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(&dynid
->node
, &dynids
->list
);
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
= driver_create_file(&usb_drv
->drvwrap
.driver
,
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 driver_remove_file(&usb_drv
->drvwrap
.driver
,
107 &driver_attr_new_id
);
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
= to_usb_device(dev
);
160 dev_dbg(dev
, "%s\n", __FUNCTION__
);
162 /* TODO: Add real matching code */
164 /* The device should always appear to be in use
165 * unless the driver suports autosuspend.
167 udev
->pm_usage_cnt
= !(udriver
->supports_autosuspend
);
169 error
= udriver
->probe(udev
);
173 /* called from driver core with dev locked */
174 static int usb_unbind_device(struct device
*dev
)
176 struct usb_device_driver
*udriver
= to_usb_device_driver(dev
->driver
);
178 udriver
->disconnect(to_usb_device(dev
));
183 * Cancel any pending scheduled resets
185 * [see usb_queue_reset_device()]
187 * Called after unconfiguring / when releasing interfaces. See
188 * comments in __usb_queue_reset_device() regarding
189 * udev->reset_running.
191 static void usb_cancel_queued_reset(struct usb_interface
*iface
)
193 if (iface
->reset_running
== 0)
194 cancel_work_sync(&iface
->reset_ws
);
197 /* called from driver core with dev locked */
198 static int usb_probe_interface(struct device
*dev
)
200 struct usb_driver
*driver
= to_usb_driver(dev
->driver
);
201 struct usb_interface
*intf
= to_usb_interface(dev
);
202 struct usb_device
*udev
= interface_to_usbdev(intf
);
203 const struct usb_device_id
*id
;
206 dev_dbg(dev
, "%s\n", __FUNCTION__
);
208 intf
->needs_binding
= 0;
210 id
= usb_match_id(intf
, driver
->id_table
);
212 id
= usb_match_dynamic_id(intf
, driver
);
214 dev_dbg(dev
, "%s - got id\n", __FUNCTION__
);
216 error
= usb_autoresume_device(udev
);
220 /* Interface "power state" doesn't correspond to any hardware
221 * state whatsoever. We use it to record when it's bound to
222 * a driver that may start I/0: it's not frozen/quiesced.
225 intf
->condition
= USB_INTERFACE_BINDING
;
227 /* The interface should always appear to be in use
228 * unless the driver suports autosuspend.
230 intf
->pm_usage_cnt
= !(driver
->supports_autosuspend
);
232 error
= driver
->probe(intf
, id
);
235 intf
->needs_remote_wakeup
= 0;
236 intf
->condition
= USB_INTERFACE_UNBOUND
;
237 usb_cancel_queued_reset(intf
);
239 intf
->condition
= USB_INTERFACE_BOUND
;
241 usb_autosuspend_device(udev
);
247 /* called from driver core with dev locked */
248 static int usb_unbind_interface(struct device
*dev
)
250 struct usb_driver
*driver
= to_usb_driver(dev
->driver
);
251 struct usb_interface
*intf
= to_usb_interface(dev
);
252 struct usb_device
*udev
;
255 intf
->condition
= USB_INTERFACE_UNBINDING
;
257 /* Autoresume for set_interface call below */
258 udev
= interface_to_usbdev(intf
);
259 error
= usb_autoresume_device(udev
);
261 /* Terminate all URBs for this interface unless the driver
262 * supports "soft" unbinding.
264 if (!driver
->soft_unbind
)
265 usb_disable_interface(udev
, intf
);
267 driver
->disconnect(intf
);
268 usb_cancel_queued_reset(intf
);
270 /* reset other interface state */
271 usb_set_interface(udev
, intf
->altsetting
[0].desc
.bInterfaceNumber
, 0);
272 usb_set_intfdata(intf
, NULL
);
274 intf
->condition
= USB_INTERFACE_UNBOUND
;
276 intf
->needs_remote_wakeup
= 0;
279 usb_autosuspend_device(udev
);
285 * usb_driver_claim_interface - bind a driver to an interface
286 * @driver: the driver to be bound
287 * @iface: the interface to which it will be bound; must be in the
288 * usb device's active configuration
289 * @priv: driver data associated with that interface
291 * This is used by usb device drivers that need to claim more than one
292 * interface on a device when probing (audio and acm are current examples).
293 * No device driver should directly modify internal usb_interface or
294 * usb_device structure members.
296 * Few drivers should need to use this routine, since the most natural
297 * way to bind to an interface is to return the private data from
298 * the driver's probe() method.
300 * Callers must own the device lock, so driver probe() entries don't need
301 * extra locking, but other call contexts may need to explicitly claim that
304 int usb_driver_claim_interface(struct usb_driver
*driver
,
305 struct usb_interface
*iface
, void *priv
)
307 struct device
*dev
= &iface
->dev
;
308 struct usb_device
*udev
= interface_to_usbdev(iface
);
314 dev
->driver
= &driver
->drvwrap
.driver
;
315 usb_set_intfdata(iface
, priv
);
316 iface
->needs_binding
= 0;
319 iface
->condition
= USB_INTERFACE_BOUND
;
321 iface
->pm_usage_cnt
= !(driver
->supports_autosuspend
);
324 /* if interface was already added, bind now; else let
325 * the future device_add() bind it, bypassing probe()
327 if (device_is_registered(dev
))
328 retval
= device_bind_driver(dev
);
332 EXPORT_SYMBOL_GPL(usb_driver_claim_interface
);
335 * usb_driver_release_interface - unbind a driver from an interface
336 * @driver: the driver to be unbound
337 * @iface: the interface from which it will be unbound
339 * This can be used by drivers to release an interface without waiting
340 * for their disconnect() methods to be called. In typical cases this
341 * also causes the driver disconnect() method to be called.
343 * This call is synchronous, and may not be used in an interrupt context.
