_id(struct usb_dynids *dynids, 38 struct device_driver *driver, 39 const char *buf, size_t count) 40{ 41 struct usb_dynid *dynid; 42 u32 idVendor = 0; 43 u32 idProduct = 0; 44 int fields = 0; 45 int retval = 0; 46 47 fields = sscanf(buf, "%x %x", &idVendor, &idProduct); 48 if (fields < 2) 49 return -EINVAL; 50 51 dynid = kzalloc(sizeof(*dynid), GFP_KERNEL); 52 if (!dynid) 53 return -ENOMEM; 54 55 INIT_LIST_HEAD(&dynid->node); 56 dynid->id.idVendor = idVendor; 57 dynid->id.idProduct = idProduct; 58 dynid->id.match_flags = USB_DEVICE_ID_MATCH_DEVICE; 59 60 spin_lock(&dynids->lock); 61 list_add_tail(&dynids->list, &dynid->node); 62 spin_unlock(&dynids->lock); 63 64 if (get_driver(driver)) { 65 retval = driver_attach(driver); 66 put_driver(driver); 67 } 68 69 if (retval) 70 return retval; 71 return count; 72} 73EXPORT_SYMBOL_GPL(usb_store_new_id); 74 75static ssize_t store_new_id(struct device_driver *driver, 76 const char *buf, size_t count) 77{ 78 struct usb_driver *usb_drv = to_usb_driver(driver); 79 80 return usb_store_new_id(&usb_drv->dynids, driver, buf, count); 81} 82static DRIVER_ATTR(new_id, S_IWUSR, NULL, store_new_id); 83 84static int usb_create_newid_file(struct usb_driver *usb_drv) 85{ 86 int error = 0; 87 88 if (usb_drv->no_dynamic_id) 89 goto exit; 90 91 if (usb_drv->probe != NULL) 92 error = sysfs_create_file(&usb_drv->drvwrap.driver.kobj, 93 &driver_attr_new_id.attr); 94exit: 95 return error; 96} 97 98static void usb_remove_newid_file(struct usb_driver *usb_drv) 99{ 100 if (usb_drv->no_dynamic_id) 101 return; 102 103 if (usb_drv->probe != NULL) 104 sysfs_remove_file(&usb_drv->drvwrap.driver.kobj, 105 &driver_attr_new_id.attr); 106} 107 108static void usb_free_dynids(struct usb_driver *usb_drv) 109{ 110 struct usb_dynid *dynid, *n; 111 112 spin_lock(&usb_drv->dynids.lock); 113 list_for_each_entry_safe(dynid, n, &usb_drv->dynids.list, node) { 114 list_del(&dynid->node); 115 kfree(dynid); 116 } 117 spin_unlock(&usb_drv->dynids.lock); 118} 119#else 120static inline int usb_create_newid_file(struct usb_driver *usb_drv) 121{ 122 return 0; 123} 124 125static void usb_remove_newid_file(struct usb_driver *usb_drv) 126{ 127} 128 129static inline void usb_free_dynids(struct usb_driver *usb_drv) 130{ 131} 132#endif 133 134static const struct usb_device_id *usb_match_dynamic_id(struct usb_interface *intf, 135 struct usb_driver *drv) 136{ 137 struct usb_dynid *dynid; 138 139 spin_lock(&drv->dynids.lock); 140 list_for_each_entry(dynid, &drv->dynids.list, node) { 141 if (usb_match_one_id(intf, &dynid->id)) { 142 spin_unlock(&drv->dynids.lock); 143 return &dynid->id; 144 } 145 } 146 spin_unlock(&drv->dynids.lock); 147 return NULL; 148} 149 150 151/* called from driver core with dev locked */ 152static int usb_probe_device(struct device *dev) 153{ 154 struct usb_device_driver *udriver = to_usb_device_driver(dev->driver); 155 struct usb_device *udev; 156 int error = -ENODEV; 157 158 dev_dbg(dev, "%s\n", __FUNCTION__); 159 160 if (!is_usb_device(dev)) /* Sanity check */ 161 return error; 162 163 udev = to_usb_device(dev); 164 165 /* TODO: Add real matching code */ 166 167 /* The device should always appear to be in use 168 * unless the driver suports autosuspend. 169 */ 170 udev->pm_usage_cnt = !(udriver->supports_autosuspend); 171 172 error = udriver->probe(udev); 173 return error; 174} 175 176/* called from driver core with dev locked */ 177static int usb_unbind_device(struct device *dev) 178{ 179 struct usb_device_driver *udriver = to_usb_device_driver(dev->driver); 180 181 udriver->disconnect(to_usb_device(dev)); 182 return 0; 183} 184 185 186/* called from driver core with dev locked */ 187static int usb_probe_interface(struct device *dev) 188{ 189 struct usb_driver *driver = to_usb_driver(dev->driver); 190 struct usb_interface *intf; 191 struct usb_device *udev; 192 const struct usb_device_id *id; 193 int error = -ENODEV; 194 195 dev_dbg(dev, "%s\n", __FUNCTION__); 196 197 if (is_usb_device(dev)) /* Sanity check */ 198 return error; 199 200 intf = to_usb_interface(dev); 201 udev = interface_to_usbdev(intf); 202 203 id = usb_match_id(intf, driver->id_table); 204 if (!id) 205 id = usb_match_dynamic_id(intf, driver); 206 if (id) { 207 dev_dbg(dev, "%s - got id\n", __FUNCTION__); 208 209 error = usb_autoresume_device(udev); 210 if (error) 211 return error; 212 213 /* Interface "power state" doesn't correspond to any hardware 214 * state whatsoever. We use it to record when it's bound to 215 * a driver that may start I/0: it's not frozen/quiesced. 216 */ 217 mark_active(intf); 218 intf->condition = USB_INTERFACE_BINDING; 219 220 /* The interface should always appear to be in use 221 * unless the driver suports autosuspend. 222 */ 223 intf->pm_usage_cnt = !(driver->supports_autosuspend); 224 225 error = driver->probe(intf, id); 226 if (error) { 227 mark_quiesced(intf); 228 intf->needs_remote_wakeup = 0; 229 intf->condition = USB_INTERFACE_UNBOUND; 230 } else 231 intf->condition = USB_INTERFACE_BOUND; 232 233 usb_autosuspend_device(udev); 234 } 235 236 return error; 237} 238 239/* called from driver core with dev locked */ 240static int usb_unbind_interface(struct device *dev) 241{ 242 struct usb_driver *driver = to_usb_driver(dev->driver); 243 struct usb_interface *intf = to_usb_interface(dev); 244 struct usb_device *udev; 245 int error; 246 247 intf->condition = USB_INTERFACE_UNBINDING; 248 249 /* Autoresume for set_interface call below */ 250 udev = interface_to_usbdev(intf); 251 error = usb_autoresume_device(udev); 252 253 /* release all urbs for this interface */ 254 usb_disable_interface(interface_to_usbdev(intf), intf); 255 256 driver->disconnect(intf); 257 258 /* reset other interface state */ 259 usb_set_interface(interface_to_usbdev(intf), 260 intf->altsetting[0].desc.bInterfaceNumber, 261 0); 262 usb_set_intfdata(intf, NULL); 263 264 intf->condition = USB_INTERFACE_UNBOUND; 265 mark_quiesced(intf); 266 intf->needs_remote_wakeup = 0; 267 268 if (!error) 269 usb_autosuspend_device(udev); 270 271 return 0; 272} 273 274/** 275 * usb_driver_claim_interface - bind a driver to an interface 276 * @driver: the driver to be bound 277 * @iface: the interface to which it will be bound; must be in the 278 * usb device's active configuration 279 * @priv: driver data associated with that interface 280 * 281 * This is used by usb device drivers that need to claim more than one 282 * interface on a device when probing (audio and acm are current examples). 