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>
36 * Adds a new dynamic USBdevice ID to this driver,
37 * and cause the driver to probe for all devices again.
39 ssize_t usb_store_new_id(struct usb_dynids *dynids,
40 const struct usb_device_id *id_table,
41 struct device_driver *driver,
42 const char *buf, size_t count)
44 struct usb_dynid *dynid;
47 unsigned int bInterfaceClass = 0;
48 u32 refVendor, refProduct;
52 fields = sscanf(buf, "%x %x %x %x %x", &idVendor, &idProduct,
53 &bInterfaceClass, &refVendor, &refProduct);
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;
65 if (fields > 2 && bInterfaceClass) {
66 if (bInterfaceClass > 255)
69 dynid->id.bInterfaceClass = (u8)bInterfaceClass;
70 dynid->id.match_flags |= USB_DEVICE_ID_MATCH_INT_CLASS;
74 const struct usb_device_id *id = id_table;
76 for (; id->match_flags; id++)
77 if (id->idVendor == refVendor && id->idProduct == refProduct) {
78 dynid->id.driver_info = id->driver_info;
83 spin_lock(&dynids->lock);
84 list_add_tail(&dynid->node, &dynids->list);
85 spin_unlock(&dynids->lock);
87 retval = driver_attach(driver);
93 EXPORT_SYMBOL_GPL(usb_store_new_id);
95 ssize_t usb_show_dynids(struct usb_dynids *dynids, char *buf)
97 struct usb_dynid *dynid;
100 list_for_each_entry(dynid, &dynids->list, node)
101 if (dynid->id.bInterfaceClass != 0)
102 count += scnprintf(&buf[count], PAGE_SIZE - count, "%04x %04x %02x\n",
103 dynid->id.idVendor, dynid->id.idProduct,
104 dynid->id.bInterfaceClass);
106 count += scnprintf(&buf[count], PAGE_SIZE - count, "%04x %04x\n",
107 dynid->id.idVendor, dynid->id.idProduct);
110 EXPORT_SYMBOL_GPL(usb_show_dynids);
112 static ssize_t new_id_show(struct device_driver *driver, char *buf)
114 struct usb_driver *usb_drv = to_usb_driver(driver);
116 return usb_show_dynids(&usb_drv->dynids, buf);
119 static ssize_t new_id_store(struct device_driver *driver,
120 const char *buf, size_t count)
122 struct usb_driver *usb_drv = to_usb_driver(driver);
124 return usb_store_new_id(&usb_drv->dynids, usb_drv->id_table, driver, buf, count);
126 static DRIVER_ATTR_RW(new_id);
129 * Remove a USB device ID from this driver
131 static ssize_t remove_id_store(struct device_driver *driver, const char *buf,
134 struct usb_dynid *dynid, *n;
135 struct usb_driver *usb_driver = to_usb_driver(driver);
140 fields = sscanf(buf, "%x %x", &idVendor, &idProduct);
144 spin_lock(&usb_driver->dynids.lock);
145 list_for_each_entry_safe(dynid, n, &usb_driver->dynids.list, node) {
146 struct usb_device_id *id = &dynid->id;
147 if ((id->idVendor == idVendor) &&
148 (id->idProduct == idProduct)) {
149 list_del(&dynid->node);
154 spin_unlock(&usb_driver->dynids.lock);
158 static ssize_t remove_id_show(struct device_driver *driver, char *buf)
160 return new_id_show(driver, buf);
162 static DRIVER_ATTR_RW(remove_id);
164 static int usb_create_newid_files(struct usb_driver *usb_drv)
168 if (usb_drv->no_dynamic_id)
171 if (usb_drv->probe != NULL) {
172 error = driver_create_file(&usb_drv->drvwrap.driver,
173 &driver_attr_new_id);
175 error = driver_create_file(&usb_drv->drvwrap.driver,
176 &driver_attr_remove_id);
178 driver_remove_file(&usb_drv->drvwrap.driver,
179 &driver_attr_new_id);
186 static void usb_remove_newid_files(struct usb_driver *usb_drv)
188 if (usb_drv->no_dynamic_id)
191 if (usb_drv->probe != NULL) {
192 driver_remove_file(&usb_drv->drvwrap.driver,
193 &driver_attr_remove_id);
194 driver_remove_file(&usb_drv->drvwrap.driver,
195 &driver_attr_new_id);
199 static void usb_free_dynids(struct usb_driver *usb_drv)
201 struct usb_dynid *dynid, *n;
203 spin_lock(&usb_drv->dynids.lock);
204 list_for_each_entry_safe(dynid, n, &usb_drv->dynids.list, node) {
205 list_del(&dynid->node);
208 spin_unlock(&usb_drv->dynids.lock);
211 static const struct usb_device_id *usb_match_dynamic_id(struct usb_interface *intf,
212 struct usb_driver *drv)
214 struct usb_dynid *dynid;
216 spin_lock(&drv->dynids.lock);
217 list_for_each_entry(dynid, &drv->dynids.list, node) {
218 if (usb_match_one_id(intf, &dynid->id)) {
219 spin_unlock(&drv->dynids.lock);
223 spin_unlock(&drv->dynids.lock);
228 /* called from driver core with dev locked */
229 static int usb_probe_device(struct device *dev)
231 struct usb_device_driver *udriver = to_usb_device_driver(dev->driver);
232 struct usb_device *udev = to_usb_device(dev);
235 dev_dbg(dev, "%s\n", __func__);
237 /* TODO: Add real matching code */
239 /* The device should always appear to be in use
240 * unless the driver supports autosuspend.
242 if (!udriver->supports_autosuspend)
243 error = usb_autoresume_device(udev);
246 error = udriver->probe(udev);
250 /* called from driver core with dev locked */
251 static int usb_unbind_device(struct device *dev)
253 struct usb_device *udev = to_usb_device(dev);
254 struct usb_device_driver *udriver = to_usb_device_driver(dev->driver);
256 udriver->disconnect(udev);
257 if (!udriver->supports_autosuspend)
258 usb_autosuspend_device(udev);
263 * Cancel any pending scheduled resets
265 * [see usb_queue_reset_device()]
267 * Called after unconfiguring / when releasing interfaces. See
268 * comments in __usb_queue_reset_device() regarding
269 * udev->reset_running.
271 static void usb_cancel_queued_reset(struct usb_interface *iface)
273 if (iface->reset_running == 0)
274 cancel_work_sync(&iface->reset_ws);
277 /* called from driver core with dev locked */
278 static int usb_probe_interface(struct device *dev)
280 struct usb_driver *driver = to_usb_driver(dev->driver);
281 struct usb_interface *intf = to_usb_interface(dev);
282 struct usb_device *udev = interface_to_usbdev(intf);
283 const struct usb_device_id *id;
285 int lpm_disable_error;
287 dev_dbg(dev, "%s\n", __func__);
289 intf->needs_binding = 0;
291 if (usb_device_is_owned(udev))
294 if (udev->authorized == 0) {
295 dev_err(&intf->dev, "Device is not authorized for usage\n");
299 id = usb_match_id(intf, driver->id_table);
301 id = usb_match_dynamic_id(intf, driver);
305 dev_dbg(dev, "%s - got id\n", __func__);
307 error = usb_autoresume_device(udev);
311 intf->condition = USB_INTERFACE_BINDING;
313 /* Probed interfaces are initially active. They are
314 * runtime-PM-enabled only if the driver has autosuspend support.
