dm thin metadata: fix __udivdi3 undefined on 32-bit
[linux/fpc-iii.git] / drivers / usb / core / driver.c
blobe9d6cf146fccd380e6baa2696add244053bd598c
1 /*
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
21 * real drivers.
25 #include <linux/device.h>
26 #include <linux/slab.h>
27 #include <linux/export.h>
28 #include <linux/usb.h>
29 #include <linux/usb/quirks.h>
30 #include <linux/usb/hcd.h>
32 #include "usb.h"
36 * Adds a new dynamic USBdevice ID to this driver,
37 * and cause the driver to probe for all devices again.
39 ssize_t usb_store_new_id(struct usb_dynids *dynids,
40 const struct usb_device_id *id_table,
41 struct device_driver *driver,
42 const char *buf, size_t count)
44 struct usb_dynid *dynid;
45 u32 idVendor = 0;
46 u32 idProduct = 0;
47 unsigned int bInterfaceClass = 0;
48 u32 refVendor, refProduct;
49 int fields = 0;
50 int retval = 0;
52 fields = sscanf(buf, "%x %x %x %x %x", &idVendor, &idProduct,
53 &bInterfaceClass, &refVendor, &refProduct);
54 if (fields < 2)
55 return -EINVAL;
57 dynid = kzalloc(sizeof(*dynid), GFP_KERNEL);
58 if (!dynid)
59 return -ENOMEM;
61 INIT_LIST_HEAD(&dynid->node);
62 dynid->id.idVendor = idVendor;
63 dynid->id.idProduct = idProduct;
64 dynid->id.match_flags = USB_DEVICE_ID_MATCH_DEVICE;
65 if (fields > 2 && bInterfaceClass) {
66 if (bInterfaceClass > 255) {
67 retval = -EINVAL;
68 goto fail;
71 dynid->id.bInterfaceClass = (u8)bInterfaceClass;
72 dynid->id.match_flags |= USB_DEVICE_ID_MATCH_INT_CLASS;
75 if (fields > 4) {
76 const struct usb_device_id *id = id_table;
78 if (!id) {
79 retval = -ENODEV;
80 goto fail;
83 for (; id->match_flags; id++)
84 if (id->idVendor == refVendor && id->idProduct == refProduct)
85 break;
87 if (id->match_flags) {
88 dynid->id.driver_info = id->driver_info;
89 } else {
90 retval = -ENODEV;
91 goto fail;
95 spin_lock(&dynids->lock);
96 list_add_tail(&dynid->node, &dynids->list);
97 spin_unlock(&dynids->lock);
99 retval = driver_attach(driver);
101 if (retval)
102 return retval;
103 return count;
105 fail:
106 kfree(dynid);
107 return retval;
109 EXPORT_SYMBOL_GPL(usb_store_new_id);
111 ssize_t usb_show_dynids(struct usb_dynids *dynids, char *buf)
113 struct usb_dynid *dynid;
114 size_t count = 0;
116 list_for_each_entry(dynid, &dynids->list, node)
117 if (dynid->id.bInterfaceClass != 0)
118 count += scnprintf(&buf[count], PAGE_SIZE - count, "%04x %04x %02x\n",
119 dynid->id.idVendor, dynid->id.idProduct,
120 dynid->id.bInterfaceClass);
121 else
122 count += scnprintf(&buf[count], PAGE_SIZE - count, "%04x %04x\n",
123 dynid->id.idVendor, dynid->id.idProduct);
124 return count;
126 EXPORT_SYMBOL_GPL(usb_show_dynids);
128 static ssize_t new_id_show(struct device_driver *driver, char *buf)
130 struct usb_driver *usb_drv = to_usb_driver(driver);
132 return usb_show_dynids(&usb_drv->dynids, buf);
135 static ssize_t new_id_store(struct device_driver *driver,
136 const char *buf, size_t count)