283 * No device driver should directly modify internal usb_interface or 284 * usb_device structure members. 285 * 286 * Few drivers should need to use this routine, since the most natural 287 * way to bind to an interface is to return the private data from 288 * the driver's probe() method. 289 * 290 * Callers must own the device lock, so driver probe() entries don't need 291 * extra locking, but other call contexts may need to explicitly claim that 292 * lock. 293 */ 294int usb_driver_claim_interface(struct usb_driver *driver, 295 struct usb_interface *iface, void* priv) 296{ 297 struct device *dev = &iface->dev; 298 struct usb_device *udev = interface_to_usbdev(iface); 299 int retval = 0; 300 301 if (dev->driver) 302 return -EBUSY; 303 304 dev->driver = &driver->drvwrap.driver; 305 usb_set_intfdata(iface, priv); 306 307 usb_pm_lock(udev); 308 iface->condition = USB_INTERFACE_BOUND; 309 mark_active(iface); 310 iface->pm_usage_cnt = !(driver->supports_autosuspend); 311 usb_pm_unlock(udev); 312 313 /* if interface was already added, bind now; else let 314 * the future device_add() bind it, bypassing probe() 315 */ 316 if (device_is_registered(dev)) 317 retval = device_bind_driver(dev); 318 319 return retval; 320} 321EXPORT_SYMBOL(usb_driver_claim_interface); 322 323/** 324 * usb_driver_release_interface - unbind a driver from an interface 325 * @driver: the driver to be unbound 326 * @iface: the interface from which it will be unbound 327 * 328 * This can be used by drivers to release an interface without waiting 329 * for their disconnect() methods to be called. In typical cases this 330 * also causes the driver disconnect() method to be called. 331 * 332 * This call is synchronous, and may not be used in an interrupt context. 333 * Callers must own the device lock, so driver disconnect() entries don't 334 * need extra locking, but other call contexts may need to explicitly claim 335 * that lock. 336 */ 337void usb_driver_release_interface(struct usb_driver *driver, 338 struct usb_interface *iface) 339{ 340 struct device *dev = &iface->dev; 341 struct usb_device *udev = interface_to_usbdev(iface); 342 343 /* this should never happen, don't release something that's not ours */ 344 if (!dev->driver || dev->driver != &driver->drvwrap.driver) 345 return; 346 347 /* don't release from within disconnect() */ 348 if (iface->condition != USB_INTERFACE_BOUND) 349 return; 350 351 /* don't release if the interface hasn't been added yet */ 352 if (device_is_registered(dev)) { 353 iface->condition = USB_INTERFACE_UNBINDING; 354 device_release_driver(dev); 355 } 356 357 dev->driver = NULL; 358 usb_set_intfdata(iface, NULL); 359 360 usb_pm_lock(udev); 361 iface->condition = USB_INTERFACE_UNBOUND; 362 mark_quiesced(iface); 363 iface->needs_remote_wakeup = 0; 364 usb_pm_unlock(udev); 365} 366EXPORT_SYMBOL(usb_driver_release_interface); 367 368/* returns 0 if no match, 1 if match */ 369int usb_match_device(struct usb_device *dev, const struct usb_device_id *id) 370{ 371 if ((id->match_flags & USB_DEVICE_ID_MATCH_VENDOR) && 372 id->idVendor != le16_to_cpu(dev->descriptor.idVendor)) 373 return 0; 374 375 if ((id->match_flags & USB_DEVICE_ID_MATCH_PRODUCT) && 376 id->idProduct != le16_to_cpu(dev->descriptor.idProduct)) 377 return 0; 378 379 /* No need to test id->bcdDevice_lo != 0, since 0 is never 380 greater than any unsigned number. */ 381 if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_LO) && 382 (id->bcdDevice_lo > le16_to_cpu(dev->descriptor.bcdDevice))) 383 return 0; 384 385 if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_HI) && 386 (id->bcdDevice_hi < le16_to_cpu(dev->descriptor.bcdDevice))) 387 return 0; 388 389 if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_CLASS) && 390 (id->bDeviceClass != dev->descriptor.bDeviceClass)) 391 return 0; 392 393 if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_SUBCLASS) && 394 (id->bDeviceSubClass!= dev->descriptor.bDeviceSubClass)) 395 return 0; 396 397 if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_PROTOCOL) && 398 (id->bDeviceProtocol != dev->descriptor.bDeviceProtocol)) 399 return 0; 400 401 return 1; 402} 403 404/* returns 0 if no match, 1 if match */ 405int usb_match_one_id(struct usb_interface *interface, 406 const struct usb_device_id *id) 407{ 408 struct usb_host_interface *intf; 409 struct usb_device *dev; 410 411 /* proc_connectinfo in devio.c may call us with id == NULL. */ 412 if (id == NULL) 413 return 0; 414 415 intf = interface->cur_altsetting; 416 dev = interface_to_usbdev(interface); 417 418 if (!usb_match_device(dev, id)) 419 return 0; 420 421 /* The interface class, subclass, and protocol should never be 422 * checked for a match if the device class is Vendor Specific, 423 * unless the match record specifies the Vendor ID. */ 424 if (dev->descriptor.bDeviceClass == USB_CLASS_VENDOR_SPEC && 425 !(id->match_flags & USB_DEVICE_ID_MATCH_VENDOR) && 426 (id->match_flags & (USB_DEVICE_ID_MATCH_INT_CLASS | 427 USB_DEVICE_ID_MATCH_INT_SUBCLASS | 428 USB_DEVICE_ID_MATCH_INT_PROTOCOL))) 429 return 0; 430 431 if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_CLASS) && 432 (id->bInterfaceClass != intf->desc.bInterfaceClass)) 433 return 0; 434 435 if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_SUBCLASS) && 436 (id->bInterfaceSubClass != intf->desc.bInterfaceSubClass)) 437 return 0; 438 439 if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_PROTOCOL) && 440 (id->bInterfaceProtocol != intf->desc.bInterfaceProtocol)) 441 return 0; 442 443 return 1; 444} 445EXPORT_SYMBOL_GPL(usb_match_one_id); 446 447/** 448 * usb_match_id - find first usb_device_id matching device or interface 449 * @interface: the interface of interest 450 * @id: array of usb_device_id structures, terminated by zero entry 451 * 452 * usb_match_id searches an array of usb_device_id's and returns 453 * the first one matching the device or interface, or null. 454 * This is used when binding (or rebinding) a driver to an interface. 