315 * They are sensitive to their children's power states.
317 pm_runtime_set_active(dev);
318 pm_suspend_ignore_children(dev, false);
319 if (driver->supports_autosuspend)
320 pm_runtime_enable(dev);
322 /* If the new driver doesn't allow hub-initiated LPM, and we can't
323 * disable hub-initiated LPM, then fail the probe.
325 * Otherwise, leaving LPM enabled should be harmless, because the
326 * endpoint intervals should remain the same, and the U1/U2 timeouts
327 * should remain the same.
329 * If we need to install alt setting 0 before probe, or another alt
330 * setting during probe, that should also be fine. usb_set_interface()
331 * will attempt to disable LPM, and fail if it can't disable it.
333 lpm_disable_error = usb_unlocked_disable_lpm(udev);
334 if (lpm_disable_error && driver->disable_hub_initiated_lpm) {
335 dev_err(&intf->dev, "%s Failed to disable LPM for driver %s\n.",
336 __func__, driver->name);
337 error = lpm_disable_error;
341 /* Carry out a deferred switch to altsetting 0 */
342 if (intf->needs_altsetting0) {
343 error = usb_set_interface(udev, intf->altsetting[0].
344 desc.bInterfaceNumber, 0);
347 intf->needs_altsetting0 = 0;
350 error = driver->probe(intf, id);
354 intf->condition = USB_INTERFACE_BOUND;
356 /* If the LPM disable succeeded, balance the ref counts. */
357 if (!lpm_disable_error)
358 usb_unlocked_enable_lpm(udev);
360 usb_autosuspend_device(udev);
364 usb_set_intfdata(intf, NULL);
365 intf->needs_remote_wakeup = 0;
366 intf->condition = USB_INTERFACE_UNBOUND;
367 usb_cancel_queued_reset(intf);
369 /* If the LPM disable succeeded, balance the ref counts. */
370 if (!lpm_disable_error)
371 usb_unlocked_enable_lpm(udev);
373 /* Unbound interfaces are always runtime-PM-disabled and -suspended */
374 if (driver->supports_autosuspend)
375 pm_runtime_disable(dev);
376 pm_runtime_set_suspended(dev);
378 usb_autosuspend_device(udev);
382 /* called from driver core with dev locked */
383 static int usb_unbind_interface(struct device *dev)
385 struct usb_driver *driver = to_usb_driver(dev->driver);
386 struct usb_interface *intf = to_usb_interface(dev);
387 struct usb_device *udev;
388 int error, r, lpm_disable_error;
390 intf->condition = USB_INTERFACE_UNBINDING;
392 /* Autoresume for set_interface call below */
393 udev = interface_to_usbdev(intf);
394 error = usb_autoresume_device(udev);
396 /* Hub-initiated LPM policy may change, so attempt to disable LPM until
397 * the driver is unbound. If LPM isn't disabled, that's fine because it
398 * wouldn't be enabled unless all the bound interfaces supported
401 lpm_disable_error = usb_unlocked_disable_lpm(udev);
403 /* Terminate all URBs for this interface unless the driver
404 * supports "soft" unbinding.
406 if (!driver->soft_unbind)
407 usb_disable_interface(udev, intf, false);
409 driver->disconnect(intf);
410 usb_cancel_queued_reset(intf);
412 /* Reset other interface state.
413 * We cannot do a Set-Interface if the device is suspended or
414 * if it is prepared for a system sleep (since installing a new
415 * altsetting means creating new endpoint device entries).
416 * When either of these happens, defer the Set-Interface.
418 if (intf->cur_altsetting->desc.bAlternateSetting == 0) {
419 /* Already in altsetting 0 so skip Set-Interface.
420 * Just re-enable it without affecting the endpoint toggles.
422 usb_enable_interface(udev, intf, false);
423 } else if (!error && !intf->dev.power.is_prepared) {
424 r = usb_set_interface(udev, intf->altsetting[0].
425 desc.bInterfaceNumber, 0);
427 intf->needs_altsetting0 = 1;
429 intf->needs_altsetting0 = 1;
431 usb_set_intfdata(intf, NULL);
433 intf->condition = USB_INTERFACE_UNBOUND;
434 intf->needs_remote_wakeup = 0;
436 /* Attempt to re-enable USB3 LPM, if the disable succeeded. */
437 if (!lpm_disable_error)
438 usb_unlocked_enable_lpm(udev);
440 /* Unbound interfaces are always runtime-PM-disabled and -suspended */
441 if (driver->supports_autosuspend)
442 pm_runtime_disable(dev);
443 pm_runtime_set_suspended(dev);
445 /* Undo any residual pm_autopm_get_interface_* calls */
446 for (r = atomic_read(&intf->pm_usage_cnt); r > 0; --r)
447 usb_autopm_put_interface_no_suspend(intf);
448 atomic_set(&intf->pm_usage_cnt, 0);
451 usb_autosuspend_device(udev);
457 * usb_driver_claim_interface - bind a driver to an interface
458 * @driver: the driver to be bound
459 * @iface: the interface to which it will be bound; must be in the
460 * usb device's active configuration
461 * @priv: driver data associated with that interface
463 * This is used by usb device drivers that need to claim more than one
464 * interface on a device when probing (audio and acm are current examples).
465 * No device driver should directly modify internal usb_interface or
466 * usb_device structure members.
468 * Few drivers should need to use this routine, since the most natural
469 * way to bind to an interface is to return the private data from
470 * the driver's probe() method.
472 * Callers must own the device lock, so driver probe() entries don't need
473 * extra locking, but other call contexts may need to explicitly claim that
476 * Return: 0 on success.
478 int usb_driver_claim_interface(struct usb_driver *driver,
479 struct usb_interface *iface, void *priv)
481 struct device *dev = &iface->dev;
482 struct usb_device *udev;
484 int lpm_disable_error;
489 udev = interface_to_usbdev(iface);
491 dev->driver = &driver->drvwrap.driver;
492 usb_set_intfdata(iface, priv);
493 iface->needs_binding = 0;
495 iface->condition = USB_INTERFACE_BOUND;
497 /* Disable LPM until this driver is bound. */
498 lpm_disable_error = usb_unlocked_disable_lpm(udev);
499 if (lpm_disable_error && driver->disable_hub_initiated_lpm) {
500 dev_err(&iface->dev, "%s Failed to disable LPM for driver %s\n.",
501 __func__, driver->name);
505 /* Claimed interfaces are initially inactive (suspended) and
506 * runtime-PM-enabled, but only if the driver has autosuspend
507 * support. Otherwise they are marked active, to prevent the
508 * device from being autosuspended, but left disabled. In either
509 * case they are sensitive to their children's power states.
