2 * drivers/usb/driver.c - most of the driver model stuff for usb
4 * (C) Copyright 2005 Greg Kroah-Hartman <gregkh@suse.de>
6 * based on drivers/usb/usb.c which had the following copyrights:
7 * (C) Copyright Linus Torvalds 1999
8 * (C) Copyright Johannes Erdfelt 1999-2001
9 * (C) Copyright Andreas Gal 1999
10 * (C) Copyright Gregory P. Smith 1999
11 * (C) Copyright Deti Fliegl 1999 (new USB architecture)
12 * (C) Copyright Randy Dunlap 2000
13 * (C) Copyright David Brownell 2000-2004
14 * (C) Copyright Yggdrasil Computing, Inc. 2000
15 * (usb_device_id matching changes by Adam J. Richter)
16 * (C) Copyright Greg Kroah-Hartman 2002-2003
18 * NOTE! This is not actually a driver at all, rather this is
19 * just a collection of helper routines that implement the
20 * matching, probing, releasing, suspending and resuming for
25 #include <linux/device.h>
26 #include <linux/usb.h>
27 #include <linux/usb/quirks.h>
28 #include <linux/workqueue.h>
36 * Adds a new dynamic USBdevice ID to this driver,
37 * and cause the driver to probe for all devices again.
39 ssize_t
usb_store_new_id(struct usb_dynids
*dynids
,
40 struct device_driver
*driver
,
41 const char *buf
, size_t count
)
43 struct usb_dynid
*dynid
;
49 fields
= sscanf(buf
, "%x %x", &idVendor
, &idProduct
);
53 dynid
= kzalloc(sizeof(*dynid
), GFP_KERNEL
);
57 INIT_LIST_HEAD(&dynid
->node
);
58 dynid
->id
.idVendor
= idVendor
;
59 dynid
->id
.idProduct
= idProduct
;
60 dynid
->id
.match_flags
= USB_DEVICE_ID_MATCH_DEVICE
;
62 spin_lock(&dynids
->lock
);
63 list_add_tail(&dynids
->list
, &dynid
->node
);
64 spin_unlock(&dynids
->lock
);
66 if (get_driver(driver
)) {
67 retval
= driver_attach(driver
);
75 EXPORT_SYMBOL_GPL(usb_store_new_id
);
77 static ssize_t
store_new_id(struct device_driver
*driver
,
78 const char *buf
, size_t count
)
80 struct usb_driver
*usb_drv
= to_usb_driver(driver
);
82 return usb_store_new_id(&usb_drv
->dynids
, driver
, buf
, count
);
84 static DRIVER_ATTR(new_id
, S_IWUSR
, NULL
, store_new_id
);
86 static int usb_create_newid_file(struct usb_driver
*usb_drv
)
90 if (usb_drv
->no_dynamic_id
)
93 if (usb_drv
->probe
!= NULL
)
94 error
= sysfs_create_file(&usb_drv
->drvwrap
.driver
.kobj
,
95 &driver_attr_new_id
.attr
);
100 static void usb_remove_newid_file(struct usb_driver
*usb_drv
)
102 if (usb_drv
->no_dynamic_id
)
105 if (usb_drv
->probe
!= NULL
)
106 sysfs_remove_file(&usb_drv
->drvwrap
.driver
.kobj
,
107 &driver_attr_new_id
.attr
);
110 static void usb_free_dynids(struct usb_driver
*usb_drv
)
112 struct usb_dynid
*dynid
, *n
;
114 spin_lock(&usb_drv
->dynids
.lock
);
115 list_for_each_entry_safe(dynid
, n
, &usb_drv
->dynids
.list
, node
) {
116 list_del(&dynid
->node
);
119 spin_unlock(&usb_drv
->dynids
.lock
);
122 static inline int usb_create_newid_file(struct usb_driver
*usb_drv
)
127 static void usb_remove_newid_file(struct usb_driver
*usb_drv
)
131 static inline void usb_free_dynids(struct usb_driver
*usb_drv
)
136 static const struct usb_device_id
*usb_match_dynamic_id(struct usb_interface
*intf
,
137 struct usb_driver
*drv
)
139 struct usb_dynid
*dynid
;
141 spin_lock(&drv
->dynids
.lock
);
142 list_for_each_entry(dynid
, &drv
->dynids
.list
, node
) {
143 if (usb_match_one_id(intf
, &dynid
->id
)) {
144 spin_unlock(&drv
->dynids
.lock
);
148 spin_unlock(&drv
->dynids
.lock
);
153 /* called from driver core with dev locked */
154 static int usb_probe_device(struct device
*dev
)
156 struct usb_device_driver
*udriver
= to_usb_device_driver(dev
->driver
);
157 struct usb_device
*udev
;
160 dev_dbg(dev
, "%s\n", __FUNCTION__
);
162 if (!is_usb_device(dev
)) /* Sanity check */
165 udev
= to_usb_device(dev
);
167 /* TODO: Add real matching code */
169 /* The device should always appear to be in use
170 * unless the driver suports autosuspend.
172 udev
->pm_usage_cnt
= !(udriver
->supports_autosuspend
);
174 error
= udriver
->probe(udev
);
178 /* called from driver core with dev locked */
179 static int usb_unbind_device(struct device
*dev
)
181 struct usb_device_driver
*udriver
= to_usb_device_driver(dev
->driver
);
183 udriver
->disconnect(to_usb_device(dev
));
188 /* called from driver core with dev locked */
189 static int usb_probe_interface(struct device
*dev
)
191 struct usb_driver
*driver
= to_usb_driver(dev
->driver
);
192 struct usb_interface
*intf
;
193 struct usb_device
*udev
;
194 const struct usb_device_id
*id
;
197 dev_dbg(dev
, "%s\n", __FUNCTION__
);
199 if (is_usb_device(dev
)) /* Sanity check */
202 intf
= to_usb_interface(dev
);
203 udev
= interface_to_usbdev(intf
);
205 id
= usb_match_id(intf
, driver
->id_table
);
207 id
= usb_match_dynamic_id(intf
, driver
);
209 dev_dbg(dev
, "%s - got id\n", __FUNCTION__
);
211 error
= usb_autoresume_device(udev
);
215 /* Interface "power state" doesn't correspond to any hardware
216 * state whatsoever. We use it to record when it's bound to
217 * a driver that may start I/0: it's not frozen/quiesced.
220 intf
->condition
= USB_INTERFACE_BINDING
;
222 /* The interface should always appear to be in use
223 * unless the driver suports autosuspend.