344 * Callers must own the device lock, so driver disconnect() entries don't
345 * need extra locking, but other call contexts may need to explicitly claim
348 void usb_driver_release_interface(struct usb_driver
*driver
,
349 struct usb_interface
*iface
)
351 struct device
*dev
= &iface
->dev
;
353 /* this should never happen, don't release something that's not ours */
354 if (!dev
->driver
|| dev
->driver
!= &driver
->drvwrap
.driver
)
357 /* don't release from within disconnect() */
358 if (iface
->condition
!= USB_INTERFACE_BOUND
)
360 iface
->condition
= USB_INTERFACE_UNBINDING
;
362 /* Release via the driver core only if the interface
363 * has already been registered
365 if (device_is_registered(dev
)) {
366 device_release_driver(dev
);
369 usb_unbind_interface(dev
);
374 EXPORT_SYMBOL_GPL(usb_driver_release_interface
);
376 /* returns 0 if no match, 1 if match */
377 int usb_match_device(struct usb_device
*dev
, const struct usb_device_id
*id
)
379 if ((id
->match_flags
& USB_DEVICE_ID_MATCH_VENDOR
) &&
380 id
->idVendor
!= le16_to_cpu(dev
->descriptor
.idVendor
))
383 if ((id
->match_flags
& USB_DEVICE_ID_MATCH_PRODUCT
) &&
384 id
->idProduct
!= le16_to_cpu(dev
->descriptor
.idProduct
))
387 /* No need to test id->bcdDevice_lo != 0, since 0 is never
388 greater than any unsigned number. */
389 if ((id
->match_flags
& USB_DEVICE_ID_MATCH_DEV_LO
) &&
390 (id
->bcdDevice_lo
> le16_to_cpu(dev
->descriptor
.bcdDevice
)))
393 if ((id
->match_flags
& USB_DEVICE_ID_MATCH_DEV_HI
) &&
394 (id
->bcdDevice_hi
< le16_to_cpu(dev
->descriptor
.bcdDevice
)))
397 if ((id
->match_flags
& USB_DEVICE_ID_MATCH_DEV_CLASS
) &&
398 (id
->bDeviceClass
!= dev
->descriptor
.bDeviceClass
))
401 if ((id
->match_flags
& USB_DEVICE_ID_MATCH_DEV_SUBCLASS
) &&
402 (id
->bDeviceSubClass
!= dev
->descriptor
.bDeviceSubClass
))
405 if ((id
->match_flags
& USB_DEVICE_ID_MATCH_DEV_PROTOCOL
) &&
406 (id
->bDeviceProtocol
!= dev
->descriptor
.bDeviceProtocol
))
412 /* returns 0 if no match, 1 if match */
413 int usb_match_one_id(struct usb_interface
*interface
,
414 const struct usb_device_id
*id
)
416 struct usb_host_interface
*intf
;
417 struct usb_device
*dev
;
419 /* proc_connectinfo in devio.c may call us with id == NULL. */
423 intf
= interface
->cur_altsetting
;
424 dev
= interface_to_usbdev(interface
);
426 if (!usb_match_device(dev
, id
))
429 /* The interface class, subclass, protocol and number should never be
430 * checked for a match if the device class is Vendor Specific,
431 * unless the match record specifies the Vendor ID. */
432 if (dev
->descriptor
.bDeviceClass
== USB_CLASS_VENDOR_SPEC
&&
433 !(id
->match_flags
& USB_DEVICE_ID_MATCH_VENDOR
) &&
434 (id
->match_flags
& (USB_DEVICE_ID_MATCH_INT_CLASS
|
435 USB_DEVICE_ID_MATCH_INT_SUBCLASS
|
436 USB_DEVICE_ID_MATCH_INT_PROTOCOL
|
437 USB_DEVICE_ID_MATCH_INT_NUMBER
)))
440 if ((id
->match_flags
& USB_DEVICE_ID_MATCH_INT_CLASS
) &&
441 (id
->bInterfaceClass
!= intf
->desc
.bInterfaceClass
))
444 if ((id
->match_flags
& USB_DEVICE_ID_MATCH_INT_SUBCLASS
) &&
445 (id
->bInterfaceSubClass
!= intf
->desc
.bInterfaceSubClass
))
448 if ((id
->match_flags
& USB_DEVICE_ID_MATCH_INT_PROTOCOL
) &&
449 (id
->bInterfaceProtocol
!= intf
->desc
.bInterfaceProtocol
))
452 if ((id
->match_flags
& USB_DEVICE_ID_MATCH_INT_NUMBER
) &&
453 (id
->bInterfaceNumber
!= intf
->desc
.bInterfaceNumber
))
458 EXPORT_SYMBOL_GPL(usb_match_one_id
);
461 * usb_match_id - find first usb_device_id matching device or interface
462 * @interface: the interface of interest
463 * @id: array of usb_device_id structures, terminated by zero entry
465 * usb_match_id searches an array of usb_device_id's and returns
466 * the first one matching the device or interface, or null.
467 * This is used when binding (or rebinding) a driver to an interface.
468 * Most USB device drivers will use this indirectly, through the usb core,
469 * but some layered driver frameworks use it directly.
470 * These device tables are exported with MODULE_DEVICE_TABLE, through
471 * modutils, to support the driver loading functionality of USB hotplugging.
475 * The "match_flags" element in a usb_device_id controls which
476 * members are used. If the corresponding bit is set, the
477 * value in the device_id must match its corresponding member
478 * in the device or interface descriptor, or else the device_id
481 * "driver_info" is normally used only by device drivers,
482 * but you can create a wildcard "matches anything" usb_device_id
483 * as a driver's "modules.usbmap" entry if you provide an id with
484 * only a nonzero "driver_info" field. If you do this, the USB device
485 * driver's probe() routine should use additional intelligence to
486 * decide whether to bind to the specified interface.
488 * What Makes Good usb_device_id Tables:
490 * The match algorithm is very simple, so that intelligence in
491 * driver selection must come from smart driver id records.
492 * Unless you have good reasons to use another selection policy,
493 * provide match elements only in related groups, and order match
494 * specifiers from specific to general. Use the macros provided
495 * for that purpose if you can.
497 * The most specific match specifiers use device descriptor
498 * data. These are commonly used with product-specific matches;
499 * the USB_DEVICE macro lets you provide vendor and product IDs,
500 * and you can also match against ranges of product revisions.
501 * These are widely used for devices with application or vendor
502 * specific bDeviceClass values.
504 * Matches based on device class/subclass/protocol specifications
505 * are slightly more general; use the USB_DEVICE_INFO macro, or
506 * its siblings. These are used with single-function devices
507 * where bDeviceClass doesn't specify that each interface has
510 * Matches based on interface class/subclass/protocol are the
511 * most general; they let drivers bind to any interface on a
512 * multiple-function device. Use the USB_INTERFACE_INFO
513 * macro, or its siblings, to match class-per-interface style
514 * devices (as recorded in bInterfaceClass).
516 * Note that an entry created by USB_INTERFACE_INFO won't match
517 * any interface if the device class is set to Vendor-Specific.