455 * Most USB device drivers will use this indirectly, through the usb core, 456 * but some layered driver frameworks use it directly. 457 * These device tables are exported with MODULE_DEVICE_TABLE, through 458 * modutils, to support the driver loading functionality of USB hotplugging. 459 * 460 * What Matches: 461 * 462 * The "match_flags" element in a usb_device_id controls which 463 * members are used. If the corresponding bit is set, the 464 * value in the device_id must match its corresponding member 465 * in the device or interface descriptor, or else the device_id 466 * does not match. 467 * 468 * "driver_info" is normally used only by device drivers, 469 * but you can create a wildcard "matches anything" usb_device_id 470 * as a driver's "modules.usbmap" entry if you provide an id with 471 * only a nonzero "driver_info" field. If you do this, the USB device 472 * driver's probe() routine should use additional intelligence to 473 * decide whether to bind to the specified interface. 474 * 475 * What Makes Good usb_device_id Tables: 476 * 477 * The match algorithm is very simple, so that intelligence in 478 * driver selection must come from smart driver id records. 479 * Unless you have good reasons to use another selection policy, 480 * provide match elements only in related groups, and order match 481 * specifiers from specific to general. Use the macros provided 482 * for that purpose if you can. 483 * 484 * The most specific match specifiers use device descriptor 485 * data. These are commonly used with product-specific matches; 486 * the USB_DEVICE macro lets you provide vendor and product IDs, 487 * and you can also match against ranges of product revisions. 488 * These are widely used for devices with application or vendor 489 * specific bDeviceClass values. 490 * 491 * Matches based on device class/subclass/protocol specifications 492 * are slightly more general; use the USB_DEVICE_INFO macro, or 493 * its siblings. These are used with single-function devices 494 * where bDeviceClass doesn't specify that each interface has 495 * its own class. 496 * 497 * Matches based on interface class/subclass/protocol are the 498 * most general; they let drivers bind to any interface on a 499 * multiple-function device. Use the USB_INTERFACE_INFO 500 * macro, or its siblings, to match class-per-interface style 501 * devices (as recorded in bInterfaceClass). 502 * 503 * Note that an entry created by USB_INTERFACE_INFO won't match 504 * any interface if the device class is set to Vendor-Specific. 505 * This is deliberate; according to the USB spec the meanings of 506 * the interface class/subclass/protocol for these devices are also 507 * vendor-specific, and hence matching against a standard product 508 * class wouldn't work anyway. If you really want to use an 509 * interface-based match for such a device, create a match record 510 * that also specifies the vendor ID. (Unforunately there isn't a 511 * standard macro for creating records like this.) 512 * 513 * Within those groups, remember that not all combinations are 514 * meaningful. For example, don't give a product version range 515 * without vendor and product IDs; or specify a protocol without 516 * its associated class and subclass. 517 */ 518const struct usb_device_id *usb_match_id(struct usb_interface *interface, 519 const struct usb_device_id *id) 520{ 521 /* proc_connectinfo in devio.c may call us with id == NULL. */ 522 if (id == NULL) 523 return NULL; 524 525 /* It is important to check that id->driver_info is nonzero, 526 since an entry that is all zeroes except for a nonzero 527 id->driver_info is the way to create an entry that 528 indicates that the driver want to examine every 529 device and interface. */ 530 for (; id->idVendor || id->bDeviceClass || id->bInterfaceClass || 531 id->driver_info; id++) { 532 if (usb_match_one_id(interface, id)) 533 return id; 534 } 535 536 return NULL; 537} 538EXPORT_SYMBOL_GPL_FUTURE(usb_match_id); 539 540static int usb_device_match(struct device *dev, struct device_driver *drv) 541{ 542 /* devices and interfaces are handled separately */ 543 if (is_usb_device(dev)) { 544 545 /* interface drivers never match devices */ 546 if (!is_usb_device_driver(drv)) 547 return 0; 548 549 /* TODO: Add real matching code */ 550 return 1; 551 552 } else { 553 struct usb_interface *intf; 554 struct usb_driver *usb_drv; 555 const struct usb_device_id *id; 556 557 /* device drivers never match interfaces */ 558 if (is_usb_device_driver(drv)) 559 return 0; 560 561 intf = to_usb_interface(dev); 562 usb_drv = to_usb_driver(drv); 563 564 id = usb_match_id(intf, usb_drv->id_table); 565 if (id) 566 return 1; 567 568 id = usb_match_dynamic_id(intf, usb_drv); 569 if (id) 570 return 1; 571 } 572 573 return 0; 574} 575 576#ifdef CONFIG_HOTPLUG 577static int usb_uevent(struct device *dev, char **envp, int num_envp, 578 char *buffer, int buffer_size) 579{ 580 struct usb_device *usb_dev; 581 int i = 0; 582 int length = 0; 583 584 if (!dev) 585 return -ENODEV; 586 587 /* driver is often null here; dev_dbg() would oops */ 588 pr_debug ("usb %s: uevent\n", dev->bus_id); 589 590 if (is_usb_device(dev)) 591 usb_dev = to_usb_device(dev); 592 else { 593 struct usb_interface *intf = to_usb_interface(dev); 594 usb_dev = interface_to_usbdev(intf); 595 } 596 597 if (usb_dev->devnum < 0) { 598 pr_debug ("usb %s: already deleted?\n", dev->bus_id); 599 return -ENODEV; 600 } 601 if (!usb_dev->bus) { 602 pr_debug ("usb %s: bus removed?\n", dev->bus_id); 603 return -ENODEV; 604 } 605 606#ifdef CONFIG_USB_DEVICEFS 607 /* If this is available, userspace programs can directly read 608 * all the device descriptors we don't tell them about. Or 609 * act as usermode drivers. 