511 pm_suspend_ignore_children(dev, false);
512 if (driver->supports_autosuspend)
513 pm_runtime_enable(dev);
515 pm_runtime_set_active(dev);
517 /* if interface was already added, bind now; else let
518 * the future device_add() bind it, bypassing probe()
520 if (device_is_registered(dev))
521 retval = device_bind_driver(dev);
523 /* Attempt to re-enable USB3 LPM, if the disable was successful. */
524 if (!lpm_disable_error)
525 usb_unlocked_enable_lpm(udev);
529 EXPORT_SYMBOL_GPL(usb_driver_claim_interface);
532 * usb_driver_release_interface - unbind a driver from an interface
533 * @driver: the driver to be unbound
534 * @iface: the interface from which it will be unbound
536 * This can be used by drivers to release an interface without waiting
537 * for their disconnect() methods to be called. In typical cases this
538 * also causes the driver disconnect() method to be called.
540 * This call is synchronous, and may not be used in an interrupt context.
541 * Callers must own the device lock, so driver disconnect() entries don't
542 * need extra locking, but other call contexts may need to explicitly claim
545 void usb_driver_release_interface(struct usb_driver *driver,
546 struct usb_interface *iface)
548 struct device *dev = &iface->dev;
550 /* this should never happen, don't release something that's not ours */
551 if (!dev->driver || dev->driver != &driver->drvwrap.driver)
554 /* don't release from within disconnect() */
555 if (iface->condition != USB_INTERFACE_BOUND)
557 iface->condition = USB_INTERFACE_UNBINDING;
559 /* Release via the driver core only if the interface
560 * has already been registered
562 if (device_is_registered(dev)) {
563 device_release_driver(dev);
566 usb_unbind_interface(dev);
571 EXPORT_SYMBOL_GPL(usb_driver_release_interface);
573 /* returns 0 if no match, 1 if match */
574 int usb_match_device(struct usb_device *dev, const struct usb_device_id *id)
576 if ((id->match_flags & USB_DEVICE_ID_MATCH_VENDOR) &&
577 id->idVendor != le16_to_cpu(dev->descriptor.idVendor))
580 if ((id->match_flags & USB_DEVICE_ID_MATCH_PRODUCT) &&
581 id->idProduct != le16_to_cpu(dev->descriptor.idProduct))
584 /* No need to test id->bcdDevice_lo != 0, since 0 is never
585 greater than any unsigned number. */
586 if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_LO) &&
587 (id->bcdDevice_lo > le16_to_cpu(dev->descriptor.bcdDevice)))
590 if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_HI) &&
591 (id->bcdDevice_hi < le16_to_cpu(dev->descriptor.bcdDevice)))
594 if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_CLASS) &&
595 (id->bDeviceClass != dev->descriptor.bDeviceClass))
598 if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_SUBCLASS) &&
599 (id->bDeviceSubClass != dev->descriptor.bDeviceSubClass))
602 if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_PROTOCOL) &&
603 (id->bDeviceProtocol != dev->descriptor.bDeviceProtocol))
609 /* returns 0 if no match, 1 if match */
610 int usb_match_one_id_intf(struct usb_device *dev,
611 struct usb_host_interface *intf,
612 const struct usb_device_id *id)
614 /* The interface class, subclass, protocol and number should never be
615 * checked for a match if the device class is Vendor Specific,
616 * unless the match record specifies the Vendor ID. */
617 if (dev->descriptor.bDeviceClass == USB_CLASS_VENDOR_SPEC &&
618 !(id->match_flags & USB_DEVICE_ID_MATCH_VENDOR) &&
619 (id->match_flags & (USB_DEVICE_ID_MATCH_INT_CLASS |
620 USB_DEVICE_ID_MATCH_INT_SUBCLASS |
621 USB_DEVICE_ID_MATCH_INT_PROTOCOL |
622 USB_DEVICE_ID_MATCH_INT_NUMBER)))
625 if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_CLASS) &&
626 (id->bInterfaceClass != intf->desc.bInterfaceClass))
629 if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_SUBCLASS) &&
630 (id->bInterfaceSubClass != intf->desc.bInterfaceSubClass))
633 if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_PROTOCOL) &&
634 (id->bInterfaceProtocol != intf->desc.bInterfaceProtocol))
637 if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_NUMBER) &&
638 (id->bInterfaceNumber != intf->desc.bInterfaceNumber))
644 /* returns 0 if no match, 1 if match */
645 int usb_match_one_id(struct usb_interface *interface,
646 const struct usb_device_id *id)
648 struct usb_host_interface *intf;
649 struct usb_device *dev;
651 /* proc_connectinfo in devio.c may call us with id == NULL. */
655 intf = interface->cur_altsetting;
656 dev = interface_to_usbdev(interface);
658 if (!usb_match_device(dev, id))
661 return usb_match_one_id_intf(dev, intf, id);
663 EXPORT_SYMBOL_GPL(usb_match_one_id);
666 * usb_match_id - find first usb_device_id matching device or interface
667 * @interface: the interface of interest
668 * @id: array of usb_device_id structures, terminated by zero entry
670 * usb_match_id searches an array of usb_device_id's and returns
671 * the first one matching the device or interface, or null.
672 * This is used when binding (or rebinding) a driver to an interface.
673 * Most USB device drivers will use this indirectly, through the usb core,
674 * but some layered driver frameworks use it directly.
675 * These device tables are exported with MODULE_DEVICE_TABLE, through
676 * modutils, to support the driver loading functionality of USB hotplugging.
678 * Return: The first matching usb_device_id, or %NULL.
682 * The "match_flags" element in a usb_device_id controls which
683 * members are used. If the corresponding bit is set, the
684 * value in the device_id must match its corresponding member
685 * in the device or interface descriptor, or else the device_id
688 * "driver_info" is normally used only by device drivers,
689 * but you can create a wildcard "matches anything" usb_device_id
690 * as a driver's "modules.usbmap" entry if you provide an id with
691 * only a nonzero "driver_info" field. If you do this, the USB device
692 * driver's probe() routine should use additional intelligence to
693 * decide whether to bind to the specified interface.
695 * What Makes Good usb_device_id Tables:
697 * The match algorithm is very simple, so that intelligence in
698 * driver selection must come from smart driver id records.
699 * Unless you have good reasons to use another selection policy,
700 * provide match elements only in related groups, and order match
701 * specifiers from specific to general. Use the macros provided
702 * for that purpose if you can.
704 * The most specific match specifiers use device descriptor
705 * data. These are commonly used with product-specific matches;
706 * the USB_DEVICE macro lets you provide vendor and product IDs,
707 * and you can also match against ranges of product revisions.
708 * These are widely used for devices with application or vendor
709 * specific bDeviceClass values.