518 * This is deliberate; according to the USB spec the meanings of
519 * the interface class/subclass/protocol for these devices are also
520 * vendor-specific, and hence matching against a standard product
521 * class wouldn't work anyway. If you really want to use an
522 * interface-based match for such a device, create a match record
523 * that also specifies the vendor ID. (Unforunately there isn't a
524 * standard macro for creating records like this.)
526 * Within those groups, remember that not all combinations are
527 * meaningful. For example, don't give a product version range
528 * without vendor and product IDs; or specify a protocol without
529 * its associated class and subclass.
531 const struct usb_device_id
*usb_match_id(struct usb_interface
*interface
,
532 const struct usb_device_id
*id
)
534 /* proc_connectinfo in devio.c may call us with id == NULL. */
538 /* It is important to check that id->driver_info is nonzero,
539 since an entry that is all zeroes except for a nonzero
540 id->driver_info is the way to create an entry that
541 indicates that the driver want to examine every
542 device and interface. */
543 for (; id
->idVendor
|| id
->idProduct
|| id
->bDeviceClass
||
544 id
->bInterfaceClass
|| id
->driver_info
; id
++) {
545 if (usb_match_one_id(interface
, id
))
551 EXPORT_SYMBOL_GPL(usb_match_id
);
553 static int usb_device_match(struct device
*dev
, struct device_driver
*drv
)
555 /* devices and interfaces are handled separately */
556 if (is_usb_device(dev
)) {
558 /* interface drivers never match devices */
559 if (!is_usb_device_driver(drv
))
562 /* TODO: Add real matching code */
565 } else if (is_usb_interface(dev
)) {
566 struct usb_interface
*intf
;
567 struct usb_driver
*usb_drv
;
568 const struct usb_device_id
*id
;
570 /* device drivers never match interfaces */
571 if (is_usb_device_driver(drv
))
574 intf
= to_usb_interface(dev
);
575 usb_drv
= to_usb_driver(drv
);
577 id
= usb_match_id(intf
, usb_drv
->id_table
);
581 id
= usb_match_dynamic_id(intf
, usb_drv
);
589 #ifdef CONFIG_HOTPLUG
590 static int usb_uevent(struct device
*dev
, char **envp
, int num_envp
,
591 char *buffer
, int buffer_size
)
593 struct usb_device
*usb_dev
;
600 /* driver is often null here; dev_dbg() would oops */
601 pr_debug("usb %s: uevent\n", dev
->bus_id
);
603 if (is_usb_device(dev
)) {
604 usb_dev
= to_usb_device(dev
);
605 } else if (is_usb_interface(dev
)) {
606 struct usb_interface
*intf
= to_usb_interface(dev
);
608 usb_dev
= interface_to_usbdev(intf
);
613 if (usb_dev
->devnum
< 0) {
614 pr_debug("usb %s: already deleted?\n", dev
->bus_id
);
618 pr_debug("usb %s: bus removed?\n", dev
->bus_id
);
622 #ifdef CONFIG_USB_DEVICEFS
623 /* If this is available, userspace programs can directly read
624 * all the device descriptors we don't tell them about. Or
625 * act as usermode drivers.
627 if (add_uevent_var(envp
, num_envp
, &i
,
628 buffer
, buffer_size
, &length
,
629 "DEVICE=/proc/bus/usb/%03d/%03d",
630 usb_dev
->bus
->busnum
, usb_dev
->devnum
))
634 /* per-device configurations are common */
635 if (add_uevent_var(envp
, num_envp
, &i
,
636 buffer
, buffer_size
, &length
,
638 le16_to_cpu(usb_dev
->descriptor
.idVendor
),
639 le16_to_cpu(usb_dev
->descriptor
.idProduct
),
640 le16_to_cpu(usb_dev
->descriptor
.bcdDevice
)))
643 /* class-based driver binding models */
644 if (add_uevent_var(envp
, num_envp
, &i
,
645 buffer
, buffer_size
, &length
,
647 usb_dev
->descriptor
.bDeviceClass
,
648 usb_dev
->descriptor
.bDeviceSubClass
,
649 usb_dev
->descriptor
.bDeviceProtocol
))
652 if (add_uevent_var(envp
, num_envp
, &i
,
653 buffer
, buffer_size
, &length
,
655 usb_dev
->bus
->busnum
))
658 if (add_uevent_var(envp
, num_envp
, &i
,
659 buffer
, buffer_size
, &length
,
670 static int usb_uevent(struct device
*dev
, char **envp
,
671 int num_envp
, char *buffer
, int buffer_size
)
675 #endif /* CONFIG_HOTPLUG */
678 * usb_register_device_driver - register a USB device (not interface) driver
679 * @new_udriver: USB operations for the device driver
680 * @owner: module owner of this driver.
682 * Registers a USB device driver with the USB core. The list of
683 * unattached devices will be rescanned whenever a new driver is
684 * added, allowing the new driver to attach to any recognized devices.
685 * Returns a negative error code on failure and 0 on success.
687 int usb_register_device_driver(struct usb_device_driver
*new_udriver
,
688 struct module
*owner
)
695 new_udriver
->drvwrap
.for_devices
= 1;
696 new_udriver
->drvwrap
.driver
.name
= (char *) new_udriver
->name
;
697 new_udriver
->drvwrap
.driver
.bus
= &usb_bus_type
;
698 new_udriver
->drvwrap
.driver
.probe
= usb_probe_device
;
699 new_udriver
->drvwrap
.driver
.remove
= usb_unbind_device
;
700 new_udriver
->drvwrap
.driver
.owner
= owner
;
702 retval
= driver_register(&new_udriver
->drvwrap
.driver
);
705 pr_info("%s: registered new device driver %s\n",
706 usbcore_name
, new_udriver
->name
);
707 usbfs_update_special();
709 printk(KERN_ERR
"%s: error %d registering device "
711 usbcore_name
, retval
, new_udriver
->name
);
716 EXPORT_SYMBOL_GPL(usb_register_device_driver
);
719 * usb_deregister_device_driver - unregister a USB device (not interface) driver
720 * @udriver: USB operations of the device driver to unregister
721 * Context: must be able to sleep
723 * Unlinks the specified driver from the internal USB driver list.
725 void usb_deregister_device_driver(struct usb_device_driver
*udriver
)
727 pr_info("%s: deregistering device driver %s\n",
728 usbcore_name
, udriver
->name
);
730 driver_unregister(&udriver
->drvwrap
.driver
);
731 usbfs_update_special();
733 EXPORT_SYMBOL_GPL(usb_deregister_device_driver
);
736 * usb_register_driver - register a USB interface driver
737 * @new_driver: USB operations for the interface driver
738 * @owner: module owner of this driver.