610 */ 611 if (add_uevent_var(envp, num_envp, &i, 612 buffer, buffer_size, &length, 613 "DEVICE=/proc/bus/usb/%03d/%03d", 614 usb_dev->bus->busnum, usb_dev->devnum)) 615 return -ENOMEM; 616#endif 617 618 /* per-device configurations are common */ 619 if (add_uevent_var(envp, num_envp, &i, 620 buffer, buffer_size, &length, 621 "PRODUCT=%x/%x/%x", 622 le16_to_cpu(usb_dev->descriptor.idVendor), 623 le16_to_cpu(usb_dev->descriptor.idProduct), 624 le16_to_cpu(usb_dev->descriptor.bcdDevice))) 625 return -ENOMEM; 626 627 /* class-based driver binding models */ 628 if (add_uevent_var(envp, num_envp, &i, 629 buffer, buffer_size, &length, 630 "TYPE=%d/%d/%d", 631 usb_dev->descriptor.bDeviceClass, 632 usb_dev->descriptor.bDeviceSubClass, 633 usb_dev->descriptor.bDeviceProtocol)) 634 return -ENOMEM; 635 636 if (add_uevent_var(envp, num_envp, &i, 637 buffer, buffer_size, &length, 638 "BUSNUM=%03d", 639 usb_dev->bus->busnum)) 640 return -ENOMEM; 641 642 if (add_uevent_var(envp, num_envp, &i, 643 buffer, buffer_size, &length, 644 "DEVNUM=%03d", 645 usb_dev->devnum)) 646 return -ENOMEM; 647 648 envp[i] = NULL; 649 return 0; 650} 651 652#else 653 654static int usb_uevent(struct device *dev, char **envp, 655 int num_envp, char *buffer, int buffer_size) 656{ 657 return -ENODEV; 658} 659#endif /* CONFIG_HOTPLUG */ 660 661/** 662 * usb_register_device_driver - register a USB device (not interface) driver 663 * @new_udriver: USB operations for the device driver 664 * @owner: module owner of this driver. 665 * 666 * Registers a USB device driver with the USB core. The list of 667 * unattached devices will be rescanned whenever a new driver is 668 * added, allowing the new driver to attach to any recognized devices. 669 * Returns a negative error code on failure and 0 on success. 670 */ 671int usb_register_device_driver(struct usb_device_driver *new_udriver, 672 struct module *owner) 673{ 674 int retval = 0; 675 676 if (usb_disabled()) 677 return -ENODEV; 678 679 new_udriver->drvwrap.for_devices = 1; 680 new_udriver->drvwrap.driver.name = (char *) new_udriver->name; 681 new_udriver->drvwrap.driver.bus = &usb_bus_type; 682 new_udriver->drvwrap.driver.probe = usb_probe_device; 683 new_udriver->drvwrap.driver.remove = usb_unbind_device; 684 new_udriver->drvwrap.driver.owner = owner; 685 686 retval = driver_register(&new_udriver->drvwrap.driver); 687 688 if (!retval) { 689 pr_info("%s: registered new device driver %s\n", 690 usbcore_name, new_udriver->name); 691 usbfs_update_special(); 692 } else { 693 printk(KERN_ERR "%s: error %d registering device " 694 " driver %s\n", 695 usbcore_name, retval, new_udriver->name); 696 } 697 698 return retval; 699} 700EXPORT_SYMBOL_GPL(usb_register_device_driver); 701 702/** 703 * usb_deregister_device_driver - unregister a USB device (not interface) driver 704 * @udriver: USB operations of the device driver to unregister 705 * Context: must be able to sleep 706 * 707 * Unlinks the specified driver from the internal USB driver list. 708 */ 709void usb_deregister_device_driver(struct usb_device_driver *udriver) 710{ 711 pr_info("%s: deregistering device driver %s\n", 712 usbcore_name, udriver->name); 713 714 driver_unregister(&udriver->drvwrap.driver); 715 usbfs_update_special(); 716} 717EXPORT_SYMBOL_GPL(usb_deregister_device_driver); 718 719/** 720 * usb_register_driver - register a USB interface driver 721 * @new_driver: USB operations for the interface driver 722 * @owner: module owner of this driver. 723 * @mod_name: module name string 724 * 725 * Registers a USB interface driver with the USB core. The list of 726 * unattached interfaces will be rescanned whenever a new driver is 727 * added, allowing the new driver to attach to any recognized interfaces. 728 * Returns a negative error code on failure and 0 on success. 729 * 730 * NOTE: if you want your driver to use the USB major number, you must call 731 * usb_register_dev() to enable that functionality. This function no longer 732 * takes care of that. 733 */ 734int usb_register_driver(struct usb_driver *new_driver, struct module *owner, 735 const char *mod_name) 736{ 737 int retval = 0; 738 739 if (usb_disabled()) 740 return -ENODEV; 741 742 new_driver->drvwrap.for_devices = 0; 743 new_driver->drvwrap.driver.name = (char *) new_driver->name; 744 new_driver->drvwrap.driver.bus = &usb_bus_type; 745 new_driver->drvwrap.driver.probe = usb_probe_interface; 746 new_driver->drvwrap.driver.remove = usb_unbind_interface; 747 new_driver->drvwrap.driver.owner = owner; 748 new_driver->drvwrap.driver.mod_name = mod_name; 749 spin_lock_init(&new_driver->dynids.lock); 750 INIT_LIST_HEAD(&new_driver->dynids.list); 751 752 retval = driver_register(&new_driver->drvwrap.driver); 753 754 if (!retval) { 755 pr_info("%s: registered new interface driver %s\n", 756 usbcore_name, new_driver->name); 757 usbfs_update_special(); 758 usb_create_newid_file(new_driver); 759 } else { 760 printk(KERN_ERR "%s: error %d registering interface " 761 " driver %s\n", 762 usbcore_name, retval, new_driver->name); 763 } 764 765 return retval; 766} 767EXPORT_SYMBOL_GPL_FUTURE(usb_register_driver); 768 769/** 770 * usb_deregister - unregister a USB interface driver 771 * @driver: USB operations of the interface driver to unregister 772 * Context: must be able to sleep 773 * 774 * Unlinks the specified driver from the internal USB driver list. 775 * 776 * NOTE: If you called usb_register_dev(), you still need to call 777 * usb_deregister_dev() to clean up your driver's allocated minor numbers, 778 * this * call will no longer do it for you. 779 */ 780void usb_deregister(struct usb_driver *driver) 781{ 782 pr_info("%s: deregistering interface driver %s\n", 783 usbcore_name, driver->name); 784 785 usb_remove_newid_file(driver); 786 usb_free_dynids(driver); 787 driver_unregister(&driver->drvwrap.driver); 788 789 usbfs_update_special(); 790} 791EXPORT_SYMBOL_GPL_FUTURE(usb_deregister); 792 793#ifdef CONFIG_PM 794 795/* Caller has locked udev's pm_mutex */ 796static int usb_suspend_device(struct usb_device *udev, pm_message_t msg) 797{ 798 struct usb_device_driver *udriver; 799 int status = 0; 800 801 if (udev->state == USB_STATE_NOTATTACHED || 802 udev->state == USB_STATE_SUSPENDED) 803 goto done; 804 805 /* For devices that don't have a driver, we do a standard suspend. */ 806 if (udev->dev.driver == NULL) { 807 udev->do_remote_wakeup = 0; 808 status = usb_port_suspend(udev); 809 goto done; 810 } 811 812 udriver = to_usb_device_driver(udev->dev.driver); 813 status = udriver->suspend(udev, msg); 814 815done: 816 // dev_dbg(&udev->dev, "%s: status %d\n", __FUNCTION__, status); 817 if (status == 