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/slab.h>
27 #include <linux/usb.h>
28 #include <linux/usb/quirks.h>
29 #include <linux/usb/hcd.h>
30 #include <linux/pm_runtime.h>
38 * Adds a new dynamic USBdevice ID to this driver,
39 * and cause the driver to probe for all devices again.
41 ssize_t usb_store_new_id(struct usb_dynids *dynids,
42 struct device_driver *driver,
43 const char *buf, size_t count)
45 struct usb_dynid *dynid;
51 fields = sscanf(buf, "%x %x", &idVendor, &idProduct);
55 dynid = kzalloc(sizeof(*dynid), GFP_KERNEL);
59 INIT_LIST_HEAD(&dynid->node);
60 dynid->id.idVendor = idVendor;
61 dynid->id.idProduct = idProduct;
62 dynid->id.match_flags = USB_DEVICE_ID_MATCH_DEVICE;
64 spin_lock(&dynids->lock);
65 list_add_tail(&dynid->node, &dynids->list);
66 spin_unlock(&dynids->lock);
68 if (get_driver(driver)) {
69 retval = driver_attach(driver);
77 EXPORT_SYMBOL_GPL(usb_store_new_id);
79 static ssize_t store_new_id(struct device_driver *driver,
80 const char *buf, size_t count)
82 struct usb_driver *usb_drv = to_usb_driver(driver);
84 return usb_store_new_id(&usb_drv->dynids, driver, buf, count);
86 static DRIVER_ATTR(new_id, S_IWUSR, NULL, store_new_id);
89 * store_remove_id - remove a USB device ID from this driver
90 * @driver: target device driver
91 * @buf: buffer for scanning device ID data
94 * Removes a dynamic usb device ID from this driver.
97 store_remove_id(struct device_driver *driver, const char *buf, size_t count)
99 struct usb_dynid *dynid, *n;
100 struct usb_driver *usb_driver = to_usb_driver(driver);
106 fields = sscanf(buf, "%x %x", &idVendor, &idProduct);
110 spin_lock(&usb_driver->dynids.lock);
111 list_for_each_entry_safe(dynid, n, &usb_driver->dynids.list, node) {
112 struct usb_device_id *id = &dynid->id;
113 if ((id->idVendor == idVendor) &&
114 (id->idProduct == idProduct)) {
115 list_del(&dynid->node);
121 spin_unlock(&usb_driver->dynids.lock);
127 static DRIVER_ATTR(remove_id, S_IWUSR, NULL, store_remove_id);
129 static int usb_create_newid_file(struct usb_driver *usb_drv)
133 if (usb_drv->no_dynamic_id)
136 if (usb_drv->probe != NULL)
137 error = driver_create_file(&usb_drv->drvwrap.driver,
138 &driver_attr_new_id);
143 static void usb_remove_newid_file(struct usb_driver *usb_drv)
145 if (usb_drv->no_dynamic_id)
148 if (usb_drv->probe != NULL)
149 driver_remove_file(&usb_drv->drvwrap.driver,
150 &driver_attr_new_id);
154 usb_create_removeid_file(struct usb_driver *drv)
157 if (drv->probe != NULL)
158 error = driver_create_file(&drv->drvwrap.driver,
159 &driver_attr_remove_id);
163 static void usb_remove_removeid_file(struct usb_driver *drv)
165 driver_remove_file(&drv->drvwrap.driver, &driver_attr_remove_id);
168 static void usb_free_dynids(struct usb_driver *usb_drv)
170 struct usb_dynid *dynid, *n;
172 spin_lock(&usb_drv->dynids.lock);
173 list_for_each_entry_safe(dynid, n, &usb_drv->dynids.list, node) {
174 list_del(&dynid->node);
177 spin_unlock(&usb_drv->dynids.lock);
180 static inline int usb_create_newid_file(struct usb_driver *usb_drv)
185 static void usb_remove_newid_file(struct usb_driver *usb_drv)
190 usb_create_removeid_file(struct usb_driver *drv)
195 static void usb_remove_removeid_file(struct usb_driver *drv)
199 static inline void usb_free_dynids(struct usb_driver *usb_drv)
204 static const struct usb_device_id *usb_match_dynamic_id(struct usb_interface *intf,
205 struct usb_driver *drv)
207 struct usb_dynid *dynid;
209 spin_lock(&drv->dynids.lock);
210 list_for_each_entry(dynid, &drv->dynids.list, node) {
211 if (usb_match_one_id(intf, &dynid->id)) {
212 spin_unlock(&drv->dynids.lock);
216 spin_unlock(&drv->dynids.lock);
221 /* called from driver core with dev locked */
222 static int usb_probe_device(struct device *dev)
224 struct usb_device_driver *udriver = to_usb_device_driver(dev->driver);
225 struct usb_device *udev = to_usb_device(dev);
228 dev_dbg(dev, "%s\n", __func__);
230 /* TODO: Add real matching code */
232 /* The device should always appear to be in use
233 * unless the driver suports autosuspend.
235 if (!udriver->supports_autosuspend)
236 error = usb_autoresume_device(udev);
239 error = udriver->probe(udev);
243 /* called from driver core with dev locked */
244 static int usb_unbind_device(struct device *dev)
246 struct usb_device *udev = to_usb_device(dev);
247 struct usb_device_driver *udriver = to_usb_device_driver(dev->driver);
249 udriver->disconnect(udev);
250 if (!udriver->supports_autosuspend)
251 usb_autosuspend_device(udev);
256 * Cancel any pending scheduled resets
258 * [see usb_queue_reset_device()]
260 * Called after unconfiguring / when releasing interfaces. See
261 * comments in __usb_queue_reset_device() regarding
262 * udev->reset_running.
264 static void usb_cancel_queued_reset(struct usb_interface *iface)
266 if (iface->reset_running == 0)
267 cancel_work_sync(&iface->reset_ws);
270 /* called from driver core with dev locked */
271 static int usb_probe_interface(struct device *dev)
273 struct usb_driver *driver = to_usb_driver(dev->driver);
274 struct usb_interface *intf = to_usb_interface(dev);
275 struct usb_device *udev = interface_to_usbdev(intf);
276 const struct usb_device_id *id;
279 dev_dbg(dev, "%s\n", __func__);
281 intf->needs_binding = 0;
283 if (usb_device_is_owned(udev))
286 if (udev->authorized == 0) {
287 dev_err(&intf->dev, "Device is not authorized for usage\n");
291 id = usb_match_id(intf, driver->id_table);
293 id = usb_match_dynamic_id(intf, driver);
297 dev_dbg(dev, "%s - got id\n", __func__);
299 error = usb_autoresume_device(udev);
303 intf->condition = USB_INTERFACE_BINDING;
305 /* Probed interfaces are initially active. They are
306 * runtime-PM-enabled only if the driver has autosuspend support.