711 * Matches based on device class/subclass/protocol specifications
712 * are slightly more general; use the USB_DEVICE_INFO macro, or
713 * its siblings. These are used with single-function devices
714 * where bDeviceClass doesn't specify that each interface has
717 * Matches based on interface class/subclass/protocol are the
718 * most general; they let drivers bind to any interface on a
719 * multiple-function device. Use the USB_INTERFACE_INFO
720 * macro, or its siblings, to match class-per-interface style
721 * devices (as recorded in bInterfaceClass).
723 * Note that an entry created by USB_INTERFACE_INFO won't match
724 * any interface if the device class is set to Vendor-Specific.
725 * This is deliberate; according to the USB spec the meanings of
726 * the interface class/subclass/protocol for these devices are also
727 * vendor-specific, and hence matching against a standard product
728 * class wouldn't work anyway. If you really want to use an
729 * interface-based match for such a device, create a match record
730 * that also specifies the vendor ID. (Unforunately there isn't a
731 * standard macro for creating records like this.)
733 * Within those groups, remember that not all combinations are
734 * meaningful. For example, don't give a product version range
735 * without vendor and product IDs; or specify a protocol without
736 * its associated class and subclass.
738 const struct usb_device_id *usb_match_id(struct usb_interface *interface,
739 const struct usb_device_id *id)
741 /* proc_connectinfo in devio.c may call us with id == NULL. */
745 /* It is important to check that id->driver_info is nonzero,
746 since an entry that is all zeroes except for a nonzero
747 id->driver_info is the way to create an entry that
748 indicates that the driver want to examine every
749 device and interface. */
750 for (; id->idVendor || id->idProduct || id->bDeviceClass ||
751 id->bInterfaceClass || id->driver_info; id++) {
752 if (usb_match_one_id(interface, id))
758 EXPORT_SYMBOL_GPL(usb_match_id);
760 static int usb_device_match(struct device *dev, struct device_driver *drv)
762 /* devices and interfaces are handled separately */
763 if (is_usb_device(dev)) {
765 /* interface drivers never match devices */
766 if (!is_usb_device_driver(drv))
769 /* TODO: Add real matching code */
772 } else if (is_usb_interface(dev)) {
773 struct usb_interface *intf;
774 struct usb_driver *usb_drv;
775 const struct usb_device_id *id;
777 /* device drivers never match interfaces */
778 if (is_usb_device_driver(drv))
781 intf = to_usb_interface(dev);
782 usb_drv = to_usb_driver(drv);
784 id = usb_match_id(intf, usb_drv->id_table);
788 id = usb_match_dynamic_id(intf, usb_drv);
796 static int usb_uevent(struct device *dev, struct kobj_uevent_env *env)
798 struct usb_device *usb_dev;
800 if (is_usb_device(dev)) {
801 usb_dev = to_usb_device(dev);
802 } else if (is_usb_interface(dev)) {
803 struct usb_interface *intf = to_usb_interface(dev);
805 usb_dev = interface_to_usbdev(intf);
810 if (usb_dev->devnum < 0) {
811 /* driver is often null here; dev_dbg() would oops */
812 pr_debug("usb %s: already deleted?\n", dev_name(dev));
816 pr_debug("usb %s: bus removed?\n", dev_name(dev));
820 /* per-device configurations are common */
821 if (add_uevent_var(env, "PRODUCT=%x/%x/%x",
822 le16_to_cpu(usb_dev->descriptor.idVendor),
823 le16_to_cpu(usb_dev->descriptor.idProduct),
824 le16_to_cpu(usb_dev->descriptor.bcdDevice)))
827 /* class-based driver binding models */
828 if (add_uevent_var(env, "TYPE=%d/%d/%d",
829 usb_dev->descriptor.bDeviceClass,
830 usb_dev->descriptor.bDeviceSubClass,
831 usb_dev->descriptor.bDeviceProtocol))
838 * usb_register_device_driver - register a USB device (not interface) driver
839 * @new_udriver: USB operations for the device driver
840 * @owner: module owner of this driver.
842 * Registers a USB device driver with the USB core. The list of
843 * unattached devices will be rescanned whenever a new driver is
844 * added, allowing the new driver to attach to any recognized devices.
846 * Return: A negative error code on failure and 0 on success.
848 int usb_register_device_driver(struct usb_device_driver *new_udriver,
849 struct module *owner)
856 new_udriver->drvwrap.for_devices = 1;
857 new_udriver->drvwrap.driver.name = new_udriver->name;
858 new_udriver->drvwrap.driver.bus = &usb_bus_type;
859 new_udriver->drvwrap.driver.probe = usb_probe_device;
860 new_udriver->drvwrap.driver.remove = usb_unbind_device;
861 new_udriver->drvwrap.driver.owner = owner;
863 retval = driver_register(&new_udriver->drvwrap.driver);
866 pr_info("%s: registered new device driver %s\n",
867 usbcore_name, new_udriver->name);
869 printk(KERN_ERR "%s: error %d registering device "
871 usbcore_name, retval, new_udriver->name);
875 EXPORT_SYMBOL_GPL(usb_register_device_driver);
878 * usb_deregister_device_driver - unregister a USB device (not interface) driver
879 * @udriver: USB operations of the device driver to unregister
880 * Context: must be able to sleep
882 * Unlinks the specified driver from the internal USB driver list.
884 void usb_deregister_device_driver(struct usb_device_driver *udriver)
886 pr_info("%s: deregistering device driver %s\n",
887 usbcore_name, udriver->name);
889 driver_unregister(&udriver->drvwrap.driver);
891 EXPORT_SYMBOL_GPL(usb_deregister_device_driver);
894 * usb_register_driver - register a USB interface driver
895 * @new_driver: USB operations for the interface driver
896 * @owner: module owner of this driver.
897 * @mod_name: module name string
899 * Registers a USB interface driver with the USB core. The list of
900 * unattached interfaces will be rescanned whenever a new driver is
901 * added, allowing the new driver to attach to any recognized interfaces.
903 * Return: A negative error code on failure and 0 on success.
905 * NOTE: if you want your driver to use the USB major number, you must call
906 * usb_register_dev() to enable that functionality. This function no longer
907 * takes care of that.
909 int usb_register_driver(struct usb_driver *new_driver, struct module *owner,
910 const char *mod_name)
917 new_driver->drvwrap.for_devices = 0;
918 new_driver->drvwrap.driver.name = new_driver->name;
919 new_driver->drvwrap.driver.bus = &usb_bus_type;
920 new_driver->drvwrap.driver.probe = usb_probe_interface;
921 new_driver->drvwrap.driver.remove = usb_unbind_interface;
922 new_driver->drvwrap.driver.owner = owner;
923 new_driver->drvwrap.driver.mod_name = mod_name;
924 spin_lock_init(&new_driver->dynids.lock);
925 INIT_LIST_HEAD(&new_driver->dynids.list);
927 retval = driver_register(&new_driver->drvwrap.driver);
931 retval = usb_create_newid_files(new_driver);
935 pr_info("%s: registered new interface driver %s\n",
936 usbcore_name, new_driver->name);
942 driver_unregister(&new_driver->drvwrap.driver);
944 printk(KERN_ERR "%s: error %d registering interface "
946 usbcore_name, retval, new_driver->name);
949 EXPORT_SYMBOL_GPL(usb_register_driver);
952 * usb_deregister - unregister a USB interface driver
953 * @driver: USB operations of the interface driver to unregister
954 * Context: must be able to sleep
956 * Unlinks the specified driver from the internal USB driver list.