739 * @mod_name: module name string
741 * Registers a USB interface driver with the USB core. The list of
742 * unattached interfaces will be rescanned whenever a new driver is
743 * added, allowing the new driver to attach to any recognized interfaces.
744 * Returns a negative error code on failure and 0 on success.
746 * NOTE: if you want your driver to use the USB major number, you must call
747 * usb_register_dev() to enable that functionality. This function no longer
748 * takes care of that.
750 int usb_register_driver(struct usb_driver
*new_driver
, struct module
*owner
,
751 const char *mod_name
)
758 new_driver
->drvwrap
.for_devices
= 0;
759 new_driver
->drvwrap
.driver
.name
= (char *) new_driver
->name
;
760 new_driver
->drvwrap
.driver
.bus
= &usb_bus_type
;
761 new_driver
->drvwrap
.driver
.probe
= usb_probe_interface
;
762 new_driver
->drvwrap
.driver
.remove
= usb_unbind_interface
;
763 new_driver
->drvwrap
.driver
.owner
= owner
;
764 new_driver
->drvwrap
.driver
.mod_name
= mod_name
;
765 spin_lock_init(&new_driver
->dynids
.lock
);
766 INIT_LIST_HEAD(&new_driver
->dynids
.list
);
768 retval
= driver_register(&new_driver
->drvwrap
.driver
);
771 pr_info("%s: registered new interface driver %s\n",
772 usbcore_name
, new_driver
->name
);
773 usbfs_update_special();
774 usb_create_newid_file(new_driver
);
776 printk(KERN_ERR
"%s: error %d registering interface "
778 usbcore_name
, retval
, new_driver
->name
);
783 EXPORT_SYMBOL_GPL(usb_register_driver
);
786 * usb_deregister - unregister a USB interface driver
787 * @driver: USB operations of the interface driver to unregister
788 * Context: must be able to sleep
790 * Unlinks the specified driver from the internal USB driver list.
792 * NOTE: If you called usb_register_dev(), you still need to call
793 * usb_deregister_dev() to clean up your driver's allocated minor numbers,
794 * this * call will no longer do it for you.
796 void usb_deregister(struct usb_driver
*driver
)
798 pr_info("%s: deregistering interface driver %s\n",
799 usbcore_name
, driver
->name
);
801 usb_remove_newid_file(driver
);
802 usb_free_dynids(driver
);
803 driver_unregister(&driver
->drvwrap
.driver
);
805 usbfs_update_special();
807 EXPORT_SYMBOL_GPL(usb_deregister
);
809 /* Forced unbinding of a USB interface driver, either because
810 * it doesn't support pre_reset/post_reset/reset_resume or
811 * because it doesn't support suspend/resume.
813 * The caller must hold @intf's device's lock, but not its pm_mutex
814 * and not @intf->dev.sem.
816 void usb_forced_unbind_intf(struct usb_interface
*intf
)
818 struct usb_driver
*driver
= to_usb_driver(intf
->dev
.driver
);
820 dev_dbg(&intf
->dev
, "forced unbind\n");
821 usb_driver_release_interface(driver
, intf
);
823 /* Mark the interface for later rebinding */
824 intf
->needs_binding
= 1;
827 /* Delayed forced unbinding of a USB interface driver and scan
830 * The caller must hold @intf's device's lock, but not its pm_mutex
831 * and not @intf->dev.sem.
833 * FIXME: The caller must block system sleep transitions.
835 void usb_rebind_intf(struct usb_interface
*intf
)
839 /* Delayed unbind of an existing driver */
840 if (intf
->dev
.driver
) {
841 struct usb_driver
*driver
=
842 to_usb_driver(intf
->dev
.driver
);
844 dev_dbg(&intf
->dev
, "forced unbind\n");
845 usb_driver_release_interface(driver
, intf
);
848 /* Try to rebind the interface */
849 intf
->needs_binding
= 0;
850 rc
= device_attach(&intf
->dev
);
852 dev_warn(&intf
->dev
, "rebind failed: %d\n", rc
);
860 /* Unbind drivers for @udev's interfaces that don't support suspend/resume,
861 * or rebind interfaces that have been unbound, according to @action.
863 * The caller must hold @udev's device lock.
864 * FIXME: For rebinds, the caller must block system sleep transitions.
866 static void do_unbind_rebind(struct usb_device
*udev
, int action
)
868 struct usb_host_config
*config
;
870 struct usb_interface
*intf
;
871 struct usb_driver
*drv
;
873 config
= udev
->actconfig
;
875 for (i
= 0; i
< config
->desc
.bNumInterfaces
; ++i
) {
876 intf
= config
->interface
[i
];
879 if (intf
->dev
.driver
) {
880 drv
= to_usb_driver(intf
->dev
.driver
);
881 if (!drv
->suspend
|| !drv
->resume
)
882 usb_forced_unbind_intf(intf
);
886 if (intf
->needs_binding
) {
888 /* FIXME: The next line is needed because we are going to probe
889 * the interface, but as far as the PM core is concerned the
890 * interface is still suspended. The problem wouldn't exist
891 * if we could rebind the interface during the interface's own
892 * resume() call, but at the time the usb_device isn't locked!
