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/export.h>
28 #include <linux/usb.h>
29 #include <linux/usb/quirks.h>
30 #include <linux/usb/hcd.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;
48 unsigned int bInterfaceClass = 0;
52 fields = sscanf(buf, "%x %x %x", &idVendor, &idProduct,
57 dynid = kzalloc(sizeof(*dynid), GFP_KERNEL);
61 INIT_LIST_HEAD(&dynid->node);
62 dynid->id.idVendor = idVendor;
63 dynid->id.idProduct = idProduct;
64 dynid->id.match_flags = USB_DEVICE_ID_MATCH_DEVICE;
66 dynid->id.bInterfaceClass = (u8)bInterfaceClass;
67 dynid->id.match_flags |= USB_DEVICE_ID_MATCH_INT_CLASS;
70 spin_lock(&dynids->lock);
71 list_add_tail(&dynid->node, &dynids->list);
72 spin_unlock(&dynids->lock);
74 retval = driver_attach(driver);
80 EXPORT_SYMBOL_GPL(usb_store_new_id);
82 ssize_t usb_show_dynids(struct usb_dynids *dynids, char *buf)
84 struct usb_dynid *dynid;
87 list_for_each_entry(dynid, &dynids->list, node)
88 if (dynid->id.bInterfaceClass != 0)
89 count += scnprintf(&buf[count], PAGE_SIZE - count, "%04x %04x %02x\n",
90 dynid->id.idVendor, dynid->id.idProduct,
91 dynid->id.bInterfaceClass);
93 count += scnprintf(&buf[count], PAGE_SIZE - count, "%04x %04x\n",
94 dynid->id.idVendor, dynid->id.idProduct);
97 EXPORT_SYMBOL_GPL(usb_show_dynids);
99 static ssize_t show_dynids(struct device_driver *driver, char *buf)
101 struct usb_driver *usb_drv = to_usb_driver(driver);
103 return usb_show_dynids(&usb_drv->dynids, buf);
106 static ssize_t store_new_id(struct device_driver *driver,
107 const char *buf, size_t count)
109 struct usb_driver *usb_drv = to_usb_driver(driver);
111 return usb_store_new_id(&usb_drv->dynids, driver, buf, count);
113 static DRIVER_ATTR(new_id, S_IRUGO | S_IWUSR, show_dynids, store_new_id);
116 * store_remove_id - remove a USB device ID from this driver
117 * @driver: target device driver
118 * @buf: buffer for scanning device ID data
121 * Removes a dynamic usb device ID from this driver.
124 store_remove_id(struct device_driver *driver, const char *buf, size_t count)
126 struct usb_dynid *dynid, *n;
127 struct usb_driver *usb_driver = to_usb_driver(driver);
133 fields = sscanf(buf, "%x %x", &idVendor, &idProduct);
137 spin_lock(&usb_driver->dynids.lock);
138 list_for_each_entry_safe(dynid, n, &usb_driver->dynids.list, node) {
139 struct usb_device_id *id = &dynid->id;
140 if ((id->idVendor == idVendor) &&
141 (id->idProduct == idProduct)) {
142 list_del(&dynid->node);
148 spin_unlock(&usb_driver->dynids.lock);
154 static DRIVER_ATTR(remove_id, S_IRUGO | S_IWUSR, show_dynids, store_remove_id);
156 static int usb_create_newid_files(struct usb_driver *usb_drv)
160 if (usb_drv->no_dynamic_id)
163 if (usb_drv->probe != NULL) {
164 error = driver_create_file(&usb_drv->drvwrap.driver,
165 &driver_attr_new_id);
167 error = driver_create_file(&usb_drv->drvwrap.driver,
168 &driver_attr_remove_id);
170 driver_remove_file(&usb_drv->drvwrap.driver,
171 &driver_attr_new_id);
178 static void usb_remove_newid_files(struct usb_driver *usb_drv)
180 if (usb_drv->no_dynamic_id)
183 if (usb_drv->probe != NULL) {
184 driver_remove_file(&usb_drv->drvwrap.driver,
185 &driver_attr_remove_id);
186 driver_remove_file(&usb_drv->drvwrap.driver,
187 &driver_attr_new_id);
191 static void usb_free_dynids(struct usb_driver *usb_drv)
193 struct usb_dynid *dynid, *n;
195 spin_lock(&usb_drv->dynids.lock);
196 list_for_each_entry_safe(dynid, n, &usb_drv->dynids.list, node) {
197 list_del(&dynid->node);
200 spin_unlock(&usb_drv->dynids.lock);
203 static inline int usb_create_newid_files(struct usb_driver *usb_drv)
208 static void usb_remove_newid_files(struct usb_driver *usb_drv)
212 static inline void usb_free_dynids(struct usb_driver *usb_drv)
217 static const struct usb_device_id *usb_match_dynamic_id(struct usb_interface *intf,
218 struct usb_driver *drv)
220 struct usb_dynid *dynid;
222 spin_lock(&drv->dynids.lock);
223 list_for_each_entry(dynid, &drv->dynids.list, node) {
224 if (usb_match_one_id(intf, &dynid->id)) {
225 spin_unlock(&drv->dynids.lock);
229 spin_unlock(&drv->dynids.lock);
234 /* called from driver core with dev locked */
235 static int usb_probe_device(struct device *dev)
237 struct usb_device_driver *udriver = to_usb_device_driver(dev->driver);
238 struct usb_device *udev = to_usb_device(dev);
241 dev_dbg(dev, "%s\n", __func__);
243 /* TODO: Add real matching code */
245 /* The device should always appear to be in use
246 * unless the driver suports autosuspend.
248 if (!udriver->supports_autosuspend)
249 error = usb_autoresume_device(udev);
252 error = udriver->probe(udev);
256 /* called from driver core with dev locked */
257 static int usb_unbind_device(struct device *dev)
259 struct usb_device *udev = to_usb_device(dev);
260 struct usb_device_driver *udriver = to_usb_device_driver(dev->driver);
262 udriver->disconnect(udev);
263 if (!udriver->supports_autosuspend)
264 usb_autosuspend_device(udev);
269 * Cancel any pending scheduled resets
271 * [see usb_queue_reset_device()]
273 * Called after unconfiguring / when releasing interfaces. See
274 * comments in __usb_queue_reset_device() regarding
275 * udev->reset_running.