138 struct usb_driver *usb_drv = to_usb_driver(driver);
140 return usb_store_new_id(&usb_drv->dynids, usb_drv->id_table, driver, buf, count);
142 static DRIVER_ATTR_RW(new_id);
145 * Remove a USB device ID from this driver
147 static ssize_t remove_id_store(struct device_driver *driver, const char *buf,
148 size_t count)
150 struct usb_dynid *dynid, *n;
151 struct usb_driver *usb_driver = to_usb_driver(driver);
152 u32 idVendor;
153 u32 idProduct;
154 int fields;
156 fields = sscanf(buf, "%x %x", &idVendor, &idProduct);
157 if (fields < 2)
158 return -EINVAL;
160 spin_lock(&usb_driver->dynids.lock);
161 list_for_each_entry_safe(dynid, n, &usb_driver->dynids.list, node) {
162 struct usb_device_id *id = &dynid->id;
164 if ((id->idVendor == idVendor) &&
165 (id->idProduct == idProduct)) {
166 list_del(&dynid->node);
167 kfree(dynid);
168 break;
171 spin_unlock(&usb_driver->dynids.lock);
172 return count;
175 static ssize_t remove_id_show(struct device_driver *driver, char *buf)
177 return new_id_show(driver, buf);
179 static DRIVER_ATTR_RW(remove_id);
181 static int usb_create_newid_files(struct usb_driver *usb_drv)
183 int error = 0;
185 if (usb_drv->no_dynamic_id)
186 goto exit;
188 if (usb_drv->probe != NULL) {
189 error = driver_create_file(&usb_drv->drvwrap.driver,
190 &driver_attr_new_id);
191 if (error == 0) {
192 error = driver_create_file(&usb_drv->drvwrap.driver,
193 &driver_attr_remove_id);
194 if (error)
195 driver_remove_file(&usb_drv->drvwrap.driver,
196 &driver_attr_new_id);
199 exit:
200 return error;
203 static void usb_remove_newid_files(struct usb_driver *usb_drv)
205 if (usb_drv->no_dynamic_id)
206 return;
208 if (usb_drv->probe != NULL) {
209 driver_remove_file(&usb_drv->drvwrap.driver,
210 &driver_attr_remove_id);
211 driver_remove_file(&usb_drv->drvwrap.driver,
212 &driver_attr_new_id);
216 static void usb_free_dynids(struct usb_driver *usb_drv)
218 struct usb_dynid *dynid, *n;
220 spin_lock(&usb_drv->dynids.lock);
221 list_for_each_entry_safe(dynid, n, &usb_drv->dynids.list, node) {
222 list_del(&dynid->node);
223 kfree(dynid);
225 spin_unlock(&usb_drv->dynids.lock);
228 static const struct usb_device_id *usb_match_dynamic_id(struct usb_interface *intf,
229 struct usb_driver *drv)
231 struct usb_dynid *dynid;
233 spin_lock(&drv->dynids.lock);
234 list_for_each_entry(dynid, &drv->dynids.list, node) {
235 if (usb_match_one_id(intf, &dynid->id)) {
236 spin_unlock(&drv->dynids.lock);
237 return &dynid->id;
240 spin_unlock(&drv->dynids.lock);
241 return NULL;
245 /* called from driver core with dev locked */
246 static int usb_probe_device(struct device *dev)
248 struct usb_device_driver *udriver = to_usb_device_driver(dev->driver);
249 struct usb_device *udev = to_usb_device(dev);
250 int error = 0;
252 dev_dbg(dev, "%s\n", __func__);
254 /* TODO: Add real matching code */
256 /* The device should always appear to be in use
257 * unless the driver supports autosuspend.