225 intf
->pm_usage_cnt
= !(driver
->supports_autosuspend
);
227 error
= driver
->probe(intf
, id
);
230 intf
->needs_remote_wakeup
= 0;
231 intf
->condition
= USB_INTERFACE_UNBOUND
;
233 intf
->condition
= USB_INTERFACE_BOUND
;
235 usb_autosuspend_device(udev
);
241 /* called from driver core with dev locked */
242 static int usb_unbind_interface(struct device
*dev
)
244 struct usb_driver
*driver
= to_usb_driver(dev
->driver
);
245 struct usb_interface
*intf
= to_usb_interface(dev
);
246 struct usb_device
*udev
;
249 intf
->condition
= USB_INTERFACE_UNBINDING
;
251 /* Autoresume for set_interface call below */
252 udev
= interface_to_usbdev(intf
);
253 error
= usb_autoresume_device(udev
);
255 /* release all urbs for this interface */
256 usb_disable_interface(interface_to_usbdev(intf
), intf
);
258 driver
->disconnect(intf
);
260 /* reset other interface state */
261 usb_set_interface(interface_to_usbdev(intf
),
262 intf
->altsetting
[0].desc
.bInterfaceNumber
,
264 usb_set_intfdata(intf
, NULL
);
266 intf
->condition
= USB_INTERFACE_UNBOUND
;
268 intf
->needs_remote_wakeup
= 0;
271 usb_autosuspend_device(udev
);
277 * usb_driver_claim_interface - bind a driver to an interface
278 * @driver: the driver to be bound
279 * @iface: the interface to which it will be bound; must be in the
280 * usb device's active configuration
281 * @priv: driver data associated with that interface
283 * This is used by usb device drivers that need to claim more than one
284 * interface on a device when probing (audio and acm are current examples).
285 * No device driver should directly modify internal usb_interface or
286 * usb_device structure members.
288 * Few drivers should need to use this routine, since the most natural
289 * way to bind to an interface is to return the private data from
290 * the driver's probe() method.
292 * Callers must own the device lock, so driver probe() entries don't need
293 * extra locking, but other call contexts may need to explicitly claim that
296 int usb_driver_claim_interface(struct usb_driver
*driver
,
297 struct usb_interface
*iface
, void* priv
)
299 struct device
*dev
= &iface
->dev
;
300 struct usb_device
*udev
= interface_to_usbdev(iface
);
306 dev
->driver
= &driver
->drvwrap
.driver
;
307 usb_set_intfdata(iface
, priv
);
310 iface
->condition
= USB_INTERFACE_BOUND
;
312 iface
->pm_usage_cnt
= !(driver
->supports_autosuspend
);
315 /* if interface was already added, bind now; else let
316 * the future device_add() bind it, bypassing probe()
318 if (device_is_registered(dev
))
319 retval
= device_bind_driver(dev
);
323 EXPORT_SYMBOL(usb_driver_claim_interface
);
326 * usb_driver_release_interface - unbind a driver from an interface
327 * @driver: the driver to be unbound
328 * @iface: the interface from which it will be unbound
330 * This can be used by drivers to release an interface without waiting
331 * for their disconnect() methods to be called. In typical cases this
332 * also causes the driver disconnect() method to be called.
334 * This call is synchronous, and may not be used in an interrupt context.
335 * Callers must own the device lock, so driver disconnect() entries don't
336 * need extra locking, but other call contexts may need to explicitly claim
339 void usb_driver_release_interface(struct usb_driver
*driver
,
340 struct usb_interface
*iface
)
342 struct device
*dev
= &iface
->dev
;
343 struct usb_device
*udev
= interface_to_usbdev(iface
);
345 /* this should never happen, don't release something that's not ours */
346 if (!dev
->driver
|| dev
->driver
!= &driver
->drvwrap
.driver
)
349 /* don't release from within disconnect() */
350 if (iface
->condition
!= USB_INTERFACE_BOUND
)
353 /* don't release if the interface hasn't been added yet */
354 if (device_is_registered(dev
)) {
355 iface
->condition
= USB_INTERFACE_UNBINDING
;
356 device_release_driver(dev
);
360 usb_set_intfdata(iface
, NULL
);
363 iface
->condition
= USB_INTERFACE_UNBOUND
;
364 mark_quiesced(iface
);
365 iface
->needs_remote_wakeup
= 0;
368 EXPORT_SYMBOL(usb_driver_release_interface
);
370 /* returns 0 if no match, 1 if match */
371 int usb_match_device(struct usb_device
*dev
, const struct usb_device_id
*id
)
373 if ((id
->match_flags
& USB_DEVICE_ID_MATCH_VENDOR
) &&
374 id
->idVendor
!= le16_to_cpu(dev
->descriptor
.idVendor
))
377 if ((id
->match_flags
& USB_DEVICE_ID_MATCH_PRODUCT
) &&
378 id
->idProduct
!= le16_to_cpu(dev
->descriptor
.idProduct
))
381 /* No need to test id->bcdDevice_lo != 0, since 0 is never
382 greater than any unsigned number. */
383 if ((id
->match_flags
& USB_DEVICE_ID_MATCH_DEV_LO
) &&
384 (id
->bcdDevice_lo
> le16_to_cpu(dev
->descriptor
.bcdDevice
)))
387 if ((id
->match_flags
& USB_DEVICE_ID_MATCH_DEV_HI
) &&
388 (id
->bcdDevice_hi
< le16_to_cpu(dev
->descriptor
.bcdDevice
)))
391 if ((id
->match_flags
& USB_DEVICE_ID_MATCH_DEV_CLASS
) &&
392 (id
->bDeviceClass
!= dev
->descriptor
.bDeviceClass
))
395 if ((id
->match_flags
& USB_DEVICE_ID_MATCH_DEV_SUBCLASS
) &&
396 (id
->bDeviceSubClass
!= dev
->descriptor
.bDeviceSubClass
))
399 if ((id
->match_flags
& USB_DEVICE_ID_MATCH_DEV_PROTOCOL
) &&
400 (id
->bDeviceProtocol
!= dev
->descriptor
.bDeviceProtocol
))
406 /* returns 0 if no match, 1 if match */
407 int usb_match_one_id(struct usb_interface
*interface
,
408 const struct usb_device_id
*id
)
410 struct usb_host_interface
*intf
;
411 struct usb_device
*dev
;
413 /* proc_connectinfo in devio.c may call us with id == NULL. */
417 intf
= interface
->cur_altsetting
;
418 dev
= interface_to_usbdev(interface
);
420 if (!usb_match_device(dev
, id
))
423 /* The interface class, subclass, and protocol should never be
424 * checked for a match if the device class is Vendor Specific,
425 * unless the match record specifies the Vendor ID. */
426 if (dev
->descriptor
.bDeviceClass
== USB_CLASS_VENDOR_SPEC
&&
427 !(id
->match_flags
& USB_DEVICE_ID_MATCH_VENDOR
) &&
428 (id
->match_flags
& (USB_DEVICE_ID_MATCH_INT_CLASS
|
429 USB_DEVICE_ID_MATCH_INT_SUBCLASS
|
430 USB_DEVICE_ID_MATCH_INT_PROTOCOL
)))
433 if ((id
->match_flags
& USB_DEVICE_ID_MATCH_INT_CLASS
) &&
434 (id
->bInterfaceClass
!= intf
->desc
.bInterfaceClass
))
437 if ((id
->match_flags
& USB_DEVICE_ID_MATCH_INT_SUBCLASS
) &&
438 (id
->bInterfaceSubClass
!= intf
->desc
.bInterfaceSubClass
))
441 if ((id
->match_flags
& USB_DEVICE_ID_MATCH_INT_PROTOCOL
) &&
442 (id
->bInterfaceProtocol
!= intf
->desc
.bInterfaceProtocol
))
447 EXPORT_SYMBOL_GPL(usb_match_one_id
);
450 * usb_match_id - find first usb_device_id matching device or interface
451 * @interface: the interface of interest
452 * @id: array of usb_device_id structures, terminated by zero entry
454 * usb_match_id searches an array of usb_device_id's and returns
455 * the first one matching the device or interface, or null.