277 static void usb_cancel_queued_reset(struct usb_interface *iface)
279 if (iface->reset_running == 0)
280 cancel_work_sync(&iface->reset_ws);
283 /* called from driver core with dev locked */
284 static int usb_probe_interface(struct device *dev)
286 struct usb_driver *driver = to_usb_driver(dev->driver);
287 struct usb_interface *intf = to_usb_interface(dev);
288 struct usb_device *udev = interface_to_usbdev(intf);
289 const struct usb_device_id *id;
291 int lpm_disable_error;
293 dev_dbg(dev, "%s\n", __func__);
295 intf->needs_binding = 0;
297 if (usb_device_is_owned(udev))
300 if (udev->authorized == 0) {
301 dev_err(&intf->dev, "Device is not authorized for usage\n");
305 id = usb_match_id(intf, driver->id_table);
307 id = usb_match_dynamic_id(intf, driver);
311 dev_dbg(dev, "%s - got id\n", __func__);
313 error = usb_autoresume_device(udev);
317 intf->condition = USB_INTERFACE_BINDING;
319 /* Probed interfaces are initially active. They are
320 * runtime-PM-enabled only if the driver has autosuspend support.
321 * They are sensitive to their children's power states.
323 pm_runtime_set_active(dev);
324 pm_suspend_ignore_children(dev, false);
325 if (driver->supports_autosuspend)
326 pm_runtime_enable(dev);
328 /* If the new driver doesn't allow hub-initiated LPM, and we can't
329 * disable hub-initiated LPM, then fail the probe.
331 * Otherwise, leaving LPM enabled should be harmless, because the
332 * endpoint intervals should remain the same, and the U1/U2 timeouts
333 * should remain the same.
335 * If we need to install alt setting 0 before probe, or another alt
336 * setting during probe, that should also be fine. usb_set_interface()
337 * will attempt to disable LPM, and fail if it can't disable it.
339 lpm_disable_error = usb_unlocked_disable_lpm(udev);
340 if (lpm_disable_error && driver->disable_hub_initiated_lpm) {
341 dev_err(&intf->dev, "%s Failed to disable LPM for driver %s\n.",
342 __func__, driver->name);
343 error = lpm_disable_error;
347 /* Carry out a deferred switch to altsetting 0 */
348 if (intf->needs_altsetting0) {
349 error = usb_set_interface(udev, intf->altsetting[0].
350 desc.bInterfaceNumber, 0);
353 intf->needs_altsetting0 = 0;
356 error = driver->probe(intf, id);
360 intf->condition = USB_INTERFACE_BOUND;
362 /* If the LPM disable succeeded, balance the ref counts. */
363 if (!lpm_disable_error)
364 usb_unlocked_enable_lpm(udev);
366 usb_autosuspend_device(udev);
370 intf->needs_remote_wakeup = 0;
371 intf->condition = USB_INTERFACE_UNBOUND;
372 usb_cancel_queued_reset(intf);
374 /* Unbound interfaces are always runtime-PM-disabled and -suspended */
375 if (driver->supports_autosuspend)
376 pm_runtime_disable(dev);
377 pm_runtime_set_suspended(dev);
379 usb_autosuspend_device(udev);
383 /* called from driver core with dev locked */
384 static int usb_unbind_interface(struct device *dev)
386 struct usb_driver *driver = to_usb_driver(dev->driver);
387 struct usb_interface *intf = to_usb_interface(dev);
388 struct usb_device *udev;
389 int error, r, lpm_disable_error;
391 intf->condition = USB_INTERFACE_UNBINDING;
393 /* Autoresume for set_interface call below */
394 udev = interface_to_usbdev(intf);
395 error = usb_autoresume_device(udev);
397 /* Hub-initiated LPM policy may change, so attempt to disable LPM until
398 * the driver is unbound. If LPM isn't disabled, that's fine because it
399 * wouldn't be enabled unless all the bound interfaces supported
402 lpm_disable_error = usb_unlocked_disable_lpm(udev);
404 /* Terminate all URBs for this interface unless the driver
405 * supports "soft" unbinding.
407 if (!driver->soft_unbind)
408 usb_disable_interface(udev, intf, false);
410 driver->disconnect(intf);
411 usb_cancel_queued_reset(intf);
413 /* Reset other interface state.
414 * We cannot do a Set-Interface if the device is suspended or
415 * if it is prepared for a system sleep (since installing a new
416 * altsetting means creating new endpoint device entries).
417 * When either of these happens, defer the Set-Interface.
419 if (intf->cur_altsetting->desc.bAlternateSetting == 0) {
420 /* Already in altsetting 0 so skip Set-Interface.
421 * Just re-enable it without affecting the endpoint toggles.
423 usb_enable_interface(udev, intf, false);
424 } else if (!error && !intf->dev.power.is_prepared) {
425 r = usb_set_interface(udev, intf->altsetting[0].
426 desc.bInterfaceNumber, 0);
428 intf->needs_altsetting0 = 1;
430 intf->needs_altsetting0 = 1;
432 usb_set_intfdata(intf, NULL);
434 intf->condition = USB_INTERFACE_UNBOUND;
435 intf->needs_remote_wakeup = 0;
437 /* Attempt to re-enable USB3 LPM, if the disable succeeded. */
438 if (!lpm_disable_error)
439 usb_unlocked_enable_lpm(udev);
441 /* Unbound interfaces are always runtime-PM-disabled and -suspended */
442 if (driver->supports_autosuspend)
443 pm_runtime_disable(dev);
444 pm_runtime_set_suspended(dev);
446 /* Undo any residual pm_autopm_get_interface_* calls */
447 for (r = atomic_read(&intf->pm_usage_cnt); r > 0; --r)
448 usb_autopm_put_interface_no_suspend(intf);
449 atomic_set(&intf->pm_usage_cnt, 0);
452 usb_autosuspend_device(udev);
458 * usb_driver_claim_interface - bind a driver to an interface
459 * @driver: the driver to be bound
460 * @iface: the interface to which it will be bound; must be in the
461 * usb device's active configuration
462 * @priv: driver data associated with that interface
464 * This is used by usb device drivers that need to claim more than one
465 * interface on a device when probing (audio and acm are current examples).
466 * No device driver should directly modify internal usb_interface or
467 * usb_device structure members.
469 * Few drivers should need to use this routine, since the most natural
470 * way to bind to an interface is to return the private data from
471 * the driver's probe() method.
473 * Callers must own the device lock, so driver probe() entries don't need
474 * extra locking, but other call contexts may need to explicitly claim that
477 int usb_driver_claim_interface(struct usb_driver *driver,
478 struct usb_interface *iface, void *priv)
480 struct device *dev = &iface->dev;
481 struct usb_device *udev;
483 int lpm_disable_error;
488 udev = interface_to_usbdev(iface);
490 dev->driver = &driver->drvwrap.driver;
491 usb_set_intfdata(iface, priv);
492 iface->needs_binding = 0;
494 iface->condition = USB_INTERFACE_BOUND;
496 /* Disable LPM until this driver is bound. */
497 lpm_disable_error = usb_unlocked_disable_lpm(udev);
498 if (lpm_disable_error && driver->disable_hub_initiated_lpm) {
499 dev_err(&iface->dev, "%s Failed to disable LPM for driver %s\n.",
500 __func__, driver->name);
504 /* Claimed interfaces are initially inactive (suspended) and
505 * runtime-PM-enabled, but only if the driver has autosuspend
506 * support. Otherwise they are marked active, to prevent the
507 * device from being autosuspended, but left disabled. In either
508 * case they are sensitive to their children's power states.