259 if (!udriver->supports_autosuspend)
260 error = usb_autoresume_device(udev);
262 if (!error)
263 error = udriver->probe(udev);
264 return error;
267 /* called from driver core with dev locked */
268 static int usb_unbind_device(struct device *dev)
270 struct usb_device *udev = to_usb_device(dev);
271 struct usb_device_driver *udriver = to_usb_device_driver(dev->driver);
273 udriver->disconnect(udev);
274 if (!udriver->supports_autosuspend)
275 usb_autosuspend_device(udev);
276 return 0;
279 /* called from driver core with dev locked */
280 static int usb_probe_interface(struct device *dev)
282 struct usb_driver *driver = to_usb_driver(dev->driver);
283 struct usb_interface *intf = to_usb_interface(dev);
284 struct usb_device *udev = interface_to_usbdev(intf);
285 const struct usb_device_id *id;
286 int error = -ENODEV;
287 int lpm_disable_error = -ENODEV;
289 dev_dbg(dev, "%s\n", __func__);
291 intf->needs_binding = 0;
293 if (usb_device_is_owned(udev))
294 return error;
296 if (udev->authorized == 0) {
297 dev_err(&intf->dev, "Device is not authorized for usage\n");
298 return error;
299 } else if (intf->authorized == 0) {
300 dev_err(&intf->dev, "Interface %d is not authorized for usage\n",
301 intf->altsetting->desc.bInterfaceNumber);
302 return error;
305 id = usb_match_dynamic_id(intf, driver);
306 if (!id)
307 id = usb_match_id(intf, driver->id_table);
308 if (!id)
309 return error;
311 dev_dbg(dev, "%s - got id\n", __func__);
313 error = usb_autoresume_device(udev);
314 if (error)
315 return error;
317 intf->condition = USB_INTERFACE_BINDING;
319 /* Probed interfaces are initially active. They are
320 * runtime-PM-enabled only if the driver has autosuspend support.
321 * They are sensitive to their children's power states.
323 pm_runtime_set_active(dev);
324 pm_suspend_ignore_children(dev, false);
325 if (driver->supports_autosuspend)
326 pm_runtime_enable(dev);
328 /* If the new driver doesn't allow hub-initiated LPM, and we can't
329 * disable hub-initiated LPM, then fail the probe.
331 * Otherwise, leaving LPM enabled should be harmless, because the
332 * endpoint intervals should remain the same, and the U1/U2 timeouts
333 * should remain the same.
335 * If we need to install alt setting 0 before probe, or another alt
336 * setting during probe, that should also be fine. usb_set_interface()
337 * will attempt to disable LPM, and fail if it can't disable it.
339 if (driver->disable_hub_initiated_lpm) {
340 lpm_disable_error = usb_unlocked_disable_lpm(udev);
341 if (lpm_disable_error) {
342 dev_err(&intf->dev, "%s Failed to disable LPM for driver %s\n.",
343 __func__, driver->name);
344 error = lpm_disable_error;
345 goto err;
349 /* Carry out a deferred switch to altsetting 0 */
350 if (intf->needs_altsetting0) {
351 error = usb_set_interface(udev, intf->altsetting[0].
352 desc.bInterfaceNumber, 0);
353 if (error < 0)
354 goto err;
355 intf->needs_altsetting0 = 0;
358 error = driver->probe(intf, id);
359 if (error)
360 goto err;
362 intf->condition = USB_INTERFACE_BOUND;
364 /* If the LPM disable succeeded, balance the ref counts. */
365 if (!lpm_disable_error)
366 usb_unlocked_enable_lpm(udev);
368 usb_autosuspend_device(udev);
369 return error;
371 err:
372 usb_set_intfdata(intf, NULL);
373 intf->needs_remote_wakeup = 0;
374 intf->condition = USB_INTERFACE_UNBOUND;
376 /* If the LPM disable succeeded, balance the ref counts. */
377 if (!lpm_disable_error)
378 usb_unlocked_enable_lpm(udev);
380 /* Unbound interfaces are always runtime-PM-disabled and -suspended */
381 if (driver->supports_autosuspend)
382 pm_runtime_disable(dev);
383 pm_runtime_set_suspended(dev);
385 usb_autosuspend_device(udev);
386 return error;
389 /* called from driver core with dev locked */
390 static int usb_unbind_interface(struct device *dev)
392 struct usb_driver *driver = to_usb_driver(dev->driver);
393 struct usb_interface *intf = to_usb_interface(dev);
394 struct usb_host_endpoint *ep, **eps = NULL;
395 struct usb_device *udev;
396 int i, j, error, r;
397 int lpm_disable_error = -ENODEV;
399 intf->condition = USB_INTERFACE_UNBINDING;
401 /* Autoresume for set_interface call below */
402 udev = interface_to_usbdev(intf);
403 error = usb_autoresume_device(udev);
405 /* If hub-initiated LPM policy may change, attempt to disable LPM until
406 * the driver is unbound. If LPM isn't disabled, that's fine because it
407 * wouldn't be enabled unless all the bound interfaces supported
408 * hub-initiated LPM.