307 * They are sensitive to their children's power states.
309 pm_runtime_set_active(dev);
310 pm_suspend_ignore_children(dev, false);
311 if (driver->supports_autosuspend)
312 pm_runtime_enable(dev);
314 /* Carry out a deferred switch to altsetting 0 */
315 if (intf->needs_altsetting0) {
316 error = usb_set_interface(udev, intf->altsetting[0].
317 desc.bInterfaceNumber, 0);
320 intf->needs_altsetting0 = 0;
323 error = driver->probe(intf, id);
327 intf->condition = USB_INTERFACE_BOUND;
328 usb_autosuspend_device(udev);
332 intf->needs_remote_wakeup = 0;
333 intf->condition = USB_INTERFACE_UNBOUND;
334 usb_cancel_queued_reset(intf);
336 /* Unbound interfaces are always runtime-PM-disabled and -suspended */
337 pm_runtime_disable(dev);
338 pm_runtime_set_suspended(dev);
340 usb_autosuspend_device(udev);
344 /* called from driver core with dev locked */
345 static int usb_unbind_interface(struct device *dev)
347 struct usb_driver *driver = to_usb_driver(dev->driver);
348 struct usb_interface *intf = to_usb_interface(dev);
349 struct usb_device *udev;
352 intf->condition = USB_INTERFACE_UNBINDING;
354 /* Autoresume for set_interface call below */
355 udev = interface_to_usbdev(intf);
356 error = usb_autoresume_device(udev);
358 /* Terminate all URBs for this interface unless the driver
359 * supports "soft" unbinding.
361 if (!driver->soft_unbind)
362 usb_disable_interface(udev, intf, false);
364 driver->disconnect(intf);
365 usb_cancel_queued_reset(intf);
367 /* Reset other interface state.
368 * We cannot do a Set-Interface if the device is suspended or
369 * if it is prepared for a system sleep (since installing a new
370 * altsetting means creating new endpoint device entries).
371 * When either of these happens, defer the Set-Interface.
373 if (intf->cur_altsetting->desc.bAlternateSetting == 0) {
374 /* Already in altsetting 0 so skip Set-Interface.
375 * Just re-enable it without affecting the endpoint toggles.
377 usb_enable_interface(udev, intf, false);
378 } else if (!error && intf->dev.power.status == DPM_ON) {
379 r = usb_set_interface(udev, intf->altsetting[0].
380 desc.bInterfaceNumber, 0);
382 intf->needs_altsetting0 = 1;
384 intf->needs_altsetting0 = 1;
386 usb_set_intfdata(intf, NULL);
388 intf->condition = USB_INTERFACE_UNBOUND;
389 intf->needs_remote_wakeup = 0;
391 /* Unbound interfaces are always runtime-PM-disabled and -suspended */
392 pm_runtime_disable(dev);
393 pm_runtime_set_suspended(dev);
395 /* Undo any residual pm_autopm_get_interface_* calls */
396 for (r = atomic_read(&intf->pm_usage_cnt); r > 0; --r)
397 usb_autopm_put_interface_no_suspend(intf);
398 atomic_set(&intf->pm_usage_cnt, 0);
401 usb_autosuspend_device(udev);
407 * usb_driver_claim_interface - bind a driver to an interface
408 * @driver: the driver to be bound
409 * @iface: the interface to which it will be bound; must be in the
410 * usb device's active configuration
411 * @priv: driver data associated with that interface
413 * This is used by usb device drivers that need to claim more than one
414 * interface on a device when probing (audio and acm are current examples).
415 * No device driver should directly modify internal usb_interface or
416 * usb_device structure members.
418 * Few drivers should need to use this routine, since the most natural
419 * way to bind to an interface is to return the private data from
420 * the driver's probe() method.
422 * Callers must own the device lock, so driver probe() entries don't need
423 * extra locking, but other call contexts may need to explicitly claim that
426 int usb_driver_claim_interface(struct usb_driver *driver,
427 struct usb_interface *iface, void *priv)
429 struct device *dev = &iface->dev;
435 dev->driver = &driver->drvwrap.driver;
436 usb_set_intfdata(iface, priv);
437 iface->needs_binding = 0;
439 iface->condition = USB_INTERFACE_BOUND;
441 /* Claimed interfaces are initially inactive (suspended). They are
442 * runtime-PM-enabled only if the driver has autosuspend support.
443 * They are sensitive to their children's power states.
445 pm_runtime_set_suspended(dev);
446 pm_suspend_ignore_children(dev, false);
447 if (driver->supports_autosuspend)
448 pm_runtime_enable(dev);
450 /* if interface was already added, bind now; else let
451 * the future device_add() bind it, bypassing probe()
453 if (device_is_registered(dev))
454 retval = device_bind_driver(dev);
458 EXPORT_SYMBOL_GPL(usb_driver_claim_interface);
461 * usb_driver_release_interface - unbind a driver from an interface
462 * @driver: the driver to be unbound
463 * @iface: the interface from which it will be unbound
465 * This can be used by drivers to release an interface without waiting
466 * for their disconnect() methods to be called. In typical cases this
467 * also causes the driver disconnect() method to be called.
469 * This call is synchronous, and may not be used in an interrupt context.