510 pm_suspend_ignore_children(dev, false);
511 if (driver->supports_autosuspend)
512 pm_runtime_enable(dev);
514 pm_runtime_set_active(dev);
516 /* if interface was already added, bind now; else let
517 * the future device_add() bind it, bypassing probe()
519 if (device_is_registered(dev))
520 retval = device_bind_driver(dev);
522 /* Attempt to re-enable USB3 LPM, if the disable was successful. */
523 if (!lpm_disable_error)
524 usb_unlocked_enable_lpm(udev);
528 EXPORT_SYMBOL_GPL(usb_driver_claim_interface);
531 * usb_driver_release_interface - unbind a driver from an interface
532 * @driver: the driver to be unbound
533 * @iface: the interface from which it will be unbound
535 * This can be used by drivers to release an interface without waiting
536 * for their disconnect() methods to be called. In typical cases this
537 * also causes the driver disconnect() method to be called.
539 * This call is synchronous, and may not be used in an interrupt context.
540 * Callers must own the device lock, so driver disconnect() entries don't
541 * need extra locking, but other call contexts may need to explicitly claim
544 void usb_driver_release_interface(struct usb_driver *driver,
545 struct usb_interface *iface)
547 struct device *dev = &iface->dev;
549 /* this should never happen, don't release something that's not ours */
550 if (!dev->driver || dev->driver != &driver->drvwrap.driver)
553 /* don't release from within disconnect() */
554 if (iface->condition != USB_INTERFACE_BOUND)
556 iface->condition = USB_INTERFACE_UNBINDING;
558 /* Release via the driver core only if the interface
559 * has already been registered
561 if (device_is_registered(dev)) {
562 device_release_driver(dev);
565 usb_unbind_interface(dev);
570 EXPORT_SYMBOL_GPL(usb_driver_release_interface);
572 /* returns 0 if no match, 1 if match */
573 int usb_match_device(struct usb_device *dev, const struct usb_device_id *id)
575 if ((id->match_flags & USB_DEVICE_ID_MATCH_VENDOR) &&
576 id->idVendor != le16_to_cpu(dev->descriptor.idVendor))
579 if ((id->match_flags & USB_DEVICE_ID_MATCH_PRODUCT) &&
580 id->idProduct != le16_to_cpu(dev->descriptor.idProduct))
583 /* No need to test id->bcdDevice_lo != 0, since 0 is never
584 greater than any unsigned number. */
585 if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_LO) &&
586 (id->bcdDevice_lo > le16_to_cpu(dev->descriptor.bcdDevice)))
589 if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_HI) &&
590 (id->bcdDevice_hi < le16_to_cpu(dev->descriptor.bcdDevice)))
593 if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_CLASS) &&
594 (id->bDeviceClass != dev->descriptor.bDeviceClass))
597 if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_SUBCLASS) &&
598 (id->bDeviceSubClass != dev->descriptor.bDeviceSubClass))
601 if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_PROTOCOL) &&
602 (id->bDeviceProtocol != dev->descriptor.bDeviceProtocol))
608 /* returns 0 if no match, 1 if match */
609 int usb_match_one_id(struct usb_interface *interface,
610 const struct usb_device_id *id)
612 struct usb_host_interface *intf;
613 struct usb_device *dev;
615 /* proc_connectinfo in devio.c may call us with id == NULL. */
619 intf = interface->cur_altsetting;
620 dev = interface_to_usbdev(interface);
622 if (!usb_match_device(dev, id))
625 /* The interface class, subclass, and protocol should never be
626 * checked for a match if the device class is Vendor Specific,
627 * unless the match record specifies the Vendor ID. */
628 if (dev->descriptor.bDeviceClass == USB_CLASS_VENDOR_SPEC &&
629 !(id->match_flags & USB_DEVICE_ID_MATCH_VENDOR) &&
630 (id->match_flags & (USB_DEVICE_ID_MATCH_INT_CLASS |
631 USB_DEVICE_ID_MATCH_INT_SUBCLASS |
632 USB_DEVICE_ID_MATCH_INT_PROTOCOL)))
635 if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_CLASS) &&
636 (id->bInterfaceClass != intf->desc.bInterfaceClass))
639 if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_SUBCLASS) &&
640 (id->bInterfaceSubClass != intf->desc.bInterfaceSubClass))
643 if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_PROTOCOL) &&
644 (id->bInterfaceProtocol != intf->desc.bInterfaceProtocol))
649 EXPORT_SYMBOL_GPL(usb_match_one_id);
652 * usb_match_id - find first usb_device_id matching device or interface
653 * @interface: the interface of interest
654 * @id: array of usb_device_id structures, terminated by zero entry
656 * usb_match_id searches an array of usb_device_id's and returns
657 * the first one matching the device or interface, or null.
658 * This is used when binding (or rebinding) a driver to an interface.
659 * Most USB device drivers will use this indirectly, through the usb core,
660 * but some layered driver frameworks use it directly.
661 * These device tables are exported with MODULE_DEVICE_TABLE, through
662 * modutils, to support the driver loading functionality of USB hotplugging.
666 * The "match_flags" element in a usb_device_id controls which
667 * members are used. If the corresponding bit is set, the
668 * value in the device_id must match its corresponding member
669 * in the device or interface descriptor, or else the device_id
672 * "driver_info" is normally used only by device drivers,
673 * but you can create a wildcard "matches anything" usb_device_id
674 * as a driver's "modules.usbmap" entry if you provide an id with
675 * only a nonzero "driver_info" field. If you do this, the USB device
676 * driver's probe() routine should use additional intelligence to
677 * decide whether to bind to the specified interface.
679 * What Makes Good usb_device_id Tables:
681 * The match algorithm is very simple, so that intelligence in
682 * driver selection must come from smart driver id records.
683 * Unless you have good reasons to use another selection policy,
684 * provide match elements only in related groups, and order match
685 * specifiers from specific to general. Use the macros provided
686 * for that purpose if you can.
688 * The most specific match specifiers use device descriptor
689 * data. These are commonly used with product-specific matches;
690 * the USB_DEVICE macro lets you provide vendor and product IDs,
691 * and you can also match against ranges of product revisions.
692 * These are widely used for devices with application or vendor
693 * specific bDeviceClass values.
695 * Matches based on device class/subclass/protocol specifications
696 * are slightly more general; use the USB_DEVICE_INFO macro, or
697 * its siblings. These are used with single-function devices
698 * where bDeviceClass doesn't specify that each interface has
701 * Matches based on interface class/subclass/protocol are the
702 * most general; they let drivers bind to any interface on a
703 * multiple-function device. Use the USB_INTERFACE_INFO
704 * macro, or its siblings, to match class-per-interface style
705 * devices (as recorded in bInterfaceClass).