958 * NOTE: If you called usb_register_dev(), you still need to call
959 * usb_deregister_dev() to clean up your driver's allocated minor numbers,
960 * this * call will no longer do it for you.
962 void usb_deregister(struct usb_driver *driver)
964 pr_info("%s: deregistering interface driver %s\n",
965 usbcore_name, driver->name);
967 usb_remove_newid_files(driver);
968 driver_unregister(&driver->drvwrap.driver);
969 usb_free_dynids(driver);
971 EXPORT_SYMBOL_GPL(usb_deregister);
973 /* Forced unbinding of a USB interface driver, either because
974 * it doesn't support pre_reset/post_reset/reset_resume or
975 * because it doesn't support suspend/resume.
977 * The caller must hold @intf's device's lock, but not its pm_mutex
978 * and not @intf->dev.sem.
980 void usb_forced_unbind_intf(struct usb_interface *intf)
982 struct usb_driver *driver = to_usb_driver(intf->dev.driver);
984 dev_dbg(&intf->dev, "forced unbind\n");
985 usb_driver_release_interface(driver, intf);
987 /* Mark the interface for later rebinding */
988 intf->needs_binding = 1;
991 /* Delayed forced unbinding of a USB interface driver and scan
994 * The caller must hold @intf's device's lock, but not its pm_mutex
995 * and not @intf->dev.sem.
997 * Note: Rebinds will be skipped if a system sleep transition is in
998 * progress and the PM "complete" callback hasn't occurred yet.
1000 void usb_rebind_intf(struct usb_interface *intf)
1004 /* Delayed unbind of an existing driver */
1005 if (intf->dev.driver)
1006 usb_forced_unbind_intf(intf);
1008 /* Try to rebind the interface */
1009 if (!intf->dev.power.is_prepared) {
1010 intf->needs_binding = 0;
1011 rc = device_attach(&intf->dev);
1013 dev_warn(&intf->dev, "rebind failed: %d\n", rc);
1019 /* Unbind drivers for @udev's interfaces that don't support suspend/resume
1020 * There is no check for reset_resume here because it can be determined
1021 * only during resume whether reset_resume is needed.
1023 * The caller must hold @udev's device lock.
1025 static void unbind_no_pm_drivers_interfaces(struct usb_device *udev)
1027 struct usb_host_config *config;
1029 struct usb_interface *intf;
1030 struct usb_driver *drv;
1032 config = udev->actconfig;
1034 for (i = 0; i < config->desc.bNumInterfaces; ++i) {
1035 intf = config->interface[i];
1037 if (intf->dev.driver) {
1038 drv = to_usb_driver(intf->dev.driver);
1039 if (!drv->suspend || !drv->resume)
1040 usb_forced_unbind_intf(intf);
1046 /* Unbind drivers for @udev's interfaces that failed to support reset-resume.
1047 * These interfaces have the needs_binding flag set by usb_resume_interface().
1049 * The caller must hold @udev's device lock.
1051 static void unbind_no_reset_resume_drivers_interfaces(struct usb_device *udev)
1053 struct usb_host_config *config;
1055 struct usb_interface *intf;
1057 config = udev->actconfig;
1059 for (i = 0; i < config->desc.bNumInterfaces; ++i) {
1060 intf = config->interface[i];
1061 if (intf->dev.driver && intf->needs_binding)
1062 usb_forced_unbind_intf(intf);
1067 static void do_rebind_interfaces(struct usb_device *udev)
1069 struct usb_host_config *config;
1071 struct usb_interface *intf;
1073 config = udev->actconfig;
1075 for (i = 0; i < config->desc.bNumInterfaces; ++i) {
1076 intf = config->interface[i];
1077 if (intf->needs_binding)
1078 usb_rebind_intf(intf);
1083 static int usb_suspend_device(struct usb_device *udev, pm_message_t msg)
1085 struct usb_device_driver *udriver;
1088 if (udev->state == USB_STATE_NOTATTACHED ||
1089 udev->state == USB_STATE_SUSPENDED)
1092 /* For devices that don't have a driver, we do a generic suspend. */
1093 if (udev->dev.driver)
1094 udriver = to_usb_device_driver(udev->dev.driver);
1096 udev->do_remote_wakeup = 0;
1097 udriver = &usb_generic_driver;
1099 status = udriver->suspend(udev, msg);
1102 dev_vdbg(&udev->dev, "%s: status %d\n", __func__, status);
1106 static int usb_resume_device(struct usb_device *udev, pm_message_t msg)
1108 struct usb_device_driver *udriver;
1111 if (udev->state == USB_STATE_NOTATTACHED)
1114 /* Can't resume it if it doesn't have a driver. */
1115 if (udev->dev.driver == NULL) {
1120 /* Non-root devices on a full/low-speed bus must wait for their
1121 * companion high-speed root hub, in case a handoff is needed.
1123 if (!PMSG_IS_AUTO(msg) && udev->parent && udev->bus->hs_companion)
1124 device_pm_wait_for_dev(&udev->dev,
1125 &udev->bus->hs_companion->root_hub->dev);
1127 if (udev->quirks & USB_QUIRK_RESET_RESUME)
1128 udev->reset_resume = 1;
1130 udriver = to_usb_device_driver(udev->dev.driver);
1131 status = udriver->resume(udev, msg);
1134 dev_vdbg(&udev->dev, "%s: status %d\n", __func__, status);
1138 static int usb_suspend_interface(struct usb_device *udev,
1139 struct usb_interface *intf, pm_message_t msg)
1141 struct usb_driver *driver;
1144 if (udev->state == USB_STATE_NOTATTACHED ||
1145 intf->condition == USB_INTERFACE_UNBOUND)
1147 driver = to_usb_driver(intf->dev.driver);
1149 /* at this time we know the driver supports suspend */
1150 status = driver->suspend(intf, msg);
1151 if (status && !PMSG_IS_AUTO(msg))
1152 dev_err(&intf->dev, "suspend error %d\n", status);
1155 dev_vdbg(&intf->dev, "%s: status %d\n", __func__, status);
1159 static int usb_resume_interface(struct usb_device *udev,
1160 struct usb_interface *intf, pm_message_t msg, int reset_resume)
1162 struct usb_driver *driver;
1165 if (udev->state == USB_STATE_NOTATTACHED)
1168 /* Don't let autoresume interfere with unbinding */
1169 if (intf->condition == USB_INTERFACE_UNBINDING)
1172 /* Can't resume it if it doesn't have a driver. */
1173 if (intf->condition == USB_INTERFACE_UNBOUND) {
1175 /* Carry out a deferred switch to altsetting 0 */
1176 if (intf->needs_altsetting0 && !intf->dev.power.is_prepared) {
1177 usb_set_interface(udev, intf->altsetting[0].