0) 818 udev->dev.power.power_state.event = msg.event; 819 return status; 820} 821 822/* Caller has locked udev's pm_mutex */ 823static int usb_resume_device(struct usb_device *udev) 824{ 825 struct usb_device_driver *udriver; 826 int status = 0; 827 828 if (udev->state == USB_STATE_NOTATTACHED || 829 udev->state != USB_STATE_SUSPENDED) 830 goto done; 831 832 /* Can't resume it if it doesn't have a driver. */ 833 if (udev->dev.driver == NULL) { 834 status = -ENOTCONN; 835 goto done; 836 } 837 838 udriver = to_usb_device_driver(udev->dev.driver); 839 status = udriver->resume(udev); 840 841done: 842 // dev_dbg(&udev->dev, "%s: status %d\n", __FUNCTION__, status); 843 if (status == 0) { 844 udev->autoresume_disabled = 0; 845 udev->dev.power.power_state.event = PM_EVENT_ON; 846 } 847 return status; 848} 849 850/* Caller has locked intf's usb_device's pm mutex */ 851static int usb_suspend_interface(struct usb_interface *intf, pm_message_t msg) 852{ 853 struct usb_driver *driver; 854 int status = 0; 855 856 /* with no hardware, USB interfaces only use FREEZE and ON states */ 857 if (interface_to_usbdev(intf)->state == USB_STATE_NOTATTACHED || 858 !is_active(intf)) 859 goto done; 860 861 if (intf->condition == USB_INTERFACE_UNBOUND) /* This can't happen */ 862 goto done; 863 driver = to_usb_driver(intf->dev.driver); 864 865 if (driver->suspend && driver->resume) { 866 status = driver->suspend(intf, msg); 867 if (status == 0) 868 mark_quiesced(intf); 869 else if (!interface_to_usbdev(intf)->auto_pm) 870 dev_err(&intf->dev, "%s error %d\n", 871 "suspend", status); 872 } else { 873 // Not possible if auto_pm is set... 874 dev_warn(&intf->dev, "no suspend for driver %s?\n", 875 driver->name); 876 mark_quiesced(intf); 877 } 878 879done: 880 // dev_dbg(&intf->dev, "%s: status %d\n", __FUNCTION__, status); 881 if (status == 0) 882 intf->dev.power.power_state.event = msg.event; 883 return status; 884} 885 886/* Caller has locked intf's usb_device's pm_mutex */ 887static int usb_resume_interface(struct usb_interface *intf) 888{ 889 struct usb_driver *driver; 890 int status = 0; 891 892 if (interface_to_usbdev(intf)->state == USB_STATE_NOTATTACHED || 893 is_active(intf)) 894 goto done; 895 896 /* Don't let autoresume interfere with unbinding */ 897 if (intf->condition == USB_INTERFACE_UNBINDING) 898 goto done; 899 900 /* Can't resume it if it doesn't have a driver. */ 901 if (intf->condition == USB_INTERFACE_UNBOUND) { 902 status = -ENOTCONN; 903 goto done; 904 } 905 driver = to_usb_driver(intf->dev.driver); 906 907 if (driver->resume) { 908 status = driver->resume(intf); 909 if (status) 910 dev_err(&intf->dev, "%s error %d\n", 911 "resume", status); 912 else 913 mark_active(intf); 914 } else { 915 dev_warn(&intf->dev, "no resume for driver %s?\n", 916 driver->name); 917 mark_active(intf); 918 } 919 920done: 921 // dev_dbg(&intf->dev, "%s: status %d\n", __FUNCTION__, status); 922 if (status == 0) 923 intf->dev.power.power_state.event = PM_EVENT_ON; 924 return status; 925} 926 927#ifdef CONFIG_USB_SUSPEND 928 929/* Internal routine to check whether we may autosuspend a device. */ 930static int autosuspend_check(struct usb_device *udev) 931{ 932 int i; 933 struct usb_interface *intf; 934 unsigned long suspend_time; 935 936 /* For autosuspend, fail fast if anything is in use or autosuspend 937 * is disabled. Also fail if any interfaces require remote wakeup 938 * but it isn't available. 939 */ 940 udev->do_remote_wakeup = device_may_wakeup(&udev->dev); 941 if (udev->pm_usage_cnt > 0) 942 return -EBUSY; 943 if (udev->autosuspend_delay < 0 || udev->autosuspend_disabled) 944 return -EPERM; 945 946 suspend_time = udev->last_busy + udev->autosuspend_delay; 947 if (udev->actconfig) { 948 for (i = 0; i < udev->actconfig->desc.bNumInterfaces; i++) { 949 intf = udev->actconfig->interface[i]; 950 if (!is_active(intf)) 951 continue; 952 if (intf->pm_usage_cnt > 0) 953 return -EBUSY; 954 if (intf->needs_remote_wakeup && 955 !udev->do_remote_wakeup) { 956 dev_dbg(&udev->dev, "remote wakeup needed " 957 "for autosuspend\n"); 958 return -EOPNOTSUPP; 959 } 960 } 961 } 962 963 /* If everything is okay but the device hasn't been idle for long 964 * enough, queue a delayed autosuspend request. 965 */ 966 if (time_after(suspend_time, jiffies)) { 967 if (!timer_pending(&udev->autosuspend.timer)) { 968 969 /* The value of jiffies may change between the 970 * time_after() comparison above and the subtraction 971 * below. That's okay; the system behaves sanely 972 * when a timer is registered for the present moment 973 * or for the past. 974 */ 975 queue_delayed_work(ksuspend_usb_wq, &udev->autosuspend, 976 suspend_time - jiffies); 977 } 978 return -EAGAIN; 979 } 980 return 0; 981} 982 983#else 984 985static inline int autosuspend_check(struct usb_device *udev) 986{ 987 return 0; 988} 989 990#endif /* CONFIG_USB_SUSPEND */ 991 992/** 993 * usb_suspend_both - suspend a USB device and its interfaces 994 * @udev: the usb_device to suspend 995 * @msg: Power Management message describing this state transition 996 * 997 * This is the central routine for suspending USB devices. It calls the 998 * suspend methods for all the interface drivers in @udev and then calls 999 * the suspend method for @udev itself. If an error occurs at any stage, 1000 * all the interfaces which were suspended are resumed so that they remain 1001 * in the same state as the device. 1002 * 1003 * If an autosuspend is in progress (@udev->auto_pm is set), the routine 1004 * checks first to make sure that neither the device itself or any of its 1005 * active interfaces is in use (pm_usage_cnt is greater than 0). If they 1006 * are, the autosuspend fails. 1007 * 1008 * If the suspend succeeds, the routine recursively queues an autosuspend 1009 * request for @udev's parent device, thereby propagating the change up 1010 * the device tree. If all of the parent's children are now suspended, 1011 * the parent will autosuspend in turn. 1012 * 1013 * The suspend method calls are subject to mutual exclusion under control 1014 * of @udev's pm_mutex. Many of these calls are also under the protection 1015 * of @udev's device lock (including all requests originating outside the 1016 * USB subsystem), but autosuspend requests generated by a child device or 1017 * interface driver may not be. Usbcore will insure that the method calls 1018 * do not arrive during bind, unbind, or reset operations. However, drivers 1019 * must be prepared to handle suspend calls arriving at unpredictable times. 