410 if (driver->disable_hub_initiated_lpm)
411 lpm_disable_error = usb_unlocked_disable_lpm(udev);
414 * Terminate all URBs for this interface unless the driver
415 * supports "soft" unbinding and the device is still present.
417 if (!driver->soft_unbind || udev->state == USB_STATE_NOTATTACHED)
418 usb_disable_interface(udev, intf, false);
420 driver->disconnect(intf);
422 /* Free streams */
423 for (i = 0, j = 0; i < intf->cur_altsetting->desc.bNumEndpoints; i++) {
424 ep = &intf->cur_altsetting->endpoint[i];
425 if (ep->streams == 0)
426 continue;
427 if (j == 0) {
428 eps = kmalloc_array(USB_MAXENDPOINTS, sizeof(void *),
429 GFP_KERNEL);
430 if (!eps)
431 break;
433 eps[j++] = ep;
435 if (j) {
436 usb_free_streams(intf, eps, j, GFP_KERNEL);
437 kfree(eps);
440 /* Reset other interface state.
441 * We cannot do a Set-Interface if the device is suspended or
442 * if it is prepared for a system sleep (since installing a new
443 * altsetting means creating new endpoint device entries).
444 * When either of these happens, defer the Set-Interface.
446 if (intf->cur_altsetting->desc.bAlternateSetting == 0) {
447 /* Already in altsetting 0 so skip Set-Interface.
448 * Just re-enable it without affecting the endpoint toggles.
450 usb_enable_interface(udev, intf, false);
451 } else if (!error && !intf->dev.power.is_prepared) {
452 r = usb_set_interface(udev, intf->altsetting[0].
453 desc.bInterfaceNumber, 0);
454 if (r < 0)
455 intf->needs_altsetting0 = 1;
456 } else {
457 intf->needs_altsetting0 = 1;
459 usb_set_intfdata(intf, NULL);
461 intf->condition = USB_INTERFACE_UNBOUND;
462 intf->needs_remote_wakeup = 0;
464 /* Attempt to re-enable USB3 LPM, if the disable succeeded. */
465 if (!lpm_disable_error)
466 usb_unlocked_enable_lpm(udev);
468 /* Unbound interfaces are always runtime-PM-disabled and -suspended */
469 if (driver->supports_autosuspend)
470 pm_runtime_disable(dev);
471 pm_runtime_set_suspended(dev);
473 /* Undo any residual pm_autopm_get_interface_* calls */
474 for (r = atomic_read(&intf->pm_usage_cnt); r > 0; --r)
475 usb_autopm_put_interface_no_suspend(intf);
476 atomic_set(&intf->pm_usage_cnt, 0);
478 if (!error)
479 usb_autosuspend_device(udev);
481 return 0;
485 * usb_driver_claim_interface - bind a driver to an interface
486 * @driver: the driver to be bound
487 * @iface: the interface to which it will be bound; must be in the
488 * usb device's active configuration
489 * @priv: driver data associated with that interface
491 * This is used by usb device drivers that need to claim more than one
492 * interface on a device when probing (audio and acm are current examples).
493 * No device driver should directly modify internal usb_interface or
494 * usb_device structure members.
496 * Few drivers should need to use this routine, since the most natural
497 * way to bind to an interface is to return the private data from
498 * the driver's probe() method.
500 * Callers must own the device lock, so driver probe() entries don't need
501 * extra locking, but other call contexts may need to explicitly claim that
502 * lock.
504 * Return: 0 on success.
506 int usb_driver_claim_interface(struct usb_driver *driver,
507 struct usb_interface *iface, void *priv)
509 struct device *dev;
510 struct usb_device *udev;
511 int retval = 0;
513 if (!iface)
514 return -ENODEV;
516 dev = &iface->dev;
517 if (dev->driver)
518 return -EBUSY;
520 /* reject claim if interface is not authorized */
521 if (!iface->authorized)
522 return -ENODEV;
524 udev = interface_to_usbdev(iface);
526 dev->driver = &driver->drvwrap.driver;
527 usb_set_intfdata(iface, priv);
528 iface->needs_binding = 0;
530 iface->condition = USB_INTERFACE_BOUND;
532 /* Claimed interfaces are initially inactive (suspended) and
533 * runtime-PM-enabled, but only if the driver has autosuspend
534 * support. Otherwise they are marked active, to prevent the
535 * device from being autosuspended, but left disabled. In either
536 * case they are sensitive to their children's power states.