470 * Callers must own the device lock, so driver disconnect() entries don't
471 * need extra locking, but other call contexts may need to explicitly claim
474 void usb_driver_release_interface(struct usb_driver *driver,
475 struct usb_interface *iface)
477 struct device *dev = &iface->dev;
479 /* this should never happen, don't release something that's not ours */
480 if (!dev->driver || dev->driver != &driver->drvwrap.driver)
483 /* don't release from within disconnect() */
484 if (iface->condition != USB_INTERFACE_BOUND)
486 iface->condition = USB_INTERFACE_UNBINDING;
488 /* Release via the driver core only if the interface
489 * has already been registered
491 if (device_is_registered(dev)) {
492 device_release_driver(dev);
495 usb_unbind_interface(dev);
500 EXPORT_SYMBOL_GPL(usb_driver_release_interface);
502 /* returns 0 if no match, 1 if match */
503 int usb_match_device(struct usb_device *dev, const struct usb_device_id *id)
505 if ((id->match_flags & USB_DEVICE_ID_MATCH_VENDOR) &&
506 id->idVendor != le16_to_cpu(dev->descriptor.idVendor))
509 if ((id->match_flags & USB_DEVICE_ID_MATCH_PRODUCT) &&
510 id->idProduct != le16_to_cpu(dev->descriptor.idProduct))
513 /* No need to test id->bcdDevice_lo != 0, since 0 is never
514 greater than any unsigned number. */
515 if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_LO) &&
516 (id->bcdDevice_lo > le16_to_cpu(dev->descriptor.bcdDevice)))
519 if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_HI) &&
520 (id->bcdDevice_hi < le16_to_cpu(dev->descriptor.bcdDevice)))
523 if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_CLASS) &&
524 (id->bDeviceClass != dev->descriptor.bDeviceClass))
527 if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_SUBCLASS) &&
528 (id->bDeviceSubClass != dev->descriptor.bDeviceSubClass))
531 if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_PROTOCOL) &&
532 (id->bDeviceProtocol != dev->descriptor.bDeviceProtocol))
538 /* returns 0 if no match, 1 if match */
539 int usb_match_one_id(struct usb_interface *interface,
540 const struct usb_device_id *id)
542 struct usb_host_interface *intf;
543 struct usb_device *dev;
545 /* proc_connectinfo in devio.c may call us with id == NULL. */
549 intf = interface->cur_altsetting;
550 dev = interface_to_usbdev(interface);
552 if (!usb_match_device(dev, id))
555 /* The interface class, subclass, and protocol should never be
556 * checked for a match if the device class is Vendor Specific,
557 * unless the match record specifies the Vendor ID. */
558 if (dev->descriptor.bDeviceClass == USB_CLASS_VENDOR_SPEC &&
559 !(id->match_flags & USB_DEVICE_ID_MATCH_VENDOR) &&
560 (id->match_flags & (USB_DEVICE_ID_MATCH_INT_CLASS |
561 USB_DEVICE_ID_MATCH_INT_SUBCLASS |
562 USB_DEVICE_ID_MATCH_INT_PROTOCOL)))
565 if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_CLASS) &&
566 (id->bInterfaceClass != intf->desc.bInterfaceClass))
569 if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_SUBCLASS) &&
570 (id->bInterfaceSubClass != intf->desc.bInterfaceSubClass))
573 if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_PROTOCOL) &&
574 (id->bInterfaceProtocol != intf->desc.bInterfaceProtocol))
579 EXPORT_SYMBOL_GPL(usb_match_one_id);
582 * usb_match_id - find first usb_device_id matching device or interface
583 * @interface: the interface of interest
584 * @id: array of usb_device_id structures, terminated by zero entry
586 * usb_match_id searches an array of usb_device_id's and returns
587 * the first one matching the device or interface, or null.
588 * This is used when binding (or rebinding) a driver to an interface.
589 * Most USB device drivers will use this indirectly, through the usb core,
590 * but some layered driver frameworks use it directly.
591 * These device tables are exported with MODULE_DEVICE_TABLE, through
592 * modutils, to support the driver loading functionality of USB hotplugging.
596 * The "match_flags" element in a usb_device_id controls which
597 * members are used. If the corresponding bit is set, the
598 * value in the device_id must match its corresponding member
599 * in the device or interface descriptor, or else the device_id
602 * "driver_info" is normally used only by device drivers,
603 * but you can create a wildcard "matches anything" usb_device_id
604 * as a driver's "modules.usbmap" entry if you provide an id with
605 * only a nonzero "driver_info" field. If you do this, the USB device
606 * driver's probe() routine should use additional intelligence to
607 * decide whether to bind to the specified interface.
609 * What Makes Good usb_device_id Tables:
611 * The match algorithm is very simple, so that intelligence in
612 * driver selection must come from smart driver id records.
613 * Unless you have good reasons to use another selection policy,
614 * provide match elements only in related groups, and order match
615 * specifiers from specific to general. Use the macros provided
616 * for that purpose if you can.
618 * The most specific match specifiers use device descriptor
619 * data. These are commonly used with product-specific matches;
620 * the USB_DEVICE macro lets you provide vendor and product IDs,
621 * and you can also match against ranges of product revisions.
622 * These are widely used for devices with application or vendor
623 * specific bDeviceClass values.
625 * Matches based on device class/subclass/protocol specifications
626 * are slightly more general; use the USB_DEVICE_INFO macro, or
627 * its siblings. These are used with single-function devices
628 * where bDeviceClass doesn't specify that each interface has
631 * Matches based on interface class/subclass/protocol are the
632 * most general; they let drivers bind to any interface on a
633 * multiple-function device. Use the USB_INTERFACE_INFO
634 * macro, or its siblings, to match class-per-interface style
635 * devices (as recorded in bInterfaceClass).
637 * Note that an entry created by USB_INTERFACE_INFO won't match
638 * any interface if the device class is set to Vendor-Specific.
639 * This is deliberate; according to the USB spec the meanings of
640 * the interface class/subclass/protocol for these devices are also
641 * vendor-specific, and hence matching against a standard product
642 * class wouldn't work anyway. If you really want to use an
643 * interface-based match for such a device, create a match record
644 * that also specifies the vendor ID. (Unforunately there isn't a
645 * standard macro for creating records like this.)
647 * Within those groups, remember that not all combinations are
648 * meaningful. For example, don't give a product version range
649 * without vendor and product IDs; or specify a protocol without
650 * its associated class and subclass.
652 const struct usb_device_id *usb_match_id(struct usb_interface *interface,
653 const struct usb_device_id *id)
655 /* proc_connectinfo in devio.c may call us with id == NULL. */
659 /* It is important to check that id->driver_info is nonzero,
660 since an entry that is all zeroes except for a nonzero
661 id->driver_info is the way to create an entry that
662 indicates that the driver want to examine every
663 device and interface. */
664 for (; id->idVendor || id->idProduct || id->bDeviceClass ||
665 id->bInterfaceClass || id->driver_info; id++) {
666 if (usb_match_one_id(interface, id))
672 EXPORT_SYMBOL_GPL(usb_match_id);
674 static int usb_device_match(struct device *dev, struct device_driver *drv)
676 /* devices and interfaces are handled separately */
677 if (is_usb_device(dev)) {
679 /* interface drivers never match devices */
680 if (!is_usb_device_driver(drv))
683 /* TODO: Add real matching code */
686 } else if (is_usb_interface(dev)) {
687 struct usb_interface *intf;
688 struct usb_driver *usb_drv;
689 const struct usb_device_id *id;
691 /* device drivers never match interfaces */
692 if (is_usb_device_driver(drv))
695 intf = to_usb_interface(dev);
696 usb_drv = to_usb_driver(drv);
698 id = usb_match_id(intf, usb_drv->id_table);
702 id = usb_match_dynamic_id(intf, usb_drv);
710 #ifdef CONFIG_HOTPLUG
711 static int usb_uevent(struct device *dev, struct kobj_uevent_env *env)
713 struct usb_device *usb_dev;
715 if (is_usb_device(dev)) {
716 usb_dev = to_usb_device(dev);
717 } else if (is_usb_interface(dev)) {
718 struct usb_interface *intf = to_usb_interface(dev);
720 usb_dev = interface_to_usbdev(intf);
725 if (usb_dev->devnum < 0) {
726 /* driver is often null here; dev_dbg() would oops */
727 pr_debug("usb %s: already deleted?\n", dev_name(dev));
731 pr_debug("usb %s: bus removed?\n", dev_name(dev));
735 #ifdef CONFIG_USB_DEVICEFS
736 /* If this is available, userspace programs can directly read
737 * all the device descriptors we don't tell them about. Or
738 * act as usermode drivers.