1020 * The only way to block such calls is to do an autoresume (preventing 1021 * autosuspends) while holding @udev's device lock (preventing outside 1022 * suspends). 1023 * 1024 * The caller must hold @udev->pm_mutex. 1025 * 1026 * This routine can run only in process context. 1027 */ 1028static int usb_suspend_both(struct usb_device *udev, pm_message_t msg) 1029{ 1030 int status = 0; 1031 int i = 0; 1032 struct usb_interface *intf; 1033 struct usb_device *parent = udev->parent; 1034 1035 if (udev->state == USB_STATE_NOTATTACHED || 1036 udev->state == USB_STATE_SUSPENDED) 1037 goto done; 1038 1039 udev->do_remote_wakeup = device_may_wakeup(&udev->dev); 1040 1041 if (udev->auto_pm) { 1042 status = autosuspend_check(udev); 1043 if (status < 0) 1044 goto done; 1045 } 1046 1047 /* Suspend all the interfaces and then udev itself */ 1048 if (udev->actconfig) { 1049 for (; i < udev->actconfig->desc.bNumInterfaces; i++) { 1050 intf = udev->actconfig->interface[i]; 1051 status = usb_suspend_interface(intf, msg); 1052 if (status != 0) 1053 break; 1054 } 1055 } 1056 if (status == 0) 1057 status = usb_suspend_device(udev, msg); 1058 1059 /* If the suspend failed, resume interfaces that did get suspended */ 1060 if (status != 0) { 1061 while (--i >= 0) { 1062 intf = udev->actconfig->interface[i]; 1063 usb_resume_interface(intf); 1064 } 1065 1066 /* Try another autosuspend when the interfaces aren't busy */ 1067 if (udev->auto_pm) 1068 autosuspend_check(udev); 1069 1070 /* If the suspend succeeded, propagate it up the tree */ 1071 } else { 1072 cancel_delayed_work(&udev->autosuspend); 1073 if (parent) 1074 usb_autosuspend_device(parent); 1075 } 1076 1077 done: 1078 // dev_dbg(&udev->dev, "%s: status %d\n", __FUNCTION__, status); 1079 return status; 1080} 1081 1082/** 1083 * usb_resume_both - resume a USB device and its interfaces 1084 * @udev: the usb_device to resume 1085 * 1086 * This is the central routine for resuming USB devices. It calls the 1087 * the resume method for @udev and then calls the resume methods for all 1088 * the interface drivers in @udev. 1089 * 1090 * Before starting the resume, the routine calls itself recursively for 1091 * the parent device of @udev, thereby propagating the change up the device 1092 * tree and assuring that @udev will be able to resume. If the parent is 1093 * unable to resume successfully, the routine fails. 1094 * 1095 * The resume method calls are subject to mutual exclusion under control 1096 * of @udev's pm_mutex. Many of these calls are also under the protection 1097 * of @udev's device lock (including all requests originating outside the 1098 * USB subsystem), but autoresume requests generated by a child device or 1099 * interface driver may not be. Usbcore will insure that the method calls 1100 * do not arrive during bind, unbind, or reset operations. However, drivers 1101 * must be prepared to handle resume calls arriving at unpredictable times. 1102 * The only way to block such calls is to do an autoresume (preventing 1103 * other autoresumes) while holding @udev's device lock (preventing outside 1104 * resumes). 1105 * 1106 * The caller must hold @udev->pm_mutex. 1107 * 1108 * This routine can run only in process context. 1109 */ 1110static int usb_resume_both(struct usb_device *udev) 1111{ 1112 int status = 0; 1113 int i; 1114 struct usb_interface *intf; 1115 struct usb_device *parent = udev->parent; 1116 1117 cancel_delayed_work(&udev->autosuspend); 1118 if (udev->state == USB_STATE_NOTATTACHED) { 1119 status = -ENODEV; 1120 goto done; 1121 } 1122 1123 /* Propagate the resume up the tree, if necessary */ 1124 if (udev->state == USB_STATE_SUSPENDED) { 1125 if (udev->auto_pm && udev->autoresume_disabled) { 1126 status = -EPERM; 1127 goto done; 1128 } 1129 if (parent) { 1130 status = usb_autoresume_device(parent); 1131 if (status == 0) { 1132 status = usb_resume_device(udev); 1133 if (status) { 1134 usb_autosuspend_device(parent); 1135 1136 /* It's possible usb_resume_device() 1137 * failed after the port was 1138 * unsuspended, causing udev to be 1139 * logically disconnected. We don't 1140 * want usb_disconnect() to autosuspend 1141 * the parent again, so tell it that 1142 * udev disconnected while still 1143 * suspended. */ 1144 if (udev->state == 1145 USB_STATE_NOTATTACHED) 1146 udev->discon_suspended = 1; 1147 } 1148 } 1149 } else { 1150 1151 /* We can't progagate beyond the USB subsystem, 1152 * so if a root hub's controller is suspended 1153 * then we're stuck. */ 1154 if (udev->dev.parent->power.power_state.event != 1155 PM_EVENT_ON) 1156 status = -EHOSTUNREACH; 1157 else 1158 status = usb_resume_device(udev); 1159 } 1160 } else { 1161 1162 /* Needed only for setting udev->dev.power.power_state.event 1163 * and for possible debugging message. */ 1164 status = usb_resume_device(udev); 1165 } 1166 1167 if (status == 0 && udev->actconfig) { 1168 for (i = 0; i < udev->actconfig->desc.bNumInterfaces; i++) { 1169 intf = udev->actconfig->interface[i]; 1170 usb_resume_interface(intf); 1171 } 1172 } 1173 1174 done: 1175 // dev_dbg(&udev->dev, "%s: status %d\n", __FUNCTION__, status); 1176 return status; 1177} 1178 1179#ifdef CONFIG_USB_SUSPEND 1180 1181/* Internal routine to adjust a device's usage counter and change 1182 * its autosuspend state. 