456 * This is used when binding (or rebinding) a driver to an interface.
457 * Most USB device drivers will use this indirectly, through the usb core,
458 * but some layered driver frameworks use it directly.
459 * These device tables are exported with MODULE_DEVICE_TABLE, through
460 * modutils, to support the driver loading functionality of USB hotplugging.
464 * The "match_flags" element in a usb_device_id controls which
465 * members are used. If the corresponding bit is set, the
466 * value in the device_id must match its corresponding member
467 * in the device or interface descriptor, or else the device_id
470 * "driver_info" is normally used only by device drivers,
471 * but you can create a wildcard "matches anything" usb_device_id
472 * as a driver's "modules.usbmap" entry if you provide an id with
473 * only a nonzero "driver_info" field. If you do this, the USB device
474 * driver's probe() routine should use additional intelligence to
475 * decide whether to bind to the specified interface.
477 * What Makes Good usb_device_id Tables:
479 * The match algorithm is very simple, so that intelligence in
480 * driver selection must come from smart driver id records.
481 * Unless you have good reasons to use another selection policy,
482 * provide match elements only in related groups, and order match
483 * specifiers from specific to general. Use the macros provided
484 * for that purpose if you can.
486 * The most specific match specifiers use device descriptor
487 * data. These are commonly used with product-specific matches;
488 * the USB_DEVICE macro lets you provide vendor and product IDs,
489 * and you can also match against ranges of product revisions.
490 * These are widely used for devices with application or vendor
491 * specific bDeviceClass values.
493 * Matches based on device class/subclass/protocol specifications
494 * are slightly more general; use the USB_DEVICE_INFO macro, or
495 * its siblings. These are used with single-function devices
496 * where bDeviceClass doesn't specify that each interface has
499 * Matches based on interface class/subclass/protocol are the
500 * most general; they let drivers bind to any interface on a
501 * multiple-function device. Use the USB_INTERFACE_INFO
502 * macro, or its siblings, to match class-per-interface style
503 * devices (as recorded in bInterfaceClass).
505 * Note that an entry created by USB_INTERFACE_INFO won't match
506 * any interface if the device class is set to Vendor-Specific.
507 * This is deliberate; according to the USB spec the meanings of
508 * the interface class/subclass/protocol for these devices are also
509 * vendor-specific, and hence matching against a standard product
510 * class wouldn't work anyway. If you really want to use an
511 * interface-based match for such a device, create a match record
512 * that also specifies the vendor ID. (Unforunately there isn't a
513 * standard macro for creating records like this.)
515 * Within those groups, remember that not all combinations are
516 * meaningful. For example, don't give a product version range
517 * without vendor and product IDs; or specify a protocol without
518 * its associated class and subclass.
520 const struct usb_device_id
*usb_match_id(struct usb_interface
*interface
,
521 const struct usb_device_id
*id
)
523 /* proc_connectinfo in devio.c may call us with id == NULL. */
527 /* It is important to check that id->driver_info is nonzero,
528 since an entry that is all zeroes except for a nonzero
529 id->driver_info is the way to create an entry that
530 indicates that the driver want to examine every
531 device and interface. */
532 for (; id
->idVendor
|| id
->bDeviceClass
|| id
->bInterfaceClass
||
533 id
->driver_info
; id
++) {
534 if (usb_match_one_id(interface
, id
))
540 EXPORT_SYMBOL_GPL_FUTURE(usb_match_id
);
542 static int usb_device_match(struct device
*dev
, struct device_driver
*drv
)
544 /* devices and interfaces are handled separately */
545 if (is_usb_device(dev
)) {
547 /* interface drivers never match devices */
548 if (!is_usb_device_driver(drv
))
551 /* TODO: Add real matching code */
555 struct usb_interface
*intf
;
556 struct usb_driver
*usb_drv
;
557 const struct usb_device_id
*id
;
559 /* device drivers never match interfaces */
560 if (is_usb_device_driver(drv
))
563 intf
= to_usb_interface(dev
);
564 usb_drv
= to_usb_driver(drv
);
566 id
= usb_match_id(intf
, usb_drv
->id_table
);
570 id
= usb_match_dynamic_id(intf
, usb_drv
);
578 #ifdef CONFIG_HOTPLUG
579 static int usb_uevent(struct device
*dev
, char **envp
, int num_envp
,
580 char *buffer
, int buffer_size
)
582 struct usb_device
*usb_dev
;
589 /* driver is often null here; dev_dbg() would oops */
590 pr_debug ("usb %s: uevent\n", dev
->bus_id
);
592 if (is_usb_device(dev
))
593 usb_dev
= to_usb_device(dev
);
595 struct usb_interface
*intf
= to_usb_interface(dev
);
596 usb_dev
= interface_to_usbdev(intf
);
599 if (usb_dev
->devnum
< 0) {
600 pr_debug ("usb %s: already deleted?\n", dev
->bus_id
);
604 pr_debug ("usb %s: bus removed?\n", dev
->bus_id
);
608 #ifdef CONFIG_USB_DEVICEFS
609 /* If this is available, userspace programs can directly read
610 * all the device descriptors we don't tell them about. Or
611 * act as usermode drivers.
