2 * drivers/usb/driver.c - most of the driver model stuff for usb
4 * (C) Copyright 2005 Greg Kroah-Hartman <gregkh@suse.de>
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
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
25 #include <linux/device.h>
26 #include <linux/usb.h>
27 #include <linux/usb/quirks.h>
28 #include <linux/workqueue.h>
36 * Adds a new dynamic USBdevice ID to this driver,
37 * and cause the driver to probe for all devices again.
39 ssize_t usb_store_new_id(struct usb_dynids *dynids,
40 struct device_driver *driver,
41 const char *buf, size_t count)
43 struct usb_dynid *dynid;
49 fields = sscanf(buf, "%x %x", &idVendor, &idProduct);
53 dynid = kzalloc(sizeof(*dynid), GFP_KERNEL);
57 INIT_LIST_HEAD(&dynid->node);
58 dynid->id.idVendor = idVendor;
59 dynid->id.idProduct = idProduct;
60 dynid->id.match_flags = USB_DEVICE_ID_MATCH_DEVICE;
62 spin_lock(&dynids->lock);
63 list_add_tail(&dynid->node, &dynids->list);
64 spin_unlock(&dynids->lock);
66 if (get_driver(driver)) {
67 retval = driver_attach(driver);
75 EXPORT_SYMBOL_GPL(usb_store_new_id);
77 static ssize_t store_new_id(struct device_driver *driver,
78 const char *buf, size_t count)
80 struct usb_driver *usb_drv = to_usb_driver(driver);
82 return usb_store_new_id(&usb_drv->dynids, driver, buf, count);
84 static DRIVER_ATTR(new_id, S_IWUSR, NULL, store_new_id);
86 static int usb_create_newid_file(struct usb_driver *usb_drv)
90 if (usb_drv->no_dynamic_id)
93 if (usb_drv->probe != NULL)
94 error = driver_create_file(&usb_drv->drvwrap.driver,
100 static void usb_remove_newid_file(struct usb_driver *usb_drv)
102 if (usb_drv->no_dynamic_id)
105 if (usb_drv->probe != NULL)
106 driver_remove_file(&usb_drv->drvwrap.driver,
107 &driver_attr_new_id);
110 static void usb_free_dynids(struct usb_driver *usb_drv)
112 struct usb_dynid *dynid, *n;
114 spin_lock(&usb_drv->dynids.lock);
115 list_for_each_entry_safe(dynid, n, &usb_drv->dynids.list, node) {
116 list_del(&dynid->node);
119 spin_unlock(&usb_drv->dynids.lock);
122 static inline int usb_create_newid_file(struct usb_driver *usb_drv)
127 static void usb_remove_newid_file(struct usb_driver *usb_drv)
131 static inline void usb_free_dynids(struct usb_driver *usb_drv)
136 static const struct usb_device_id *usb_match_dynamic_id(struct usb_interface *intf,
137 struct usb_driver *drv)
139 struct usb_dynid *dynid;
141 spin_lock(&drv->dynids.lock);
142 list_for_each_entry(dynid, &drv->dynids.list, node) {
143 if (usb_match_one_id(intf, &dynid->id)) {
144 spin_unlock(&drv->dynids.lock);
148 spin_unlock(&drv->dynids.lock);
153 /* called from driver core with dev locked */
154 static int usb_probe_device(struct device *dev)
156 struct usb_device_driver *udriver = to_usb_device_driver(dev->driver);
157 struct usb_device *udev = to_usb_device(dev);
160 dev_dbg(dev, "%s\n", __func__);
162 /* TODO: Add real matching code */
164 /* The device should always appear to be in use
165 * unless the driver suports autosuspend.
167 udev->pm_usage_cnt = !(udriver->supports_autosuspend);
169 error = udriver->probe(udev);
173 /* called from driver core with dev locked */
174 static int usb_unbind_device(struct device *dev)
176 struct usb_device_driver *udriver = to_usb_device_driver(dev->driver);
178 udriver->disconnect(to_usb_device(dev));
183 * Cancel any pending scheduled resets
185 * [see usb_queue_reset_device()]
187 * Called after unconfiguring / when releasing interfaces. See
188 * comments in __usb_queue_reset_device() regarding
189 * udev->reset_running.
191 static void usb_cancel_queued_reset(struct usb_interface *iface)
193 if (iface->reset_running == 0)
194 cancel_work_sync(&iface->reset_ws);
197 /* called from driver core with dev locked */
198 static int usb_probe_interface(struct device *dev)
200 struct usb_driver *driver = to_usb_driver(dev->driver);
201 struct usb_interface *intf = to_usb_interface(dev);
202 struct usb_device *udev = interface_to_usbdev(intf);
203 const struct usb_device_id *id;
206 dev_dbg(dev, "%s\n", __func__);
208 intf->needs_binding = 0;
210 if (usb_device_is_owned(udev))
213 if (udev->authorized == 0) {
214 dev_err(&intf->dev, "Device is not authorized for usage\n");
218 id = usb_match_id(intf, driver->id_table);
220 id = usb_match_dynamic_id(intf, driver);
222 dev_dbg(dev, "%s - got id\n", __func__);
224 error = usb_autoresume_device(udev);
228 /* Interface "power state" doesn't correspond to any hardware
229 * state whatsoever. We use it to record when it's bound to
230 * a driver that may start I/0: it's not frozen/quiesced.
233 intf->condition = USB_INTERFACE_BINDING;
235 /* The interface should always appear to be in use
236 * unless the driver suports autosuspend.
238 atomic_set(&intf->pm_usage_cnt, !driver->supports_autosuspend);
240 /* Carry out a deferred switch to altsetting 0 */
241 if (intf->needs_altsetting0) {
242 error = usb_set_interface(udev, intf->altsetting[0].
243 desc.bInterfaceNumber, 0);
247 intf->needs_altsetting0 = 0;
250 error = driver->probe(intf, id);
254 intf->condition = USB_INTERFACE_BOUND;
255 usb_autosuspend_device(udev);
262 intf->needs_remote_wakeup = 0;
263 intf->condition = USB_INTERFACE_UNBOUND;
264 usb_cancel_queued_reset(intf);
265 usb_autosuspend_device(udev);
269 /* called from driver core with dev locked */
270 static int usb_unbind_interface(struct device *dev)
272 struct usb_driver *driver = to_usb_driver(dev->driver);
273 struct usb_interface *intf = to_usb_interface(dev);
274 struct usb_device *udev;
277 intf->condition = USB_INTERFACE_UNBINDING;
279 /* Autoresume for set_interface call below */
280 udev = interface_to_usbdev(intf);
281 error = usb_autoresume_device(udev);
283 /* Terminate all URBs for this interface unless the driver
284 * supports "soft" unbinding.
286 if (!driver->soft_unbind)
287 usb_disable_interface(udev, intf, false);
289 driver->disconnect(intf);
290 usb_cancel_queued_reset(intf);
292 /* Reset other interface state.