740 if (add_uevent_var(env, "DEVICE=/proc/bus/usb/%03d/%03d",
741 usb_dev->bus->busnum, usb_dev->devnum))
745 /* per-device configurations are common */
746 if (add_uevent_var(env, "PRODUCT=%x/%x/%x",
747 le16_to_cpu(usb_dev->descriptor.idVendor),
748 le16_to_cpu(usb_dev->descriptor.idProduct),
749 le16_to_cpu(usb_dev->descriptor.bcdDevice)))
752 /* class-based driver binding models */
753 if (add_uevent_var(env, "TYPE=%d/%d/%d",
754 usb_dev->descriptor.bDeviceClass,
755 usb_dev->descriptor.bDeviceSubClass,
756 usb_dev->descriptor.bDeviceProtocol))
764 static int usb_uevent(struct device *dev, struct kobj_uevent_env *env)
768 #endif /* CONFIG_HOTPLUG */
771 * usb_register_device_driver - register a USB device (not interface) driver
772 * @new_udriver: USB operations for the device driver
773 * @owner: module owner of this driver.
775 * Registers a USB device driver with the USB core. The list of
776 * unattached devices will be rescanned whenever a new driver is
777 * added, allowing the new driver to attach to any recognized devices.
778 * Returns a negative error code on failure and 0 on success.
780 int usb_register_device_driver(struct usb_device_driver *new_udriver,
781 struct module *owner)
788 new_udriver->drvwrap.for_devices = 1;
789 new_udriver->drvwrap.driver.name = (char *) new_udriver->name;
790 new_udriver->drvwrap.driver.bus = &usb_bus_type;
791 new_udriver->drvwrap.driver.probe = usb_probe_device;
792 new_udriver->drvwrap.driver.remove = usb_unbind_device;
793 new_udriver->drvwrap.driver.owner = owner;
795 retval = driver_register(&new_udriver->drvwrap.driver);
798 pr_info("%s: registered new device driver %s\n",
799 usbcore_name, new_udriver->name);
800 usbfs_update_special();
802 printk(KERN_ERR "%s: error %d registering device "
804 usbcore_name, retval, new_udriver->name);
809 EXPORT_SYMBOL_GPL(usb_register_device_driver);
812 * usb_deregister_device_driver - unregister a USB device (not interface) driver
813 * @udriver: USB operations of the device driver to unregister
814 * Context: must be able to sleep
816 * Unlinks the specified driver from the internal USB driver list.
818 void usb_deregister_device_driver(struct usb_device_driver *udriver)
820 pr_info("%s: deregistering device driver %s\n",
821 usbcore_name, udriver->name);
823 driver_unregister(&udriver->drvwrap.driver);
824 usbfs_update_special();
826 EXPORT_SYMBOL_GPL(usb_deregister_device_driver);
829 * usb_register_driver - register a USB interface driver
830 * @new_driver: USB operations for the interface driver
831 * @owner: module owner of this driver.
832 * @mod_name: module name string
834 * Registers a USB interface driver with the USB core. The list of
835 * unattached interfaces will be rescanned whenever a new driver is
836 * added, allowing the new driver to attach to any recognized interfaces.
837 * Returns a negative error code on failure and 0 on success.
839 * NOTE: if you want your driver to use the USB major number, you must call
840 * usb_register_dev() to enable that functionality. This function no longer
841 * takes care of that.
843 int usb_register_driver(struct usb_driver *new_driver, struct module *owner,
844 const char *mod_name)
851 new_driver->drvwrap.for_devices = 0;
852 new_driver->drvwrap.driver.name = (char *) new_driver->name;
853 new_driver->drvwrap.driver.bus = &usb_bus_type;
854 new_driver->drvwrap.driver.probe = usb_probe_interface;
855 new_driver->drvwrap.driver.remove = usb_unbind_interface;
856 new_driver->drvwrap.driver.owner = owner;
857 new_driver->drvwrap.driver.mod_name = mod_name;
858 spin_lock_init(&new_driver->dynids.lock);
859 INIT_LIST_HEAD(&new_driver->dynids.list);
861 retval = driver_register(&new_driver->drvwrap.driver);
865 usbfs_update_special();
867 retval = usb_create_newid_file(new_driver);
871 retval = usb_create_removeid_file(new_driver);
875 pr_info("%s: registered new interface driver %s\n",
876 usbcore_name, new_driver->name);
882 usb_remove_newid_file(new_driver);
884 driver_unregister(&new_driver->drvwrap.driver);
886 printk(KERN_ERR "%s: error %d registering interface "
888 usbcore_name, retval, new_driver->name);
891 EXPORT_SYMBOL_GPL(usb_register_driver);
894 * usb_deregister - unregister a USB interface driver
895 * @driver: USB operations of the interface driver to unregister
896 * Context: must be able to sleep
898 * Unlinks the specified driver from the internal USB driver list.
900 * NOTE: If you called usb_register_dev(), you still need to call
901 * usb_deregister_dev() to clean up your driver's allocated minor numbers,
902 * this * call will no longer do it for you.
904 void usb_deregister(struct usb_driver *driver)
906 pr_info("%s: deregistering interface driver %s\n",
907 usbcore_name, driver->name);
909 usb_remove_removeid_file(driver);
910 usb_remove_newid_file(driver);
911 usb_free_dynids(driver);
912 driver_unregister(&driver->drvwrap.driver);
914 usbfs_update_special();
916 EXPORT_SYMBOL_GPL(usb_deregister);
918 /* Forced unbinding of a USB interface driver, either because
919 * it doesn't support pre_reset/post_reset/reset_resume or
920 * because it doesn't support suspend/resume.
922 * The caller must hold @intf's device's lock, but not its pm_mutex
923 * and not @intf->dev.sem.
925 void usb_forced_unbind_intf(struct usb_interface *intf)
927 struct usb_driver *driver = to_usb_driver(intf->dev.driver);
929 dev_dbg(&intf->dev, "forced unbind\n");
930 usb_driver_release_interface(driver, intf);
932 /* Mark the interface for later rebinding */
933 intf->needs_binding = 1;
936 /* Delayed forced unbinding of a USB interface driver and scan
939 * The caller must hold @intf's device's lock, but not its pm_mutex
940 * and not @intf->dev.sem.
942 * Note: Rebinds will be skipped if a system sleep transition is in
943 * progress and the PM "complete" callback hasn't occurred yet.