613 if (add_uevent_var(envp
, num_envp
, &i
,
614 buffer
, buffer_size
, &length
,
615 "DEVICE=/proc/bus/usb/%03d/%03d",
616 usb_dev
->bus
->busnum
, usb_dev
->devnum
))
620 /* per-device configurations are common */
621 if (add_uevent_var(envp
, num_envp
, &i
,
622 buffer
, buffer_size
, &length
,
624 le16_to_cpu(usb_dev
->descriptor
.idVendor
),
625 le16_to_cpu(usb_dev
->descriptor
.idProduct
),
626 le16_to_cpu(usb_dev
->descriptor
.bcdDevice
)))
629 /* class-based driver binding models */
630 if (add_uevent_var(envp
, num_envp
, &i
,
631 buffer
, buffer_size
, &length
,
633 usb_dev
->descriptor
.bDeviceClass
,
634 usb_dev
->descriptor
.bDeviceSubClass
,
635 usb_dev
->descriptor
.bDeviceProtocol
))
638 if (add_uevent_var(envp
, num_envp
, &i
,
639 buffer
, buffer_size
, &length
,
641 usb_dev
->bus
->busnum
))
644 if (add_uevent_var(envp
, num_envp
, &i
,
645 buffer
, buffer_size
, &length
,
656 static int usb_uevent(struct device
*dev
, char **envp
,
657 int num_envp
, char *buffer
, int buffer_size
)
661 #endif /* CONFIG_HOTPLUG */
664 * usb_register_device_driver - register a USB device (not interface) driver
665 * @new_udriver: USB operations for the device driver
666 * @owner: module owner of this driver.
668 * Registers a USB device driver with the USB core. The list of
669 * unattached devices will be rescanned whenever a new driver is
670 * added, allowing the new driver to attach to any recognized devices.
671 * Returns a negative error code on failure and 0 on success.
673 int usb_register_device_driver(struct usb_device_driver
*new_udriver
,
674 struct module
*owner
)
681 new_udriver
->drvwrap
.for_devices
= 1;
682 new_udriver
->drvwrap
.driver
.name
= (char *) new_udriver
->name
;
683 new_udriver
->drvwrap
.driver
.bus
= &usb_bus_type
;
684 new_udriver
->drvwrap
.driver
.probe
= usb_probe_device
;
685 new_udriver
->drvwrap
.driver
.remove
= usb_unbind_device
;
686 new_udriver
->drvwrap
.driver
.owner
= owner
;
688 retval
= driver_register(&new_udriver
->drvwrap
.driver
);
691 pr_info("%s: registered new device driver %s\n",
692 usbcore_name
, new_udriver
->name
);
693 usbfs_update_special();
695 printk(KERN_ERR
"%s: error %d registering device "
697 usbcore_name
, retval
, new_udriver
->name
);
702 EXPORT_SYMBOL_GPL(usb_register_device_driver
);
705 * usb_deregister_device_driver - unregister a USB device (not interface) driver
706 * @udriver: USB operations of the device driver to unregister
707 * Context: must be able to sleep
709 * Unlinks the specified driver from the internal USB driver list.
711 void usb_deregister_device_driver(struct usb_device_driver
*udriver
)
713 pr_info("%s: deregistering device driver %s\n",
714 usbcore_name
, udriver
->name
);
716 driver_unregister(&udriver
->drvwrap
.driver
);
717 usbfs_update_special();
719 EXPORT_SYMBOL_GPL(usb_deregister_device_driver
);
722 * usb_register_driver - register a USB interface driver
723 * @new_driver: USB operations for the interface driver
724 * @owner: module owner of this driver.
725 * @mod_name: module name string
727 * Registers a USB interface driver with the USB core. The list of
728 * unattached interfaces will be rescanned whenever a new driver is
729 * added, allowing the new driver to attach to any recognized interfaces.
730 * Returns a negative error code on failure and 0 on success.
732 * NOTE: if you want your driver to use the USB major number, you must call
733 * usb_register_dev() to enable that functionality. This function no longer
734 * takes care of that.
736 int usb_register_driver(struct usb_driver
*new_driver
, struct module
*owner
,
737 const char *mod_name
)
744 new_driver
->drvwrap
.for_devices
= 0;
745 new_driver
->drvwrap
.driver
.name
= (char *) new_driver
->name
;
746 new_driver
->drvwrap
.driver
.bus
= &usb_bus_type
;
747 new_driver
->drvwrap
.driver
.probe
= usb_probe_interface
;
748 new_driver
->drvwrap
.driver
.remove
= usb_unbind_interface
;
749 new_driver
->drvwrap
.driver
.owner
= owner
;
750 new_driver
->drvwrap
.driver
.mod_name
= mod_name
;
751 spin_lock_init(&new_driver
->dynids
.lock
);
752 INIT_LIST_HEAD(&new_driver
->dynids
.list
);
754 retval
= driver_register(&new_driver
->drvwrap
.driver
);
757 pr_info("%s: registered new interface driver %s\n",
758 usbcore_name
, new_driver
->name
);
759 usbfs_update_special();
760 usb_create_newid_file(new_driver
);
762 printk(KERN_ERR
"%s: error %d registering interface "
764 usbcore_name
, retval
, new_driver
->name
);
769 EXPORT_SYMBOL_GPL_FUTURE(usb_register_driver
);
772 * usb_deregister - unregister a USB interface driver
773 * @driver: USB operations of the interface driver to unregister
774 * Context: must be able to sleep
776 * Unlinks the specified driver from the internal USB driver list.
778 * NOTE: If you called usb_register_dev(), you still need to call
779 * usb_deregister_dev() to clean up your driver's allocated minor numbers,
780 * this * call will no longer do it for you.