293 * We cannot do a Set-Interface if the device is suspended or
294 * if it is prepared for a system sleep (since installing a new
295 * altsetting means creating new endpoint device entries).
296 * When either of these happens, defer the Set-Interface.
298 if (intf->cur_altsetting->desc.bAlternateSetting == 0) {
299 /* Already in altsetting 0 so skip Set-Interface.
300 * Just re-enable it without affecting the endpoint toggles.
302 usb_enable_interface(udev, intf, false);
303 } else if (!error && intf->dev.power.status == DPM_ON) {
304 r = usb_set_interface(udev, intf->altsetting[0].
305 desc.bInterfaceNumber, 0);
307 intf->needs_altsetting0 = 1;
309 intf->needs_altsetting0 = 1;
311 usb_set_intfdata(intf, NULL);
313 intf->condition = USB_INTERFACE_UNBOUND;
315 intf->needs_remote_wakeup = 0;
318 usb_autosuspend_device(udev);
324 * usb_driver_claim_interface - bind a driver to an interface
325 * @driver: the driver to be bound
326 * @iface: the interface to which it will be bound; must be in the
327 * usb device's active configuration
328 * @priv: driver data associated with that interface
330 * This is used by usb device drivers that need to claim more than one
331 * interface on a device when probing (audio and acm are current examples).
332 * No device driver should directly modify internal usb_interface or
333 * usb_device structure members.
335 * Few drivers should need to use this routine, since the most natural
336 * way to bind to an interface is to return the private data from
337 * the driver's probe() method.
339 * Callers must own the device lock, so driver probe() entries don't need
340 * extra locking, but other call contexts may need to explicitly claim that
343 int usb_driver_claim_interface(struct usb_driver *driver,
344 struct usb_interface *iface, void *priv)
346 struct device *dev = &iface->dev;
347 struct usb_device *udev = interface_to_usbdev(iface);
353 dev->driver = &driver->drvwrap.driver;
354 usb_set_intfdata(iface, priv);
355 iface->needs_binding = 0;
358 iface->condition = USB_INTERFACE_BOUND;
360 atomic_set(&iface->pm_usage_cnt, !driver->supports_autosuspend);
363 /* if interface was already added, bind now; else let
364 * the future device_add() bind it, bypassing probe()
366 if (device_is_registered(dev))
367 retval = device_bind_driver(dev);
371 EXPORT_SYMBOL_GPL(usb_driver_claim_interface);
374 * usb_driver_release_interface - unbind a driver from an interface
375 * @driver: the driver to be unbound
376 * @iface: the interface from which it will be unbound
378 * This can be used by drivers to release an interface without waiting
379 * for their disconnect() methods to be called. In typical cases this
380 * also causes the driver disconnect() method to be called.
382 * This call is synchronous, and may not be used in an interrupt context.
383 * Callers must own the device lock, so driver disconnect() entries don't
384 * need extra locking, but other call contexts may need to explicitly claim
387 void usb_driver_release_interface(struct usb_driver *driver,
388 struct usb_interface *iface)
390 struct device *dev = &iface->dev;
392 /* this should never happen, don't release something that's not ours */
393 if (!dev->driver || dev->driver != &driver->drvwrap.driver)
396 /* don't release from within disconnect() */
397 if (iface->condition != USB_INTERFACE_BOUND)
399 iface->condition = USB_INTERFACE_UNBINDING;
401 /* Release via the driver core only if the interface
402 * has already been registered
404 if (device_is_registered(dev)) {
405 device_release_driver(dev);
408 usb_unbind_interface(dev);
413 EXPORT_SYMBOL_GPL(usb_driver_release_interface);
415 /* returns 0 if no match, 1 if match */
416 int usb_match_device(struct usb_device *dev, const struct usb_device_id *id)
418 if ((id->match_flags & USB_DEVICE_ID_MATCH_VENDOR) &&
419 id->idVendor != le16_to_cpu(dev->descriptor.idVendor))
422 if ((id->match_flags & USB_DEVICE_ID_MATCH_PRODUCT) &&
423 id->idProduct != le16_to_cpu(dev->descriptor.idProduct))
426 /* No need to test id->bcdDevice_lo != 0, since 0 is never
427 greater than any unsigned number. */
428 if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_LO) &&
429 (id->bcdDevice_lo > le16_to_cpu(dev->descriptor.bcdDevice)))
432 if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_HI) &&
433 (id->bcdDevice_hi < le16_to_cpu(dev->descriptor.bcdDevice)))
436 if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_CLASS) &&
437 (id->bDeviceClass != dev->descriptor.bDeviceClass))
440 if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_SUBCLASS) &&
441 (id->bDeviceSubClass != dev->descriptor.bDeviceSubClass))
444 if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_PROTOCOL) &&
445 (id->bDeviceProtocol != dev->descriptor.bDeviceProtocol))
451 /* returns 0 if no match, 1 if match */
452 int usb_match_one_id(struct usb_interface *interface,
453 const struct usb_device_id *id)
455 struct usb_host_interface *intf;
456 struct usb_device *dev;
458 /* proc_connectinfo in devio.c may call us with id == NULL. */
462 intf = interface->cur_altsetting;
463 dev = interface_to_usbdev(interface);
465 if (!usb_match_device(dev, id))
468 /* The interface class, subclass, and protocol should never be
469 * checked for a match if the device class is Vendor Specific,
470 * unless the match record specifies the Vendor ID. */
471 if (dev->descriptor.bDeviceClass == USB_CLASS_VENDOR_SPEC &&
472 !(id->match_flags & USB_DEVICE_ID_MATCH_VENDOR) &&
473 (id->match_flags & (USB_DEVICE_ID_MATCH_INT_CLASS |
474 USB_DEVICE_ID_MATCH_INT_SUBCLASS |
475 USB_DEVICE_ID_MATCH_INT_PROTOCOL)))
478 if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_CLASS) &&
479 (id->bInterfaceClass != intf->desc.bInterfaceClass))
482 if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_SUBCLASS) &&
483 (id->bInterfaceSubClass != intf->desc.bInterfaceSubClass))
486 if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_PROTOCOL) &&
487 (id->bInterfaceProtocol != intf->desc.bInterfaceProtocol))
492 EXPORT_SYMBOL_GPL(usb_match_one_id);
495 * usb_match_id - find first usb_device_id matching device or interface
496 * @interface: the interface of interest
497 * @id: array of usb_device_id structures, terminated by zero entry
499 * usb_match_id searches an array of usb_device_id's and returns
500 * the first one matching the device or interface, or null.
501 * This is used when binding (or rebinding) a driver to an interface.
502 * Most USB device drivers will use this indirectly, through the usb core,
503 * but some layered driver frameworks use it directly.