1178 desc.bInterfaceNumber, 0);
1179 intf->needs_altsetting0 = 0;
1184 /* Don't resume if the interface is marked for rebinding */
1185 if (intf->needs_binding)
1187 driver = to_usb_driver(intf->dev.driver);
1190 if (driver->reset_resume) {
1191 status = driver->reset_resume(intf);
1193 dev_err(&intf->dev, "%s error %d\n",
1194 "reset_resume", status);
1196 intf->needs_binding = 1;
1197 dev_dbg(&intf->dev, "no reset_resume for driver %s?\n",
1201 status = driver->resume(intf);
1203 dev_err(&intf->dev, "resume error %d\n", status);
1207 dev_vdbg(&intf->dev, "%s: status %d\n", __func__, status);
1209 /* Later we will unbind the driver and/or reprobe, if necessary */
1214 * usb_suspend_both - suspend a USB device and its interfaces
1215 * @udev: the usb_device to suspend
1216 * @msg: Power Management message describing this state transition
1218 * This is the central routine for suspending USB devices. It calls the
1219 * suspend methods for all the interface drivers in @udev and then calls
1220 * the suspend method for @udev itself. When the routine is called in
1221 * autosuspend, if an error occurs at any stage, all the interfaces
1222 * which were suspended are resumed so that they remain in the same
1223 * state as the device, but when called from system sleep, all error
1224 * from suspend methods of interfaces and the non-root-hub device itself
1225 * are simply ignored, so all suspended interfaces are only resumed
1226 * to the device's state when @udev is root-hub and its suspend method
1229 * Autosuspend requests originating from a child device or an interface
1230 * driver may be made without the protection of @udev's device lock, but
1231 * all other suspend calls will hold the lock. Usbcore will insure that
1232 * method calls do not arrive during bind, unbind, or reset operations.
1233 * However drivers must be prepared to handle suspend calls arriving at
1234 * unpredictable times.
1236 * This routine can run only in process context.
1238 * Return: 0 if the suspend succeeded.
1240 static int usb_suspend_both(struct usb_device *udev, pm_message_t msg)
1244 struct usb_interface *intf;
1246 if (udev->state == USB_STATE_NOTATTACHED ||
1247 udev->state == USB_STATE_SUSPENDED)
1250 /* Suspend all the interfaces and then udev itself */
1251 if (udev->actconfig) {
1252 n = udev->actconfig->desc.bNumInterfaces;
1253 for (i = n - 1; i >= 0; --i) {
1254 intf = udev->actconfig->interface[i];
1255 status = usb_suspend_interface(udev, intf, msg);
1257 /* Ignore errors during system sleep transitions */
1258 if (!PMSG_IS_AUTO(msg))
1265 status = usb_suspend_device(udev, msg);
1268 * Ignore errors from non-root-hub devices during
1269 * system sleep transitions. For the most part,
1270 * these devices should go to low power anyway when
1271 * the entire bus is suspended.
1273 if (udev->parent && !PMSG_IS_AUTO(msg))
1277 /* If the suspend failed, resume interfaces that did get suspended */
1279 if (udev->actconfig) {
1280 msg.event ^= (PM_EVENT_SUSPEND | PM_EVENT_RESUME);
1282 intf = udev->actconfig->interface[i];
1283 usb_resume_interface(udev, intf, msg, 0);
1287 /* If the suspend succeeded then prevent any more URB submissions
1288 * and flush any outstanding URBs.
1291 udev->can_submit = 0;
1292 for (i = 0; i < 16; ++i) {
1293 usb_hcd_flush_endpoint(udev, udev->ep_out[i]);
1294 usb_hcd_flush_endpoint(udev, udev->ep_in[i]);
1299 dev_vdbg(&udev->dev, "%s: status %d\n", __func__, status);
1304 * usb_resume_both - resume a USB device and its interfaces
1305 * @udev: the usb_device to resume
1306 * @msg: Power Management message describing this state transition
1308 * This is the central routine for resuming USB devices. It calls the
1309 * the resume method for @udev and then calls the resume methods for all
1310 * the interface drivers in @udev.
1312 * Autoresume requests originating from a child device or an interface
1313 * driver may be made without the protection of @udev's device lock, but
1314 * all other resume calls will hold the lock. Usbcore will insure that
1315 * method calls do not arrive during bind, unbind, or reset operations.
1316 * However drivers must be prepared to handle resume calls arriving at
1317 * unpredictable times.
1319 * This routine can run only in process context.
1321 * Return: 0 on success.
1323 static int usb_resume_both(struct usb_device *udev, pm_message_t msg)
1327 struct usb_interface *intf;
1329 if (udev->state == USB_STATE_NOTATTACHED) {
1333 udev->can_submit = 1;
1335 /* Resume the device */
1336 if (udev->state == USB_STATE_SUSPENDED || udev->reset_resume)
1337 status = usb_resume_device(udev, msg);
1339 /* Resume the interfaces */
1340 if (status == 0 && udev->actconfig) {
1341 for (i = 0; i < udev->actconfig->desc.bNumInterfaces; i++) {
1342 intf = udev->actconfig->interface[i];
1343 usb_resume_interface(udev, intf, msg,
1344 udev->reset_resume);
1347 usb_mark_last_busy(udev);
1350 dev_vdbg(&udev->dev, "%s: status %d\n", __func__, status);
1352 udev->reset_resume = 0;
1356 static void choose_wakeup(struct usb_device *udev, pm_message_t msg)
1360 /* Remote wakeup is needed only when we actually go to sleep.
1361 * For things like FREEZE and QUIESCE, if the device is already
1362 * autosuspended then its current wakeup setting is okay.
1364 if (msg.event == PM_EVENT_FREEZE || msg.event == PM_EVENT_QUIESCE) {
1365 if (udev->state != USB_STATE_SUSPENDED)
1366 udev->do_remote_wakeup = 0;
1370 /* Enable remote wakeup if it is allowed, even if no interface drivers
1373 w = device_may_wakeup(&udev->dev);
1375 /* If the device is autosuspended with the wrong wakeup setting,
1376 * autoresume now so the setting can be changed.