945 void usb_rebind_intf(struct usb_interface *intf)
949 /* Delayed unbind of an existing driver */
950 if (intf->dev.driver) {
951 struct usb_driver *driver =
952 to_usb_driver(intf->dev.driver);
954 dev_dbg(&intf->dev, "forced unbind\n");
955 usb_driver_release_interface(driver, intf);
958 /* Try to rebind the interface */
959 if (intf->dev.power.status == DPM_ON) {
960 intf->needs_binding = 0;
961 rc = device_attach(&intf->dev);
963 dev_warn(&intf->dev, "rebind failed: %d\n", rc);
972 /* Unbind drivers for @udev's interfaces that don't support suspend/resume,
973 * or rebind interfaces that have been unbound, according to @action.
975 * The caller must hold @udev's device lock.
977 static void do_unbind_rebind(struct usb_device *udev, int action)
979 struct usb_host_config *config;
981 struct usb_interface *intf;
982 struct usb_driver *drv;
984 config = udev->actconfig;
986 for (i = 0; i < config->desc.bNumInterfaces; ++i) {
987 intf = config->interface[i];
990 if (intf->dev.driver) {
991 drv = to_usb_driver(intf->dev.driver);
992 if (!drv->suspend || !drv->resume)
993 usb_forced_unbind_intf(intf);
997 if (intf->needs_binding)
998 usb_rebind_intf(intf);
1005 static int usb_suspend_device(struct usb_device *udev, pm_message_t msg)
1007 struct usb_device_driver *udriver;
1010 if (udev->state == USB_STATE_NOTATTACHED ||
1011 udev->state == USB_STATE_SUSPENDED)
1014 /* For devices that don't have a driver, we do a generic suspend. */
1015 if (udev->dev.driver)
1016 udriver = to_usb_device_driver(udev->dev.driver);
1018 udev->do_remote_wakeup = 0;
1019 udriver = &usb_generic_driver;
1021 status = udriver->suspend(udev, msg);
1024 dev_vdbg(&udev->dev, "%s: status %d\n", __func__, status);
1028 static int usb_resume_device(struct usb_device *udev, pm_message_t msg)
1030 struct usb_device_driver *udriver;
1033 if (udev->state == USB_STATE_NOTATTACHED)
1036 /* Can't resume it if it doesn't have a driver. */
1037 if (udev->dev.driver == NULL) {
1042 /* Non-root devices on a full/low-speed bus must wait for their
1043 * companion high-speed root hub, in case a handoff is needed.
1045 if (!(msg.event & PM_EVENT_AUTO) && udev->parent &&
1046 udev->bus->hs_companion)
1047 device_pm_wait_for_dev(&udev->dev,
1048 &udev->bus->hs_companion->root_hub->dev);
1050 if (udev->quirks & USB_QUIRK_RESET_RESUME)
1051 udev->reset_resume = 1;
1053 udriver = to_usb_device_driver(udev->dev.driver);
1054 status = udriver->resume(udev, msg);
1057 dev_vdbg(&udev->dev, "%s: status %d\n", __func__, status);
1061 static int usb_suspend_interface(struct usb_device *udev,
1062 struct usb_interface *intf, pm_message_t msg)
1064 struct usb_driver *driver;
1067 if (udev->state == USB_STATE_NOTATTACHED ||
1068 intf->condition == USB_INTERFACE_UNBOUND)
1070 driver = to_usb_driver(intf->dev.driver);
1072 if (driver->suspend) {
1073 status = driver->suspend(intf, msg);
1074 if (status && !(msg.event & PM_EVENT_AUTO))
1075 dev_err(&intf->dev, "%s error %d\n",
1078 /* Later we will unbind the driver and reprobe */
1079 intf->needs_binding = 1;
1080 dev_warn(&intf->dev, "no %s for driver %s?\n",
1081 "suspend", driver->name);
1085 dev_vdbg(&intf->dev, "%s: status %d\n", __func__, status);
1089 static int usb_resume_interface(struct usb_device *udev,
1090 struct usb_interface *intf, pm_message_t msg, int reset_resume)
1092 struct usb_driver *driver;
1095 if (udev->state == USB_STATE_NOTATTACHED)
1098 /* Don't let autoresume interfere with unbinding */
1099 if (intf->condition == USB_INTERFACE_UNBINDING)
1102 /* Can't resume it if it doesn't have a driver. */
1103 if (intf->condition == USB_INTERFACE_UNBOUND) {
1105 /* Carry out a deferred switch to altsetting 0 */
1106 if (intf->needs_altsetting0 &&
1107 intf->dev.power.status == DPM_ON) {
1108 usb_set_interface(udev, intf->altsetting[0].
1109 desc.bInterfaceNumber, 0);
1110 intf->needs_altsetting0 = 0;
1115 /* Don't resume if the interface is marked for rebinding */
1116 if (intf->needs_binding)
1118 driver = to_usb_driver(intf->dev.driver);
1121 if (driver->reset_resume) {
1122 status = driver->reset_resume(intf);
1124 dev_err(&intf->dev, "%s error %d\n",
1125 "reset_resume", status);
1127 intf->needs_binding = 1;
1128 dev_warn(&intf->dev, "no %s for driver %s?\n",
1129 "reset_resume", driver->name);
1132 if (driver->resume) {
1133 status = driver->resume(intf);
1135 dev_err(&intf->dev, "%s error %d\n",
1138 intf->needs_binding = 1;
1139 dev_warn(&intf->dev, "no %s for driver %s?\n",
1140 "resume", driver->name);
1145 dev_vdbg(&intf->dev, "%s: status %d\n", __func__, status);
1147 /* Later we will unbind the driver and/or reprobe, if necessary */
1152 * usb_suspend_both - suspend a USB device and its interfaces
1153 * @udev: the usb_device to suspend
1154 * @msg: Power Management message describing this state transition
1156 * This is the central routine for suspending USB devices. It calls the
1157 * suspend methods for all the interface drivers in @udev and then calls
1158 * the suspend method for @udev itself. If an error occurs at any stage,
1159 * all the interfaces which were suspended are resumed so that they remain
1160 * in the same state as the device.
1162 * Autosuspend requests originating from a child device or an interface
1163 * driver may be made without the protection of @udev's device lock, but
1164 * all other suspend calls will hold the lock. Usbcore will insure that
1165 * method calls do not arrive during bind, unbind, or reset operations.
1166 * However drivers must be prepared to handle suspend calls arriving at
1167 * unpredictable times.
1169 * This routine can run only in process context.