504 * These device tables are exported with MODULE_DEVICE_TABLE, through
505 * modutils, to support the driver loading functionality of USB hotplugging.
509 * The "match_flags" element in a usb_device_id controls which
510 * members are used. If the corresponding bit is set, the
511 * value in the device_id must match its corresponding member
512 * in the device or interface descriptor, or else the device_id
515 * "driver_info" is normally used only by device drivers,
516 * but you can create a wildcard "matches anything" usb_device_id
517 * as a driver's "modules.usbmap" entry if you provide an id with
518 * only a nonzero "driver_info" field. If you do this, the USB device
519 * driver's probe() routine should use additional intelligence to
520 * decide whether to bind to the specified interface.
522 * What Makes Good usb_device_id Tables:
524 * The match algorithm is very simple, so that intelligence in
525 * driver selection must come from smart driver id records.
526 * Unless you have good reasons to use another selection policy,
527 * provide match elements only in related groups, and order match
528 * specifiers from specific to general. Use the macros provided
529 * for that purpose if you can.
531 * The most specific match specifiers use device descriptor
532 * data. These are commonly used with product-specific matches;
533 * the USB_DEVICE macro lets you provide vendor and product IDs,
534 * and you can also match against ranges of product revisions.
535 * These are widely used for devices with application or vendor
536 * specific bDeviceClass values.
538 * Matches based on device class/subclass/protocol specifications
539 * are slightly more general; use the USB_DEVICE_INFO macro, or
540 * its siblings. These are used with single-function devices
541 * where bDeviceClass doesn't specify that each interface has
544 * Matches based on interface class/subclass/protocol are the
545 * most general; they let drivers bind to any interface on a
546 * multiple-function device. Use the USB_INTERFACE_INFO
547 * macro, or its siblings, to match class-per-interface style
548 * devices (as recorded in bInterfaceClass).
550 * Note that an entry created by USB_INTERFACE_INFO won't match
551 * any interface if the device class is set to Vendor-Specific.
552 * This is deliberate; according to the USB spec the meanings of
553 * the interface class/subclass/protocol for these devices are also
554 * vendor-specific, and hence matching against a standard product
555 * class wouldn't work anyway. If you really want to use an
556 * interface-based match for such a device, create a match record
557 * that also specifies the vendor ID. (Unforunately there isn't a
558 * standard macro for creating records like this.)
560 * Within those groups, remember that not all combinations are
561 * meaningful. For example, don't give a product version range
562 * without vendor and product IDs; or specify a protocol without
563 * its associated class and subclass.
565 const struct usb_device_id *usb_match_id(struct usb_interface *interface,
566 const struct usb_device_id *id)
568 /* proc_connectinfo in devio.c may call us with id == NULL. */
572 /* It is important to check that id->driver_info is nonzero,
573 since an entry that is all zeroes except for a nonzero
574 id->driver_info is the way to create an entry that
575 indicates that the driver want to examine every
576 device and interface. */
577 for (; id->idVendor || id->idProduct || id->bDeviceClass ||
578 id->bInterfaceClass || id->driver_info; id++) {
579 if (usb_match_one_id(interface, id))
585 EXPORT_SYMBOL_GPL(usb_match_id);
587 static int usb_device_match(struct device *dev, struct device_driver *drv)
589 /* devices and interfaces are handled separately */
590 if (is_usb_device(dev)) {
592 /* interface drivers never match devices */
593 if (!is_usb_device_driver(drv))
596 /* TODO: Add real matching code */
599 } else if (is_usb_interface(dev)) {
600 struct usb_interface *intf;
601 struct usb_driver *usb_drv;
602 const struct usb_device_id *id;
604 /* device drivers never match interfaces */
605 if (is_usb_device_driver(drv))
608 intf = to_usb_interface(dev);
609 usb_drv = to_usb_driver(drv);
611 id = usb_match_id(intf, usb_drv->id_table);
615 id = usb_match_dynamic_id(intf, usb_drv);
623 #ifdef CONFIG_HOTPLUG
624 static int usb_uevent(struct device *dev, struct kobj_uevent_env *env)
626 struct usb_device *usb_dev;
628 /* driver is often null here; dev_dbg() would oops */
629 pr_debug("usb %s: uevent\n", dev_name(dev));
631 if (is_usb_device(dev)) {
632 usb_dev = to_usb_device(dev);
633 } else if (is_usb_interface(dev)) {
634 struct usb_interface *intf = to_usb_interface(dev);
636 usb_dev = interface_to_usbdev(intf);
641 if (usb_dev->devnum < 0) {
642 pr_debug("usb %s: already deleted?\n", dev_name(dev));
646 pr_debug("usb %s: bus removed?\n", dev_name(dev));
650 #ifdef CONFIG_USB_DEVICEFS
651 /* If this is available, userspace programs can directly read
652 * all the device descriptors we don't tell them about. Or
653 * act as usermode drivers.
655 if (add_uevent_var(env, "DEVICE=/proc/bus/usb/%03d/%03d",
656 usb_dev->bus->busnum, usb_dev->devnum))
660 /* per-device configurations are common */
661 if (add_uevent_var(env, "PRODUCT=%x/%x/%x",
662 le16_to_cpu(usb_dev->descriptor.idVendor),
663 le16_to_cpu(usb_dev->descriptor.idProduct),
664 le16_to_cpu(usb_dev->descriptor.bcdDevice)))
667 /* class-based driver binding models */
668 if (add_uevent_var(env, "TYPE=%d/%d/%d",
669 usb_dev->descriptor.bDeviceClass,
670 usb_dev->descriptor.bDeviceSubClass,
671 usb_dev->descriptor.bDeviceProtocol))
679 static int usb_uevent(struct device *dev, struct kobj_uevent_env *env)
683 #endif /* CONFIG_HOTPLUG */
686 * usb_register_device_driver - register a USB device (not interface) driver
687 * @new_udriver: USB operations for the device driver
688 * @owner: module owner of this driver.
690 * Registers a USB device driver with the USB core. The list of
691 * unattached devices will be rescanned whenever a new driver is
692 * added, allowing the new driver to attach to any recognized devices.
693 * Returns a negative error code on failure and 0 on success.
695 int usb_register_device_driver(struct usb_device_driver *new_udriver,
696 struct module *owner)
703 new_udriver->drvwrap.for_devices = 1;
704 new_udriver->drvwrap.driver.name = (char *) new_udriver->name;
705 new_udriver->drvwrap.driver.bus = &usb_bus_type;
706 new_udriver->drvwrap.driver.probe = usb_probe_device;
707 new_udriver->drvwrap.driver.remove = usb_unbind_device;
708 new_udriver->drvwrap.driver.owner = owner;
710 retval = driver_register(&new_udriver->drvwrap.driver);
713 pr_info("%s: registered new device driver %s\n",
714 usbcore_name, new_udriver->name);
715 usbfs_update_special();
717 printk(KERN_ERR "%s: error %d registering device "
719 usbcore_name, retval, new_udriver->name);
724 EXPORT_SYMBOL_GPL(usb_register_device_driver);
727 * usb_deregister_device_driver - unregister a USB device (not interface) driver
728 * @udriver: USB operations of the device driver to unregister
729 * Context: must be able to sleep
731 * Unlinks the specified driver from the internal USB driver list.