894 * The real solution will be to carry this out during the device's
895 * complete() callback. Until that is implemented, we have to
898 // intf->dev.power.sleeping = 0;
900 usb_rebind_intf(intf
);
908 /* Caller has locked udev's pm_mutex */
909 static int usb_suspend_device(struct usb_device
*udev
, pm_message_t msg
)
911 struct usb_device_driver
*udriver
;
914 if (udev
->state
== USB_STATE_NOTATTACHED
||
915 udev
->state
== USB_STATE_SUSPENDED
)
918 /* For devices that don't have a driver, we do a generic suspend. */
919 if (udev
->dev
.driver
)
920 udriver
= to_usb_device_driver(udev
->dev
.driver
);
922 udev
->do_remote_wakeup
= 0;
923 udriver
= &usb_generic_driver
;
925 status
= udriver
->suspend(udev
, msg
);
928 dev_vdbg(&udev
->dev
, "%s: status %d\n", __FUNCTION__
, status
);
932 /* Caller has locked udev's pm_mutex */
933 static int usb_resume_device(struct usb_device
*udev
)
935 struct usb_device_driver
*udriver
;
938 if (udev
->state
== USB_STATE_NOTATTACHED
)
941 /* Can't resume it if it doesn't have a driver. */
942 if (udev
->dev
.driver
== NULL
) {
947 if (udev
->quirks
& USB_QUIRK_RESET_RESUME
)
948 udev
->reset_resume
= 1;
950 udriver
= to_usb_device_driver(udev
->dev
.driver
);
951 status
= udriver
->resume(udev
);
954 dev_vdbg(&udev
->dev
, "%s: status %d\n", __FUNCTION__
, status
);
956 udev
->autoresume_disabled
= 0;
960 /* Caller has locked intf's usb_device's pm mutex */
961 static int usb_suspend_interface(struct usb_device
*udev
,
962 struct usb_interface
*intf
, pm_message_t msg
)
964 struct usb_driver
*driver
;
967 /* with no hardware, USB interfaces only use FREEZE and ON states */
968 if (udev
->state
== USB_STATE_NOTATTACHED
|| !is_active(intf
))
971 /* This can happen; see usb_driver_release_interface() */
972 if (intf
->condition
== USB_INTERFACE_UNBOUND
)
974 driver
= to_usb_driver(intf
->dev
.driver
);
976 if (driver
->suspend
) {
977 status
= driver
->suspend(intf
, msg
);
980 else if (!udev
->auto_pm
)
981 dev_err(&intf
->dev
, "%s error %d\n",
984 /* Later we will unbind the driver and reprobe */
985 intf
->needs_binding
= 1;
986 dev_warn(&intf
->dev
, "no %s for driver %s?\n",
987 "suspend", driver
->name
);
992 dev_vdbg(&intf
->dev
, "%s: status %d\n", __FUNCTION__
, status
);
996 /* Caller has locked intf's usb_device's pm_mutex */
997 static int usb_resume_interface(struct usb_device
*udev
,
998 struct usb_interface
*intf
, int reset_resume
)
1000 struct usb_driver
*driver
;
1003 if (udev
->state
== USB_STATE_NOTATTACHED
|| is_active(intf
))
1006 /* Don't let autoresume interfere with unbinding */
1007 if (intf
->condition
== USB_INTERFACE_UNBINDING
)
1010 /* Can't resume it if it doesn't have a driver. */
1011 if (intf
->condition
== USB_INTERFACE_UNBOUND
)
1014 /* Don't resume if the interface is marked for rebinding */
1015 if (intf
->needs_binding
)
1017 driver
= to_usb_driver(intf
->dev
.driver
);
1020 if (driver
->reset_resume
) {
1021 status
= driver
->reset_resume(intf
);
1023 dev_err(&intf
->dev
, "%s error %d\n",
1024 "reset_resume", status
);
1026 intf
->needs_binding
= 1;
1027 dev_warn(&intf
->dev
, "no %s for driver %s?\n",
1028 "reset_resume", driver
->name
);
1031 if (driver
->resume
) {
1032 status
= driver
->resume(intf
);
1034 dev_err(&intf
->dev
, "%s error %d\n",
1037 intf
->needs_binding
= 1;
1038 dev_warn(&intf
->dev
, "no %s for driver %s?\n",
1039 "resume", driver
->name
);
1044 dev_vdbg(&intf
->dev
, "%s: status %d\n", __FUNCTION__
, status
);
1045 if (status
== 0 && intf
->condition
== USB_INTERFACE_BOUND
)
1048 /* Later we will unbind the driver and/or reprobe, if necessary */
1052 #ifdef CONFIG_USB_SUSPEND
1054 /* Internal routine to check whether we may autosuspend a device. */
1055 static int autosuspend_check(struct usb_device
*udev
, int reschedule
)
1058 struct usb_interface
*intf
;
1059 unsigned long suspend_time
, j
;
1061 /* For autosuspend, fail fast if anything is in use or autosuspend
1062 * is disabled. Also fail if any interfaces require remote wakeup
1063 * but it isn't available.
1065 if (udev
->pm_usage_cnt
> 0)
1067 if (udev
->autosuspend_delay
< 0 || udev
->autosuspend_disabled
)
1070 suspend_time
= udev
->last_busy
+ udev
->autosuspend_delay
;
1071 if (udev
->actconfig
) {
1072 for (i
= 0; i
< udev
->actconfig
->desc
.bNumInterfaces
; i
++) {
1073 intf
= udev
->actconfig
->interface
[i
];
1074 if (!is_active(intf
))
1076 if (intf
->pm_usage_cnt
> 0)
1078 if (intf
->needs_remote_wakeup
&&
1079 !udev
->do_remote_wakeup
) {
1080 dev_dbg(&udev
->dev
, "remote wakeup needed "
1081 "for autosuspend\n");
1085 /* Don't allow autosuspend if the device will need
1086 * a reset-resume and any of its interface drivers
1087 * doesn't include support.
1089 if (udev
->quirks
& USB_QUIRK_RESET_RESUME
) {
1090 struct usb_driver
*driver
;
1092 driver
= to_usb_driver(intf
->dev
.driver
);
1093 if (!driver
->reset_resume
||
1094 intf
->needs_remote_wakeup
)
1100 /* If everything is okay but the device hasn't been idle for long
1101 * enough, queue a delayed autosuspend request. If the device
1102 * _has_ been idle for long enough and the reschedule flag is set,
1103 * likewise queue a delayed (1 second) autosuspend request.
1106 if (time_before(j
, suspend_time
))
1109 suspend_time
= j
+ HZ
;
1111 if (!timer_pending(&udev
->autosuspend
.timer
)) {
1112 queue_delayed_work(ksuspend_usb_wq
, &udev
->autosuspend
,
1113 round_jiffies_relative(suspend_time
- j
));
1122 static inline int autosuspend_check(struct usb_device
*udev
, int reschedule
)
1127 #endif /* CONFIG_USB_SUSPEND */
1130 * usb_suspend_both - suspend a USB device and its interfaces
1131 * @udev: the usb_device to suspend
1132 * @msg: Power Management message describing this state transition
1134 * This is the central routine for suspending USB devices. It calls the
1135 * suspend methods for all the interface drivers in @udev and then calls
1136 * the suspend method for @udev itself. If an error occurs at any stage,
1137 * all the interfaces which were suspended are resumed so that they remain
1138 * in the same state as the device.
1140 * If an autosuspend is in progress (@udev->auto_pm is set), the routine
1141 * checks first to make sure that neither the device itself or any of its
1142 * active interfaces is in use (pm_usage_cnt is greater than 0). If they
1143 * are, the autosuspend fails.
1145 * If the suspend succeeds, the routine recursively queues an autosuspend
1146 * request for @udev's parent device, thereby propagating the change up
1147 * the device tree. If all of the parent's children are now suspended,
1148 * the parent will autosuspend in turn.