538 pm_suspend_ignore_children(dev, false);
539 if (driver->supports_autosuspend)
540 pm_runtime_enable(dev);
541 else
542 pm_runtime_set_active(dev);
544 /* if interface was already added, bind now; else let
545 * the future device_add() bind it, bypassing probe()
547 if (device_is_registered(dev))
548 retval = device_bind_driver(dev);
550 if (retval) {
551 dev->driver = NULL;
552 usb_set_intfdata(iface, NULL);
553 iface->needs_remote_wakeup = 0;
554 iface->condition = USB_INTERFACE_UNBOUND;
557 * Unbound interfaces are always runtime-PM-disabled
558 * and runtime-PM-suspended
560 if (driver->supports_autosuspend)
561 pm_runtime_disable(dev);
562 pm_runtime_set_suspended(dev);
565 return retval;
567 EXPORT_SYMBOL_GPL(usb_driver_claim_interface);
570 * usb_driver_release_interface - unbind a driver from an interface
571 * @driver: the driver to be unbound
572 * @iface: the interface from which it will be unbound
574 * This can be used by drivers to release an interface without waiting
575 * for their disconnect() methods to be called. In typical cases this
576 * also causes the driver disconnect() method to be called.
578 * This call is synchronous, and may not be used in an interrupt context.
579 * Callers must own the device lock, so driver disconnect() entries don't
580 * need extra locking, but other call contexts may need to explicitly claim
581 * that lock.
583 void usb_driver_release_interface(struct usb_driver *driver,
584 struct usb_interface *iface)
586 struct device *dev = &iface->dev;
588 /* this should never happen, don't release something that's not ours */
589 if (!dev->driver || dev->driver != &driver->drvwrap.driver)
590 return;
592 /* don't release from within disconnect() */
593 if (iface->condition != USB_INTERFACE_BOUND)
594 return;
595 iface->condition = USB_INTERFACE_UNBINDING;
597 /* Release via the driver core only if the interface
598 * has already been registered
600 if (device_is_registered(dev)) {
601 device_release_driver(dev);
602 } else {
603 device_lock(dev);
604 usb_unbind_interface(dev);
605 dev->driver = NULL;
606 device_unlock(dev);
609 EXPORT_SYMBOL_GPL(usb_driver_release_interface);
611 /* returns 0 if no match, 1 if match */
612 int usb_match_device(struct usb_device *dev, const struct usb_device_id *id)
614 if ((id->match_flags & USB_DEVICE_ID_MATCH_VENDOR) &&
615 id->idVendor != le16_to_cpu(dev->descriptor.idVendor))
616 return 0;
618 if ((id->match_flags & USB_DEVICE_ID_MATCH_PRODUCT) &&
619 id->idProduct != le16_to_cpu(dev->descriptor.idProduct))
620 return 0;
622 /* No need to test id->bcdDevice_lo != 0, since 0 is never
623 greater than any unsigned number. */
624 if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_LO) &&
625 (id->bcdDevice_lo > le16_to_cpu(dev->descriptor.bcdDevice)))
626 return 0;
628 if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_HI) &&
629 (id->bcdDevice_hi < le16_to_cpu(dev->descriptor.bcdDevice)))
630 return 0;
632 if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_CLASS) &&
633 (id->bDeviceClass != dev->descriptor.bDeviceClass))
634 return 0;
636 if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_SUBCLASS) &&
637 (id->bDeviceSubClass != dev->descriptor.bDeviceSubClass))
638 return 0;
640 if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_PROTOCOL) &&
641 (id->bDeviceProtocol != dev->descriptor.bDeviceProtocol))
642 return 0;
644 return 1;
647 /* returns 0 if no match, 1 if match */
648 int usb_match_one_id_intf(struct usb_device *dev,
649 struct usb_host_interface *intf,
650 const struct usb_device_id *id)
652 /* The interface class, subclass, protocol and number should never be
653 * checked for a match if the device class is Vendor Specific,
654 * unless the match record specifies the Vendor ID. */
655 if (dev->descriptor.bDeviceClass == USB_CLASS_VENDOR_SPEC &&
656 !(id->match_flags & USB_DEVICE_ID_MATCH_VENDOR) &&
657 (id->match_flags & (USB_DEVICE_ID_MATCH_INT_CLASS |
658 USB_DEVICE_ID_MATCH_INT_SUBCLASS |