733 void usb_deregister_device_driver(struct usb_device_driver *udriver)
735 pr_info("%s: deregistering device driver %s\n",
736 usbcore_name, udriver->name);
738 driver_unregister(&udriver->drvwrap.driver);
739 usbfs_update_special();
741 EXPORT_SYMBOL_GPL(usb_deregister_device_driver);
744 * usb_register_driver - register a USB interface driver
745 * @new_driver: USB operations for the interface driver
746 * @owner: module owner of this driver.
747 * @mod_name: module name string
749 * Registers a USB interface driver with the USB core. The list of
750 * unattached interfaces will be rescanned whenever a new driver is
751 * added, allowing the new driver to attach to any recognized interfaces.
752 * Returns a negative error code on failure and 0 on success.
754 * NOTE: if you want your driver to use the USB major number, you must call
755 * usb_register_dev() to enable that functionality. This function no longer
756 * takes care of that.
758 int usb_register_driver(struct usb_driver *new_driver, struct module *owner,
759 const char *mod_name)
766 new_driver->drvwrap.for_devices = 0;
767 new_driver->drvwrap.driver.name = (char *) new_driver->name;
768 new_driver->drvwrap.driver.bus = &usb_bus_type;
769 new_driver->drvwrap.driver.probe = usb_probe_interface;
770 new_driver->drvwrap.driver.remove = usb_unbind_interface;
771 new_driver->drvwrap.driver.owner = owner;
772 new_driver->drvwrap.driver.mod_name = mod_name;
773 spin_lock_init(&new_driver->dynids.lock);
774 INIT_LIST_HEAD(&new_driver->dynids.list);
776 retval = driver_register(&new_driver->drvwrap.driver);
779 pr_info("%s: registered new interface driver %s\n",
780 usbcore_name, new_driver->name);
781 usbfs_update_special();
782 usb_create_newid_file(new_driver);
784 printk(KERN_ERR "%s: error %d registering interface "
786 usbcore_name, retval, new_driver->name);
791 EXPORT_SYMBOL_GPL(usb_register_driver);
794 * usb_deregister - unregister a USB interface driver
795 * @driver: USB operations of the interface driver to unregister
796 * Context: must be able to sleep
798 * Unlinks the specified driver from the internal USB driver list.
800 * NOTE: If you called usb_register_dev(), you still need to call
801 * usb_deregister_dev() to clean up your driver's allocated minor numbers,
802 * this * call will no longer do it for you.
804 void usb_deregister(struct usb_driver *driver)
806 pr_info("%s: deregistering interface driver %s\n",
807 usbcore_name, driver->name);
809 usb_remove_newid_file(driver);
810 usb_free_dynids(driver);
811 driver_unregister(&driver->drvwrap.driver);
813 usbfs_update_special();
815 EXPORT_SYMBOL_GPL(usb_deregister);
817 /* Forced unbinding of a USB interface driver, either because
818 * it doesn't support pre_reset/post_reset/reset_resume or
819 * because it doesn't support suspend/resume.
821 * The caller must hold @intf's device's lock, but not its pm_mutex
822 * and not @intf->dev.sem.
824 void usb_forced_unbind_intf(struct usb_interface *intf)
826 struct usb_driver *driver = to_usb_driver(intf->dev.driver);
828 dev_dbg(&intf->dev, "forced unbind\n");
829 usb_driver_release_interface(driver, intf);
831 /* Mark the interface for later rebinding */
832 intf->needs_binding = 1;
835 /* Delayed forced unbinding of a USB interface driver and scan
838 * The caller must hold @intf's device's lock, but not its pm_mutex
839 * and not @intf->dev.sem.
841 * Note: Rebinds will be skipped if a system sleep transition is in
842 * progress and the PM "complete" callback hasn't occurred yet.
844 void usb_rebind_intf(struct usb_interface *intf)
848 /* Delayed unbind of an existing driver */
849 if (intf->dev.driver) {
850 struct usb_driver *driver =
851 to_usb_driver(intf->dev.driver);
853 dev_dbg(&intf->dev, "forced unbind\n");
854 usb_driver_release_interface(driver, intf);
857 /* Try to rebind the interface */
858 if (intf->dev.power.status == DPM_ON) {
859 intf->needs_binding = 0;
860 rc = device_attach(&intf->dev);
862 dev_warn(&intf->dev, "rebind failed: %d\n", rc);
871 /* Unbind drivers for @udev's interfaces that don't support suspend/resume,
872 * or rebind interfaces that have been unbound, according to @action.
874 * The caller must hold @udev's device lock.
876 static void do_unbind_rebind(struct usb_device *udev, int action)
878 struct usb_host_config *config;
880 struct usb_interface *intf;
881 struct usb_driver *drv;
883 config = udev->actconfig;
885 for (i = 0; i < config->desc.bNumInterfaces; ++i) {
886 intf = config->interface[i];
889 if (intf->dev.driver) {
890 drv = to_usb_driver(intf->dev.driver);
891 if (!drv->suspend || !drv->resume)
892 usb_forced_unbind_intf(intf);
896 if (intf->needs_binding)
897 usb_rebind_intf(intf);
904 /* Caller has locked udev's pm_mutex */
905 static int usb_suspend_device(struct usb_device *udev, pm_message_t msg)
907 struct usb_device_driver *udriver;
910 if (udev->state == USB_STATE_NOTATTACHED ||
911 udev->state == USB_STATE_SUSPENDED)
914 /* For devices that don't have a driver, we do a generic suspend. */
915 if (udev->dev.driver)
916 udriver = to_usb_device_driver(udev->dev.driver);
918 udev->do_remote_wakeup = 0;
919 udriver = &usb_generic_driver;
921 status = udriver->suspend(udev, msg);
924 dev_vdbg(&udev->dev, "%s: status %d\n", __func__, status);
928 /* Caller has locked udev's pm_mutex */
929 static int usb_resume_device(struct usb_device *udev, pm_message_t msg)
931 struct usb_device_driver *udriver;
934 if (udev->state == USB_STATE_NOTATTACHED)
937 /* Can't resume it if it doesn't have a driver. */
938 if (udev->dev.driver == NULL) {
943 if (udev->quirks & USB_QUIRK_RESET_RESUME)
944 udev->reset_resume = 1;
946 udriver = to_usb_device_driver(udev->dev.driver);
947 status = udriver->resume(udev, msg);
950 dev_vdbg(&udev->dev, "%s: status %d\n", __func__, status);
954 /* Caller has locked intf's usb_device's pm mutex */
955 static int usb_suspend_interface(struct usb_device *udev,
956 struct usb_interface *intf, pm_message_t msg)
958 struct usb_driver *driver;
961 /* with no hardware, USB interfaces only use FREEZE and ON states */
962 if (udev->state == USB_STATE_NOTATTACHED || !is_active(intf))
965 /* This can happen; see usb_driver_release_interface() */
966 if (intf->condition == USB_INTERFACE_UNBOUND)
968 driver = to_usb_driver(intf->dev.driver);
970 if (driver->suspend) {
971 status = driver->suspend(intf, msg);
974 else if (!(msg.event & PM_EVENT_AUTO))
975 dev_err(&intf->dev, "%s error %d\n",
978 /* Later we will unbind the driver and reprobe */
979 intf->needs_binding = 1;
980 dev_warn(&intf->dev, "no %s for driver %s?\n",
981 "suspend", driver->name);
986 dev_vdbg(&intf->dev, "%s: status %d\n", __func__, status);
990 /* Caller has locked intf's usb_device's pm_mutex */
991 static int usb_resume_interface(struct usb_device *udev,
992 struct usb_interface *intf, pm_message_t msg, int reset_resume)
994 struct usb_driver *driver;
997 if (udev->state == USB_STATE_NOTATTACHED || is_active(intf))
1000 /* Don't let autoresume interfere with unbinding */
1001 if (intf->condition == USB_INTERFACE_UNBINDING)
1004 /* Can't resume it if it doesn't have a driver. */
1005 if (intf->condition == USB_INTERFACE_UNBOUND) {
1007 /* Carry out a deferred switch to altsetting 0 */
1008 if (intf->needs_altsetting0 &&
1009 intf->dev.power.status == DPM_ON) {
1010 usb_set_interface(udev, intf->altsetting[0].