1150 * The suspend method calls are subject to mutual exclusion under control
1151 * of @udev's pm_mutex. Many of these calls are also under the protection
1152 * of @udev's device lock (including all requests originating outside the
1153 * USB subsystem), but autosuspend requests generated by a child device or
1154 * interface driver may not be. Usbcore will insure that the method calls
1155 * do not arrive during bind, unbind, or reset operations. However, drivers
1156 * must be prepared to handle suspend calls arriving at unpredictable times.
1157 * The only way to block such calls is to do an autoresume (preventing
1158 * autosuspends) while holding @udev's device lock (preventing outside
1161 * The caller must hold @udev->pm_mutex.
1163 * This routine can run only in process context.
1165 static int usb_suspend_both(struct usb_device
*udev
, pm_message_t msg
)
1169 struct usb_interface
*intf
;
1170 struct usb_device
*parent
= udev
->parent
;
1172 if (udev
->state
== USB_STATE_NOTATTACHED
||
1173 udev
->state
== USB_STATE_SUSPENDED
)
1176 udev
->do_remote_wakeup
= device_may_wakeup(&udev
->dev
);
1178 if (udev
->auto_pm
) {
1179 status
= autosuspend_check(udev
, 0);
1184 /* Suspend all the interfaces and then udev itself */
1185 if (udev
->actconfig
) {
1186 for (; i
< udev
->actconfig
->desc
.bNumInterfaces
; i
++) {
1187 intf
= udev
->actconfig
->interface
[i
];
1188 status
= usb_suspend_interface(udev
, intf
, msg
);
1194 status
= usb_suspend_device(udev
, msg
);
1196 /* If the suspend failed, resume interfaces that did get suspended */
1199 intf
= udev
->actconfig
->interface
[i
];
1200 usb_resume_interface(udev
, intf
, 0);
1203 /* Try another autosuspend when the interfaces aren't busy */
1205 autosuspend_check(udev
, status
== -EBUSY
);
1207 /* If the suspend succeeded then prevent any more URB submissions,
1208 * flush any outstanding URBs, and propagate the suspend up the tree.
1211 cancel_delayed_work(&udev
->autosuspend
);
1212 udev
->can_submit
= 0;
1213 for (i
= 0; i
< 16; ++i
) {
1214 usb_hcd_flush_endpoint(udev
, udev
->ep_out
[i
]);
1215 usb_hcd_flush_endpoint(udev
, udev
->ep_in
[i
]);
1218 /* If this is just a FREEZE or a PRETHAW, udev might
1219 * not really be suspended. Only true suspends get
1220 * propagated up the device tree.
1222 if (parent
&& udev
->state
== USB_STATE_SUSPENDED
)
1223 usb_autosuspend_device(parent
);
1227 dev_vdbg(&udev
->dev
, "%s: status %d\n", __FUNCTION__
, status
);
1232 * usb_resume_both - resume a USB device and its interfaces
1233 * @udev: the usb_device to resume
1235 * This is the central routine for resuming USB devices. It calls the
1236 * the resume method for @udev and then calls the resume methods for all
1237 * the interface drivers in @udev.
1239 * Before starting the resume, the routine calls itself recursively for
1240 * the parent device of @udev, thereby propagating the change up the device
1241 * tree and assuring that @udev will be able to resume. If the parent is
1242 * unable to resume successfully, the routine fails.
1244 * The resume method calls are subject to mutual exclusion under control
1245 * of @udev's pm_mutex. Many of these calls are also under the protection
1246 * of @udev's device lock (including all requests originating outside the
1247 * USB subsystem), but autoresume requests generated by a child device or
1248 * interface driver may not be. Usbcore will insure that the method calls
1249 * do not arrive during bind, unbind, or reset operations. However, drivers
1250 * must be prepared to handle resume calls arriving at unpredictable times.
1251 * The only way to block such calls is to do an autoresume (preventing
1252 * other autoresumes) while holding @udev's device lock (preventing outside
1255 * The caller must hold @udev->pm_mutex.
1257 * This routine can run only in process context.
1259 static int usb_resume_both(struct usb_device
*udev
)
1263 struct usb_interface
*intf
;
1264 struct usb_device
*parent
= udev
->parent
;
1266 cancel_delayed_work(&udev
->autosuspend
);
1267 if (udev
->state
== USB_STATE_NOTATTACHED
) {
1271 udev
->can_submit
= 1;
1273 /* Propagate the resume up the tree, if necessary */
1274 if (udev
->state
== USB_STATE_SUSPENDED
) {
1275 if (udev
->auto_pm
&& udev
->autoresume_disabled
) {
1280 status
= usb_autoresume_device(parent
);
1282 status
= usb_resume_device(udev
);
1283 if (status
|| udev
->state
==
1284 USB_STATE_NOTATTACHED
) {
1285 usb_autosuspend_device(parent
);
1287 /* It's possible usb_resume_device()
1288 * failed after the port was
1289 * unsuspended, causing udev to be
1290 * logically disconnected. We don't
1291 * want usb_disconnect() to autosuspend
1292 * the parent again, so tell it that
1293 * udev disconnected while still
1296 USB_STATE_NOTATTACHED
)
1297 udev
->discon_suspended
= 1;
1302 /* We can't progagate beyond the USB subsystem,
1303 * so if a root hub's controller is suspended
1304 * then we're stuck. */
1305 status
= usb_resume_device(udev
);
1307 } else if (udev
->reset_resume
)
1308 status
= usb_resume_device(udev
);
1310 if (status
== 0 && udev
->actconfig
) {
1311 for (i
= 0; i
< udev
->actconfig
->desc
.bNumInterfaces
; i
++) {
1312 intf
= udev
->actconfig
->interface
[i
];
1313 usb_resume_interface(udev
, intf
, udev
->reset_resume
);
1318 dev_vdbg(&udev
->dev
, "%s: status %d\n", __FUNCTION__
, status
);
1320 udev
->reset_resume
= 0;
1324 #ifdef CONFIG_USB_SUSPEND
1326 /* Internal routine to adjust a device's usage counter and change
1327 * its autosuspend state.