1378 if (udev->state == USB_STATE_SUSPENDED && w != udev->do_remote_wakeup)
1379 pm_runtime_resume(&udev->dev);
1380 udev->do_remote_wakeup = w;
1383 /* The device lock is held by the PM core */
1384 int usb_suspend(struct device *dev, pm_message_t msg)
1386 struct usb_device *udev = to_usb_device(dev);
1388 unbind_no_pm_drivers_interfaces(udev);
1390 /* From now on we are sure all drivers support suspend/resume
1391 * but not necessarily reset_resume()
1392 * so we may still need to unbind and rebind upon resume
1394 choose_wakeup(udev, msg);
1395 return usb_suspend_both(udev, msg);
1398 /* The device lock is held by the PM core */
1399 int usb_resume_complete(struct device *dev)
1401 struct usb_device *udev = to_usb_device(dev);
1403 /* For PM complete calls, all we do is rebind interfaces
1404 * whose needs_binding flag is set
1406 if (udev->state != USB_STATE_NOTATTACHED)
1407 do_rebind_interfaces(udev);
1411 /* The device lock is held by the PM core */
1412 int usb_resume(struct device *dev, pm_message_t msg)
1414 struct usb_device *udev = to_usb_device(dev);
1417 /* For all calls, take the device back to full power and
1418 * tell the PM core in case it was autosuspended previously.
1419 * Unbind the interfaces that will need rebinding later,
1420 * because they fail to support reset_resume.
1421 * (This can't be done in usb_resume_interface()
1422 * above because it doesn't own the right set of locks.)
1424 status = usb_resume_both(udev, msg);
1426 pm_runtime_disable(dev);
1427 pm_runtime_set_active(dev);
1428 pm_runtime_enable(dev);
1429 unbind_no_reset_resume_drivers_interfaces(udev);
1432 /* Avoid PM error messages for devices disconnected while suspended
1433 * as we'll display regular disconnect messages just a bit later.
1435 if (status == -ENODEV || status == -ESHUTDOWN)
1440 #endif /* CONFIG_PM */
1442 #ifdef CONFIG_PM_RUNTIME
1445 * usb_enable_autosuspend - allow a USB device to be autosuspended
1446 * @udev: the USB device which may be autosuspended
1448 * This routine allows @udev to be autosuspended. An autosuspend won't
1449 * take place until the autosuspend_delay has elapsed and all the other
1450 * necessary conditions are satisfied.
1452 * The caller must hold @udev's device lock.
1454 void usb_enable_autosuspend(struct usb_device *udev)
1456 pm_runtime_allow(&udev->dev);
1458 EXPORT_SYMBOL_GPL(usb_enable_autosuspend);
1461 * usb_disable_autosuspend - prevent a USB device from being autosuspended
1462 * @udev: the USB device which may not be autosuspended
1464 * This routine prevents @udev from being autosuspended and wakes it up
1465 * if it is already autosuspended.
1467 * The caller must hold @udev's device lock.
1469 void usb_disable_autosuspend(struct usb_device *udev)
1471 pm_runtime_forbid(&udev->dev);
1473 EXPORT_SYMBOL_GPL(usb_disable_autosuspend);
1476 * usb_autosuspend_device - delayed autosuspend of a USB device and its interfaces
1477 * @udev: the usb_device to autosuspend
1479 * This routine should be called when a core subsystem is finished using
1480 * @udev and wants to allow it to autosuspend. Examples would be when
1481 * @udev's device file in usbfs is closed or after a configuration change.
1483 * @udev's usage counter is decremented; if it drops to 0 and all the
1484 * interfaces are inactive then a delayed autosuspend will be attempted.
1485 * The attempt may fail (see autosuspend_check()).
1487 * The caller must hold @udev's device lock.
1489 * This routine can run only in process context.
1491 void usb_autosuspend_device(struct usb_device *udev)
1495 usb_mark_last_busy(udev);
1496 status = pm_runtime_put_sync_autosuspend(&udev->dev);
1497 dev_vdbg(&udev->dev, "%s: cnt %d -> %d\n",
1498 __func__, atomic_read(&udev->dev.power.usage_count),
1503 * usb_autoresume_device - immediately autoresume a USB device and its interfaces
1504 * @udev: the usb_device to autoresume
1506 * This routine should be called when a core subsystem wants to use @udev
1507 * and needs to guarantee that it is not suspended. No autosuspend will
1508 * occur until usb_autosuspend_device() is called. (Note that this will
1509 * not prevent suspend events originating in the PM core.) Examples would
1510 * be when @udev's device file in usbfs is opened or when a remote-wakeup
1511 * request is received.
1513 * @udev's usage counter is incremented to prevent subsequent autosuspends.
1514 * However if the autoresume fails then the usage counter is re-decremented.
1516 * The caller must hold @udev's device lock.
1518 * This routine can run only in process context.
1520 * Return: 0 on success. A negative error code otherwise.
1522 int usb_autoresume_device(struct usb_device *udev)
1526 status = pm_runtime_get_sync(&udev->dev);
1528 pm_runtime_put_sync(&udev->dev);
1529 dev_vdbg(&udev->dev, "%s: cnt %d -> %d\n",
1530 __func__, atomic_read(&udev->dev.power.usage_count),
1538 * usb_autopm_put_interface - decrement a USB interface's PM-usage counter
1539 * @intf: the usb_interface whose counter should be decremented
1541 * This routine should be called by an interface driver when it is
1542 * finished using @intf and wants to allow it to autosuspend. A typical
1543 * example would be a character-device driver when its device file is
1546 * The routine decrements @intf's usage counter. When the counter reaches
1547 * 0, a delayed autosuspend request for @intf's device is attempted. The
1548 * attempt may fail (see autosuspend_check()).
1550 * This routine can run only in process context.
1552 void usb_autopm_put_interface(struct usb_interface *intf)
1554 struct usb_device *udev = interface_to_usbdev(intf);
1557 usb_mark_last_busy(udev);
1558 atomic_dec(&intf->pm_usage_cnt);
1559 status = pm_runtime_put_sync(&intf->dev);
1560 dev_vdbg(&intf->dev, "%s: cnt %d -> %d\n",
1561 __func__, atomic_read(&intf->dev.power.usage_count),
1564 EXPORT_SYMBOL_GPL(usb_autopm_put_interface);
1567 * usb_autopm_put_interface_async - decrement a USB interface's PM-usage counter
1568 * @intf: the usb_interface whose counter should be decremented
1570 * This routine does much the same thing as usb_autopm_put_interface():
1571 * It decrements @intf's usage counter and schedules a delayed
1572 * autosuspend request if the counter is <= 0. The difference is that it
1573 * does not perform any synchronization; callers should hold a private
1574 * lock and handle all synchronization issues themselves.
1576 * Typically a driver would call this routine during an URB's completion
1577 * handler, if no more URBs were pending.
1579 * This routine can run in atomic context.
1581 void usb_autopm_put_interface_async(struct usb_interface *intf)
1583 struct usb_device *udev = interface_to_usbdev(intf);
1586 usb_mark_last_busy(udev);
1587 atomic_dec(&intf->pm_usage_cnt);
1588 status = pm_runtime_put(&intf->dev);
1589 dev_vdbg(&intf->dev, "%s: cnt %d -> %d\n",
1590 __func__, atomic_read(&intf->dev.power.usage_count),
1593 EXPORT_SYMBOL_GPL(usb_autopm_put_interface_async);
1596 * usb_autopm_put_interface_no_suspend - decrement a USB interface's PM-usage counter
1597 * @intf: the usb_interface whose counter should be decremented
1599 * This routine decrements @intf's usage counter but does not carry out an
1602 * This routine can run in atomic context.