782 void usb_deregister(struct usb_driver
*driver
)
784 pr_info("%s: deregistering interface driver %s\n",
785 usbcore_name
, driver
->name
);
787 usb_remove_newid_file(driver
);
788 usb_free_dynids(driver
);
789 driver_unregister(&driver
->drvwrap
.driver
);
791 usbfs_update_special();
793 EXPORT_SYMBOL_GPL_FUTURE(usb_deregister
);
797 /* Caller has locked udev's pm_mutex */
798 static int usb_suspend_device(struct usb_device
*udev
, pm_message_t msg
)
800 struct usb_device_driver
*udriver
;
803 if (udev
->state
== USB_STATE_NOTATTACHED
||
804 udev
->state
== USB_STATE_SUSPENDED
)
807 /* For devices that don't have a driver, we do a generic suspend. */
808 if (udev
->dev
.driver
)
809 udriver
= to_usb_device_driver(udev
->dev
.driver
);
811 udev
->do_remote_wakeup
= 0;
812 udriver
= &usb_generic_driver
;
814 status
= udriver
->suspend(udev
, msg
);
817 dev_vdbg(&udev
->dev
, "%s: status %d\n", __FUNCTION__
, status
);
819 udev
->dev
.power
.power_state
.event
= msg
.event
;
823 /* Caller has locked udev's pm_mutex */
824 static int usb_resume_device(struct usb_device
*udev
)
826 struct usb_device_driver
*udriver
;
829 if (udev
->state
== USB_STATE_NOTATTACHED
)
831 if (udev
->state
!= USB_STATE_SUSPENDED
&& !udev
->reset_resume
)
834 /* Can't resume it if it doesn't have a driver. */
835 if (udev
->dev
.driver
== NULL
) {
840 if (udev
->quirks
& USB_QUIRK_RESET_RESUME
)
841 udev
->reset_resume
= 1;
843 udriver
= to_usb_device_driver(udev
->dev
.driver
);
844 status
= udriver
->resume(udev
);
847 dev_vdbg(&udev
->dev
, "%s: status %d\n", __FUNCTION__
, status
);
849 udev
->autoresume_disabled
= 0;
850 udev
->dev
.power
.power_state
.event
= PM_EVENT_ON
;
855 /* Caller has locked intf's usb_device's pm mutex */
856 static int usb_suspend_interface(struct usb_interface
*intf
, pm_message_t msg
)
858 struct usb_driver
*driver
;
861 /* with no hardware, USB interfaces only use FREEZE and ON states */
862 if (interface_to_usbdev(intf
)->state
== USB_STATE_NOTATTACHED
||
866 if (intf
->condition
== USB_INTERFACE_UNBOUND
) /* This can't happen */
868 driver
= to_usb_driver(intf
->dev
.driver
);
870 if (driver
->suspend
&& driver
->resume
) {
871 status
= driver
->suspend(intf
, msg
);
874 else if (!interface_to_usbdev(intf
)->auto_pm
)
875 dev_err(&intf
->dev
, "%s error %d\n",
878 // FIXME else if there's no suspend method, disconnect...
879 // Not possible if auto_pm is set...
880 dev_warn(&intf
->dev
, "no suspend for driver %s?\n",
886 dev_vdbg(&intf
->dev
, "%s: status %d\n", __FUNCTION__
, status
);
890 /* Caller has locked intf's usb_device's pm_mutex */
891 static int usb_resume_interface(struct usb_interface
*intf
, int reset_resume
)
893 struct usb_driver
*driver
;
896 if (interface_to_usbdev(intf
)->state
== USB_STATE_NOTATTACHED
||
900 /* Don't let autoresume interfere with unbinding */
901 if (intf
->condition
== USB_INTERFACE_UNBINDING
)
904 /* Can't resume it if it doesn't have a driver. */
905 if (intf
->condition
== USB_INTERFACE_UNBOUND
) {
909 driver
= to_usb_driver(intf
->dev
.driver
);
912 if (driver
->reset_resume
) {
913 status
= driver
->reset_resume(intf
);
915 dev_err(&intf
->dev
, "%s error %d\n",
916 "reset_resume", status
);
918 // status = -EOPNOTSUPP;
919 dev_warn(&intf
->dev
, "no %s for driver %s?\n",
920 "reset_resume", driver
->name
);
923 if (driver
->resume
) {
924 status
= driver
->resume(intf
);
926 dev_err(&intf
->dev
, "%s error %d\n",
929 // status = -EOPNOTSUPP;
930 dev_warn(&intf
->dev
, "no %s for driver %s?\n",
931 "resume", driver
->name
);
936 dev_vdbg(&intf
->dev
, "%s: status %d\n", __FUNCTION__
, status
);
940 /* FIXME: Unbind the driver and reprobe if the resume failed
941 * (not possible if auto_pm is set) */
945 #ifdef CONFIG_USB_SUSPEND
947 /* Internal routine to check whether we may autosuspend a device. */
948 static int autosuspend_check(struct usb_device
*udev
)
951 struct usb_interface
*intf
;
952 unsigned long suspend_time
;
954 /* For autosuspend, fail fast if anything is in use or autosuspend
955 * is disabled. Also fail if any interfaces require remote wakeup
956 * but it isn't available.
958 udev
->do_remote_wakeup
= device_may_wakeup(&udev
->dev
);
959 if (udev
->pm_usage_cnt
> 0)
961 if (udev
->autosuspend_delay
< 0 || udev
->autosuspend_disabled
)
964 suspend_time
= udev
->last_busy
+ udev
->autosuspend_delay
;
965 if (udev
->actconfig
) {
966 for (i
= 0; i
< udev
->actconfig
->desc
.bNumInterfaces
; i
++) {
967 intf
= udev
->actconfig
->interface
[i
];
968 if (!is_active(intf
))
970 if (intf
->pm_usage_cnt
> 0)
972 if (intf
->needs_remote_wakeup
&&
973 !udev
->do_remote_wakeup
) {
974 dev_dbg(&udev
->dev
, "remote wakeup needed "
975 "for autosuspend\n");
979 /* Don't allow autosuspend if the device will need
980 * a reset-resume and any of its interface drivers
981 * doesn't include support.
983 if (udev
->quirks
& USB_QUIRK_RESET_RESUME
) {
984 struct usb_driver
*driver
;
986 driver
= to_usb_driver(intf
->dev
.driver
);
987 if (!driver
->reset_resume
)
993 /* If everything is okay but the device hasn't been idle for long
994 * enough, queue a delayed autosuspend request.