1171 static int usb_suspend_both(struct usb_device *udev, pm_message_t msg)
1175 struct usb_interface *intf;
1177 if (udev->state == USB_STATE_NOTATTACHED ||
1178 udev->state == USB_STATE_SUSPENDED)
1181 /* Suspend all the interfaces and then udev itself */
1182 if (udev->actconfig) {
1183 n = udev->actconfig->desc.bNumInterfaces;
1184 for (i = n - 1; i >= 0; --i) {
1185 intf = udev->actconfig->interface[i];
1186 status = usb_suspend_interface(udev, intf, msg);
1192 status = usb_suspend_device(udev, msg);
1194 /* If the suspend failed, resume interfaces that did get suspended */
1196 msg.event ^= (PM_EVENT_SUSPEND | PM_EVENT_RESUME);
1198 intf = udev->actconfig->interface[i];
1199 usb_resume_interface(udev, intf, msg, 0);
1202 /* If the suspend succeeded then prevent any more URB submissions
1203 * and flush any outstanding URBs.
1206 udev->can_submit = 0;
1207 for (i = 0; i < 16; ++i) {
1208 usb_hcd_flush_endpoint(udev, udev->ep_out[i]);
1209 usb_hcd_flush_endpoint(udev, udev->ep_in[i]);
1214 dev_vdbg(&udev->dev, "%s: status %d\n", __func__, status);
1219 * usb_resume_both - resume a USB device and its interfaces
1220 * @udev: the usb_device to resume
1221 * @msg: Power Management message describing this state transition
1223 * This is the central routine for resuming USB devices. It calls the
1224 * the resume method for @udev and then calls the resume methods for all
1225 * the interface drivers in @udev.
1227 * Autoresume requests originating from a child device or an interface
1228 * driver may be made without the protection of @udev's device lock, but
1229 * all other resume calls will hold the lock. Usbcore will insure that
1230 * method calls do not arrive during bind, unbind, or reset operations.
1231 * However drivers must be prepared to handle resume calls arriving at
1232 * unpredictable times.
1234 * This routine can run only in process context.
1236 static int usb_resume_both(struct usb_device *udev, pm_message_t msg)
1240 struct usb_interface *intf;
1242 if (udev->state == USB_STATE_NOTATTACHED) {
1246 udev->can_submit = 1;
1248 /* Resume the device */
1249 if (udev->state == USB_STATE_SUSPENDED || udev->reset_resume)
1250 status = usb_resume_device(udev, msg);
1252 /* Resume the interfaces */
1253 if (status == 0 && udev->actconfig) {
1254 for (i = 0; i < udev->actconfig->desc.bNumInterfaces; i++) {
1255 intf = udev->actconfig->interface[i];
1256 usb_resume_interface(udev, intf, msg,
1257 udev->reset_resume);
1262 dev_vdbg(&udev->dev, "%s: status %d\n", __func__, status);
1264 udev->reset_resume = 0;
1268 static void choose_wakeup(struct usb_device *udev, pm_message_t msg)
1271 struct usb_interface *intf;
1273 /* Remote wakeup is needed only when we actually go to sleep.
1274 * For things like FREEZE and QUIESCE, if the device is already
1275 * autosuspended then its current wakeup setting is okay.
1277 if (msg.event == PM_EVENT_FREEZE || msg.event == PM_EVENT_QUIESCE) {
1278 if (udev->state != USB_STATE_SUSPENDED)
1279 udev->do_remote_wakeup = 0;
1283 /* If remote wakeup is permitted, see whether any interface drivers
1287 if (device_may_wakeup(&udev->dev) && udev->actconfig) {
1288 for (i = 0; i < udev->actconfig->desc.bNumInterfaces; i++) {
1289 intf = udev->actconfig->interface[i];
1290 w |= intf->needs_remote_wakeup;
1294 /* If the device is autosuspended with the wrong wakeup setting,
1295 * autoresume now so the setting can be changed.
1297 if (udev->state == USB_STATE_SUSPENDED && w != udev->do_remote_wakeup)
1298 pm_runtime_resume(&udev->dev);
1299 udev->do_remote_wakeup = w;
1302 /* The device lock is held by the PM core */
1303 int usb_suspend(struct device *dev, pm_message_t msg)
1305 struct usb_device *udev = to_usb_device(dev);
1307 do_unbind_rebind(udev, DO_UNBIND);
1308 choose_wakeup(udev, msg);
1309 return usb_suspend_both(udev, msg);
1312 /* The device lock is held by the PM core */
1313 int usb_resume(struct device *dev, pm_message_t msg)
1315 struct usb_device *udev = to_usb_device(dev);
1318 /* For PM complete calls, all we do is rebind interfaces */
1319 if (msg.event == PM_EVENT_ON) {
1320 if (udev->state != USB_STATE_NOTATTACHED)
1321 do_unbind_rebind(udev, DO_REBIND);
1324 /* For all other calls, take the device back to full power and
1325 * tell the PM core in case it was autosuspended previously.
1328 status = usb_resume_both(udev, msg);
1330 pm_runtime_disable(dev);
1331 pm_runtime_set_active(dev);
1332 pm_runtime_enable(dev);
1333 udev->last_busy = jiffies;
1337 /* Avoid PM error messages for devices disconnected while suspended
1338 * as we'll display regular disconnect messages just a bit later.
1340 if (status == -ENODEV)
1345 #endif /* CONFIG_PM */
1347 #ifdef CONFIG_USB_SUSPEND
1350 * usb_enable_autosuspend - allow a USB device to be autosuspended
1351 * @udev: the USB device which may be autosuspended
1353 * This routine allows @udev to be autosuspended. An autosuspend won't
1354 * take place until the autosuspend_delay has elapsed and all the other
1355 * necessary conditions are satisfied.
1357 * The caller must hold @udev's device lock.
1359 int usb_enable_autosuspend(struct usb_device *udev)
1361 if (udev->autosuspend_disabled) {
1362 udev->autosuspend_disabled = 0;
1363 usb_autosuspend_device(udev);
1367 EXPORT_SYMBOL_GPL(usb_enable_autosuspend);
1370 * usb_disable_autosuspend - prevent a USB device from being autosuspended
1371 * @udev: the USB device which may not be autosuspended
1373 * This routine prevents @udev from being autosuspended and wakes it up
1374 * if it is already autosuspended.
1376 * The caller must hold @udev's device lock.
1378 int usb_disable_autosuspend(struct usb_device *udev)
1382 if (!udev->autosuspend_disabled) {
1383 rc = usb_autoresume_device(udev);
1385 udev->autosuspend_disabled = 1;
1389 EXPORT_SYMBOL_GPL(usb_disable_autosuspend);
1392 * usb_autosuspend_device - delayed autosuspend of a USB device and its interfaces
1393 * @udev: the usb_device to autosuspend
1395 * This routine should be called when a core subsystem is finished using
1396 * @udev and wants to allow it to autosuspend. Examples would be when
1397 * @udev's device file in usbfs is closed or after a configuration change.
1399 * @udev's usage counter is decremented; if it drops to 0 and all the
1400 * interfaces are inactive then a delayed autosuspend will be attempted.