1183 */ 1184static int usb_autopm_do_device(struct usb_device *udev, int inc_usage_cnt) 1185{ 1186 int status = 0; 1187 1188 usb_pm_lock(udev); 1189 udev->auto_pm = 1; 1190 udev->pm_usage_cnt += inc_usage_cnt; 1191 WARN_ON(udev->pm_usage_cnt < 0); 1192 if (inc_usage_cnt >= 0 && udev->pm_usage_cnt > 0) { 1193 if (udev->state == USB_STATE_SUSPENDED) 1194 status = usb_resume_both(udev); 1195 if (status != 0) 1196 udev->pm_usage_cnt -= inc_usage_cnt; 1197 else if (inc_usage_cnt) 1198 udev->last_busy = jiffies; 1199 } else if (inc_usage_cnt <= 0 && udev->pm_usage_cnt <= 0) { 1200 if (inc_usage_cnt) 1201 udev->last_busy = jiffies; 1202 status = usb_suspend_both(udev, PMSG_SUSPEND); 1203 } 1204 usb_pm_unlock(udev); 1205 return status; 1206} 1207 1208/* usb_autosuspend_work - callback routine to autosuspend a USB device */ 1209void usb_autosuspend_work(struct work_struct *work) 1210{ 1211 struct usb_device *udev = 1212 container_of(work, struct usb_device, autosuspend.work); 1213 1214 usb_autopm_do_device(udev, 0); 1215} 1216 1217/** 1218 * usb_autosuspend_device - delayed autosuspend of a USB device and its interfaces 1219 * @udev: the usb_device to autosuspend 1220 * 1221 * This routine should be called when a core subsystem is finished using 1222 * @udev and wants to allow it to autosuspend. Examples would be when 1223 * @udev's device file in usbfs is closed or after a configuration change. 1224 * 1225 * @udev's usage counter is decremented. If it or any of the usage counters 1226 * for an active interface is greater than 0, no autosuspend request will be 1227 * queued. (If an interface driver does not support autosuspend then its 1228 * usage counter is permanently positive.) Furthermore, if an interface 1229 * driver requires remote-wakeup capability during autosuspend but remote 1230 * wakeup is disabled, the autosuspend will fail. 1231 * 1232 * Often the caller will hold @udev's device lock, but this is not 1233 * necessary. 1234 * 1235 * This routine can run only in process context. 1236 */ 1237void usb_autosuspend_device(struct usb_device *udev) 1238{ 1239 int status; 1240 1241 status = usb_autopm_do_device(udev, -1); 1242 // dev_dbg(&udev->dev, "%s: cnt %d\n", 1243 // __FUNCTION__, udev->pm_usage_cnt); 1244} 1245 1246/** 1247 * usb_try_autosuspend_device - attempt an autosuspend of a USB device and its interfaces 1248 * @udev: the usb_device to autosuspend 1249 * 1250 * This routine should be called when a core subsystem thinks @udev may 1251 * be ready to autosuspend. 1252 * 1253 * @udev's usage counter left unchanged. If it or any of the usage counters 1254 * for an active interface is greater than 0, or autosuspend is not allowed 1255 * for any other reason, no autosuspend request will be queued. 1256 * 1257 * This routine can run only in process context. 1258 */ 1259void usb_try_autosuspend_device(struct usb_device *udev) 1260{ 1261 usb_autopm_do_device(udev, 0); 1262 // dev_dbg(&udev->dev, "%s: cnt %d\n", 1263 // __FUNCTION__, udev->pm_usage_cnt); 1264} 1265 1266/** 1267 * usb_autoresume_device - immediately autoresume a USB device and its interfaces 1268 * @udev: the usb_device to autoresume 1269 * 1270 * This routine should be called when a core subsystem wants to use @udev 1271 * and needs to guarantee that it is not suspended. No autosuspend will 1272 * occur until usb_autosuspend_device is called. (Note that this will not 1273 * prevent suspend events originating in the PM core.) Examples would be 1274 * when @udev's device file in usbfs is opened or when a remote-wakeup 1275 * request is received. 1276 * 1277 * @udev's usage counter is incremented to prevent subsequent autosuspends. 1278 * However if the autoresume fails then the usage counter is re-decremented. 1279 * 1280 * Often the caller will hold @udev's device lock, but this is not 1281 * necessary (and attempting it might cause deadlock). 1282 * 1283 * This routine can run only in process context. 1284 */ 1285int usb_autoresume_device(struct usb_device *udev) 1286{ 1287 int status; 1288 1289 status = usb_autopm_do_device(udev, 1); 1290 // dev_dbg(&udev->dev, "%s: status %d cnt %d\n", 1291 // __FUNCTION__, status, udev->pm_usage_cnt); 1292 return status; 1293} 1294 1295/* Internal routine to adjust an interface's usage counter and change 1296 * its device's autosuspend state. 1297 */ 1298static int usb_autopm_do_interface(struct usb_interface *intf, 1299 int inc_usage_cnt) 1300{ 1301 struct usb_device *udev = interface_to_usbdev(intf); 1302 int status = 0; 1303 1304 usb_pm_lock(udev); 1305 if (intf->condition == USB_INTERFACE_UNBOUND) 1306 status = -ENODEV; 1307 else { 1308 udev->auto_pm = 1; 1309 intf->pm_usage_cnt += inc_usage_cnt; 1310 if (inc_usage_cnt >= 0 && intf->pm_usage_cnt > 0) { 1311 if (udev->state == USB_STATE_SUSPENDED) 1312 status = usb_resume_both(udev); 1313 if (status != 0) 1314 intf->pm_usage_cnt -= inc_usage_cnt; 1315 else if (inc_usage_cnt) 1316 udev->last_busy = jiffies; 1317 } else if (inc_usage_cnt <= 0 && intf->pm_usage_cnt <= 0) { 1318 if (inc_usage_cnt) 1319 udev->last_busy = jiffies; 1320 status = usb_suspend_both(udev, PMSG_SUSPEND); 1321 } 1322 } 1323 usb_pm_unlock(udev); 1324 return status; 1325} 1326 1327/** 1328 * usb_autopm_put_interface - decrement a USB interface's PM-usage counter 1329 * @intf: the usb_interface whose counter should be decremented 1330 * 1331 * This routine should be called by an interface driver when it is 1332 * finished using @intf and wants to allow it to autosuspend. A typical 1333 * example would be a character-device driver when its device file is 1334 * closed. 1335 * 1336 * The routine decrements @intf's usage counter. When the counter reaches 1337 * 0, a delayed autosuspend request for @intf's device is queued. When 1338 * the delay expires, if @intf->pm_usage_cnt is still <= 0 along with all 1339 * the other usage counters for the sibling interfaces and @intf's 1340 * usb_device, the device and all its interfaces will be autosuspended. 1341 * 1342 * Note that @intf->pm_usage_cnt is owned by the interface driver. The 1343 * core will not change its value other than the increment and decrement 1344 * in usb_autopm_get_interface and usb_autopm_put_interface. The driver 1345 * may use this simple counter-oriented discipline or may set the value 1346 * any way it likes. 1347 * 1348 * If the driver has set @intf->needs_remote_wakeup then autosuspend will 1349 * take place only if the device's remote-wakeup facility is enabled. 1350 * 1351 * Suspend method calls queued by this routine can arrive at any time 1352 * while @intf is resumed and its usage counter is equal to 0. They are 1353 * not protected by the usb_device's lock but only by its pm_mutex. 1354 * Drivers must provide their own synchronization. 1355 * 1356 * This routine can run only in process context. 