707 * Note that an entry created by USB_INTERFACE_INFO won't match
708 * any interface if the device class is set to Vendor-Specific.
709 * This is deliberate; according to the USB spec the meanings of
710 * the interface class/subclass/protocol for these devices are also
711 * vendor-specific, and hence matching against a standard product
712 * class wouldn't work anyway. If you really want to use an
713 * interface-based match for such a device, create a match record
714 * that also specifies the vendor ID. (Unforunately there isn't a
715 * standard macro for creating records like this.)
717 * Within those groups, remember that not all combinations are
718 * meaningful. For example, don't give a product version range
719 * without vendor and product IDs; or specify a protocol without
720 * its associated class and subclass.
722 const struct usb_device_id *usb_match_id(struct usb_interface *interface,
723 const struct usb_device_id *id)
725 /* proc_connectinfo in devio.c may call us with id == NULL. */
729 /* It is important to check that id->driver_info is nonzero,
730 since an entry that is all zeroes except for a nonzero
731 id->driver_info is the way to create an entry that
732 indicates that the driver want to examine every
733 device and interface. */
734 for (; id->idVendor || id->idProduct || id->bDeviceClass ||
735 id->bInterfaceClass || id->driver_info; id++) {
736 if (usb_match_one_id(interface, id))
742 EXPORT_SYMBOL_GPL(usb_match_id);
744 static int usb_device_match(struct device *dev, struct device_driver *drv)
746 /* devices and interfaces are handled separately */
747 if (is_usb_device(dev)) {
749 /* interface drivers never match devices */
750 if (!is_usb_device_driver(drv))
753 /* TODO: Add real matching code */
756 } else if (is_usb_interface(dev)) {
757 struct usb_interface *intf;
758 struct usb_driver *usb_drv;
759 const struct usb_device_id *id;
761 /* device drivers never match interfaces */
762 if (is_usb_device_driver(drv))
765 intf = to_usb_interface(dev);
766 usb_drv = to_usb_driver(drv);
768 id = usb_match_id(intf, usb_drv->id_table);
772 id = usb_match_dynamic_id(intf, usb_drv);
780 #ifdef CONFIG_HOTPLUG
781 static int usb_uevent(struct device *dev, struct kobj_uevent_env *env)
783 struct usb_device *usb_dev;
785 if (is_usb_device(dev)) {
786 usb_dev = to_usb_device(dev);
787 } else if (is_usb_interface(dev)) {
788 struct usb_interface *intf = to_usb_interface(dev);
790 usb_dev = interface_to_usbdev(intf);
795 if (usb_dev->devnum < 0) {
796 /* driver is often null here; dev_dbg() would oops */
797 pr_debug("usb %s: already deleted?\n", dev_name(dev));
801 pr_debug("usb %s: bus removed?\n", dev_name(dev));
805 /* per-device configurations are common */
806 if (add_uevent_var(env, "PRODUCT=%x/%x/%x",
807 le16_to_cpu(usb_dev->descriptor.idVendor),
808 le16_to_cpu(usb_dev->descriptor.idProduct),
809 le16_to_cpu(usb_dev->descriptor.bcdDevice)))
812 /* class-based driver binding models */
813 if (add_uevent_var(env, "TYPE=%d/%d/%d",
814 usb_dev->descriptor.bDeviceClass,
815 usb_dev->descriptor.bDeviceSubClass,
816 usb_dev->descriptor.bDeviceProtocol))
824 static int usb_uevent(struct device *dev, struct kobj_uevent_env *env)
828 #endif /* CONFIG_HOTPLUG */
831 * usb_register_device_driver - register a USB device (not interface) driver
832 * @new_udriver: USB operations for the device driver
833 * @owner: module owner of this driver.
835 * Registers a USB device driver with the USB core. The list of
836 * unattached devices will be rescanned whenever a new driver is
837 * added, allowing the new driver to attach to any recognized devices.
838 * Returns a negative error code on failure and 0 on success.
840 int usb_register_device_driver(struct usb_device_driver *new_udriver,
841 struct module *owner)
848 new_udriver->drvwrap.for_devices = 1;
849 new_udriver->drvwrap.driver.name = (char *) new_udriver->name;
850 new_udriver->drvwrap.driver.bus = &usb_bus_type;
851 new_udriver->drvwrap.driver.probe = usb_probe_device;
852 new_udriver->drvwrap.driver.remove = usb_unbind_device;
853 new_udriver->drvwrap.driver.owner = owner;
855 retval = driver_register(&new_udriver->drvwrap.driver);
858 pr_info("%s: registered new device driver %s\n",
859 usbcore_name, new_udriver->name);
861 printk(KERN_ERR "%s: error %d registering device "
863 usbcore_name, retval, new_udriver->name);
867 EXPORT_SYMBOL_GPL(usb_register_device_driver);
870 * usb_deregister_device_driver - unregister a USB device (not interface) driver
871 * @udriver: USB operations of the device driver to unregister
872 * Context: must be able to sleep
874 * Unlinks the specified driver from the internal USB driver list.
876 void usb_deregister_device_driver(struct usb_device_driver *udriver)
878 pr_info("%s: deregistering device driver %s\n",
879 usbcore_name, udriver->name);
881 driver_unregister(&udriver->drvwrap.driver);
883 EXPORT_SYMBOL_GPL(usb_deregister_device_driver);
886 * usb_register_driver - register a USB interface driver
887 * @new_driver: USB operations for the interface driver
888 * @owner: module owner of this driver.
889 * @mod_name: module name string
891 * Registers a USB interface driver with the USB core. The list of
892 * unattached interfaces will be rescanned whenever a new driver is
893 * added, allowing the new driver to attach to any recognized interfaces.
894 * Returns a negative error code on failure and 0 on success.
896 * NOTE: if you want your driver to use the USB major number, you must call
897 * usb_register_dev() to enable that functionality. This function no longer
898 * takes care of that.
900 int usb_register_driver(struct usb_driver *new_driver, struct module *owner,
901 const char *mod_name)
908 new_driver->drvwrap.for_devices = 0;
909 new_driver->drvwrap.driver.name = (char *) new_driver->name;
910 new_driver->drvwrap.driver.bus = &usb_bus_type;
911 new_driver->drvwrap.driver.probe = usb_probe_interface;
912 new_driver->drvwrap.driver.remove = usb_unbind_interface;
913 new_driver->drvwrap.driver.owner = owner;
914 new_driver->drvwrap.driver.mod_name = mod_name;
915 spin_lock_init(&new_driver->dynids.lock);
916 INIT_LIST_HEAD(&new_driver->dynids.list);
918 retval = driver_register(&new_driver->drvwrap.driver);
922 retval = usb_create_newid_files(new_driver);
926 pr_info("%s: registered new interface driver %s\n",
927 usbcore_name, new_driver->name);
933 driver_unregister(&new_driver->drvwrap.driver);
935 printk(KERN_ERR "%s: error %d registering interface "
937 usbcore_name, retval, new_driver->name);
940 EXPORT_SYMBOL_GPL(usb_register_driver);
943 * usb_deregister - unregister a USB interface driver
944 * @driver: USB operations of the interface driver to unregister
945 * Context: must be able to sleep
947 * Unlinks the specified driver from the internal USB driver list.