1401 * The attempt may fail (see autosuspend_check()).
1403 * The caller must hold @udev's device lock.
1405 * This routine can run only in process context.
1407 void usb_autosuspend_device(struct usb_device *udev)
1411 udev->last_busy = jiffies;
1412 status = pm_runtime_put_sync(&udev->dev);
1413 dev_vdbg(&udev->dev, "%s: cnt %d -> %d\n",
1414 __func__, atomic_read(&udev->dev.power.usage_count),
1419 * usb_try_autosuspend_device - attempt an autosuspend of a USB device and its interfaces
1420 * @udev: the usb_device to autosuspend
1422 * This routine should be called when a core subsystem thinks @udev may
1423 * be ready to autosuspend.
1425 * @udev's usage counter left unchanged. If it is 0 and all the interfaces
1426 * are inactive then an autosuspend will be attempted. The attempt may
1427 * fail or be delayed.
1429 * The caller must hold @udev's device lock.
1431 * This routine can run only in process context.
1433 void usb_try_autosuspend_device(struct usb_device *udev)
1437 status = pm_runtime_idle(&udev->dev);
1438 dev_vdbg(&udev->dev, "%s: cnt %d -> %d\n",
1439 __func__, atomic_read(&udev->dev.power.usage_count),
1444 * usb_autoresume_device - immediately autoresume a USB device and its interfaces
1445 * @udev: the usb_device to autoresume
1447 * This routine should be called when a core subsystem wants to use @udev
1448 * and needs to guarantee that it is not suspended. No autosuspend will
1449 * occur until usb_autosuspend_device() is called. (Note that this will
1450 * not prevent suspend events originating in the PM core.) Examples would
1451 * be when @udev's device file in usbfs is opened or when a remote-wakeup
1452 * request is received.
1454 * @udev's usage counter is incremented to prevent subsequent autosuspends.
1455 * However if the autoresume fails then the usage counter is re-decremented.
1457 * The caller must hold @udev's device lock.
1459 * This routine can run only in process context.
1461 int usb_autoresume_device(struct usb_device *udev)
1465 status = pm_runtime_get_sync(&udev->dev);
1467 pm_runtime_put_sync(&udev->dev);
1468 dev_vdbg(&udev->dev, "%s: cnt %d -> %d\n",
1469 __func__, atomic_read(&udev->dev.power.usage_count),
1477 * usb_autopm_put_interface - decrement a USB interface's PM-usage counter
1478 * @intf: the usb_interface whose counter should be decremented
1480 * This routine should be called by an interface driver when it is
1481 * finished using @intf and wants to allow it to autosuspend. A typical
1482 * example would be a character-device driver when its device file is
1485 * The routine decrements @intf's usage counter. When the counter reaches
1486 * 0, a delayed autosuspend request for @intf's device is attempted. The
1487 * attempt may fail (see autosuspend_check()).
1489 * This routine can run only in process context.
1491 void usb_autopm_put_interface(struct usb_interface *intf)
1493 struct usb_device *udev = interface_to_usbdev(intf);
1496 udev->last_busy = jiffies;
1497 atomic_dec(&intf->pm_usage_cnt);
1498 status = pm_runtime_put_sync(&intf->dev);
1499 dev_vdbg(&intf->dev, "%s: cnt %d -> %d\n",
1500 __func__, atomic_read(&intf->dev.power.usage_count),
1503 EXPORT_SYMBOL_GPL(usb_autopm_put_interface);
1506 * usb_autopm_put_interface_async - decrement a USB interface's PM-usage counter
1507 * @intf: the usb_interface whose counter should be decremented
1509 * This routine does much the same thing as usb_autopm_put_interface():
1510 * It decrements @intf's usage counter and schedules a delayed
1511 * autosuspend request if the counter is <= 0. The difference is that it
1512 * does not perform any synchronization; callers should hold a private
1513 * lock and handle all synchronization issues themselves.
1515 * Typically a driver would call this routine during an URB's completion
1516 * handler, if no more URBs were pending.
1518 * This routine can run in atomic context.
1520 void usb_autopm_put_interface_async(struct usb_interface *intf)
1522 struct usb_device *udev = interface_to_usbdev(intf);
1523 unsigned long last_busy;
1526 last_busy = udev->last_busy;
1527 udev->last_busy = jiffies;
1528 atomic_dec(&intf->pm_usage_cnt);
1529 pm_runtime_put_noidle(&intf->dev);
1531 if (!udev->autosuspend_disabled) {
1532 /* Optimization: Don't schedule a delayed autosuspend if
1533 * the timer is already running and the expiration time
1536 * We have to use the interface's timer. Attempts to
1537 * schedule a suspend for the device would fail because
1538 * the interface is still active.
1540 if (intf->dev.power.timer_expires == 0 ||
1541 round_jiffies_up(last_busy) !=
1542 round_jiffies_up(jiffies)) {
1543 status = pm_schedule_suspend(&intf->dev,
1545 round_jiffies_up_relative(
1546 udev->autosuspend_delay)));
1549 dev_vdbg(&intf->dev, "%s: cnt %d -> %d\n",
1550 __func__, atomic_read(&intf->dev.power.usage_count),
1553 EXPORT_SYMBOL_GPL(usb_autopm_put_interface_async);
1556 * usb_autopm_put_interface_no_suspend - decrement a USB interface's PM-usage counter
1557 * @intf: the usb_interface whose counter should be decremented
1559 * This routine decrements @intf's usage counter but does not carry out an
1562 * This routine can run in atomic context.
1564 void usb_autopm_put_interface_no_suspend(struct usb_interface *intf)
1566 struct usb_device *udev = interface_to_usbdev(intf);
1568 udev->last_busy = jiffies;
1569 atomic_dec(&intf->pm_usage_cnt);
1570 pm_runtime_put_noidle(&intf->dev);
1572 EXPORT_SYMBOL_GPL(usb_autopm_put_interface_no_suspend);
1575 * usb_autopm_get_interface - increment a USB interface's PM-usage counter
1576 * @intf: the usb_interface whose counter should be incremented
1578 * This routine should be called by an interface driver when it wants to
1579 * use @intf and needs to guarantee that it is not suspended. In addition,
1580 * the routine prevents @intf from being autosuspended subsequently. (Note
1581 * that this will not prevent suspend events originating in the PM core.)
1582 * This prevention will persist until usb_autopm_put_interface() is called
1583 * or @intf is unbound. A typical example would be a character-device
1584 * driver when its device file is opened.
1586 * @intf's usage counter is incremented to prevent subsequent autosuspends.
1587 * However if the autoresume fails then the counter is re-decremented.
1589 * This routine can run only in process context.