1357 */ 1358void usb_autopm_put_interface(struct usb_interface *intf) 1359{ 1360 int status; 1361 1362 status = usb_autopm_do_interface(intf, -1); 1363 // dev_dbg(&intf->dev, "%s: status %d cnt %d\n", 1364 // __FUNCTION__, status, intf->pm_usage_cnt); 1365} 1366EXPORT_SYMBOL_GPL(usb_autopm_put_interface); 1367 1368/** 1369 * usb_autopm_get_interface - increment a USB interface's PM-usage counter 1370 * @intf: the usb_interface whose counter should be incremented 1371 * 1372 * This routine should be called by an interface driver when it wants to 1373 * use @intf and needs to guarantee that it is not suspended. In addition, 1374 * the routine prevents @intf from being autosuspended subsequently. (Note 1375 * that this will not prevent suspend events originating in the PM core.) 1376 * This prevention will persist until usb_autopm_put_interface() is called 1377 * or @intf is unbound. A typical example would be a character-device 1378 * driver when its device file is opened. 1379 * 1380 * 1381 * The routine increments @intf's usage counter. (However if the 1382 * autoresume fails then the counter is re-decremented.) So long as the 1383 * counter is greater than 0, autosuspend will not be allowed for @intf 1384 * or its usb_device. When the driver is finished using @intf it should 1385 * call usb_autopm_put_interface() to decrement the usage counter and 1386 * queue a delayed autosuspend request (if the counter is <= 0). 1387 * 1388 * 1389 * Note that @intf->pm_usage_cnt is owned by the interface driver. The 1390 * core will not change its value other than the increment and decrement 1391 * in usb_autopm_get_interface and usb_autopm_put_interface. The driver 1392 * may use this simple counter-oriented discipline or may set the value 1393 * any way it likes. 1394 * 1395 * Resume method calls generated by this routine can arrive at any time 1396 * while @intf is suspended. They are not protected by the usb_device's 1397 * lock but only by its pm_mutex. Drivers must provide their own 1398 * synchronization. 1399 * 1400 * This routine can run only in process context. 1401 */ 1402int usb_autopm_get_interface(struct usb_interface *intf) 1403{ 1404 int status; 1405 1406 status = usb_autopm_do_interface(intf, 1); 1407 // dev_dbg(&intf->dev, "%s: status %d cnt %d\n", 1408 // __FUNCTION__, status, intf->pm_usage_cnt); 1409 return status; 1410} 1411EXPORT_SYMBOL_GPL(usb_autopm_get_interface); 1412 1413/** 1414 * usb_autopm_set_interface - set a USB interface's autosuspend state 1415 * @intf: the usb_interface whose state should be set 1416 * 1417 * This routine sets the autosuspend state of @intf's device according 1418 * to @intf's usage counter, which the caller must have set previously. 1419 * If the counter is <= 0, the device is autosuspended (if it isn't 1420 * already suspended and if nothing else prevents the autosuspend). If 1421 * the counter is > 0, the device is autoresumed (if it isn't already 1422 * awake). 1423 */ 1424int usb_autopm_set_interface(struct usb_interface *intf) 1425{ 1426 int status; 1427 1428 status = usb_autopm_do_interface(intf, 0); 1429 // dev_dbg(&intf->dev, "%s: status %d cnt %d\n", 1430 // __FUNCTION__, status, intf->pm_usage_cnt); 1431 return status; 1432} 1433EXPORT_SYMBOL_GPL(usb_autopm_set_interface); 1434 1435#else 1436 1437void usb_autosuspend_work(struct work_struct *work) 1438{} 1439 1440#endif /* CONFIG_USB_SUSPEND */ 1441 1442/** 1443 * usb_external_suspend_device - external suspend of a USB device and its interfaces 1444 * @udev: the usb_device to suspend 1445 * @msg: Power Management message describing this state transition 1446 * 1447 * This routine handles external suspend requests: ones not generated 1448 * internally by a USB driver (autosuspend) but rather coming from the user 1449 * (via sysfs) or the PM core (system sleep). The suspend will be carried 1450 * out regardless of @udev's usage counter or those of its interfaces, 1451 * and regardless of whether or not remote wakeup is enabled. Of course, 1452 * interface drivers still have the option of failing the suspend (if 1453 * there are unsuspended children, for example). 1454 * 1455 * The caller must hold @udev's device lock. 1456 */ 1457int usb_external_suspend_device(struct usb_device *udev, pm_message_t msg) 1458{ 1459 int status; 1460 1461 usb_pm_lock(udev); 1462 udev->auto_pm = 0; 1463 status = usb_suspend_both(udev, msg); 1464 usb_pm_unlock(udev); 1465 return status; 1466} 1467 1468/** 1469 * usb_external_resume_device - external resume of a USB device and its interfaces 1470 * @udev: the usb_device to resume 1471 * 1472 * This routine handles external resume requests: ones not generated 1473 * internally by a USB driver (autoresume) but rather coming from the user 1474 * (via sysfs), the PM core (system resume), or the device itself (remote 1475 * wakeup). @udev's usage counter is unaffected. 1476 * 1477 * The caller must hold @udev's device lock. 1478 */ 1479int usb_external_resume_device(struct usb_device *udev) 1480{ 1481 int status; 1482 1483 usb_pm_lock(udev); 1484 udev->auto_pm = 0; 1485 status = usb_resume_both(udev); 1486 udev->last_busy = jiffies; 1487 usb_pm_unlock(udev); 1488 1489 /* Now that the device is awake, we can start trying to autosuspend 1490 * it again. */ 1491 if (status == 0) 1492 usb_try_autosuspend_device(udev); 1493 return status; 1494} 1495 1496static int usb_suspend(struct device *dev, pm_message_t message) 1497{ 1498 if (!is_usb_device(dev)) /* Ignore PM for interfaces */ 1499 return 0; 1500 return usb_external_suspend_device(to_usb_device(dev), message); 1501} 1502 1503static int usb_resume(struct device *dev) 1504{ 1505 struct usb_device *udev; 1506 1507 if (!is_usb_device(dev)) /* Ignore PM for interfaces */ 1508 return 0; 1509 udev = to_usb_device(dev); 1510 if (udev->autoresume_disabled) 1511 return -EPERM; 1512 return usb_external_resume_device(udev); 1513} 1514 1515#else 1516 1517#define usb_suspend NULL 1518#define usb_resume NULL 1519 1520#endif /* CONFIG_PM */ 1521 1522struct bus_type usb_bus_type = { 1523 .name = "usb", 1524 .match = usb_device_match, 1525 .uevent = usb_uevent, 1526 .suspend = usb_suspend, 1527 .resume = usb_resume, 1528}; 1529