949 * NOTE: If you called usb_register_dev(), you still need to call
950 * usb_deregister_dev() to clean up your driver's allocated minor numbers,
951 * this * call will no longer do it for you.
953 void usb_deregister(struct usb_driver *driver)
955 pr_info("%s: deregistering interface driver %s\n",
956 usbcore_name, driver->name);
958 usb_remove_newid_files(driver);
959 driver_unregister(&driver->drvwrap.driver);
960 usb_free_dynids(driver);
962 EXPORT_SYMBOL_GPL(usb_deregister);
964 /* Forced unbinding of a USB interface driver, either because
965 * it doesn't support pre_reset/post_reset/reset_resume or
966 * because it doesn't support suspend/resume.
968 * The caller must hold @intf's device's lock, but not its pm_mutex
969 * and not @intf->dev.sem.
971 void usb_forced_unbind_intf(struct usb_interface *intf)
973 struct usb_driver *driver = to_usb_driver(intf->dev.driver);
975 dev_dbg(&intf->dev, "forced unbind\n");
976 usb_driver_release_interface(driver, intf);
978 /* Mark the interface for later rebinding */
979 intf->needs_binding = 1;
982 /* Delayed forced unbinding of a USB interface driver and scan
985 * The caller must hold @intf's device's lock, but not its pm_mutex
986 * and not @intf->dev.sem.
988 * Note: Rebinds will be skipped if a system sleep transition is in
989 * progress and the PM "complete" callback hasn't occurred yet.
991 void usb_rebind_intf(struct usb_interface *intf)
995 /* Delayed unbind of an existing driver */
996 if (intf->dev.driver)
997 usb_forced_unbind_intf(intf);
999 /* Try to rebind the interface */
1000 if (!intf->dev.power.is_prepared) {
1001 intf->needs_binding = 0;
1002 rc = device_attach(&intf->dev);
1004 dev_warn(&intf->dev, "rebind failed: %d\n", rc);
1010 /* Unbind drivers for @udev's interfaces that don't support suspend/resume
1011 * There is no check for reset_resume here because it can be determined
1012 * only during resume whether reset_resume is needed.
1014 * The caller must hold @udev's device lock.
1016 static void unbind_no_pm_drivers_interfaces(struct usb_device *udev)
1018 struct usb_host_config *config;
1020 struct usb_interface *intf;
1021 struct usb_driver *drv;
1023 config = udev->actconfig;
1025 for (i = 0; i < config->desc.bNumInterfaces; ++i) {
1026 intf = config->interface[i];
1028 if (intf->dev.driver) {
1029 drv = to_usb_driver(intf->dev.driver);
1030 if (!drv->suspend || !drv->resume)
1031 usb_forced_unbind_intf(intf);
1037 /* Unbind drivers for @udev's interfaces that failed to support reset-resume.
1038 * These interfaces have the needs_binding flag set by usb_resume_interface().
1040 * The caller must hold @udev's device lock.
1042 static void unbind_no_reset_resume_drivers_interfaces(struct usb_device *udev)
1044 struct usb_host_config *config;
1046 struct usb_interface *intf;
1048 config = udev->actconfig;
1050 for (i = 0; i < config->desc.bNumInterfaces; ++i) {
1051 intf = config->interface[i];
1052 if (intf->dev.driver && intf->needs_binding)
1053 usb_forced_unbind_intf(intf);
1058 static void do_rebind_interfaces(struct usb_device *udev)
1060 struct usb_host_config *config;
1062 struct usb_interface *intf;
1064 config = udev->actconfig;
1066 for (i = 0; i < config->desc.bNumInterfaces; ++i) {
1067 intf = config->interface[i];
1068 if (intf->needs_binding)
1069 usb_rebind_intf(intf);
1074 static int usb_suspend_device(struct usb_device *udev, pm_message_t msg)
1076 struct usb_device_driver *udriver;
1079 if (udev->state == USB_STATE_NOTATTACHED ||
1080 udev->state == USB_STATE_SUSPENDED)
1083 /* For devices that don't have a driver, we do a generic suspend. */
1084 if (udev->dev.driver)
1085 udriver = to_usb_device_driver(udev->dev.driver);
1087 udev->do_remote_wakeup = 0;
1088 udriver = &usb_generic_driver;
1090 status = udriver->suspend(udev, msg);
1093 dev_vdbg(&udev->dev, "%s: status %d\n", __func__, status);
1097 static int usb_resume_device(struct usb_device *udev, pm_message_t msg)
1099 struct usb_device_driver *udriver;
1102 if (udev->state == USB_STATE_NOTATTACHED)
1105 /* Can't resume it if it doesn't have a driver. */
1106 if (udev->dev.driver == NULL) {
1111 /* Non-root devices on a full/low-speed bus must wait for their
1112 * companion high-speed root hub, in case a handoff is needed.
1114 if (!PMSG_IS_AUTO(msg) && udev->parent && udev->bus->hs_companion)
1115 device_pm_wait_for_dev(&udev->dev,
1116 &udev->bus->hs_companion->root_hub->dev);
1118 if (udev->quirks & USB_QUIRK_RESET_RESUME)
1119 udev->reset_resume = 1;
1121 udriver = to_usb_device_driver(udev->dev.driver);
1122 status = udriver->resume(udev, msg);
1125 dev_vdbg(&udev->dev, "%s: status %d\n", __func__, status);
1129 static int usb_suspend_interface(struct usb_device *udev,
1130 struct usb_interface *intf, pm_message_t msg)
1132 struct usb_driver *driver;
1135 if (udev->state == USB_STATE_NOTATTACHED ||
1136 intf->condition == USB_INTERFACE_UNBOUND)
1138 driver = to_usb_driver(intf->dev.driver);
1140 /* at this time we know the driver supports suspend */
1141 status = driver->suspend(intf, msg);
1142 if (status && !PMSG_IS_AUTO(msg))
1143 dev_err(&intf->dev, "suspend error %d\n", status);
1146 dev_vdbg(&intf->dev, "%s: status %d\n", __func__, status);
1150 static int usb_resume_interface(struct usb_device *udev,
1151 struct usb_interface *intf, pm_message_t msg, int reset_resume)
1153 struct usb_driver *driver;
1156 if (udev->state == USB_STATE_NOTATTACHED)
1159 /* Don't let autoresume interfere with unbinding */
1160 if (intf->condition == USB_INTERFACE_UNBINDING)
1163 /* Can't resume it if it doesn't have a driver. */
1164 if (intf->condition == USB_INTERFACE_UNBOUND) {
1166 /* Carry out a deferred switch to altsetting 0 */
1167 if (intf->needs_altsetting0 && !intf->dev.power.is_prepared) {
1168 usb_set_interface(udev, intf->altsetting[0].