1011 desc.bInterfaceNumber, 0);
1012 intf->needs_altsetting0 = 0;
1017 /* Don't resume if the interface is marked for rebinding */
1018 if (intf->needs_binding)
1020 driver = to_usb_driver(intf->dev.driver);
1023 if (driver->reset_resume) {
1024 status = driver->reset_resume(intf);
1026 dev_err(&intf->dev, "%s error %d\n",
1027 "reset_resume", status);
1029 intf->needs_binding = 1;
1030 dev_warn(&intf->dev, "no %s for driver %s?\n",
1031 "reset_resume", driver->name);
1034 if (driver->resume) {
1035 status = driver->resume(intf);
1037 dev_err(&intf->dev, "%s error %d\n",
1040 intf->needs_binding = 1;
1041 dev_warn(&intf->dev, "no %s for driver %s?\n",
1042 "resume", driver->name);
1047 dev_vdbg(&intf->dev, "%s: status %d\n", __func__, status);
1048 if (status == 0 && intf->condition == USB_INTERFACE_BOUND)
1051 /* Later we will unbind the driver and/or reprobe, if necessary */
1055 #ifdef CONFIG_USB_SUSPEND
1057 /* Internal routine to check whether we may autosuspend a device. */
1058 static int autosuspend_check(struct usb_device *udev, int reschedule)
1061 struct usb_interface *intf;
1062 unsigned long suspend_time, j;
1064 /* For autosuspend, fail fast if anything is in use or autosuspend
1065 * is disabled. Also fail if any interfaces require remote wakeup
1066 * but it isn't available.
1068 if (udev->pm_usage_cnt > 0)
1070 if (udev->autosuspend_delay < 0 || udev->autosuspend_disabled)
1073 suspend_time = udev->last_busy + udev->autosuspend_delay;
1074 if (udev->actconfig) {
1075 for (i = 0; i < udev->actconfig->desc.bNumInterfaces; i++) {
1076 intf = udev->actconfig->interface[i];
1077 if (!is_active(intf))
1079 if (atomic_read(&intf->pm_usage_cnt) > 0)
1081 if (intf->needs_remote_wakeup &&
1082 !udev->do_remote_wakeup) {
1083 dev_dbg(&udev->dev, "remote wakeup needed "
1084 "for autosuspend\n");
1088 /* Don't allow autosuspend if the device will need
1089 * a reset-resume and any of its interface drivers
1090 * doesn't include support.
1092 if (udev->quirks & USB_QUIRK_RESET_RESUME) {
1093 struct usb_driver *driver;
1095 driver = to_usb_driver(intf->dev.driver);
1096 if (!driver->reset_resume ||
1097 intf->needs_remote_wakeup)
1103 /* If everything is okay but the device hasn't been idle for long
1104 * enough, queue a delayed autosuspend request. If the device
1105 * _has_ been idle for long enough and the reschedule flag is set,
1106 * likewise queue a delayed (1 second) autosuspend request.
1109 if (time_before(j, suspend_time))
1112 suspend_time = j + HZ;
1114 if (!timer_pending(&udev->autosuspend.timer)) {
1115 queue_delayed_work(ksuspend_usb_wq, &udev->autosuspend,
1116 round_jiffies_up_relative(suspend_time - j));
1125 static inline int autosuspend_check(struct usb_device *udev, int reschedule)
1130 #endif /* CONFIG_USB_SUSPEND */
1133 * usb_suspend_both - suspend a USB device and its interfaces
1134 * @udev: the usb_device to suspend
1135 * @msg: Power Management message describing this state transition
1137 * This is the central routine for suspending USB devices. It calls the
1138 * suspend methods for all the interface drivers in @udev and then calls
1139 * the suspend method for @udev itself. If an error occurs at any stage,
1140 * all the interfaces which were suspended are resumed so that they remain
1141 * in the same state as the device.
1143 * If an autosuspend is in progress the routine checks first to make sure
1144 * that neither the device itself or any of its active interfaces is in use
1145 * (pm_usage_cnt is greater than 0). If they are, the autosuspend fails.
1147 * If the suspend succeeds, the routine recursively queues an autosuspend
1148 * request for @udev's parent device, thereby propagating the change up
1149 * the device tree. If all of the parent's children are now suspended,
1150 * the parent will autosuspend in turn.
1152 * The suspend method calls are subject to mutual exclusion under control
1153 * of @udev's pm_mutex. Many of these calls are also under the protection
1154 * of @udev's device lock (including all requests originating outside the
1155 * USB subsystem), but autosuspend requests generated by a child device or
1156 * interface driver may not be. Usbcore will insure that the method calls
1157 * do not arrive during bind, unbind, or reset operations. However, drivers
1158 * must be prepared to handle suspend calls arriving at unpredictable times.
1159 * The only way to block such calls is to do an autoresume (preventing
1160 * autosuspends) while holding @udev's device lock (preventing outside
1163 * The caller must hold @udev->pm_mutex.
1165 * This routine can run only in process context.