1329 static int usb_autopm_do_device(struct usb_device
*udev
, int inc_usage_cnt
)
1335 udev
->pm_usage_cnt
+= inc_usage_cnt
;
1336 WARN_ON(udev
->pm_usage_cnt
< 0);
1338 udev
->last_busy
= jiffies
;
1339 if (inc_usage_cnt
>= 0 && udev
->pm_usage_cnt
> 0) {
1340 if (udev
->state
== USB_STATE_SUSPENDED
)
1341 status
= usb_resume_both(udev
);
1343 udev
->pm_usage_cnt
-= inc_usage_cnt
;
1344 else if (inc_usage_cnt
)
1345 udev
->last_busy
= jiffies
;
1346 } else if (inc_usage_cnt
<= 0 && udev
->pm_usage_cnt
<= 0) {
1347 status
= usb_suspend_both(udev
, PMSG_SUSPEND
);
1349 usb_pm_unlock(udev
);
1353 /* usb_autosuspend_work - callback routine to autosuspend a USB device */
1354 void usb_autosuspend_work(struct work_struct
*work
)
1356 struct usb_device
*udev
=
1357 container_of(work
, struct usb_device
, autosuspend
.work
);
1359 usb_autopm_do_device(udev
, 0);
1363 * usb_autosuspend_device - delayed autosuspend of a USB device and its interfaces
1364 * @udev: the usb_device to autosuspend
1366 * This routine should be called when a core subsystem is finished using
1367 * @udev and wants to allow it to autosuspend. Examples would be when
1368 * @udev's device file in usbfs is closed or after a configuration change.
1370 * @udev's usage counter is decremented. If it or any of the usage counters
1371 * for an active interface is greater than 0, no autosuspend request will be
1372 * queued. (If an interface driver does not support autosuspend then its
1373 * usage counter is permanently positive.) Furthermore, if an interface
1374 * driver requires remote-wakeup capability during autosuspend but remote
1375 * wakeup is disabled, the autosuspend will fail.
1377 * Often the caller will hold @udev's device lock, but this is not
1380 * This routine can run only in process context.
1382 void usb_autosuspend_device(struct usb_device
*udev
)
1386 status
= usb_autopm_do_device(udev
, -1);
1387 dev_vdbg(&udev
->dev
, "%s: cnt %d\n",
1388 __FUNCTION__
, udev
->pm_usage_cnt
);
1392 * usb_try_autosuspend_device - attempt an autosuspend of a USB device and its interfaces
1393 * @udev: the usb_device to autosuspend
1395 * This routine should be called when a core subsystem thinks @udev may
1396 * be ready to autosuspend.
1398 * @udev's usage counter left unchanged. If it or any of the usage counters
1399 * for an active interface is greater than 0, or autosuspend is not allowed
1400 * for any other reason, no autosuspend request will be queued.
1402 * This routine can run only in process context.
1404 void usb_try_autosuspend_device(struct usb_device
*udev
)
1406 usb_autopm_do_device(udev
, 0);
1407 dev_vdbg(&udev
->dev
, "%s: cnt %d\n",
1408 __FUNCTION__
, udev
->pm_usage_cnt
);
1412 * usb_autoresume_device - immediately autoresume a USB device and its interfaces
1413 * @udev: the usb_device to autoresume
1415 * This routine should be called when a core subsystem wants to use @udev
1416 * and needs to guarantee that it is not suspended. No autosuspend will
1417 * occur until usb_autosuspend_device is called. (Note that this will not
1418 * prevent suspend events originating in the PM core.) Examples would be
1419 * when @udev's device file in usbfs is opened or when a remote-wakeup
1420 * request is received.
1422 * @udev's usage counter is incremented to prevent subsequent autosuspends.
1423 * However if the autoresume fails then the usage counter is re-decremented.
1425 * Often the caller will hold @udev's device lock, but this is not
1426 * necessary (and attempting it might cause deadlock).
1428 * This routine can run only in process context.
1430 int usb_autoresume_device(struct usb_device
*udev
)
1434 status
= usb_autopm_do_device(udev
, 1);
1435 dev_vdbg(&udev
->dev
, "%s: status %d cnt %d\n",
1436 __FUNCTION__
, status
, udev
->pm_usage_cnt
);
1440 /* Internal routine to adjust an interface's usage counter and change
1441 * its device's autosuspend state.
1443 static int usb_autopm_do_interface(struct usb_interface
*intf
,
1446 struct usb_device
*udev
= interface_to_usbdev(intf
);
1450 if (intf
->condition
== USB_INTERFACE_UNBOUND
)
1454 intf
->pm_usage_cnt
+= inc_usage_cnt
;
1455 udev
->last_busy
= jiffies
;
1456 if (inc_usage_cnt
>= 0 && intf
->pm_usage_cnt
> 0) {
1457 if (udev
->state
== USB_STATE_SUSPENDED
)
1458 status
= usb_resume_both(udev
);
1460 intf
->pm_usage_cnt
-= inc_usage_cnt
;
1462 udev
->last_busy
= jiffies
;
1463 } else if (inc_usage_cnt
<= 0 && intf
->pm_usage_cnt
<= 0) {
1464 status
= usb_suspend_both(udev
, PMSG_SUSPEND
);
1467 usb_pm_unlock(udev
);
1472 * usb_autopm_put_interface - decrement a USB interface's PM-usage counter
1473 * @intf: the usb_interface whose counter should be decremented
1475 * This routine should be called by an interface driver when it is
1476 * finished using @intf and wants to allow it to autosuspend. A typical
1477 * example would be a character-device driver when its device file is
1480 * The routine decrements @intf's usage counter. When the counter reaches
1481 * 0, a delayed autosuspend request for @intf's device is queued. When
1482 * the delay expires, if @intf->pm_usage_cnt is still <= 0 along with all
1483 * the other usage counters for the sibling interfaces and @intf's
1484 * usb_device, the device and all its interfaces will be autosuspended.
1486 * Note that @intf->pm_usage_cnt is owned by the interface driver. The
1487 * core will not change its value other than the increment and decrement
1488 * in usb_autopm_get_interface and usb_autopm_put_interface. The driver
1489 * may use this simple counter-oriented discipline or may set the value
1492 * If the driver has set @intf->needs_remote_wakeup then autosuspend will
1493 * take place only if the device's remote-wakeup facility is enabled.
1495 * Suspend method calls queued by this routine can arrive at any time
1496 * while @intf is resumed and its usage counter is equal to 0. They are
1497 * not protected by the usb_device's lock but only by its pm_mutex.
1498 * Drivers must provide their own synchronization.
1500 * This routine can run only in process context.