1169 desc.bInterfaceNumber, 0);
1170 intf->needs_altsetting0 = 0;
1175 /* Don't resume if the interface is marked for rebinding */
1176 if (intf->needs_binding)
1178 driver = to_usb_driver(intf->dev.driver);
1181 if (driver->reset_resume) {
1182 status = driver->reset_resume(intf);
1184 dev_err(&intf->dev, "%s error %d\n",
1185 "reset_resume", status);
1187 intf->needs_binding = 1;
1188 dev_warn(&intf->dev, "no %s for driver %s?\n",
1189 "reset_resume", driver->name);
1192 status = driver->resume(intf);
1194 dev_err(&intf->dev, "resume error %d\n", status);
1198 dev_vdbg(&intf->dev, "%s: status %d\n", __func__, status);
1200 /* Later we will unbind the driver and/or reprobe, if necessary */
1205 * usb_suspend_both - suspend a USB device and its interfaces
1206 * @udev: the usb_device to suspend
1207 * @msg: Power Management message describing this state transition
1209 * This is the central routine for suspending USB devices. It calls the
1210 * suspend methods for all the interface drivers in @udev and then calls
1211 * the suspend method for @udev itself. If an error occurs at any stage,
1212 * all the interfaces which were suspended are resumed so that they remain
1213 * in the same state as the device.
1215 * Autosuspend requests originating from a child device or an interface
1216 * driver may be made without the protection of @udev's device lock, but
1217 * all other suspend calls will hold the lock. Usbcore will insure that
1218 * method calls do not arrive during bind, unbind, or reset operations.
1219 * However drivers must be prepared to handle suspend calls arriving at
1220 * unpredictable times.
1222 * This routine can run only in process context.
1224 static int usb_suspend_both(struct usb_device *udev, pm_message_t msg)
1228 struct usb_interface *intf;
1230 if (udev->state == USB_STATE_NOTATTACHED ||
1231 udev->state == USB_STATE_SUSPENDED)
1234 /* Suspend all the interfaces and then udev itself */
1235 if (udev->actconfig) {
1236 n = udev->actconfig->desc.bNumInterfaces;
1237 for (i = n - 1; i >= 0; --i) {
1238 intf = udev->actconfig->interface[i];
1239 status = usb_suspend_interface(udev, intf, msg);
1241 /* Ignore errors during system sleep transitions */
1242 if (!PMSG_IS_AUTO(msg))
1249 status = usb_suspend_device(udev, msg);
1252 * Ignore errors from non-root-hub devices during
1253 * system sleep transitions. For the most part,
1254 * these devices should go to low power anyway when
1255 * the entire bus is suspended.
1257 if (udev->parent && !PMSG_IS_AUTO(msg))
1261 /* If the suspend failed, resume interfaces that did get suspended */
1263 msg.event ^= (PM_EVENT_SUSPEND | PM_EVENT_RESUME);
1265 intf = udev->actconfig->interface[i];
1266 usb_resume_interface(udev, intf, msg, 0);
1269 /* If the suspend succeeded then prevent any more URB submissions
1270 * and flush any outstanding URBs.
1273 udev->can_submit = 0;
1274 for (i = 0; i < 16; ++i) {
1275 usb_hcd_flush_endpoint(udev, udev->ep_out[i]);
1276 usb_hcd_flush_endpoint(udev, udev->ep_in[i]);
1281 dev_vdbg(&udev->dev, "%s: status %d\n", __func__, status);
1286 * usb_resume_both - resume a USB device and its interfaces
1287 * @udev: the usb_device to resume
1288 * @msg: Power Management message describing this state transition
1290 * This is the central routine for resuming USB devices. It calls the
1291 * the resume method for @udev and then calls the resume methods for all
1292 * the interface drivers in @udev.
1294 * Autoresume requests originating from a child device or an interface
1295 * driver may be made without the protection of @udev's device lock, but
1296 * all other resume calls will hold the lock. Usbcore will insure that
1297 * method calls do not arrive during bind, unbind, or reset operations.
1298 * However drivers must be prepared to handle resume calls arriving at
1299 * unpredictable times.
1301 * This routine can run only in process context.
1303 static int usb_resume_both(struct usb_device *udev, pm_message_t msg)
1307 struct usb_interface *intf;
1309 if (udev->state == USB_STATE_NOTATTACHED) {
1313 udev->can_submit = 1;
1315 /* Resume the device */
1316 if (udev->state == USB_STATE_SUSPENDED || udev->reset_resume)
1317 status = usb_resume_device(udev, msg);
1319 /* Resume the interfaces */
1320 if (status == 0 && udev->actconfig) {
1321 for (i = 0; i < udev->actconfig->desc.bNumInterfaces; i++) {
1322 intf = udev->actconfig->interface[i];
1323 usb_resume_interface(udev, intf, msg,
1324 udev->reset_resume);
1327 usb_mark_last_busy(udev);
1330 dev_vdbg(&udev->dev, "%s: status %d\n", __func__, status);
1332 udev->reset_resume = 0;
1336 static void choose_wakeup(struct usb_device *udev, pm_message_t msg)
1340 /* Remote wakeup is needed only when we actually go to sleep.
1341 * For things like FREEZE and QUIESCE, if the device is already
1342 * autosuspended then its current wakeup setting is okay.
1344 if (msg.event == PM_EVENT_FREEZE || msg.event == PM_EVENT_QUIESCE) {
1345 if (udev->state != USB_STATE_SUSPENDED)
1346 udev->do_remote_wakeup = 0;
1350 /* Enable remote wakeup if it is allowed, even if no interface drivers
1353 w = device_may_wakeup(&udev->dev);
1355 /* If the device is autosuspended with the wrong wakeup setting,
1356 * autoresume now so the setting can be changed.
1358 if (udev->state == USB_STATE_SUSPENDED && w != udev->do_remote_wakeup)
1359 pm_runtime_resume(&udev->dev);
1360 udev->do_remote_wakeup = w;
1363 /* The device lock is held by the PM core */
1364 int usb_suspend(struct device *dev, pm_message_t msg)
1366 struct usb_device *udev = to_usb_device(dev);
1368 unbind_no_pm_drivers_interfaces(udev);
1370 /* From now on we are sure all drivers support suspend/resume
1371 * but not necessarily reset_resume()
1372 * so we may still need to unbind and rebind upon resume
1374 choose_wakeup(udev, msg);
1375 return usb_suspend_both(udev, msg);
1378 /* The device lock is held by the PM core */
1379 int usb_resume_complete(struct device *dev)
1381 struct usb_device *udev = to_usb_device(dev);
1383 /* For PM complete calls, all we do is rebind interfaces
1384 * whose needs_binding flag is set
1386 if (udev->state != USB_STATE_NOTATTACHED)
1387 do_rebind_interfaces(udev);
1391 /* The device lock is held by the PM core */
1392 int usb_resume(struct device *dev, pm_message_t msg)
1394 struct usb_device *udev = to_usb_device(dev);
1397 /* For all calls, take the device back to full power and
1398 * tell the PM core in case it was autosuspended previously.