1167 static int usb_suspend_both(struct usb_device *udev, pm_message_t msg)
1171 struct usb_interface *intf;
1172 struct usb_device *parent = udev->parent;
1174 if (udev->state == USB_STATE_NOTATTACHED ||
1175 udev->state == USB_STATE_SUSPENDED)
1178 udev->do_remote_wakeup = device_may_wakeup(&udev->dev);
1180 if (msg.event & PM_EVENT_AUTO) {
1181 status = autosuspend_check(udev, 0);
1186 /* Suspend all the interfaces and then udev itself */
1187 if (udev->actconfig) {
1188 for (; i < udev->actconfig->desc.bNumInterfaces; i++) {
1189 intf = udev->actconfig->interface[i];
1190 status = usb_suspend_interface(udev, intf, msg);
1196 status = usb_suspend_device(udev, msg);
1198 /* If the suspend failed, resume interfaces that did get suspended */
1202 msg2.event = msg.event ^ (PM_EVENT_SUSPEND | PM_EVENT_RESUME);
1204 intf = udev->actconfig->interface[i];
1205 usb_resume_interface(udev, intf, msg2, 0);
1208 /* Try another autosuspend when the interfaces aren't busy */
1209 if (msg.event & PM_EVENT_AUTO)
1210 autosuspend_check(udev, status == -EBUSY);
1212 /* If the suspend succeeded then prevent any more URB submissions,
1213 * flush any outstanding URBs, and propagate the suspend up the tree.
1216 cancel_delayed_work(&udev->autosuspend);
1217 udev->can_submit = 0;
1218 for (i = 0; i < 16; ++i) {
1219 usb_hcd_flush_endpoint(udev, udev->ep_out[i]);
1220 usb_hcd_flush_endpoint(udev, udev->ep_in[i]);
1223 /* If this is just a FREEZE or a PRETHAW, udev might
1224 * not really be suspended. Only true suspends get
1225 * propagated up the device tree.
1227 if (parent && udev->state == USB_STATE_SUSPENDED)
1228 usb_autosuspend_device(parent);
1232 dev_vdbg(&udev->dev, "%s: status %d\n", __func__, status);
1237 * usb_resume_both - resume a USB device and its interfaces
1238 * @udev: the usb_device to resume
1239 * @msg: Power Management message describing this state transition
1241 * This is the central routine for resuming USB devices. It calls the
1242 * the resume method for @udev and then calls the resume methods for all
1243 * the interface drivers in @udev.
1245 * Before starting the resume, the routine calls itself recursively for
1246 * the parent device of @udev, thereby propagating the change up the device
1247 * tree and assuring that @udev will be able to resume. If the parent is
1248 * unable to resume successfully, the routine fails.
1250 * The resume method calls are subject to mutual exclusion under control
1251 * of @udev's pm_mutex. Many of these calls are also under the protection
1252 * of @udev's device lock (including all requests originating outside the
1253 * USB subsystem), but autoresume requests generated by a child device or
1254 * interface driver may not be. Usbcore will insure that the method calls
1255 * do not arrive during bind, unbind, or reset operations. However, drivers
1256 * must be prepared to handle resume calls arriving at unpredictable times.
1257 * The only way to block such calls is to do an autoresume (preventing
1258 * other autoresumes) while holding @udev's device lock (preventing outside
1261 * The caller must hold @udev->pm_mutex.
1263 * This routine can run only in process context.
1265 static int usb_resume_both(struct usb_device *udev, pm_message_t msg)
1269 struct usb_interface *intf;
1270 struct usb_device *parent = udev->parent;
1272 cancel_delayed_work(&udev->autosuspend);
1273 if (udev->state == USB_STATE_NOTATTACHED) {
1277 udev->can_submit = 1;
1279 /* Propagate the resume up the tree, if necessary */
1280 if (udev->state == USB_STATE_SUSPENDED) {
1282 status = usb_autoresume_device(parent);
1284 status = usb_resume_device(udev, msg);
1285 if (status || udev->state ==
1286 USB_STATE_NOTATTACHED) {
1287 usb_autosuspend_device(parent);
1289 /* It's possible usb_resume_device()
1290 * failed after the port was
1291 * unsuspended, causing udev to be
1292 * logically disconnected. We don't
1293 * want usb_disconnect() to autosuspend
1294 * the parent again, so tell it that
1295 * udev disconnected while still
1298 USB_STATE_NOTATTACHED)
1299 udev->discon_suspended = 1;
1304 /* We can't progagate beyond the USB subsystem,
1305 * so if a root hub's controller is suspended
1306 * then we're stuck. */
1307 status = usb_resume_device(udev, msg);
1309 } else if (udev->reset_resume)
1310 status = usb_resume_device(udev, msg);
1312 if (status == 0 && udev->actconfig) {
1313 for (i = 0; i < udev->actconfig->desc.bNumInterfaces; i++) {
1314 intf = udev->actconfig->interface[i];
1315 usb_resume_interface(udev, intf, msg,
1316 udev->reset_resume);
1321 dev_vdbg(&udev->dev, "%s: status %d\n", __func__, status);
1323 udev->reset_resume = 0;
1327 #ifdef CONFIG_USB_SUSPEND
1329 /* Internal routine to adjust a device's usage counter and change
1330 * its autosuspend state.
1332 static int usb_autopm_do_device(struct usb_device *udev, int inc_usage_cnt)
1337 udev->pm_usage_cnt += inc_usage_cnt;
1338 WARN_ON(udev->pm_usage_cnt < 0);
1340 udev->last_busy = jiffies;
1341 if (inc_usage_cnt >= 0 && udev->pm_usage_cnt > 0) {
1342 if (udev->state == USB_STATE_SUSPENDED)
1343 status = usb_resume_both(udev, PMSG_AUTO_RESUME);
1345 udev->pm_usage_cnt -= inc_usage_cnt;
1346 else if (inc_usage_cnt)
1347 udev->last_busy = jiffies;
1348 } else if (inc_usage_cnt <= 0 && udev->pm_usage_cnt <= 0) {
1349 status = usb_suspend_both(udev, PMSG_AUTO_SUSPEND);
1351 usb_pm_unlock(udev);
1355 /* usb_autosuspend_work - callback routine to autosuspend a USB device */
1356 void usb_autosuspend_work(struct work_struct *work)
1358 struct usb_device *udev =
1359 container_of(work, struct usb_device, autosuspend.work);
1361 usb_autopm_do_device(udev, 0);
1364 /* usb_autoresume_work - callback routine to autoresume a USB device */
1365 void usb_autoresume_work(struct work_struct *work)
1367 struct usb_device *udev =
1368 container_of(work, struct usb_device, autoresume);
1370 /* Wake it up, let the drivers do their thing, and then put it
1373 if (usb_autopm_do_device(udev, 1) == 0)
1374 usb_autopm_do_device(udev, -1);
1378 * usb_autosuspend_device - delayed autosuspend of a USB device and its interfaces
1379 * @udev: the usb_device to autosuspend
1381 * This routine should be called when a core subsystem is finished using
1382 * @udev and wants to allow it to autosuspend. Examples would be when
1383 * @udev's device file in usbfs is closed or after a configuration change.