996 if (time_after(suspend_time
, jiffies
)) {
997 if (!timer_pending(&udev
->autosuspend
.timer
)) {
999 /* The value of jiffies may change between the
1000 * time_after() comparison above and the subtraction
1001 * below. That's okay; the system behaves sanely
1002 * when a timer is registered for the present moment
1005 queue_delayed_work(ksuspend_usb_wq
, &udev
->autosuspend
,
1006 round_jiffies_relative(suspend_time
- jiffies
));
1015 static inline int autosuspend_check(struct usb_device
*udev
)
1020 #endif /* CONFIG_USB_SUSPEND */
1023 * usb_suspend_both - suspend a USB device and its interfaces
1024 * @udev: the usb_device to suspend
1025 * @msg: Power Management message describing this state transition
1027 * This is the central routine for suspending USB devices. It calls the
1028 * suspend methods for all the interface drivers in @udev and then calls
1029 * the suspend method for @udev itself. If an error occurs at any stage,
1030 * all the interfaces which were suspended are resumed so that they remain
1031 * in the same state as the device.
1033 * If an autosuspend is in progress (@udev->auto_pm is set), the routine
1034 * checks first to make sure that neither the device itself or any of its
1035 * active interfaces is in use (pm_usage_cnt is greater than 0). If they
1036 * are, the autosuspend fails.
1038 * If the suspend succeeds, the routine recursively queues an autosuspend
1039 * request for @udev's parent device, thereby propagating the change up
1040 * the device tree. If all of the parent's children are now suspended,
1041 * the parent will autosuspend in turn.
1043 * The suspend method calls are subject to mutual exclusion under control
1044 * of @udev's pm_mutex. Many of these calls are also under the protection
1045 * of @udev's device lock (including all requests originating outside the
1046 * USB subsystem), but autosuspend requests generated by a child device or
1047 * interface driver may not be. Usbcore will insure that the method calls
1048 * do not arrive during bind, unbind, or reset operations. However, drivers
1049 * must be prepared to handle suspend calls arriving at unpredictable times.
1050 * The only way to block such calls is to do an autoresume (preventing
1051 * autosuspends) while holding @udev's device lock (preventing outside
1054 * The caller must hold @udev->pm_mutex.
1056 * This routine can run only in process context.
1058 static int usb_suspend_both(struct usb_device
*udev
, pm_message_t msg
)
1062 struct usb_interface
*intf
;
1063 struct usb_device
*parent
= udev
->parent
;
1065 if (udev
->state
== USB_STATE_NOTATTACHED
||
1066 udev
->state
== USB_STATE_SUSPENDED
)
1069 udev
->do_remote_wakeup
= device_may_wakeup(&udev
->dev
);
1071 if (udev
->auto_pm
) {
1072 status
= autosuspend_check(udev
);
1077 /* Suspend all the interfaces and then udev itself */
1078 if (udev
->actconfig
) {
1079 for (; i
< udev
->actconfig
->desc
.bNumInterfaces
; i
++) {
1080 intf
= udev
->actconfig
->interface
[i
];
1081 status
= usb_suspend_interface(intf
, msg
);
1088 /* Non-root devices don't need to do anything for FREEZE
1090 if (udev
->parent
&& (msg
.event
== PM_EVENT_FREEZE
||
1091 msg
.event
== PM_EVENT_PRETHAW
))
1093 status
= usb_suspend_device(udev
, msg
);
1096 /* If the suspend failed, resume interfaces that did get suspended */
1099 intf
= udev
->actconfig
->interface
[i
];
1100 usb_resume_interface(intf
, 0);
1103 /* Try another autosuspend when the interfaces aren't busy */
1105 autosuspend_check(udev
);
1107 /* If the suspend succeeded, propagate it up the tree */
1109 cancel_delayed_work(&udev
->autosuspend
);
1111 usb_autosuspend_device(parent
);
1115 dev_vdbg(&udev
->dev
, "%s: status %d\n", __FUNCTION__
, status
);
1120 * usb_resume_both - resume a USB device and its interfaces
1121 * @udev: the usb_device to resume
1123 * This is the central routine for resuming USB devices. It calls the
1124 * the resume method for @udev and then calls the resume methods for all
1125 * the interface drivers in @udev.
1127 * Before starting the resume, the routine calls itself recursively for
1128 * the parent device of @udev, thereby propagating the change up the device
1129 * tree and assuring that @udev will be able to resume. If the parent is
1130 * unable to resume successfully, the routine fails.
1132 * The resume method calls are subject to mutual exclusion under control
1133 * of @udev's pm_mutex. Many of these calls are also under the protection
1134 * of @udev's device lock (including all requests originating outside the
1135 * USB subsystem), but autoresume requests generated by a child device or
1136 * interface driver may not be. Usbcore will insure that the method calls
1137 * do not arrive during bind, unbind, or reset operations. However, drivers
1138 * must be prepared to handle resume calls arriving at unpredictable times.
1139 * The only way to block such calls is to do an autoresume (preventing
1140 * other autoresumes) while holding @udev's device lock (preventing outside
1143 * The caller must hold @udev->pm_mutex.
1145 * This routine can run only in process context.
1147 static int usb_resume_both(struct usb_device
*udev
)
1151 struct usb_interface
*intf
;
1152 struct usb_device
*parent
= udev
->parent
;
1154 cancel_delayed_work(&udev
->autosuspend
);
1155 if (udev
->state
== USB_STATE_NOTATTACHED
) {
1160 /* Propagate the resume up the tree, if necessary */
1161 if (udev
->state
== USB_STATE_SUSPENDED
) {
1162 if (udev
->auto_pm
&& udev
->autoresume_disabled
) {
1167 status
= usb_autoresume_device(parent
);
1169 status
= usb_resume_device(udev
);
1170 if (status
|| udev
->state
==
1171 USB_STATE_NOTATTACHED
) {
1172 usb_autosuspend_device(parent
);
1174 /* It's possible usb_resume_device()
1175 * failed after the port was
1176 * unsuspended, causing udev to be
1177 * logically disconnected. We don't
1178 * want usb_disconnect() to autosuspend
1179 * the parent again, so tell it that
1180 * udev disconnected while still
1183 USB_STATE_NOTATTACHED
)
1184 udev
->discon_suspended
= 1;
1189 /* We can't progagate beyond the USB subsystem,
1190 * so if a root hub's controller is suspended
1191 * then we're stuck. */
1192 status
= usb_resume_device(udev
);
1196 /* Needed for setting udev->dev.power.power_state.event,
1197 * for possible debugging message, and for reset_resume. */
1198 status
= usb_resume_device(udev
);
1201 if (status
== 0 && udev
->actconfig
) {
1202 for (i
= 0; i
< udev
->actconfig
->desc
.bNumInterfaces
; i
++) {
1203 intf
= udev
->actconfig
->interface
[i
];
1204 usb_resume_interface(intf
, udev
->reset_resume
);
1209 dev_vdbg(&udev
->dev
, "%s: status %d\n", __FUNCTION__
, status
);
1210 udev
->reset_resume
= 0;
1214 #ifdef CONFIG_USB_SUSPEND
1216 /* Internal routine to adjust a device's usage counter and change
1217 * its autosuspend state.