1399 * Unbind the interfaces that will need rebinding later,
1400 * because they fail to support reset_resume.
1401 * (This can't be done in usb_resume_interface()
1402 * above because it doesn't own the right set of locks.)
1404 status = usb_resume_both(udev, msg);
1406 pm_runtime_disable(dev);
1407 pm_runtime_set_active(dev);
1408 pm_runtime_enable(dev);
1409 unbind_no_reset_resume_drivers_interfaces(udev);
1412 /* Avoid PM error messages for devices disconnected while suspended
1413 * as we'll display regular disconnect messages just a bit later.
1415 if (status == -ENODEV || status == -ESHUTDOWN)
1420 #endif /* CONFIG_PM */
1422 #ifdef CONFIG_USB_SUSPEND
1425 * usb_enable_autosuspend - allow a USB device to be autosuspended
1426 * @udev: the USB device which may be autosuspended
1428 * This routine allows @udev to be autosuspended. An autosuspend won't
1429 * take place until the autosuspend_delay has elapsed and all the other
1430 * necessary conditions are satisfied.
1432 * The caller must hold @udev's device lock.
1434 void usb_enable_autosuspend(struct usb_device *udev)
1436 pm_runtime_allow(&udev->dev);
1438 EXPORT_SYMBOL_GPL(usb_enable_autosuspend);
1441 * usb_disable_autosuspend - prevent a USB device from being autosuspended
1442 * @udev: the USB device which may not be autosuspended
1444 * This routine prevents @udev from being autosuspended and wakes it up
1445 * if it is already autosuspended.
1447 * The caller must hold @udev's device lock.
1449 void usb_disable_autosuspend(struct usb_device *udev)
1451 pm_runtime_forbid(&udev->dev);
1453 EXPORT_SYMBOL_GPL(usb_disable_autosuspend);
1456 * usb_autosuspend_device - delayed autosuspend of a USB device and its interfaces
1457 * @udev: the usb_device to autosuspend
1459 * This routine should be called when a core subsystem is finished using
1460 * @udev and wants to allow it to autosuspend. Examples would be when
1461 * @udev's device file in usbfs is closed or after a configuration change.
1463 * @udev's usage counter is decremented; if it drops to 0 and all the
1464 * interfaces are inactive then a delayed autosuspend will be attempted.
1465 * The attempt may fail (see autosuspend_check()).
1467 * The caller must hold @udev's device lock.
1469 * This routine can run only in process context.
1471 void usb_autosuspend_device(struct usb_device *udev)
1475 usb_mark_last_busy(udev);
1476 status = pm_runtime_put_sync_autosuspend(&udev->dev);
1477 dev_vdbg(&udev->dev, "%s: cnt %d -> %d\n",
1478 __func__, atomic_read(&udev->dev.power.usage_count),
1483 * usb_autoresume_device - immediately autoresume a USB device and its interfaces
1484 * @udev: the usb_device to autoresume
1486 * This routine should be called when a core subsystem wants to use @udev
1487 * and needs to guarantee that it is not suspended. No autosuspend will
1488 * occur until usb_autosuspend_device() is called. (Note that this will
1489 * not prevent suspend events originating in the PM core.) Examples would
1490 * be when @udev's device file in usbfs is opened or when a remote-wakeup
1491 * request is received.
1493 * @udev's usage counter is incremented to prevent subsequent autosuspends.
1494 * However if the autoresume fails then the usage counter is re-decremented.
1496 * The caller must hold @udev's device lock.
1498 * This routine can run only in process context.
1500 int usb_autoresume_device(struct usb_device *udev)
1504 status = pm_runtime_get_sync(&udev->dev);
1506 pm_runtime_put_sync(&udev->dev);
1507 dev_vdbg(&udev->dev, "%s: cnt %d -> %d\n",
1508 __func__, atomic_read(&udev->dev.power.usage_count),
1516 * usb_autopm_put_interface - decrement a USB interface's PM-usage counter
1517 * @intf: the usb_interface whose counter should be decremented
1519 * This routine should be called by an interface driver when it is
1520 * finished using @intf and wants to allow it to autosuspend. A typical
1521 * example would be a character-device driver when its device file is
1524 * The routine decrements @intf's usage counter. When the counter reaches
1525 * 0, a delayed autosuspend request for @intf's device is attempted. The
1526 * attempt may fail (see autosuspend_check()).
1528 * This routine can run only in process context.
1530 void usb_autopm_put_interface(struct usb_interface *intf)
1532 struct usb_device *udev = interface_to_usbdev(intf);
1535 usb_mark_last_busy(udev);
1536 atomic_dec(&intf->pm_usage_cnt);
1537 status = pm_runtime_put_sync(&intf->dev);
1538 dev_vdbg(&intf->dev, "%s: cnt %d -> %d\n",
1539 __func__, atomic_read(&intf->dev.power.usage_count),
1542 EXPORT_SYMBOL_GPL(usb_autopm_put_interface);
1545 * usb_autopm_put_interface_async - decrement a USB interface's PM-usage counter
1546 * @intf: the usb_interface whose counter should be decremented
1548 * This routine does much the same thing as usb_autopm_put_interface():
1549 * It decrements @intf's usage counter and schedules a delayed
1550 * autosuspend request if the counter is <= 0. The difference is that it
1551 * does not perform any synchronization; callers should hold a private
1552 * lock and handle all synchronization issues themselves.
1554 * Typically a driver would call this routine during an URB's completion
1555 * handler, if no more URBs were pending.
1557 * This routine can run in atomic context.
1559 void usb_autopm_put_interface_async(struct usb_interface *intf)
1561 struct usb_device *udev = interface_to_usbdev(intf);
1564 usb_mark_last_busy(udev);
1565 atomic_dec(&intf->pm_usage_cnt);
1566 status = pm_runtime_put(&intf->dev);
1567 dev_vdbg(&intf->dev, "%s: cnt %d -> %d\n",
1568 __func__, atomic_read(&intf->dev.power.usage_count),
1571 EXPORT_SYMBOL_GPL(usb_autopm_put_interface_async);
1574 * usb_autopm_put_interface_no_suspend - decrement a USB interface's PM-usage counter
1575 * @intf: the usb_interface whose counter should be decremented
1577 * This routine decrements @intf's usage counter but does not carry out an
1580 * This routine can run in atomic context.