1604 void usb_autopm_put_interface_no_suspend(struct usb_interface *intf)
1606 struct usb_device *udev = interface_to_usbdev(intf);
1608 usb_mark_last_busy(udev);
1609 atomic_dec(&intf->pm_usage_cnt);
1610 pm_runtime_put_noidle(&intf->dev);
1612 EXPORT_SYMBOL_GPL(usb_autopm_put_interface_no_suspend);
1615 * usb_autopm_get_interface - increment a USB interface's PM-usage counter
1616 * @intf: the usb_interface whose counter should be incremented
1618 * This routine should be called by an interface driver when it wants to
1619 * use @intf and needs to guarantee that it is not suspended. In addition,
1620 * the routine prevents @intf from being autosuspended subsequently. (Note
1621 * that this will not prevent suspend events originating in the PM core.)
1622 * This prevention will persist until usb_autopm_put_interface() is called
1623 * or @intf is unbound. A typical example would be a character-device
1624 * driver when its device file is opened.
1626 * @intf's usage counter is incremented to prevent subsequent autosuspends.
1627 * However if the autoresume fails then the counter is re-decremented.
1629 * This routine can run only in process context.
1631 * Return: 0 on success.
1633 int usb_autopm_get_interface(struct usb_interface *intf)
1637 status = pm_runtime_get_sync(&intf->dev);
1639 pm_runtime_put_sync(&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);
1652 * usb_autopm_get_interface_async - increment a USB interface's PM-usage counter
1653 * @intf: the usb_interface whose counter should be incremented
1655 * This routine does much the same thing as
1656 * usb_autopm_get_interface(): It increments @intf's usage counter and
1657 * queues an autoresume request if the device is suspended. The
1658 * differences are that it does not perform any synchronization (callers
1659 * should hold a private lock and handle all synchronization issues
1660 * themselves), and it does not autoresume the device directly (it only
1661 * queues a request). After a successful call, the device may not yet be
1664 * This routine can run in atomic context.
1666 * Return: 0 on success. A negative error code otherwise.
1668 int usb_autopm_get_interface_async(struct usb_interface *intf)
1672 status = pm_runtime_get(&intf->dev);
1673 if (status < 0 && status != -EINPROGRESS)
1674 pm_runtime_put_noidle(&intf->dev);
1676 atomic_inc(&intf->pm_usage_cnt);
1677 dev_vdbg(&intf->dev, "%s: cnt %d -> %d\n",
1678 __func__, atomic_read(&intf->dev.power.usage_count),
1680 if (status > 0 || status == -EINPROGRESS)
1684 EXPORT_SYMBOL_GPL(usb_autopm_get_interface_async);
1687 * usb_autopm_get_interface_no_resume - increment a USB interface's PM-usage counter
1688 * @intf: the usb_interface whose counter should be incremented
1690 * This routine increments @intf's usage counter but does not carry out an
1693 * This routine can run in atomic context.
1695 void usb_autopm_get_interface_no_resume(struct usb_interface *intf)
1697 struct usb_device *udev = interface_to_usbdev(intf);
1699 usb_mark_last_busy(udev);
1700 atomic_inc(&intf->pm_usage_cnt);
1701 pm_runtime_get_noresume(&intf->dev);
1703 EXPORT_SYMBOL_GPL(usb_autopm_get_interface_no_resume);
1705 /* Internal routine to check whether we may autosuspend a device. */
1706 static int autosuspend_check(struct usb_device *udev)
1709 struct usb_interface *intf;
1711 /* Fail if autosuspend is disabled, or any interfaces are in use, or
1712 * any interface drivers require remote wakeup but it isn't available.
1715 if (udev->actconfig) {
1716 for (i = 0; i < udev->actconfig->desc.bNumInterfaces; i++) {
1717 intf = udev->actconfig->interface[i];
1719 /* We don't need to check interfaces that are
1720 * disabled for runtime PM. Either they are unbound
1721 * or else their drivers don't support autosuspend
1722 * and so they are permanently active.
1724 if (intf->dev.power.disable_depth)
1726 if (atomic_read(&intf->dev.power.usage_count) > 0)
1728 w |= intf->needs_remote_wakeup;
1730 /* Don't allow autosuspend if the device will need
1731 * a reset-resume and any of its interface drivers
1732 * doesn't include support or needs remote wakeup.
1734 if (udev->quirks & USB_QUIRK_RESET_RESUME) {
1735 struct usb_driver *driver;
1737 driver = to_usb_driver(intf->dev.driver);
1738 if (!driver->reset_resume ||
1739 intf->needs_remote_wakeup)
1744 if (w && !device_can_wakeup(&udev->dev)) {
1745 dev_dbg(&udev->dev, "remote wakeup needed for autosuspend\n");
1748 udev->do_remote_wakeup = w;
1752 int usb_runtime_suspend(struct device *dev)
1754 struct usb_device *udev = to_usb_device(dev);
1757 /* A USB device can be suspended if it passes the various autosuspend
1758 * checks. Runtime suspend for a USB device means suspending all the
1759 * interfaces and then the device itself.
1761 if (autosuspend_check(udev) != 0)
1764 status = usb_suspend_both(udev, PMSG_AUTO_SUSPEND);
1766 /* Allow a retry if autosuspend failed temporarily */
1767 if (status == -EAGAIN || status == -EBUSY)
1768 usb_mark_last_busy(udev);
1770 /* The PM core reacts badly unless the return code is 0,
1771 * -EAGAIN, or -EBUSY, so always return -EBUSY on an error.
1778 int usb_runtime_resume(struct device *dev)
1780 struct usb_device *udev = to_usb_device(dev);
1783 /* Runtime resume for a USB device means resuming both the device
1784 * and all its interfaces.
1786 status = usb_resume_both(udev, PMSG_AUTO_RESUME);
1790 int usb_runtime_idle(struct device *dev)
1792 struct usb_device *udev = to_usb_device(dev);
1794 /* An idle USB device can be suspended if it passes the various
1795 * autosuspend checks.
1797 if (autosuspend_check(udev) == 0)
1798 pm_runtime_autosuspend(dev);
1799 /* Tell the core not to suspend it, though. */
1803 int usb_set_usb2_hardware_lpm(struct usb_device *udev, int enable)
1805 struct usb_hcd *hcd = bus_to_hcd(udev->bus);
1808 if (enable && !udev->usb2_hw_lpm_allowed)
1811 if (hcd->driver->set_usb2_hw_lpm) {
1812 ret = hcd->driver->set_usb2_hw_lpm(hcd, udev, enable);
1814 udev->usb2_hw_lpm_enabled = enable;
1820 #endif /* CONFIG_PM_RUNTIME */
1822 struct bus_type usb_bus_type = {
1824 .match = usb_device_match,
1825 .uevent = usb_uevent,