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)
81 dynid->id.driver_info = id->driver_info;
86 spin_lock(&dynids->lock);
87 list_add_tail(&dynid->node, &dynids->list);
88 spin_unlock(&dynids->lock);
90 retval = driver_attach(driver);
96 EXPORT_SYMBOL_GPL(usb_store_new_id);
98 ssize_t usb_show_dynids(struct usb_dynids *dynids, char *buf)
100 struct usb_dynid *dynid;
103 list_for_each_entry(dynid, &dynids->list, node)
104 if (dynid->id.bInterfaceClass != 0)
105 count += scnprintf(&buf[count], PAGE_SIZE - count, "%04x %04x %02x\n",
106 dynid->id.idVendor, dynid->id.idProduct,
107 dynid->id.bInterfaceClass);
109 count += scnprintf(&buf[count], PAGE_SIZE - count, "%04x %04x\n",
110 dynid->id.idVendor, dynid->id.idProduct);
113 EXPORT_SYMBOL_GPL(usb_show_dynids);
115 static ssize_t new_id_show(struct device_driver *driver, char *buf)
117 struct usb_driver *usb_drv = to_usb_driver(driver);
119 return usb_show_dynids(&usb_drv->dynids, buf);
122 static ssize_t new_id_store(struct device_driver *driver,
123 const char *buf, size_t count)
125 struct usb_driver *usb_drv = to_usb_driver(driver);
127 return usb_store_new_id(&usb_drv->dynids, usb_drv->id_table, driver, buf, count);
129 static DRIVER_ATTR_RW(new_id);
132 * Remove a USB device ID from this driver
134 static ssize_t remove_id_store(struct device_driver *driver, const char *buf,
137 struct usb_dynid *dynid, *n;
138 struct usb_driver *usb_driver = to_usb_driver(driver);
143 fields = sscanf(buf, "%x %x", &idVendor, &idProduct);
147 spin_lock(&usb_driver->dynids.lock);
148 list_for_each_entry_safe(dynid, n, &usb_driver->dynids.list, node) {
149 struct usb_device_id *id = &dynid->id;
150 if ((id->idVendor == idVendor) &&
151 (id->idProduct == idProduct)) {
152 list_del(&dynid->node);
157 spin_unlock(&usb_driver->dynids.lock);
161 static ssize_t remove_id_show(struct device_driver *driver, char *buf)
163 return new_id_show(driver, buf);
165 static DRIVER_ATTR_RW(remove_id);
167 static int usb_create_newid_files(struct usb_driver *usb_drv)
171 if (usb_drv->no_dynamic_id)
174 if (usb_drv->probe != NULL) {
175 error = driver_create_file(&usb_drv->drvwrap.driver,
176 &driver_attr_new_id);
178 error = driver_create_file(&usb_drv->drvwrap.driver,
179 &driver_attr_remove_id);
181 driver_remove_file(&usb_drv->drvwrap.driver,
182 &driver_attr_new_id);
189 static void usb_remove_newid_files(struct usb_driver *usb_drv)
191 if (usb_drv->no_dynamic_id)
194 if (usb_drv->probe != NULL) {
195 driver_remove_file(&usb_drv->drvwrap.driver,
196 &driver_attr_remove_id);
197 driver_remove_file(&usb_drv->drvwrap.driver,
198 &driver_attr_new_id);
202 static void usb_free_dynids(struct usb_driver *usb_drv)
204 struct usb_dynid *dynid, *n;
206 spin_lock(&usb_drv->dynids.lock);
207 list_for_each_entry_safe(dynid, n, &usb_drv->dynids.list, node) {
208 list_del(&dynid->node);
211 spin_unlock(&usb_drv->dynids.lock);
214 static const struct usb_device_id *usb_match_dynamic_id(struct usb_interface *intf,
215 struct usb_driver *drv)
217 struct usb_dynid *dynid;
219 spin_lock(&drv->dynids.lock);
220 list_for_each_entry(dynid, &drv->dynids.list, node) {
221 if (usb_match_one_id(intf, &dynid->id)) {
222 spin_unlock(&drv->dynids.lock);
226 spin_unlock(&drv->dynids.lock);
231 /* called from driver core with dev locked */
232 static int usb_probe_device(struct device *dev)
234 struct usb_device_driver *udriver = to_usb_device_driver(dev->driver);
235 struct usb_device *udev = to_usb_device(dev);
238 dev_dbg(dev, "%s\n", __func__);
240 /* TODO: Add real matching code */
242 /* The device should always appear to be in use
243 * unless the driver supports autosuspend.
245 if (!udriver->supports_autosuspend)
246 error = usb_autoresume_device(udev);
249 error = udriver->probe(udev);
253 /* called from driver core with dev locked */
254 static int usb_unbind_device(struct device *dev)
256 struct usb_device *udev = to_usb_device(dev);
257 struct usb_device_driver *udriver = to_usb_device_driver(dev->driver);
259 udriver->disconnect(udev);
260 if (!udriver->supports_autosuspend)
261 usb_autosuspend_device(udev);
266 * Cancel any pending scheduled resets
268 * [see usb_queue_reset_device()]
270 * Called after unconfiguring / when releasing interfaces. See
271 * comments in __usb_queue_reset_device() regarding
272 * udev->reset_running.
274 static void usb_cancel_queued_reset(struct usb_interface *iface)
276 if (iface->reset_running == 0)
277 cancel_work_sync(&iface->reset_ws);
280 /* called from driver core with dev locked */
281 static int usb_probe_interface(struct device *dev)
283 struct usb_driver *driver = to_usb_driver(dev->driver);
284 struct usb_interface *intf = to_usb_interface(dev);
285 struct usb_device *udev = interface_to_usbdev(intf);
286 const struct usb_device_id *id;
288 int lpm_disable_error;
290 dev_dbg(dev, "%s\n", __func__);
292 intf->needs_binding = 0;
294 if (usb_device_is_owned(udev))
297 if (udev->authorized == 0) {
298 dev_err(&intf->dev, "Device is not authorized for usage\n");
302 id = usb_match_id(intf, driver->id_table);
304 id = usb_match_dynamic_id(intf, driver);
308 dev_dbg(dev, "%s - got id\n", __func__);
310 error = usb_autoresume_device(udev);
314 intf->condition = USB_INTERFACE_BINDING;
316 /* Probed interfaces are initially active. They are
317 * runtime-PM-enabled only if the driver has autosuspend support.
318 * They are sensitive to their children's power states.
320 pm_runtime_set_active(dev);
321 pm_suspend_ignore_children(dev, false);
322 if (driver->supports_autosuspend)
323 pm_runtime_enable(dev);
325 /* If the new driver doesn't allow hub-initiated LPM, and we can't
326 * disable hub-initiated LPM, then fail the probe.
328 * Otherwise, leaving LPM enabled should be harmless, because the
329 * endpoint intervals should remain the same, and the U1/U2 timeouts
330 * should remain the same.