1385 * @udev's usage counter is decremented. If it or any of the usage counters
1386 * for an active interface is greater than 0, no autosuspend request will be
1387 * queued. (If an interface driver does not support autosuspend then its
1388 * usage counter is permanently positive.) Furthermore, if an interface
1389 * driver requires remote-wakeup capability during autosuspend but remote
1390 * wakeup is disabled, the autosuspend will fail.
1392 * Often the caller will hold @udev's device lock, but this is not
1395 * This routine can run only in process context.
1397 void usb_autosuspend_device(struct usb_device *udev)
1401 status = usb_autopm_do_device(udev, -1);
1402 dev_vdbg(&udev->dev, "%s: cnt %d\n",
1403 __func__, udev->pm_usage_cnt);
1407 * usb_try_autosuspend_device - attempt an autosuspend of a USB device and its interfaces
1408 * @udev: the usb_device to autosuspend
1410 * This routine should be called when a core subsystem thinks @udev may
1411 * be ready to autosuspend.
1413 * @udev's usage counter left unchanged. If it or any of the usage counters
1414 * for an active interface is greater than 0, or autosuspend is not allowed
1415 * for any other reason, no autosuspend request will be queued.
1417 * This routine can run only in process context.
1419 void usb_try_autosuspend_device(struct usb_device *udev)
1421 usb_autopm_do_device(udev, 0);
1422 dev_vdbg(&udev->dev, "%s: cnt %d\n",
1423 __func__, udev->pm_usage_cnt);
1427 * usb_autoresume_device - immediately autoresume a USB device and its interfaces
1428 * @udev: the usb_device to autoresume
1430 * This routine should be called when a core subsystem wants to use @udev
1431 * and needs to guarantee that it is not suspended. No autosuspend will
1432 * occur until usb_autosuspend_device is called. (Note that this will not
1433 * prevent suspend events originating in the PM core.) Examples would be
1434 * when @udev's device file in usbfs is opened or when a remote-wakeup
1435 * request is received.
1437 * @udev's usage counter is incremented to prevent subsequent autosuspends.
1438 * However if the autoresume fails then the usage counter is re-decremented.
1440 * Often the caller will hold @udev's device lock, but this is not
1441 * necessary (and attempting it might cause deadlock).
1443 * This routine can run only in process context.
1445 int usb_autoresume_device(struct usb_device *udev)
1449 status = usb_autopm_do_device(udev, 1);
1450 dev_vdbg(&udev->dev, "%s: status %d cnt %d\n",
1451 __func__, status, udev->pm_usage_cnt);
1455 /* Internal routine to adjust an interface's usage counter and change
1456 * its device's autosuspend state.
1458 static int usb_autopm_do_interface(struct usb_interface *intf,
1461 struct usb_device *udev = interface_to_usbdev(intf);
1465 if (intf->condition == USB_INTERFACE_UNBOUND)
1468 atomic_add(inc_usage_cnt, &intf->pm_usage_cnt);
1469 udev->last_busy = jiffies;
1470 if (inc_usage_cnt >= 0 &&
1471 atomic_read(&intf->pm_usage_cnt) > 0) {
1472 if (udev->state == USB_STATE_SUSPENDED)
1473 status = usb_resume_both(udev,
1476 atomic_sub(inc_usage_cnt, &intf->pm_usage_cnt);
1478 udev->last_busy = jiffies;
1479 } else if (inc_usage_cnt <= 0 &&
1480 atomic_read(&intf->pm_usage_cnt) <= 0) {
1481 status = usb_suspend_both(udev, PMSG_AUTO_SUSPEND);
1484 usb_pm_unlock(udev);
1489 * usb_autopm_put_interface - decrement a USB interface's PM-usage counter
1490 * @intf: the usb_interface whose counter should be decremented
1492 * This routine should be called by an interface driver when it is
1493 * finished using @intf and wants to allow it to autosuspend. A typical
1494 * example would be a character-device driver when its device file is
1497 * The routine decrements @intf's usage counter. When the counter reaches
1498 * 0, a delayed autosuspend request for @intf's device is queued. When
1499 * the delay expires, if @intf->pm_usage_cnt is still <= 0 along with all
1500 * the other usage counters for the sibling interfaces and @intf's
1501 * usb_device, the device and all its interfaces will be autosuspended.
1503 * Note that @intf->pm_usage_cnt is owned by the interface driver. The
1504 * core will not change its value other than the increment and decrement
1505 * in usb_autopm_get_interface and usb_autopm_put_interface. The driver
1506 * may use this simple counter-oriented discipline or may set the value
1509 * If the driver has set @intf->needs_remote_wakeup then autosuspend will
1510 * take place only if the device's remote-wakeup facility is enabled.
1512 * Suspend method calls queued by this routine can arrive at any time
1513 * while @intf is resumed and its usage counter is equal to 0. They are
1514 * not protected by the usb_device's lock but only by its pm_mutex.
1515 * Drivers must provide their own synchronization.
1517 * This routine can run only in process context.
1519 void usb_autopm_put_interface(struct usb_interface *intf)
1523 status = usb_autopm_do_interface(intf, -1);
1524 dev_vdbg(&intf->dev, "%s: status %d cnt %d\n",
1525 __func__, status, atomic_read(&intf->pm_usage_cnt));
1527 EXPORT_SYMBOL_GPL(usb_autopm_put_interface);
1530 * usb_autopm_put_interface_async - decrement a USB interface's PM-usage counter
1531 * @intf: the usb_interface whose counter should be decremented
1533 * This routine does essentially the same thing as
1534 * usb_autopm_put_interface(): it decrements @intf's usage counter and
1535 * queues a delayed autosuspend request if the counter is <= 0. The
1536 * difference is that it does not acquire the device's pm_mutex;
1537 * callers must handle all synchronization issues themselves.
1539 * Typically a driver would call this routine during an URB's completion
1540 * handler, if no more URBs were pending.
1542 * This routine can run in atomic context.