659 USB_DEVICE_ID_MATCH_INT_PROTOCOL |
660 USB_DEVICE_ID_MATCH_INT_NUMBER)))
661 return 0;
663 if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_CLASS) &&
664 (id->bInterfaceClass != intf->desc.bInterfaceClass))
665 return 0;
667 if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_SUBCLASS) &&
668 (id->bInterfaceSubClass != intf->desc.bInterfaceSubClass))
669 return 0;
671 if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_PROTOCOL) &&
672 (id->bInterfaceProtocol != intf->desc.bInterfaceProtocol))
673 return 0;
675 if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_NUMBER) &&
676 (id->bInterfaceNumber != intf->desc.bInterfaceNumber))
677 return 0;
679 return 1;
682 /* returns 0 if no match, 1 if match */
683 int usb_match_one_id(struct usb_interface *interface,
684 const struct usb_device_id *id)
686 struct usb_host_interface *intf;
687 struct usb_device *dev;
689 /* proc_connectinfo in devio.c may call us with id == NULL. */
690 if (id == NULL)
691 return 0;
693 intf = interface->cur_altsetting;
694 dev = interface_to_usbdev(interface);
696 if (!usb_match_device(dev, id))
697 return 0;
699 return usb_match_one_id_intf(dev, intf, id);
701 EXPORT_SYMBOL_GPL(usb_match_one_id);
704 * usb_match_id - find first usb_device_id matching device or interface
705 * @interface: the interface of interest
706 * @id: array of usb_device_id structures, terminated by zero entry
708 * usb_match_id searches an array of usb_device_id's and returns
709 * the first one matching the device or interface, or null.
710 * This is used when binding (or rebinding) a driver to an interface.
711 * Most USB device drivers will use this indirectly, through the usb core,
712 * but some layered driver frameworks use it directly.
713 * These device tables are exported with MODULE_DEVICE_TABLE, through
714 * modutils, to support the driver loading functionality of USB hotplugging.
716 * Return: The first matching usb_device_id, or %NULL.
718 * What Matches:
720 * The "match_flags" element in a usb_device_id controls which
721 * members are used. If the corresponding bit is set, the
722 * value in the device_id must match its corresponding member
723 * in the device or interface descriptor, or else the device_id
724 * does not match.
726 * "driver_info" is normally used only by device drivers,
727 * but you can create a wildcard "matches anything" usb_device_id
728 * as a driver's "modules.usbmap" entry if you provide an id with
729 * only a nonzero "driver_info" field. If you do this, the USB device
730 * driver's probe() routine should use additional intelligence to
731 * decide whether to bind to the specified interface.
733 * What Makes Good usb_device_id Tables:
735 * The match algorithm is very simple, so that intelligence in
736 * driver selection must come from smart driver id records.
737 * Unless you have good reasons to use another selection policy,
738 * provide match elements only in related groups, and order match
739 * specifiers from specific to general. Use the macros provided
740 * for that purpose if you can.
742 * The most specific match specifiers use device descriptor
743 * data. These are commonly used with product-specific matches;
744 * the USB_DEVICE macro lets you provide vendor and product IDs,
745 * and you can also match against ranges of product revisions.
746 * These are widely used for devices with application or vendor
747 * specific bDeviceClass values.
749 * Matches based on device class/subclass/protocol specifications
750 * are slightly more general; use the USB_DEVICE_INFO macro, or
751 * its siblings. These are used with single-function devices
752 * where bDeviceClass doesn't specify that each interface has
753 * its own class.
755 * Matches based on interface class/subclass/protocol are the
756 * most general; they let drivers bind to any interface on a
757 * multiple-function device. Use the USB_INTERFACE_INFO
758 * macro, or its siblings, to match class-per-interface style
759 * devices (as recorded in bInterfaceClass).