332 * If we need to install alt setting 0 before probe, or another alt
333 * setting during probe, that should also be fine. usb_set_interface()
334 * will attempt to disable LPM, and fail if it can't disable it.
336 lpm_disable_error = usb_unlocked_disable_lpm(udev);
337 if (lpm_disable_error && driver->disable_hub_initiated_lpm) {
338 dev_err(&intf->dev, "%s Failed to disable LPM for driver %s\n.",
339 __func__, driver->name);
340 error = lpm_disable_error;
344 /* Carry out a deferred switch to altsetting 0 */
345 if (intf->needs_altsetting0) {
346 error = usb_set_interface(udev, intf->altsetting[0].
347 desc.bInterfaceNumber, 0);
350 intf->needs_altsetting0 = 0;
353 error = driver->probe(intf, id);
357 intf->condition = USB_INTERFACE_BOUND;
359 /* If the LPM disable succeeded, balance the ref counts. */
360 if (!lpm_disable_error)
361 usb_unlocked_enable_lpm(udev);
363 usb_autosuspend_device(udev);
367 usb_set_intfdata(intf, NULL);
368 intf->needs_remote_wakeup = 0;
369 intf->condition = USB_INTERFACE_UNBOUND;
370 usb_cancel_queued_reset(intf);
372 /* If the LPM disable succeeded, balance the ref counts. */
373 if (!lpm_disable_error)
374 usb_unlocked_enable_lpm(udev);
376 /* Unbound interfaces are always runtime-PM-disabled and -suspended */
377 if (driver->supports_autosuspend)
378 pm_runtime_disable(dev);
379 pm_runtime_set_suspended(dev);
381 usb_autosuspend_device(udev);
385 /* called from driver core with dev locked */
386 static int usb_unbind_interface(struct device *dev)
388 struct usb_driver *driver = to_usb_driver(dev->driver);
389 struct usb_interface *intf = to_usb_interface(dev);
390 struct usb_device *udev;
391 int error, r, lpm_disable_error;
393 intf->condition = USB_INTERFACE_UNBINDING;
395 /* Autoresume for set_interface call below */
396 udev = interface_to_usbdev(intf);
397 error = usb_autoresume_device(udev);
399 /* Hub-initiated LPM policy may change, so attempt to disable LPM until
400 * the driver is unbound. If LPM isn't disabled, that's fine because it
401 * wouldn't be enabled unless all the bound interfaces supported
404 lpm_disable_error = usb_unlocked_disable_lpm(udev);
406 /* Terminate all URBs for this interface unless the driver
407 * supports "soft" unbinding.
409 if (!driver->soft_unbind)
410 usb_disable_interface(udev, intf, false);
412 driver->disconnect(intf);
413 usb_cancel_queued_reset(intf);
415 /* Reset other interface state.
416 * We cannot do a Set-Interface if the device is suspended or
417 * if it is prepared for a system sleep (since installing a new
418 * altsetting means creating new endpoint device entries).
419 * When either of these happens, defer the Set-Interface.
421 if (intf->cur_altsetting->desc.bAlternateSetting == 0) {
422 /* Already in altsetting 0 so skip Set-Interface.
423 * Just re-enable it without affecting the endpoint toggles.
425 usb_enable_interface(udev, intf, false);
426 } else if (!error && !intf->dev.power.is_prepared) {
427 r = usb_set_interface(udev, intf->altsetting[0].
428 desc.bInterfaceNumber, 0);
430 intf->needs_altsetting0 = 1;
432 intf->needs_altsetting0 = 1;
434 usb_set_intfdata(intf, NULL);
436 intf->condition = USB_INTERFACE_UNBOUND;
437 intf->needs_remote_wakeup = 0;
439 /* Attempt to re-enable USB3 LPM, if the disable succeeded. */
440 if (!lpm_disable_error)
441 usb_unlocked_enable_lpm(udev);
443 /* Unbound interfaces are always runtime-PM-disabled and -suspended */
444 if (driver->supports_autosuspend)
445 pm_runtime_disable(dev);
446 pm_runtime_set_suspended(dev);
448 /* Undo any residual pm_autopm_get_interface_* calls */
449 for (r = atomic_read(&intf->pm_usage_cnt); r > 0; --r)
450 usb_autopm_put_interface_no_suspend(intf);
451 atomic_set(&intf->pm_usage_cnt, 0);
454 usb_autosuspend_device(udev);
460 * usb_driver_claim_interface - bind a driver to an interface
461 * @driver: the driver to be bound
462 * @iface: the interface to which it will be bound; must be in the
463 * usb device's active configuration
464 * @priv: driver data associated with that interface
466 * This is used by usb device drivers that need to claim more than one
467 * interface on a device when probing (audio and acm are current examples).
468 * No device driver should directly modify internal usb_interface or
469 * usb_device structure members.
471 * Few drivers should need to use this routine, since the most natural
472 * way to bind to an interface is to return the private data from
473 * the driver's probe() method.
475 * Callers must own the device lock, so driver probe() entries don't need
476 * extra locking, but other call contexts may need to explicitly claim that
479 * Return: 0 on success.
481 int usb_driver_claim_interface(struct usb_driver *driver,
482 struct usb_interface *iface, void *priv)
484 struct device *dev = &iface->dev;
485 struct usb_device *udev;
487 int lpm_disable_error;
492 udev = interface_to_usbdev(iface);
494 dev->driver = &driver->drvwrap.driver;
495 usb_set_intfdata(iface, priv);
496 iface->needs_binding = 0;
498 iface->condition = USB_INTERFACE_BOUND;
500 /* Disable LPM until this driver is bound. */
501 lpm_disable_error = usb_unlocked_disable_lpm(udev);
502 if (lpm_disable_error && driver->disable_hub_initiated_lpm) {
503 dev_err(&iface->dev, "%s Failed to disable LPM for driver %s\n.",
504 __func__, driver->name);
508 /* Claimed interfaces are initially inactive (suspended) and
509 * runtime-PM-enabled, but only if the driver has autosuspend
510 * support. Otherwise they are marked active, to prevent the
511 * device from being autosuspended, but left disabled. In either
512 * case they are sensitive to their children's power states.
514 pm_suspend_ignore_children(dev, false);
515 if (driver->supports_autosuspend)
516 pm_runtime_enable(dev);
518 pm_runtime_set_active(dev);
520 /* if interface was already added, bind now; else let
521 * the future device_add() bind it, bypassing probe()
523 if (device_is_registered(dev))
524 retval = device_bind_driver(dev);
526 /* Attempt to re-enable USB3 LPM, if the disable was successful. */
527 if (!lpm_disable_error)
528 usb_unlocked_enable_lpm(udev);
532 EXPORT_SYMBOL_GPL(usb_driver_claim_interface);
535 * usb_driver_release_interface - unbind a driver from an interface
536 * @driver: the driver to be unbound
537 * @iface: the interface from which it will be unbound
539 * This can be used by drivers to release an interface without waiting
540 * for their disconnect() methods to be called. In typical cases this
541 * also causes the driver disconnect() method to be called.