1544 void usb_autopm_put_interface_async(struct usb_interface *intf)
1546 struct usb_device *udev = interface_to_usbdev(intf);
1549 if (intf->condition == USB_INTERFACE_UNBOUND) {
1552 udev->last_busy = jiffies;
1553 atomic_dec(&intf->pm_usage_cnt);
1554 if (udev->autosuspend_disabled || udev->autosuspend_delay < 0)
1556 else if (atomic_read(&intf->pm_usage_cnt) <= 0 &&
1557 !timer_pending(&udev->autosuspend.timer)) {
1558 queue_delayed_work(ksuspend_usb_wq, &udev->autosuspend,
1559 round_jiffies_up_relative(
1560 udev->autosuspend_delay));
1563 dev_vdbg(&intf->dev, "%s: status %d cnt %d\n",
1564 __func__, status, atomic_read(&intf->pm_usage_cnt));
1566 EXPORT_SYMBOL_GPL(usb_autopm_put_interface_async);
1569 * usb_autopm_get_interface - increment a USB interface's PM-usage counter
1570 * @intf: the usb_interface whose counter should be incremented
1572 * This routine should be called by an interface driver when it wants to
1573 * use @intf and needs to guarantee that it is not suspended. In addition,
1574 * the routine prevents @intf from being autosuspended subsequently. (Note
1575 * that this will not prevent suspend events originating in the PM core.)
1576 * This prevention will persist until usb_autopm_put_interface() is called
1577 * or @intf is unbound. A typical example would be a character-device
1578 * driver when its device file is opened.
1581 * The routine increments @intf's usage counter. (However if the
1582 * autoresume fails then the counter is re-decremented.) So long as the
1583 * counter is greater than 0, autosuspend will not be allowed for @intf
1584 * or its usb_device. When the driver is finished using @intf it should
1585 * call usb_autopm_put_interface() to decrement the usage counter and
1586 * queue a delayed autosuspend request (if the counter is <= 0).
1589 * Note that @intf->pm_usage_cnt is owned by the interface driver. The
1590 * core will not change its value other than the increment and decrement
1591 * in usb_autopm_get_interface and usb_autopm_put_interface. The driver
1592 * may use this simple counter-oriented discipline or may set the value
1595 * Resume method calls generated by this routine can arrive at any time
1596 * while @intf is suspended. They are not protected by the usb_device's
1597 * lock but only by its pm_mutex. Drivers must provide their own
1600 * This routine can run only in process context.
1602 int usb_autopm_get_interface(struct usb_interface *intf)
1606 status = usb_autopm_do_interface(intf, 1);
1607 dev_vdbg(&intf->dev, "%s: status %d cnt %d\n",
1608 __func__, status, atomic_read(&intf->pm_usage_cnt));
1611 EXPORT_SYMBOL_GPL(usb_autopm_get_interface);
1614 * usb_autopm_get_interface_async - increment a USB interface's PM-usage counter
1615 * @intf: the usb_interface whose counter should be incremented
1617 * This routine does much the same thing as
1618 * usb_autopm_get_interface(): it increments @intf's usage counter and
1619 * queues an autoresume request if the result is > 0. The differences
1620 * are that it does not acquire the device's pm_mutex (callers must
1621 * handle all synchronization issues themselves), and it does not
1622 * autoresume the device directly (it only queues a request). After a
1623 * successful call, the device will generally not yet be resumed.
1625 * This routine can run in atomic context.
1627 int usb_autopm_get_interface_async(struct usb_interface *intf)
1629 struct usb_device *udev = interface_to_usbdev(intf);
1632 if (intf->condition == USB_INTERFACE_UNBOUND)
1635 atomic_inc(&intf->pm_usage_cnt);
1636 if (atomic_read(&intf->pm_usage_cnt) > 0 &&
1637 udev->state == USB_STATE_SUSPENDED)
1638 queue_work(ksuspend_usb_wq, &udev->autoresume);
1640 dev_vdbg(&intf->dev, "%s: status %d cnt %d\n",
1641 __func__, status, atomic_read(&intf->pm_usage_cnt));
1644 EXPORT_SYMBOL_GPL(usb_autopm_get_interface_async);
1648 void usb_autosuspend_work(struct work_struct *work)
1651 void usb_autoresume_work(struct work_struct *work)
1654 #endif /* CONFIG_USB_SUSPEND */
1657 * usb_external_suspend_device - external suspend of a USB device and its interfaces
1658 * @udev: the usb_device to suspend
1659 * @msg: Power Management message describing this state transition
1661 * This routine handles external suspend requests: ones not generated
1662 * internally by a USB driver (autosuspend) but rather coming from the user
1663 * (via sysfs) or the PM core (system sleep). The suspend will be carried
1664 * out regardless of @udev's usage counter or those of its interfaces,
1665 * and regardless of whether or not remote wakeup is enabled. Of course,
1666 * interface drivers still have the option of failing the suspend (if
1667 * there are unsuspended children, for example).
1669 * The caller must hold @udev's device lock.
1671 int usb_external_suspend_device(struct usb_device *udev, pm_message_t msg)
1675 do_unbind_rebind(udev, DO_UNBIND);
1677 status = usb_suspend_both(udev, msg);
1678 usb_pm_unlock(udev);
1683 * usb_external_resume_device - external resume of a USB device and its interfaces
1684 * @udev: the usb_device to resume
1685 * @msg: Power Management message describing this state transition
1687 * This routine handles external resume requests: ones not generated
1688 * internally by a USB driver (autoresume) but rather coming from the user
1689 * (via sysfs), the PM core (system resume), or the device itself (remote
1690 * wakeup). @udev's usage counter is unaffected.
1692 * The caller must hold @udev's device lock.
1694 int usb_external_resume_device(struct usb_device *udev, pm_message_t msg)
1699 status = usb_resume_both(udev, msg);
1700 udev->last_busy = jiffies;
1701 usb_pm_unlock(udev);
1703 do_unbind_rebind(udev, DO_REBIND);
1705 /* Now that the device is awake, we can start trying to autosuspend
1708 usb_try_autosuspend_device(udev);
1712 int usb_suspend(struct device *dev, pm_message_t msg)
1714 struct usb_device *udev;
1716 udev = to_usb_device(dev);
1718 /* If udev is already suspended, we can skip this suspend and
1719 * we should also skip the upcoming system resume. High-speed
1720 * root hubs are an exception; they need to resume whenever the
1721 * system wakes up in order for USB-PERSIST port handover to work
1724 if (udev->state == USB_STATE_SUSPENDED) {
1725 if (udev->parent || udev->speed != USB_SPEED_HIGH)
1726 udev->skip_sys_resume = 1;
1730 udev->skip_sys_resume = 0;
1731 return usb_external_suspend_device(udev, msg);
1734 int usb_resume(struct device *dev, pm_message_t msg)
1736 struct usb_device *udev;
1739 udev = to_usb_device(dev);
1741 /* If udev->skip_sys_resume is set then udev was already suspended
1742 * when the system sleep started, so we don't want to resume it
1743 * during this system wakeup.
1745 if (udev->skip_sys_resume)
1747 status = usb_external_resume_device(udev, msg);
1749 /* Avoid PM error messages for devices disconnected while suspended
1750 * as we'll display regular disconnect messages just a bit later.
1752 if (status == -ENODEV)
1757 #endif /* CONFIG_PM */
1759 struct bus_type usb_bus_type = {
1761 .match = usb_device_match,
1762 .uevent = usb_uevent,