1502 void usb_autopm_put_interface(struct usb_interface
*intf
)
1506 status
= usb_autopm_do_interface(intf
, -1);
1507 dev_vdbg(&intf
->dev
, "%s: status %d cnt %d\n",
1508 __FUNCTION__
, status
, intf
->pm_usage_cnt
);
1510 EXPORT_SYMBOL_GPL(usb_autopm_put_interface
);
1513 * usb_autopm_get_interface - increment a USB interface's PM-usage counter
1514 * @intf: the usb_interface whose counter should be incremented
1516 * This routine should be called by an interface driver when it wants to
1517 * use @intf and needs to guarantee that it is not suspended. In addition,
1518 * the routine prevents @intf from being autosuspended subsequently. (Note
1519 * that this will not prevent suspend events originating in the PM core.)
1520 * This prevention will persist until usb_autopm_put_interface() is called
1521 * or @intf is unbound. A typical example would be a character-device
1522 * driver when its device file is opened.
1525 * The routine increments @intf's usage counter. (However if the
1526 * autoresume fails then the counter is re-decremented.) So long as the
1527 * counter is greater than 0, autosuspend will not be allowed for @intf
1528 * or its usb_device. When the driver is finished using @intf it should
1529 * call usb_autopm_put_interface() to decrement the usage counter and
1530 * queue a delayed autosuspend request (if the counter is <= 0).
1533 * Note that @intf->pm_usage_cnt is owned by the interface driver. The
1534 * core will not change its value other than the increment and decrement
1535 * in usb_autopm_get_interface and usb_autopm_put_interface. The driver
1536 * may use this simple counter-oriented discipline or may set the value
1539 * Resume method calls generated by this routine can arrive at any time
1540 * while @intf is suspended. They are not protected by the usb_device's
1541 * lock but only by its pm_mutex. Drivers must provide their own
1544 * This routine can run only in process context.
1546 int usb_autopm_get_interface(struct usb_interface
*intf
)
1550 status
= usb_autopm_do_interface(intf
, 1);
1551 dev_vdbg(&intf
->dev
, "%s: status %d cnt %d\n",
1552 __FUNCTION__
, status
, intf
->pm_usage_cnt
);
1555 EXPORT_SYMBOL_GPL(usb_autopm_get_interface
);
1558 * usb_autopm_set_interface - set a USB interface's autosuspend state
1559 * @intf: the usb_interface whose state should be set
1561 * This routine sets the autosuspend state of @intf's device according
1562 * to @intf's usage counter, which the caller must have set previously.
1563 * If the counter is <= 0, the device is autosuspended (if it isn't
1564 * already suspended and if nothing else prevents the autosuspend). If
1565 * the counter is > 0, the device is autoresumed (if it isn't already
1568 int usb_autopm_set_interface(struct usb_interface
*intf
)
1572 status
= usb_autopm_do_interface(intf
, 0);
1573 dev_vdbg(&intf
->dev
, "%s: status %d cnt %d\n",
1574 __FUNCTION__
, status
, intf
->pm_usage_cnt
);
1577 EXPORT_SYMBOL_GPL(usb_autopm_set_interface
);
1581 void usb_autosuspend_work(struct work_struct
*work
)
1584 #endif /* CONFIG_USB_SUSPEND */
1587 * usb_external_suspend_device - external suspend of a USB device and its interfaces
1588 * @udev: the usb_device to suspend
1589 * @msg: Power Management message describing this state transition
1591 * This routine handles external suspend requests: ones not generated
1592 * internally by a USB driver (autosuspend) but rather coming from the user
1593 * (via sysfs) or the PM core (system sleep). The suspend will be carried
1594 * out regardless of @udev's usage counter or those of its interfaces,
1595 * and regardless of whether or not remote wakeup is enabled. Of course,
1596 * interface drivers still have the option of failing the suspend (if
1597 * there are unsuspended children, for example).
1599 * The caller must hold @udev's device lock.
1601 int usb_external_suspend_device(struct usb_device
*udev
, pm_message_t msg
)
1605 do_unbind_rebind(udev
, DO_UNBIND
);
1608 status
= usb_suspend_both(udev
, msg
);
1609 usb_pm_unlock(udev
);
1614 * usb_external_resume_device - external resume of a USB device and its interfaces
1615 * @udev: the usb_device to resume
1617 * This routine handles external resume requests: ones not generated
1618 * internally by a USB driver (autoresume) but rather coming from the user
1619 * (via sysfs), the PM core (system resume), or the device itself (remote
1620 * wakeup). @udev's usage counter is unaffected.
1622 * The caller must hold @udev's device lock.
1624 int usb_external_resume_device(struct usb_device
*udev
)
1630 status
= usb_resume_both(udev
);
1631 udev
->last_busy
= jiffies
;
1632 usb_pm_unlock(udev
);
1634 do_unbind_rebind(udev
, DO_REBIND
);
1636 /* Now that the device is awake, we can start trying to autosuspend
1639 usb_try_autosuspend_device(udev
);
1643 static int usb_suspend(struct device
*dev
, pm_message_t message
)
1645 struct usb_device
*udev
;
1647 if (!is_usb_device(dev
)) /* Ignore PM for interfaces */
1649 udev
= to_usb_device(dev
);
1651 /* If udev is already suspended, we can skip this suspend and
1652 * we should also skip the upcoming system resume. High-speed
1653 * root hubs are an exception; they need to resume whenever the
1654 * system wakes up in order for USB-PERSIST port handover to work
1657 if (udev
->state
== USB_STATE_SUSPENDED
) {
1658 if (udev
->parent
|| udev
->speed
!= USB_SPEED_HIGH
)
1659 udev
->skip_sys_resume
= 1;
1663 udev
->skip_sys_resume
= 0;
1664 return usb_external_suspend_device(udev
, message
);
1667 static int usb_resume(struct device
*dev
)
1669 struct usb_device
*udev
;
1672 if (!is_usb_device(dev
)) /* Ignore PM for interfaces */
1674 udev
= to_usb_device(dev
);
1676 /* If udev->skip_sys_resume is set then udev was already suspended
1677 * when the system sleep started, so we don't want to resume it
1678 * during this system wakeup.
1680 if (udev
->skip_sys_resume
)
1682 status
= usb_external_resume_device(udev
);
1684 /* Avoid PM error messages for devices disconnected while suspended
1685 * as we'll display regular disconnect messages just a bit later.
1687 if (status
== -ENODEV
|| status
== -ESHUTDOWN
)
1692 #endif /* CONFIG_PM */
1694 struct bus_type usb_bus_type
= {
1696 .match
= usb_device_match
,
1697 .uevent
= usb_uevent
,
1699 .suspend
= usb_suspend
,
1700 .resume
= usb_resume
,