543 * This call is synchronous, and may not be used in an interrupt context.
544 * Callers must own the device lock, so driver disconnect() entries don't
545 * need extra locking, but other call contexts may need to explicitly claim
548 void usb_driver_release_interface(struct usb_driver *driver,
549 struct usb_interface *iface)
551 struct device *dev = &iface->dev;
553 /* this should never happen, don't release something that's not ours */
554 if (!dev->driver || dev->driver != &driver->drvwrap.driver)
557 /* don't release from within disconnect() */
558 if (iface->condition != USB_INTERFACE_BOUND)
560 iface->condition = USB_INTERFACE_UNBINDING;
562 /* Release via the driver core only if the interface
563 * has already been registered
565 if (device_is_registered(dev)) {
566 device_release_driver(dev);
569 usb_unbind_interface(dev);
574 EXPORT_SYMBOL_GPL(usb_driver_release_interface);
576 /* returns 0 if no match, 1 if match */
577 int usb_match_device(struct usb_device *dev, const struct usb_device_id *id)
579 if ((id->match_flags & USB_DEVICE_ID_MATCH_VENDOR) &&
580 id->idVendor != le16_to_cpu(dev->descriptor.idVendor))
583 if ((id->match_flags & USB_DEVICE_ID_MATCH_PRODUCT) &&
584 id->idProduct != le16_to_cpu(dev->descriptor.idProduct))
587 /* No need to test id->bcdDevice_lo != 0, since 0 is never
588 greater than any unsigned number. */
589 if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_LO) &&
590 (id->bcdDevice_lo > le16_to_cpu(dev->descriptor.bcdDevice)))
593 if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_HI) &&
594 (id->bcdDevice_hi < le16_to_cpu(dev->descriptor.bcdDevice)))
597 if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_CLASS) &&
598 (id->bDeviceClass != dev->descriptor.bDeviceClass))
601 if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_SUBCLASS) &&
602 (id->bDeviceSubClass != dev->descriptor.bDeviceSubClass))
605 if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_PROTOCOL) &&
606 (id->bDeviceProtocol != dev->descriptor.bDeviceProtocol))
612 /* returns 0 if no match, 1 if match */
613 int usb_match_one_id_intf(struct usb_device *dev,
614 struct usb_host_interface *intf,
615 const struct usb_device_id *id)
617 /* The interface class, subclass, protocol and number should never be
618 * checked for a match if the device class is Vendor Specific,
619 * unless the match record specifies the Vendor ID. */
620 if (dev->descriptor.bDeviceClass == USB_CLASS_VENDOR_SPEC &&
621 !(id->match_flags & USB_DEVICE_ID_MATCH_VENDOR) &&
622 (id->match_flags & (USB_DEVICE_ID_MATCH_INT_CLASS |
623 USB_DEVICE_ID_MATCH_INT_SUBCLASS |
624 USB_DEVICE_ID_MATCH_INT_PROTOCOL |
625 USB_DEVICE_ID_MATCH_INT_NUMBER)))
628 if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_CLASS) &&
629 (id->bInterfaceClass != intf->desc.bInterfaceClass))
632 if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_SUBCLASS) &&
633 (id->bInterfaceSubClass != intf->desc.bInterfaceSubClass))
636 if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_PROTOCOL) &&
637 (id->bInterfaceProtocol != intf->desc.bInterfaceProtocol))
640 if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_NUMBER) &&
641 (id->bInterfaceNumber != intf->desc.bInterfaceNumber))
647 /* returns 0 if no match, 1 if match */
648 int usb_match_one_id(struct usb_interface *interface,
649 const struct usb_device_id *id)
651 struct usb_host_interface *intf;
652 struct usb_device *dev;
654 /* proc_connectinfo in devio.c may call us with id == NULL. */
658 intf = interface->cur_altsetting;
659 dev = interface_to_usbdev(interface);
661 if (!usb_match_device(dev, id))
664 return usb_match_one_id_intf(dev, intf, id);
666 EXPORT_SYMBOL_GPL(usb_match_one_id);
669 * usb_match_id - find first usb_device_id matching device or interface
670 * @interface: the interface of interest
671 * @id: array of usb_device_id structures, terminated by zero entry
673 * usb_match_id searches an array of usb_device_id's and returns
674 * the first one matching the device or interface, or null.
675 * This is used when binding (or rebinding) a driver to an interface.
676 * Most USB device drivers will use this indirectly, through the usb core,
677 * but some layered driver frameworks use it directly.
678 * These device tables are exported with MODULE_DEVICE_TABLE, through
679 * modutils, to support the driver loading functionality of USB hotplugging.
681 * Return: The first matching usb_device_id, or %NULL.
685 * The "match_flags" element in a usb_device_id controls which
686 * members are used. If the corresponding bit is set, the
687 * value in the device_id must match its corresponding member
688 * in the device or interface descriptor, or else the device_id
691 * "driver_info" is normally used only by device drivers,
692 * but you can create a wildcard "matches anything" usb_device_id
693 * as a driver's "modules.usbmap" entry if you provide an id with
694 * only a nonzero "driver_info" field. If you do this, the USB device
695 * driver's probe() routine should use additional intelligence to
696 * decide whether to bind to the specified interface.
698 * What Makes Good usb_device_id Tables:
700 * The match algorithm is very simple, so that intelligence in
701 * driver selection must come from smart driver id records.
702 * Unless you have good reasons to use another selection policy,
703 * provide match elements only in related groups, and order match
704 * specifiers from specific to general. Use the macros provided
705 * for that purpose if you can.
707 * The most specific match specifiers use device descriptor
708 * data. These are commonly used with product-specific matches;
709 * the USB_DEVICE macro lets you provide vendor and product IDs,
710 * and you can also match against ranges of product revisions.
711 * These are widely used for devices with application or vendor
712 * specific bDeviceClass values.
714 * Matches based on device class/subclass/protocol specifications
715 * are slightly more general; use the USB_DEVICE_INFO macro, or
716 * its siblings. These are used with single-function devices
717 * where bDeviceClass doesn't specify that each interface has
720 * Matches based on interface class/subclass/protocol are the
721 * most general; they let drivers bind to any interface on a
722 * multiple-function device. Use the USB_INTERFACE_INFO
723 * macro, or its siblings, to match class-per-interface style
724 * devices (as recorded in bInterfaceClass).
726 * Note that an entry created by USB_INTERFACE_INFO won't match
727 * any interface if the device class is set to Vendor-Specific.
728 * This is deliberate; according to the USB spec the meanings of
729 * the interface class/subclass/protocol for these devices are also
730 * vendor-specific, and hence matching against a standard product
731 * class wouldn't work anyway. If you really want to use an
732 * interface-based match for such a device, create a match record
733 * that also specifies the vendor ID. (Unforunately there isn't a
734 * standard macro for creating records like this.)