1219 static int usb_autopm_do_device(struct usb_device
*udev
, int inc_usage_cnt
)
1225 udev
->pm_usage_cnt
+= inc_usage_cnt
;
1226 WARN_ON(udev
->pm_usage_cnt
< 0);
1227 if (inc_usage_cnt
>= 0 && udev
->pm_usage_cnt
> 0) {
1228 if (udev
->state
== USB_STATE_SUSPENDED
)
1229 status
= usb_resume_both(udev
);
1231 udev
->pm_usage_cnt
-= inc_usage_cnt
;
1232 else if (inc_usage_cnt
)
1233 udev
->last_busy
= jiffies
;
1234 } else if (inc_usage_cnt
<= 0 && udev
->pm_usage_cnt
<= 0) {
1236 udev
->last_busy
= jiffies
;
1237 status
= usb_suspend_both(udev
, PMSG_SUSPEND
);
1239 usb_pm_unlock(udev
);
1243 /* usb_autosuspend_work - callback routine to autosuspend a USB device */
1244 void usb_autosuspend_work(struct work_struct
*work
)
1246 struct usb_device
*udev
=
1247 container_of(work
, struct usb_device
, autosuspend
.work
);
1249 usb_autopm_do_device(udev
, 0);
1253 * usb_autosuspend_device - delayed autosuspend of a USB device and its interfaces
1254 * @udev: the usb_device to autosuspend
1256 * This routine should be called when a core subsystem is finished using
1257 * @udev and wants to allow it to autosuspend. Examples would be when
1258 * @udev's device file in usbfs is closed or after a configuration change.
1260 * @udev's usage counter is decremented. If it or any of the usage counters
1261 * for an active interface is greater than 0, no autosuspend request will be
1262 * queued. (If an interface driver does not support autosuspend then its
1263 * usage counter is permanently positive.) Furthermore, if an interface
1264 * driver requires remote-wakeup capability during autosuspend but remote
1265 * wakeup is disabled, the autosuspend will fail.
1267 * Often the caller will hold @udev's device lock, but this is not
1270 * This routine can run only in process context.
1272 void usb_autosuspend_device(struct usb_device
*udev
)
1276 status
= usb_autopm_do_device(udev
, -1);
1277 dev_vdbg(&udev
->dev
, "%s: cnt %d\n",
1278 __FUNCTION__
, udev
->pm_usage_cnt
);
1282 * usb_try_autosuspend_device - attempt an autosuspend of a USB device and its interfaces
1283 * @udev: the usb_device to autosuspend
1285 * This routine should be called when a core subsystem thinks @udev may
1286 * be ready to autosuspend.
1288 * @udev's usage counter left unchanged. If it or any of the usage counters
1289 * for an active interface is greater than 0, or autosuspend is not allowed
1290 * for any other reason, no autosuspend request will be queued.
1292 * This routine can run only in process context.
1294 void usb_try_autosuspend_device(struct usb_device
*udev
)
1296 usb_autopm_do_device(udev
, 0);
1297 dev_vdbg(&udev
->dev
, "%s: cnt %d\n",
1298 __FUNCTION__
, udev
->pm_usage_cnt
);
1302 * usb_autoresume_device - immediately autoresume a USB device and its interfaces
1303 * @udev: the usb_device to autoresume
1305 * This routine should be called when a core subsystem wants to use @udev
1306 * and needs to guarantee that it is not suspended. No autosuspend will
1307 * occur until usb_autosuspend_device is called. (Note that this will not
1308 * prevent suspend events originating in the PM core.) Examples would be
1309 * when @udev's device file in usbfs is opened or when a remote-wakeup
1310 * request is received.
1312 * @udev's usage counter is incremented to prevent subsequent autosuspends.
1313 * However if the autoresume fails then the usage counter is re-decremented.
1315 * Often the caller will hold @udev's device lock, but this is not
1316 * necessary (and attempting it might cause deadlock).
1318 * This routine can run only in process context.
1320 int usb_autoresume_device(struct usb_device
*udev
)
1324 status
= usb_autopm_do_device(udev
, 1);
1325 dev_vdbg(&udev
->dev
, "%s: status %d cnt %d\n",
1326 __FUNCTION__
, status
, udev
->pm_usage_cnt
);
1330 /* Internal routine to adjust an interface's usage counter and change
1331 * its device's autosuspend state.
1333 static int usb_autopm_do_interface(struct usb_interface
*intf
,
1336 struct usb_device
*udev
= interface_to_usbdev(intf
);
1340 if (intf
->condition
== USB_INTERFACE_UNBOUND
)
1344 intf
->pm_usage_cnt
+= inc_usage_cnt
;
1345 if (inc_usage_cnt
>= 0 && intf
->pm_usage_cnt
> 0) {
1346 if (udev
->state
== USB_STATE_SUSPENDED
)
1347 status
= usb_resume_both(udev
);
1349 intf
->pm_usage_cnt
-= inc_usage_cnt
;
1350 else if (inc_usage_cnt
)
1351 udev
->last_busy
= jiffies
;
1352 } else if (inc_usage_cnt
<= 0 && intf
->pm_usage_cnt
<= 0) {
1354 udev
->last_busy
= jiffies
;
1355 status
= usb_suspend_both(udev
, PMSG_SUSPEND
);
1358 usb_pm_unlock(udev
);
1363 * usb_autopm_put_interface - decrement a USB interface's PM-usage counter
1364 * @intf: the usb_interface whose counter should be decremented
1366 * This routine should be called by an interface driver when it is
1367 * finished using @intf and wants to allow it to autosuspend. A typical
1368 * example would be a character-device driver when its device file is
1371 * The routine decrements @intf's usage counter. When the counter reaches
1372 * 0, a delayed autosuspend request for @intf's device is queued. When
1373 * the delay expires, if @intf->pm_usage_cnt is still <= 0 along with all
1374 * the other usage counters for the sibling interfaces and @intf's
1375 * usb_device, the device and all its interfaces will be autosuspended.
1377 * Note that @intf->pm_usage_cnt is owned by the interface driver. The
1378 * core will not change its value other than the increment and decrement
1379 * in usb_autopm_get_interface and usb_autopm_put_interface. The driver
1380 * may use this simple counter-oriented discipline or may set the value
1383 * If the driver has set @intf->needs_remote_wakeup then autosuspend will
1384 * take place only if the device's remote-wakeup facility is enabled.