1582 void usb_autopm_put_interface_no_suspend(struct usb_interface *intf)
1584 struct usb_device *udev = interface_to_usbdev(intf);
1586 usb_mark_last_busy(udev);
1587 atomic_dec(&intf->pm_usage_cnt);
1588 pm_runtime_put_noidle(&intf->dev);
1590 EXPORT_SYMBOL_GPL(usb_autopm_put_interface_no_suspend);
1593 * usb_autopm_get_interface - increment a USB interface's PM-usage counter
1594 * @intf: the usb_interface whose counter should be incremented
1596 * This routine should be called by an interface driver when it wants to
1597 * use @intf and needs to guarantee that it is not suspended. In addition,
1598 * the routine prevents @intf from being autosuspended subsequently. (Note
1599 * that this will not prevent suspend events originating in the PM core.)
1600 * This prevention will persist until usb_autopm_put_interface() is called
1601 * or @intf is unbound. A typical example would be a character-device
1602 * driver when its device file is opened.
1604 * @intf's usage counter is incremented to prevent subsequent autosuspends.
1605 * However if the autoresume fails then the counter is re-decremented.
1607 * This routine can run only in process context.
1609 int usb_autopm_get_interface(struct usb_interface *intf)
1613 status = pm_runtime_get_sync(&intf->dev);
1615 pm_runtime_put_sync(&intf->dev);
1617 atomic_inc(&intf->pm_usage_cnt);
1618 dev_vdbg(&intf->dev, "%s: cnt %d -> %d\n",
1619 __func__, atomic_read(&intf->dev.power.usage_count),
1625 EXPORT_SYMBOL_GPL(usb_autopm_get_interface);
1628 * usb_autopm_get_interface_async - increment a USB interface's PM-usage counter
1629 * @intf: the usb_interface whose counter should be incremented
1631 * This routine does much the same thing as
1632 * usb_autopm_get_interface(): It increments @intf's usage counter and
1633 * queues an autoresume request if the device is suspended. The
1634 * differences are that it does not perform any synchronization (callers
1635 * should hold a private lock and handle all synchronization issues
1636 * themselves), and it does not autoresume the device directly (it only
1637 * queues a request). After a successful call, the device may not yet be
1640 * This routine can run in atomic context.
1642 int usb_autopm_get_interface_async(struct usb_interface *intf)
1646 status = pm_runtime_get(&intf->dev);
1647 if (status < 0 && status != -EINPROGRESS)
1648 pm_runtime_put_noidle(&intf->dev);
1650 atomic_inc(&intf->pm_usage_cnt);
1651 dev_vdbg(&intf->dev, "%s: cnt %d -> %d\n",
1652 __func__, atomic_read(&intf->dev.power.usage_count),
1654 if (status > 0 || status == -EINPROGRESS)
1658 EXPORT_SYMBOL_GPL(usb_autopm_get_interface_async);
1661 * usb_autopm_get_interface_no_resume - increment a USB interface's PM-usage counter
1662 * @intf: the usb_interface whose counter should be incremented
1664 * This routine increments @intf's usage counter but does not carry out an
1667 * This routine can run in atomic context.
1669 void usb_autopm_get_interface_no_resume(struct usb_interface *intf)
1671 struct usb_device *udev = interface_to_usbdev(intf);
1673 usb_mark_last_busy(udev);
1674 atomic_inc(&intf->pm_usage_cnt);
1675 pm_runtime_get_noresume(&intf->dev);
1677 EXPORT_SYMBOL_GPL(usb_autopm_get_interface_no_resume);
1679 /* Internal routine to check whether we may autosuspend a device. */
1680 static int autosuspend_check(struct usb_device *udev)
1683 struct usb_interface *intf;
1685 /* Fail if autosuspend is disabled, or any interfaces are in use, or
1686 * any interface drivers require remote wakeup but it isn't available.
1689 if (udev->actconfig) {
1690 for (i = 0; i < udev->actconfig->desc.bNumInterfaces; i++) {
1691 intf = udev->actconfig->interface[i];
1693 /* We don't need to check interfaces that are
1694 * disabled for runtime PM. Either they are unbound
1695 * or else their drivers don't support autosuspend
1696 * and so they are permanently active.
1698 if (intf->dev.power.disable_depth)
1700 if (atomic_read(&intf->dev.power.usage_count) > 0)
1702 w |= intf->needs_remote_wakeup;
1704 /* Don't allow autosuspend if the device will need
1705 * a reset-resume and any of its interface drivers
1706 * doesn't include support or needs remote wakeup.
1708 if (udev->quirks & USB_QUIRK_RESET_RESUME) {
1709 struct usb_driver *driver;
1711 driver = to_usb_driver(intf->dev.driver);
1712 if (!driver->reset_resume ||
1713 intf->needs_remote_wakeup)
1718 if (w && !device_can_wakeup(&udev->dev)) {
1719 dev_dbg(&udev->dev, "remote wakeup needed for autosuspend\n");
1722 udev->do_remote_wakeup = w;
1726 int usb_runtime_suspend(struct device *dev)
1728 struct usb_device *udev = to_usb_device(dev);
1731 /* A USB device can be suspended if it passes the various autosuspend
1732 * checks. Runtime suspend for a USB device means suspending all the
1733 * interfaces and then the device itself.
1735 if (autosuspend_check(udev) != 0)
1738 status = usb_suspend_both(udev, PMSG_AUTO_SUSPEND);
1740 /* Allow a retry if autosuspend failed temporarily */
1741 if (status == -EAGAIN || status == -EBUSY)
1742 usb_mark_last_busy(udev);
1744 /* The PM core reacts badly unless the return code is 0,
1745 * -EAGAIN, or -EBUSY, so always return -EBUSY on an error.
1752 int usb_runtime_resume(struct device *dev)
1754 struct usb_device *udev = to_usb_device(dev);
1757 /* Runtime resume for a USB device means resuming both the device
1758 * and all its interfaces.
1760 status = usb_resume_both(udev, PMSG_AUTO_RESUME);
1764 int usb_runtime_idle(struct device *dev)
1766 struct usb_device *udev = to_usb_device(dev);
1768 /* An idle USB device can be suspended if it passes the various
1769 * autosuspend checks.
1771 if (autosuspend_check(udev) == 0)
1772 pm_runtime_autosuspend(dev);
1776 int usb_set_usb2_hardware_lpm(struct usb_device *udev, int enable)
1778 struct usb_hcd *hcd = bus_to_hcd(udev->bus);
1781 if (hcd->driver->set_usb2_hw_lpm) {
1782 ret = hcd->driver->set_usb2_hw_lpm(hcd, udev, enable);
1784 udev->usb2_hw_lpm_enabled = enable;
1790 #endif /* CONFIG_USB_SUSPEND */
1792 struct bus_type usb_bus_type = {
1794 .match = usb_device_match,
1795 .uevent = usb_uevent,