736 * Within those groups, remember that not all combinations are
737 * meaningful. For example, don't give a product version range
738 * without vendor and product IDs; or specify a protocol without
739 * its associated class and subclass.
741 const struct usb_device_id *usb_match_id(struct usb_interface *interface,
742 const struct usb_device_id *id)
744 /* proc_connectinfo in devio.c may call us with id == NULL. */
748 /* It is important to check that id->driver_info is nonzero,
749 since an entry that is all zeroes except for a nonzero
750 id->driver_info is the way to create an entry that
751 indicates that the driver want to examine every
752 device and interface. */
753 for (; id->idVendor || id->idProduct || id->bDeviceClass ||
754 id->bInterfaceClass || id->driver_info; id++) {
755 if (usb_match_one_id(interface, id))
761 EXPORT_SYMBOL_GPL(usb_match_id);
763 static int usb_device_match(struct device *dev, struct device_driver *drv)
765 /* devices and interfaces are handled separately */
766 if (is_usb_device(dev)) {
768 /* interface drivers never match devices */
769 if (!is_usb_device_driver(drv))
772 /* TODO: Add real matching code */
775 } else if (is_usb_interface(dev)) {
776 struct usb_interface *intf;
777 struct usb_driver *usb_drv;
778 const struct usb_device_id *id;
780 /* device drivers never match interfaces */
781 if (is_usb_device_driver(drv))
784 intf = to_usb_interface(dev);
785 usb_drv = to_usb_driver(drv);
787 id = usb_match_id(intf, usb_drv->id_table);
791 id = usb_match_dynamic_id(intf, usb_drv);
799 static int usb_uevent(struct device *dev, struct kobj_uevent_env *env)
801 struct usb_device *usb_dev;
803 if (is_usb_device(dev)) {
804 usb_dev = to_usb_device(dev);
805 } else if (is_usb_interface(dev)) {
806 struct usb_interface *intf = to_usb_interface(dev);
808 usb_dev = interface_to_usbdev(intf);
813 if (usb_dev->devnum < 0) {
814 /* driver is often null here; dev_dbg() would oops */
815 pr_debug("usb %s: already deleted?\n", dev_name(dev));
819 pr_debug("usb %s: bus removed?\n", dev_name(dev));
823 /* per-device configurations are common */
824 if (add_uevent_var(env, "PRODUCT=%x/%x/%x",
825 le16_to_cpu(usb_dev->descriptor.idVendor),
826 le16_to_cpu(usb_dev->descriptor.idProduct),
827 le16_to_cpu(usb_dev->descriptor.bcdDevice)))
830 /* class-based driver binding models */
831 if (add_uevent_var(env, "TYPE=%d/%d/%d",
832 usb_dev->descriptor.bDeviceClass,
833 usb_dev->descriptor.bDeviceSubClass,
834 usb_dev->descriptor.bDeviceProtocol))
841 * usb_register_device_driver - register a USB device (not interface) driver
842 * @new_udriver: USB operations for the device driver
843 * @owner: module owner of this driver.
845 * Registers a USB device driver with the USB core. The list of
846 * unattached devices will be rescanned whenever a new driver is
847 * added, allowing the new driver to attach to any recognized devices.
849 * Return: A negative error code on failure and 0 on success.
851 int usb_register_device_driver(struct usb_device_driver *new_udriver,
852 struct module *owner)
859 new_udriver->drvwrap.for_devices = 1;
860 new_udriver->drvwrap.driver.name = new_udriver->name;
861 new_udriver->drvwrap.driver.bus = &usb_bus_type;
862 new_udriver->drvwrap.driver.probe = usb_probe_device;
863 new_udriver->drvwrap.driver.remove = usb_unbind_device;
864 new_udriver->drvwrap.driver.owner = owner;
866 retval = driver_register(&new_udriver->drvwrap.driver);
869 pr_info("%s: registered new device driver %s\n",
870 usbcore_name, new_udriver->name);
872 printk(KERN_ERR "%s: error %d registering device "
874 usbcore_name, retval, new_udriver->name);
878 EXPORT_SYMBOL_GPL(usb_register_device_driver);
881 * usb_deregister_device_driver - unregister a USB device (not interface) driver
882 * @udriver: USB operations of the device driver to unregister
883 * Context: must be able to sleep
885 * Unlinks the specified driver from the internal USB driver list.
887 void usb_deregister_device_driver(struct usb_device_driver *udriver)
889 pr_info("%s: deregistering device driver %s\n",
890 usbcore_name, udriver->name);
892 driver_unregister(&udriver->drvwrap.driver);
894 EXPORT_SYMBOL_GPL(usb_deregister_device_driver);
897 * usb_register_driver - register a USB interface driver
898 * @new_driver: USB operations for the interface driver
899 * @owner: module owner of this driver.
900 * @mod_name: module name string
902 * Registers a USB interface driver with the USB core. The list of
903 * unattached interfaces will be rescanned whenever a new driver is
904 * added, allowing the new driver to attach to any recognized interfaces.
906 * Return: A negative error code on failure and 0 on success.
908 * NOTE: if you want your driver to use the USB major number, you must call
909 * usb_register_dev() to enable that functionality. This function no longer
910 * takes care of that.
912 int usb_register_driver(struct usb_driver *new_driver, struct module *owner,
913 const char *mod_name)
920 new_driver->drvwrap.for_devices = 0;
921 new_driver->drvwrap.driver.name = new_driver->name;
922 new_driver->drvwrap.driver.bus = &usb_bus_type;
923 new_driver->drvwrap.driver.probe = usb_probe_interface;
924 new_driver->drvwrap.driver.remove = usb_unbind_interface;
925 new_driver->drvwrap.driver.owner = owner;
926 new_driver->drvwrap.driver.mod_name = mod_name;
927 spin_lock_init(&new_driver->dynids.lock);
928 INIT_LIST_HEAD(&new_driver->dynids.list);
930 retval = driver_register(&new_driver->drvwrap.driver);
934 retval = usb_create_newid_files(new_driver);
938 pr_info("%s: registered new interface driver %s\n",
939 usbcore_name, new_driver->name);
945 driver_unregister(&new_driver->drvwrap.driver);
947 printk(KERN_ERR "%s: error %d registering interface "
949 usbcore_name, retval, new_driver->name);
952 EXPORT_SYMBOL_GPL(usb_register_driver);
955 * usb_deregister - unregister a USB interface driver
956 * @driver: USB operations of the interface driver to unregister
957 * Context: must be able to sleep
959 * Unlinks the specified driver from the internal USB driver list.
961 * NOTE: If you called usb_register_dev(), you still need to call
962 * usb_deregister_dev() to clean up your driver's allocated minor numbers,
963 * this * call will no longer do it for you.