1386 * Suspend method calls queued by this routine can arrive at any time
1387 * while @intf is resumed and its usage counter is equal to 0. They are
1388 * not protected by the usb_device's lock but only by its pm_mutex.
1389 * Drivers must provide their own synchronization.
1391 * This routine can run only in process context.
1393 void usb_autopm_put_interface(struct usb_interface
*intf
)
1397 status
= usb_autopm_do_interface(intf
, -1);
1398 dev_vdbg(&intf
->dev
, "%s: status %d cnt %d\n",
1399 __FUNCTION__
, status
, intf
->pm_usage_cnt
);
1401 EXPORT_SYMBOL_GPL(usb_autopm_put_interface
);
1404 * usb_autopm_get_interface - increment a USB interface's PM-usage counter
1405 * @intf: the usb_interface whose counter should be incremented
1407 * This routine should be called by an interface driver when it wants to
1408 * use @intf and needs to guarantee that it is not suspended. In addition,
1409 * the routine prevents @intf from being autosuspended subsequently. (Note
1410 * that this will not prevent suspend events originating in the PM core.)
1411 * This prevention will persist until usb_autopm_put_interface() is called
1412 * or @intf is unbound. A typical example would be a character-device
1413 * driver when its device file is opened.
1416 * The routine increments @intf's usage counter. (However if the
1417 * autoresume fails then the counter is re-decremented.) So long as the
1418 * counter is greater than 0, autosuspend will not be allowed for @intf
1419 * or its usb_device. When the driver is finished using @intf it should
1420 * call usb_autopm_put_interface() to decrement the usage counter and
1421 * queue a delayed autosuspend request (if the counter is <= 0).
1424 * Note that @intf->pm_usage_cnt is owned by the interface driver. The
1425 * core will not change its value other than the increment and decrement
1426 * in usb_autopm_get_interface and usb_autopm_put_interface. The driver
1427 * may use this simple counter-oriented discipline or may set the value
1430 * Resume method calls generated by this routine can arrive at any time
1431 * while @intf is suspended. They are not protected by the usb_device's
1432 * lock but only by its pm_mutex. Drivers must provide their own
1435 * This routine can run only in process context.
1437 int usb_autopm_get_interface(struct usb_interface
*intf
)
1441 status
= usb_autopm_do_interface(intf
, 1);
1442 dev_vdbg(&intf
->dev
, "%s: status %d cnt %d\n",
1443 __FUNCTION__
, status
, intf
->pm_usage_cnt
);
1446 EXPORT_SYMBOL_GPL(usb_autopm_get_interface
);
1449 * usb_autopm_set_interface - set a USB interface's autosuspend state
1450 * @intf: the usb_interface whose state should be set
1452 * This routine sets the autosuspend state of @intf's device according
1453 * to @intf's usage counter, which the caller must have set previously.
1454 * If the counter is <= 0, the device is autosuspended (if it isn't
1455 * already suspended and if nothing else prevents the autosuspend). If
1456 * the counter is > 0, the device is autoresumed (if it isn't already
1459 int usb_autopm_set_interface(struct usb_interface
*intf
)
1463 status
= usb_autopm_do_interface(intf
, 0);
1464 dev_vdbg(&intf
->dev
, "%s: status %d cnt %d\n",
1465 __FUNCTION__
, status
, intf
->pm_usage_cnt
);
1468 EXPORT_SYMBOL_GPL(usb_autopm_set_interface
);
1472 void usb_autosuspend_work(struct work_struct
*work
)
1475 #endif /* CONFIG_USB_SUSPEND */
1478 * usb_external_suspend_device - external suspend of a USB device and its interfaces
1479 * @udev: the usb_device to suspend
1480 * @msg: Power Management message describing this state transition
1482 * This routine handles external suspend requests: ones not generated
1483 * internally by a USB driver (autosuspend) but rather coming from the user
1484 * (via sysfs) or the PM core (system sleep). The suspend will be carried
1485 * out regardless of @udev's usage counter or those of its interfaces,
1486 * and regardless of whether or not remote wakeup is enabled. Of course,
1487 * interface drivers still have the option of failing the suspend (if
1488 * there are unsuspended children, for example).
1490 * The caller must hold @udev's device lock.
1492 int usb_external_suspend_device(struct usb_device
*udev
, pm_message_t msg
)
1498 status
= usb_suspend_both(udev
, msg
);
1499 usb_pm_unlock(udev
);
1504 * usb_external_resume_device - external resume of a USB device and its interfaces
1505 * @udev: the usb_device to resume
1507 * This routine handles external resume requests: ones not generated
1508 * internally by a USB driver (autoresume) but rather coming from the user
1509 * (via sysfs), the PM core (system resume), or the device itself (remote
1510 * wakeup). @udev's usage counter is unaffected.
1512 * The caller must hold @udev's device lock.
1514 int usb_external_resume_device(struct usb_device
*udev
)
1520 status
= usb_resume_both(udev
);
1521 udev
->last_busy
= jiffies
;
1522 usb_pm_unlock(udev
);
1524 /* Now that the device is awake, we can start trying to autosuspend
1527 usb_try_autosuspend_device(udev
);
1531 static int usb_suspend(struct device
*dev
, pm_message_t message
)
1533 if (!is_usb_device(dev
)) /* Ignore PM for interfaces */
1535 return usb_external_suspend_device(to_usb_device(dev
), message
);
1538 static int usb_resume(struct device
*dev
)
1540 struct usb_device
*udev
;
1542 if (!is_usb_device(dev
)) /* Ignore PM for interfaces */
1544 udev
= to_usb_device(dev
);
1546 /* If autoresume is disabled then we also want to prevent resume
1547 * during system wakeup. However, a "persistent-device" reset-resume
1548 * after power loss counts as a wakeup event. So allow a
1549 * reset-resume to occur if remote wakeup is enabled. */
1550 if (udev
->autoresume_disabled
) {
1551 if (!(udev
->reset_resume
&& udev
->do_remote_wakeup
))
1554 return usb_external_resume_device(udev
);
1559 #define usb_suspend NULL
1560 #define usb_resume NULL
1562 #endif /* CONFIG_PM */
1564 struct bus_type usb_bus_type
= {
1566 .match
= usb_device_match
,
1567 .uevent
= usb_uevent
,
1568 .suspend
= usb_suspend
,
1569 .resume
= usb_resume
,