1591 int usb_autopm_get_interface(struct usb_interface *intf)
1595 status = pm_runtime_get_sync(&intf->dev);
1597 pm_runtime_put_sync(&intf->dev);
1599 atomic_inc(&intf->pm_usage_cnt);
1600 dev_vdbg(&intf->dev, "%s: cnt %d -> %d\n",
1601 __func__, atomic_read(&intf->dev.power.usage_count),
1607 EXPORT_SYMBOL_GPL(usb_autopm_get_interface);
1610 * usb_autopm_get_interface_async - increment a USB interface's PM-usage counter
1611 * @intf: the usb_interface whose counter should be incremented
1613 * This routine does much the same thing as
1614 * usb_autopm_get_interface(): It increments @intf's usage counter and
1615 * queues an autoresume request if the device is suspended. The
1616 * differences are that it does not perform any synchronization (callers
1617 * should hold a private lock and handle all synchronization issues
1618 * themselves), and it does not autoresume the device directly (it only
1619 * queues a request). After a successful call, the device may not yet be
1622 * This routine can run in atomic context.
1624 int usb_autopm_get_interface_async(struct usb_interface *intf)
1629 /* Don't request a resume unless the interface is already suspending
1630 * or suspended. Doing so would force a running suspend timer to be
1633 pm_runtime_get_noresume(&intf->dev);
1634 s = ACCESS_ONCE(intf->dev.power.runtime_status);
1635 if (s == RPM_SUSPENDING || s == RPM_SUSPENDED)
1636 status = pm_request_resume(&intf->dev);
1638 if (status < 0 && status != -EINPROGRESS)
1639 pm_runtime_put_noidle(&intf->dev);
1641 atomic_inc(&intf->pm_usage_cnt);
1642 dev_vdbg(&intf->dev, "%s: cnt %d -> %d\n",
1643 __func__, atomic_read(&intf->dev.power.usage_count),
1649 EXPORT_SYMBOL_GPL(usb_autopm_get_interface_async);
1652 * usb_autopm_get_interface_no_resume - increment a USB interface's PM-usage counter
1653 * @intf: the usb_interface whose counter should be incremented
1655 * This routine increments @intf's usage counter but does not carry out an
1658 * This routine can run in atomic context.
1660 void usb_autopm_get_interface_no_resume(struct usb_interface *intf)
1662 struct usb_device *udev = interface_to_usbdev(intf);
1664 udev->last_busy = jiffies;
1665 atomic_inc(&intf->pm_usage_cnt);
1666 pm_runtime_get_noresume(&intf->dev);
1668 EXPORT_SYMBOL_GPL(usb_autopm_get_interface_no_resume);
1670 /* Internal routine to check whether we may autosuspend a device. */
1671 static int autosuspend_check(struct usb_device *udev)
1674 struct usb_interface *intf;
1675 unsigned long suspend_time, j;
1677 /* Fail if autosuspend is disabled, or any interfaces are in use, or
1678 * any interface drivers require remote wakeup but it isn't available.
1681 if (udev->actconfig) {
1682 for (i = 0; i < udev->actconfig->desc.bNumInterfaces; i++) {
1683 intf = udev->actconfig->interface[i];
1685 /* We don't need to check interfaces that are
1686 * disabled for runtime PM. Either they are unbound
1687 * or else their drivers don't support autosuspend
1688 * and so they are permanently active.
1690 if (intf->dev.power.disable_depth)
1692 if (atomic_read(&intf->dev.power.usage_count) > 0)
1694 w |= intf->needs_remote_wakeup;
1696 /* Don't allow autosuspend if the device will need
1697 * a reset-resume and any of its interface drivers
1698 * doesn't include support or needs remote wakeup.
1700 if (udev->quirks & USB_QUIRK_RESET_RESUME) {
1701 struct usb_driver *driver;
1703 driver = to_usb_driver(intf->dev.driver);
1704 if (!driver->reset_resume ||
1705 intf->needs_remote_wakeup)
1710 if (w && !device_can_wakeup(&udev->dev)) {
1711 dev_dbg(&udev->dev, "remote wakeup needed for autosuspend\n");
1714 udev->do_remote_wakeup = w;
1716 /* If everything is okay but the device hasn't been idle for long
1717 * enough, queue a delayed autosuspend request.
1719 j = ACCESS_ONCE(jiffies);
1720 suspend_time = udev->last_busy + udev->autosuspend_delay;
1721 if (time_before(j, suspend_time)) {
1722 pm_schedule_suspend(&udev->dev, jiffies_to_msecs(
1723 round_jiffies_up_relative(suspend_time - j)));
1729 static int usb_runtime_suspend(struct device *dev)
1733 /* A USB device can be suspended if it passes the various autosuspend
1734 * checks. Runtime suspend for a USB device means suspending all the
1735 * interfaces and then the device itself.
1737 if (is_usb_device(dev)) {
1738 struct usb_device *udev = to_usb_device(dev);
1740 if (autosuspend_check(udev) != 0)
1743 status = usb_suspend_both(udev, PMSG_AUTO_SUSPEND);
1745 /* If an interface fails the suspend, adjust the last_busy
1746 * time so that we don't get another suspend attempt right
1750 udev->last_busy = jiffies +
1751 (udev->autosuspend_delay == 0 ?
1755 /* Prevent the parent from suspending immediately after */
1756 else if (udev->parent) {
1757 udev->parent->last_busy = jiffies;
1761 /* Runtime suspend for a USB interface doesn't mean anything. */
1765 static int usb_runtime_resume(struct device *dev)
1767 /* Runtime resume for a USB device means resuming both the device
1768 * and all its interfaces.
1770 if (is_usb_device(dev)) {
1771 struct usb_device *udev = to_usb_device(dev);
1774 status = usb_resume_both(udev, PMSG_AUTO_RESUME);
1775 udev->last_busy = jiffies;
1779 /* Runtime resume for a USB interface doesn't mean anything. */
1783 static int usb_runtime_idle(struct device *dev)
1785 /* An idle USB device can be suspended if it passes the various
1786 * autosuspend checks. An idle interface can be suspended at
1789 if (is_usb_device(dev)) {
1790 struct usb_device *udev = to_usb_device(dev);
1792 if (autosuspend_check(udev) != 0)
1796 pm_runtime_suspend(dev);
1800 static struct dev_pm_ops usb_bus_pm_ops = {
1801 .runtime_suspend = usb_runtime_suspend,
1802 .runtime_resume = usb_runtime_resume,
1803 .runtime_idle = usb_runtime_idle,
1808 #define usb_bus_pm_ops (*(struct dev_pm_ops *) NULL)
1810 #endif /* CONFIG_USB_SUSPEND */
1812 struct bus_type usb_bus_type = {
1814 .match = usb_device_match,
1815 .uevent = usb_uevent,
1816 .pm = &usb_bus_pm_ops,