965 void usb_deregister(struct usb_driver *driver)
967 pr_info("%s: deregistering interface driver %s\n",
968 usbcore_name, driver->name);
970 usb_remove_newid_files(driver);
971 driver_unregister(&driver->drvwrap.driver);
972 usb_free_dynids(driver);
974 EXPORT_SYMBOL_GPL(usb_deregister);
976 /* Forced unbinding of a USB interface driver, either because
977 * it doesn't support pre_reset/post_reset/reset_resume or
978 * because it doesn't support suspend/resume.
980 * The caller must hold @intf's device's lock, but not its pm_mutex
981 * and not @intf->dev.sem.
983 void usb_forced_unbind_intf(struct usb_interface *intf)
985 struct usb_driver *driver = to_usb_driver(intf->dev.driver);
987 dev_dbg(&intf->dev, "forced unbind\n");
988 usb_driver_release_interface(driver, intf);
990 /* Mark the interface for later rebinding */
991 intf->needs_binding = 1;
994 /* Delayed forced unbinding of a USB interface driver and scan
997 * The caller must hold @intf's device's lock, but not its pm_mutex
998 * and not @intf->dev.sem.
1000 * Note: Rebinds will be skipped if a system sleep transition is in
1001 * progress and the PM "complete" callback hasn't occurred yet.
1003 void usb_rebind_intf(struct usb_interface *intf)
1007 /* Delayed unbind of an existing driver */
1008 if (intf->dev.driver)
1009 usb_forced_unbind_intf(intf);
1011 /* Try to rebind the interface */
1012 if (!intf->dev.power.is_prepared) {
1013 intf->needs_binding = 0;
1014 rc = device_attach(&intf->dev);
1016 dev_warn(&intf->dev, "rebind failed: %d\n", rc);
1022 /* Unbind drivers for @udev's interfaces that don't support suspend/resume
1023 * There is no check for reset_resume here because it can be determined
1024 * only during resume whether reset_resume is needed.
1026 * The caller must hold @udev's device lock.
1028 static void unbind_no_pm_drivers_interfaces(struct usb_device *udev)
1030 struct usb_host_config *config;
1032 struct usb_interface *intf;
1033 struct usb_driver *drv;
1035 config = udev->actconfig;
1037 for (i = 0; i < config->desc.bNumInterfaces; ++i) {
1038 intf = config->interface[i];
1040 if (intf->dev.driver) {
1041 drv = to_usb_driver(intf->dev.driver);
1042 if (!drv->suspend || !drv->resume)
1043 usb_forced_unbind_intf(intf);
1049 /* Unbind drivers for @udev's interfaces that failed to support reset-resume.
1050 * These interfaces have the needs_binding flag set by usb_resume_interface().
1052 * The caller must hold @udev's device lock.
1054 static void unbind_no_reset_resume_drivers_interfaces(struct usb_device *udev)
1056 struct usb_host_config *config;
1058 struct usb_interface *intf;
1060 config = udev->actconfig;
1062 for (i = 0; i < config->desc.bNumInterfaces; ++i) {
1063 intf = config->interface[i];
1064 if (intf->dev.driver && intf->needs_binding)
1065 usb_forced_unbind_intf(intf);
1070 static void do_rebind_interfaces(struct usb_device *udev)
1072 struct usb_host_config *config;
1074 struct usb_interface *intf;
1076 config = udev->actconfig;
1078 for (i = 0; i < config->desc.bNumInterfaces; ++i) {
1079 intf = config->interface[i];
1080 if (intf->needs_binding)
1081 usb_rebind_intf(intf);
1086 static int usb_suspend_device(struct usb_device *udev, pm_message_t msg)
1088 struct usb_device_driver *udriver;
1091 if (udev->state == USB_STATE_NOTATTACHED ||
1092 udev->state == USB_STATE_SUSPENDED)
1095 /* For devices that don't have a driver, we do a generic suspend. */
1096 if (udev->dev.driver)
1097 udriver = to_usb_device_driver(udev->dev.driver);
1099 udev->do_remote_wakeup = 0;
1100 udriver = &usb_generic_driver;
1102 status = udriver->suspend(udev, msg);
1105 dev_vdbg(&udev->dev, "%s: status %d\n", __func__, status);
1109 static int usb_resume_device(struct usb_device *udev, pm_message_t msg)
1111 struct usb_device_driver *udriver;
1114 if (udev->state == USB_STATE_NOTATTACHED)
1117 /* Can't resume it if it doesn't have a driver. */
1118 if (udev->dev.driver == NULL) {
1123 /* Non-root devices on a full/low-speed bus must wait for their
1124 * companion high-speed root hub, in case a handoff is needed.
1126 if (!PMSG_IS_AUTO(msg) && udev->parent && udev->bus->hs_companion)
1127 device_pm_wait_for_dev(&udev->dev,
1128 &udev->bus->hs_companion->root_hub->dev);
1130 if (udev->quirks & USB_QUIRK_RESET_RESUME)
1131 udev->reset_resume = 1;
1133 udriver = to_usb_device_driver(udev->dev.driver);
1134 status = udriver->resume(udev, msg);
1137 dev_vdbg(&udev->dev, "%s: status %d\n", __func__, status);
1141 static int usb_suspend_interface(struct usb_device *udev,
1142 struct usb_interface *intf, pm_message_t msg)
1144 struct usb_driver *driver;
1147 if (udev->state == USB_STATE_NOTATTACHED ||
1148 intf->condition == USB_INTERFACE_UNBOUND)
1150 driver = to_usb_driver(intf->dev.driver);
1152 /* at this time we know the driver supports suspend */
1153 status = driver->suspend(intf, msg);
1154 if (status && !PMSG_IS_AUTO(msg))
1155 dev_err(&intf->dev, "suspend error %d\n", status);
1158 dev_vdbg(&intf->dev, "%s: status %d\n", __func__, status);
1162 static int usb_resume_interface(struct usb_device *udev,
1163 struct usb_interface *intf, pm_message_t msg, int reset_resume)
1165 struct usb_driver *driver;
1168 if (udev->state == USB_STATE_NOTATTACHED)
1171 /* Don't let autoresume interfere with unbinding */
1172 if (intf->condition == USB_INTERFACE_UNBINDING)
1175 /* Can't resume it if it doesn't have a driver. */
1176 if (intf->condition == USB_INTERFACE_UNBOUND) {
1178 /* Carry out a deferred switch to altsetting 0 */
1179 if (intf->needs_altsetting0 && !intf->dev.power.is_prepared) {
1180 usb_set_interface(udev, intf->altsetting[0].
1181 desc.bInterfaceNumber, 0);
1182 intf->needs_altsetting0 = 0;
1187 /* Don't resume if the interface is marked for rebinding */
1188 if (intf->needs_binding)
1190 driver = to_usb_driver(intf->dev.driver);
1193 if (driver->reset_resume) {
1194 status = driver->reset_resume(intf);
1196 dev_err(&intf->dev, "%s error %d\n",
1197 "reset_resume", status);
1199 intf->needs_binding = 1;
1200 dev_dbg(&intf->dev, "no reset_resume for driver %s?\n",
1204 status = driver->resume(intf);
1206 dev_err(&intf->dev, "resume error %d\n", status);
1210 dev_vdbg(&intf->dev, "%s: status %d\n", __func__, status);
1212 /* Later we will unbind the driver and/or reprobe, if necessary */
1217 * usb_suspend_both - suspend a USB device and its interfaces
1218 * @udev: the usb_device to suspend
1219 * @msg: Power Management message describing this state transition
1221 * This is the central routine for suspending USB devices. It calls the
1222 * suspend methods for all the interface drivers in @udev and then calls
1223 * the suspend method for @udev itself. When the routine is called in
1224 * autosuspend, if an error occurs at any stage, all the interfaces
1225 * which were suspended are resumed so that they remain in the same
1226 * state as the device, but when called from system sleep, all error
1227 * from suspend methods of interfaces and the non-root-hub device itself
1228 * are simply ignored, so all suspended interfaces are only resumed
1229 * to the device's state when @udev is root-hub and its suspend method
1232 * Autosuspend requests originating from a child device or an interface
1233 * driver may be made without the protection of @udev's device lock, but
1234 * all other suspend calls will hold the lock. Usbcore will insure that
1235 * method calls do not arrive during bind, unbind, or reset operations.
1236 * However drivers must be prepared to handle suspend calls arriving at
1237 * unpredictable times.
1239 * This routine can run only in process context.
1241 * Return: 0 if the suspend succeeded.
1243 static int usb_suspend_both(struct usb_device *udev, pm_message_t msg)
1247 struct usb_interface *intf;
1249 if (udev->state == USB_STATE_NOTATTACHED ||
1250 udev->state == USB_STATE_SUSPENDED)
1253 /* Suspend all the interfaces and then udev itself */
1254 if (udev->actconfig) {
1255 n = udev->actconfig->desc.bNumInterfaces;
1256 for (i = n - 1; i >= 0; --i) {
1257 intf = udev->actconfig->interface[i];
1258 status = usb_suspend_interface(udev, intf, msg);
1260 /* Ignore errors during system sleep transitions */
1261 if (!PMSG_IS_AUTO(msg))
1268 status = usb_suspend_device(udev, msg);
1271 * Ignore errors from non-root-hub devices during
1272 * system sleep transitions. For the most part,
1273 * these devices should go to low power anyway when
1274 * the entire bus is suspended.
1276 if (udev->parent && !PMSG_IS_AUTO(msg))
1280 /* If the suspend failed, resume interfaces that did get suspended */
1282 if (udev->actconfig) {
1283 msg.event ^= (PM_EVENT_SUSPEND | PM_EVENT_RESUME);
1285 intf = udev->actconfig->interface[i];
1286 usb_resume_interface(udev, intf, msg, 0);
1290 /* If the suspend succeeded then prevent any more URB submissions
1291 * and flush any outstanding URBs.
1294 udev->can_submit = 0;
1295 for (i = 0; i < 16; ++i) {
1296 usb_hcd_flush_endpoint(udev, udev->ep_out[i]);
1297 usb_hcd_flush_endpoint(udev, udev->ep_in[i]);
1302 dev_vdbg(&udev->dev, "%s: status %d\n", __func__, status);
1307 * usb_resume_both - resume a USB device and its interfaces
1308 * @udev: the usb_device to resume
1309 * @msg: Power Management message describing this state transition
1311 * This is the central routine for resuming USB devices. It calls the
1312 * the resume method for @udev and then calls the resume methods for all
1313 * the interface drivers in @udev.
1315 * Autoresume requests originating from a child device or an interface
1316 * driver may be made without the protection of @udev's device lock, but
1317 * all other resume calls will hold the lock. Usbcore will insure that
1318 * method calls do not arrive during bind, unbind, or reset operations.
1319 * However drivers must be prepared to handle resume calls arriving at
1320 * unpredictable times.
1322 * This routine can run only in process context.
1324 * Return: 0 on success.
1326 static int usb_resume_both(struct usb_device *udev, pm_message_t msg)
1330 struct usb_interface *intf;
1332 if (udev->state == USB_STATE_NOTATTACHED) {
1336 udev->can_submit = 1;
1338 /* Resume the device */
1339 if (udev->state == USB_STATE_SUSPENDED || udev->reset_resume)
1340 status = usb_resume_device(udev, msg);
1342 /* Resume the interfaces */
1343 if (status == 0 && udev->actconfig) {
1344 for (i = 0; i < udev->actconfig->desc.bNumInterfaces; i++) {
1345 intf = udev->actconfig->interface[i];
1346 usb_resume_interface(udev, intf, msg,
1347 udev->reset_resume);
1350 usb_mark_last_busy(udev);
1353 dev_vdbg(&udev->dev, "%s: status %d\n", __func__, status);
1355 udev->reset_resume = 0;
1359 static void choose_wakeup(struct usb_device *udev, pm_message_t msg)
1363 /* Remote wakeup is needed only when we actually go to sleep.
1364 * For things like FREEZE and QUIESCE, if the device is already
1365 * autosuspended then its current wakeup setting is okay.
1367 if (msg.event == PM_EVENT_FREEZE || msg.event == PM_EVENT_QUIESCE) {
1368 if (udev->state != USB_STATE_SUSPENDED)
1369 udev->do_remote_wakeup = 0;
1373 /* Enable remote wakeup if it is allowed, even if no interface drivers
1376 w = device_may_wakeup(&udev->dev);
1378 /* If the device is autosuspended with the wrong wakeup setting,
1379 * autoresume now so the setting can be changed.
1381 if (udev->state == USB_STATE_SUSPENDED && w != udev->do_remote_wakeup)
1382 pm_runtime_resume(&udev->dev);
1383 udev->do_remote_wakeup = w;
1386 /* The device lock is held by the PM core */
1387 int usb_suspend(struct device *dev, pm_message_t msg)
1389 struct usb_device *udev = to_usb_device(dev);
1391 unbind_no_pm_drivers_interfaces(udev);
1393 /* From now on we are sure all drivers support suspend/resume
1394 * but not necessarily reset_resume()
1395 * so we may still need to unbind and rebind upon resume
1397 choose_wakeup(udev, msg);
1398 return usb_suspend_both(udev, msg);
1401 /* The device lock is held by the PM core */
1402 int usb_resume_complete(struct device *dev)
1404 struct usb_device *udev = to_usb_device(dev);
1406 /* For PM complete calls, all we do is rebind interfaces
1407 * whose needs_binding flag is set
1409 if (udev->state != USB_STATE_NOTATTACHED)
1410 do_rebind_interfaces(udev);
1414 /* The device lock is held by the PM core */
1415 int usb_resume(struct device *dev, pm_message_t msg)
1417 struct usb_device *udev = to_usb_device(dev);
1420 /* For all calls, take the device back to full power and
1421 * tell the PM core in case it was autosuspended previously.
1422 * Unbind the interfaces that will need rebinding later,
1423 * because they fail to support reset_resume.
1424 * (This can't be done in usb_resume_interface()
1425 * above because it doesn't own the right set of locks.)
1427 status = usb_resume_both(udev, msg);
1429 pm_runtime_disable(dev);
1430 pm_runtime_set_active(dev);
1431 pm_runtime_enable(dev);
1432 unbind_no_reset_resume_drivers_interfaces(udev);
1435 /* Avoid PM error messages for devices disconnected while suspended
1436 * as we'll display regular disconnect messages just a bit later.
1438 if (status == -ENODEV || status == -ESHUTDOWN)
1443 #endif /* CONFIG_PM */
1445 #ifdef CONFIG_PM_RUNTIME
1448 * usb_enable_autosuspend - allow a USB device to be autosuspended
1449 * @udev: the USB device which may be autosuspended
1451 * This routine allows @udev to be autosuspended. An autosuspend won't
1452 * take place until the autosuspend_delay has elapsed and all the other
1453 * necessary conditions are satisfied.
1455 * The caller must hold @udev's device lock.
1457 void usb_enable_autosuspend(struct usb_device *udev)
1459 pm_runtime_allow(&udev->dev);
1461 EXPORT_SYMBOL_GPL(usb_enable_autosuspend);
1464 * usb_disable_autosuspend - prevent a USB device from being autosuspended
1465 * @udev: the USB device which may not be autosuspended
1467 * This routine prevents @udev from being autosuspended and wakes it up
1468 * if it is already autosuspended.
1470 * The caller must hold @udev's device lock.
1472 void usb_disable_autosuspend(struct usb_device *udev)
1474 pm_runtime_forbid(&udev->dev);
1476 EXPORT_SYMBOL_GPL(usb_disable_autosuspend);
1479 * usb_autosuspend_device - delayed autosuspend of a USB device and its interfaces
1480 * @udev: the usb_device to autosuspend
1482 * This routine should be called when a core subsystem is finished using
1483 * @udev and wants to allow it to autosuspend. Examples would be when
1484 * @udev's device file in usbfs is closed or after a configuration change.
1486 * @udev's usage counter is decremented; if it drops to 0 and all the
1487 * interfaces are inactive then a delayed autosuspend will be attempted.
1488 * The attempt may fail (see autosuspend_check()).
1490 * The caller must hold @udev's device lock.
1492 * This routine can run only in process context.
1494 void usb_autosuspend_device(struct usb_device *udev)
1498 usb_mark_last_busy(udev);
1499 status = pm_runtime_put_sync_autosuspend(&udev->dev);
1500 dev_vdbg(&udev->dev, "%s: cnt %d -> %d\n",
1501 __func__, atomic_read(&udev->dev.power.usage_count),
1506 * usb_autoresume_device - immediately autoresume a USB device and its interfaces
1507 * @udev: the usb_device to autoresume
1509 * This routine should be called when a core subsystem wants to use @udev
1510 * and needs to guarantee that it is not suspended. No autosuspend will
1511 * occur until usb_autosuspend_device() is called. (Note that this will
1512 * not prevent suspend events originating in the PM core.) Examples would
1513 * be when @udev's device file in usbfs is opened or when a remote-wakeup
1514 * request is received.
1516 * @udev's usage counter is incremented to prevent subsequent autosuspends.
1517 * However if the autoresume fails then the usage counter is re-decremented.
1519 * The caller must hold @udev's device lock.
1521 * This routine can run only in process context.
1523 * Return: 0 on success. A negative error code otherwise.
1525 int usb_autoresume_device(struct usb_device *udev)
1529 status = pm_runtime_get_sync(&udev->dev);
1531 pm_runtime_put_sync(&udev->dev);
1532 dev_vdbg(&udev->dev, "%s: cnt %d -> %d\n",
1533 __func__, atomic_read(&udev->dev.power.usage_count),
1541 * usb_autopm_put_interface - decrement a USB interface's PM-usage counter
1542 * @intf: the usb_interface whose counter should be decremented
1544 * This routine should be called by an interface driver when it is
1545 * finished using @intf and wants to allow it to autosuspend. A typical
1546 * example would be a character-device driver when its device file is
1549 * The routine decrements @intf's usage counter. When the counter reaches
1550 * 0, a delayed autosuspend request for @intf's device is attempted. The
1551 * attempt may fail (see autosuspend_check()).
1553 * This routine can run only in process context.
1555 void usb_autopm_put_interface(struct usb_interface *intf)
1557 struct usb_device *udev = interface_to_usbdev(intf);
1560 usb_mark_last_busy(udev);
1561 atomic_dec(&intf->pm_usage_cnt);
1562 status = pm_runtime_put_sync(&intf->dev);
1563 dev_vdbg(&intf->dev, "%s: cnt %d -> %d\n",
1564 __func__, atomic_read(&intf->dev.power.usage_count),
1567 EXPORT_SYMBOL_GPL(usb_autopm_put_interface);
1570 * usb_autopm_put_interface_async - decrement a USB interface's PM-usage counter
1571 * @intf: the usb_interface whose counter should be decremented
1573 * This routine does much the same thing as usb_autopm_put_interface():
1574 * It decrements @intf's usage counter and schedules a delayed
1575 * autosuspend request if the counter is <= 0. The difference is that it
1576 * does not perform any synchronization; callers should hold a private
1577 * lock and handle all synchronization issues themselves.
1579 * Typically a driver would call this routine during an URB's completion
1580 * handler, if no more URBs were pending.
1582 * This routine can run in atomic context.
1584 void usb_autopm_put_interface_async(struct usb_interface *intf)
1586 struct usb_device *udev = interface_to_usbdev(intf);
1589 usb_mark_last_busy(udev);
1590 atomic_dec(&intf->pm_usage_cnt);
1591 status = pm_runtime_put(&intf->dev);
1592 dev_vdbg(&intf->dev, "%s: cnt %d -> %d\n",
1593 __func__, atomic_read(&intf->dev.power.usage_count),
1596 EXPORT_SYMBOL_GPL(usb_autopm_put_interface_async);
1599 * usb_autopm_put_interface_no_suspend - decrement a USB interface's PM-usage counter
1600 * @intf: the usb_interface whose counter should be decremented
1602 * This routine decrements @intf's usage counter but does not carry out an
1605 * This routine can run in atomic context.
1607 void usb_autopm_put_interface_no_suspend(struct usb_interface *intf)
1609 struct usb_device *udev = interface_to_usbdev(intf);
1611 usb_mark_last_busy(udev);
1612 atomic_dec(&intf->pm_usage_cnt);
1613 pm_runtime_put_noidle(&intf->dev);
1615 EXPORT_SYMBOL_GPL(usb_autopm_put_interface_no_suspend);
1618 * usb_autopm_get_interface - increment a USB interface's PM-usage counter
1619 * @intf: the usb_interface whose counter should be incremented
1621 * This routine should be called by an interface driver when it wants to
1622 * use @intf and needs to guarantee that it is not suspended. In addition,
1623 * the routine prevents @intf from being autosuspended subsequently. (Note
1624 * that this will not prevent suspend events originating in the PM core.)
1625 * This prevention will persist until usb_autopm_put_interface() is called
1626 * or @intf is unbound. A typical example would be a character-device
1627 * driver when its device file is opened.
1629 * @intf's usage counter is incremented to prevent subsequent autosuspends.
1630 * However if the autoresume fails then the counter is re-decremented.
1632 * This routine can run only in process context.
1634 * Return: 0 on success.
1636 int usb_autopm_get_interface(struct usb_interface *intf)
1640 status = pm_runtime_get_sync(&intf->dev);
1642 pm_runtime_put_sync(&intf->dev);
1644 atomic_inc(&intf->pm_usage_cnt);
1645 dev_vdbg(&intf->dev, "%s: cnt %d -> %d\n",
1646 __func__, atomic_read(&intf->dev.power.usage_count),
1652 EXPORT_SYMBOL_GPL(usb_autopm_get_interface);
1655 * usb_autopm_get_interface_async - increment a USB interface's PM-usage counter
1656 * @intf: the usb_interface whose counter should be incremented
1658 * This routine does much the same thing as
1659 * usb_autopm_get_interface(): It increments @intf's usage counter and
1660 * queues an autoresume request if the device is suspended. The
1661 * differences are that it does not perform any synchronization (callers
1662 * should hold a private lock and handle all synchronization issues
1663 * themselves), and it does not autoresume the device directly (it only
1664 * queues a request). After a successful call, the device may not yet be
1667 * This routine can run in atomic context.
1669 * Return: 0 on success. A negative error code otherwise.
1671 int usb_autopm_get_interface_async(struct usb_interface *intf)
1675 status = pm_runtime_get(&intf->dev);
1676 if (status < 0 && status != -EINPROGRESS)
1677 pm_runtime_put_noidle(&intf->dev);
1679 atomic_inc(&intf->pm_usage_cnt);
1680 dev_vdbg(&intf->dev, "%s: cnt %d -> %d\n",
1681 __func__, atomic_read(&intf->dev.power.usage_count),
1683 if (status > 0 || status == -EINPROGRESS)
1687 EXPORT_SYMBOL_GPL(usb_autopm_get_interface_async);
1690 * usb_autopm_get_interface_no_resume - increment a USB interface's PM-usage counter
1691 * @intf: the usb_interface whose counter should be incremented
1693 * This routine increments @intf's usage counter but does not carry out an
1696 * This routine can run in atomic context.
1698 void usb_autopm_get_interface_no_resume(struct usb_interface *intf)
1700 struct usb_device *udev = interface_to_usbdev(intf);
1702 usb_mark_last_busy(udev);
1703 atomic_inc(&intf->pm_usage_cnt);
1704 pm_runtime_get_noresume(&intf->dev);
1706 EXPORT_SYMBOL_GPL(usb_autopm_get_interface_no_resume);
1708 /* Internal routine to check whether we may autosuspend a device. */
1709 static int autosuspend_check(struct usb_device *udev)
1712 struct usb_interface *intf;
1714 /* Fail if autosuspend is disabled, or any interfaces are in use, or
1715 * any interface drivers require remote wakeup but it isn't available.
1718 if (udev->actconfig) {
1719 for (i = 0; i < udev->actconfig->desc.bNumInterfaces; i++) {
1720 intf = udev->actconfig->interface[i];
1722 /* We don't need to check interfaces that are
1723 * disabled for runtime PM. Either they are unbound
1724 * or else their drivers don't support autosuspend
1725 * and so they are permanently active.
1727 if (intf->dev.power.disable_depth)
1729 if (atomic_read(&intf->dev.power.usage_count) > 0)
1731 w |= intf->needs_remote_wakeup;
1733 /* Don't allow autosuspend if the device will need
1734 * a reset-resume and any of its interface drivers
1735 * doesn't include support or needs remote wakeup.
1737 if (udev->quirks & USB_QUIRK_RESET_RESUME) {
1738 struct usb_driver *driver;
1740 driver = to_usb_driver(intf->dev.driver);
1741 if (!driver->reset_resume ||
1742 intf->needs_remote_wakeup)
1747 if (w && !device_can_wakeup(&udev->dev)) {
1748 dev_dbg(&udev->dev, "remote wakeup needed for autosuspend\n");
1751 udev->do_remote_wakeup = w;
1755 int usb_runtime_suspend(struct device *dev)
1757 struct usb_device *udev = to_usb_device(dev);
1760 /* A USB device can be suspended if it passes the various autosuspend
1761 * checks. Runtime suspend for a USB device means suspending all the
1762 * interfaces and then the device itself.
1764 if (autosuspend_check(udev) != 0)
1767 status = usb_suspend_both(udev, PMSG_AUTO_SUSPEND);
1769 /* Allow a retry if autosuspend failed temporarily */
1770 if (status == -EAGAIN || status == -EBUSY)
1771 usb_mark_last_busy(udev);
1773 /* The PM core reacts badly unless the return code is 0,
1774 * -EAGAIN, or -EBUSY, so always return -EBUSY on an error.
1781 int usb_runtime_resume(struct device *dev)
1783 struct usb_device *udev = to_usb_device(dev);
1786 /* Runtime resume for a USB device means resuming both the device
1787 * and all its interfaces.
1789 status = usb_resume_both(udev, PMSG_AUTO_RESUME);
1793 int usb_runtime_idle(struct device *dev)
1795 struct usb_device *udev = to_usb_device(dev);
1797 /* An idle USB device can be suspended if it passes the various
1798 * autosuspend checks.
1800 if (autosuspend_check(udev) == 0)
1801 pm_runtime_autosuspend(dev);
1802 /* Tell the core not to suspend it, though. */
1806 int usb_set_usb2_hardware_lpm(struct usb_device *udev, int enable)
1808 struct usb_hcd *hcd = bus_to_hcd(udev->bus);
1811 if (enable && !udev->usb2_hw_lpm_allowed)
1814 if (hcd->driver->set_usb2_hw_lpm) {
1815 ret = hcd->driver->set_usb2_hw_lpm(hcd, udev, enable);
1817 udev->usb2_hw_lpm_enabled = enable;
1823 #endif /* CONFIG_PM_RUNTIME */
1825 struct bus_type usb_bus_type = {
1827 .match = usb_device_match,
1828 .uevent = usb_uevent,