761 * Note that an entry created by USB_INTERFACE_INFO won't match
762 * any interface if the device class is set to Vendor-Specific.
763 * This is deliberate; according to the USB spec the meanings of
764 * the interface class/subclass/protocol for these devices are also
765 * vendor-specific, and hence matching against a standard product
766 * class wouldn't work anyway. If you really want to use an
767 * interface-based match for such a device, create a match record
768 * that also specifies the vendor ID. (Unforunately there isn't a
769 * standard macro for creating records like this.)
771 * Within those groups, remember that not all combinations are
772 * meaningful. For example, don't give a product version range
773 * without vendor and product IDs; or specify a protocol without
774 * its associated class and subclass.
776 const struct usb_device_id *usb_match_id(struct usb_interface *interface,
777 const struct usb_device_id *id)
779 /* proc_connectinfo in devio.c may call us with id == NULL. */
780 if (id == NULL)
781 return NULL;
783 /* It is important to check that id->driver_info is nonzero,
784 since an entry that is all zeroes except for a nonzero
785 id->driver_info is the way to create an entry that
786 indicates that the driver want to examine every
787 device and interface. */
788 for (; id->idVendor || id->idProduct || id->bDeviceClass ||
789 id->bInterfaceClass || id->driver_info; id++) {
790 if (usb_match_one_id(interface, id))
791 return id;
794 return NULL;
796 EXPORT_SYMBOL_GPL(usb_match_id);
798 static int usb_device_match(struct device *dev, struct device_driver *drv)
800 /* devices and interfaces are handled separately */
801 if (is_usb_device(dev)) {
803 /* interface drivers never match devices */
804 if (!is_usb_device_driver(drv))
805 return 0;
807 /* TODO: Add real matching code */
808 return 1;
810 } else if (is_usb_interface(dev)) {
811 struct usb_interface *intf;
812 struct usb_driver *usb_drv;
813 const struct usb_device_id *id;
815 /* device drivers never match interfaces */
816 if (is_usb_device_driver(drv))
817 return 0;
819 intf = to_usb_interface(dev);
820 usb_drv = to_usb_driver(drv);
822 id = usb_match_id(intf, usb_drv->id_table);
823 if (id)
824 return 1;
826 id = usb_match_dynamic_id(intf, usb_drv);
827 if (id)
828 return 1;
831 return 0;
834 static int usb_uevent(struct device *dev, struct kobj_uevent_env *env)
836 struct usb_device *usb_dev;
838 if (is_usb_device(dev)) {
839 usb_dev = to_usb_device(dev);
840 } else if (is_usb_interface(dev)) {
841 struct usb_interface *intf = to_usb_interface(dev);
843 usb_dev = interface_to_usbdev(intf);
844 } else {
845 return 0;
848 if (usb_dev->devnum < 0) {
849 /* driver is often null here; dev_dbg() would oops */
850 pr_debug("usb %s: already deleted?\n", dev_name(dev));
851 return -ENODEV;
853 if (!usb_dev->bus) {
854 pr_debug("usb %s: bus removed?\n", dev_name(dev));
855 return -ENODEV;
858 /* per-device configurations are common */
859 if (add_uevent_var(env, "PRODUCT=%x/%x/%x",
860 le16_to_cpu(usb_dev->descriptor.idVendor),
861 le16_to_cpu(usb_dev->descriptor.idProduct),
862 le16_to_cpu(usb_dev->descriptor.bcdDevice)))
863 return -ENOMEM;
865 /* class-based driver binding models */
866 if (add_uevent_var(env, "TYPE=%d/%d/%d",
867 usb_dev->descriptor.bDeviceClass,
868 usb_dev->descriptor.bDeviceSubClass,
869 usb_dev->descriptor.bDeviceProtocol))
870 return -ENOMEM;
872 return 0;
876 * usb_register_device_driver - register a USB device (not interface) driver
877 * @new_udriver: USB operations for the device driver
878 * @owner: module owner of this driver.
880 * Registers a USB device driver with the USB core. The list of
881 * unattached devices will be rescanned whenever a new driver is
882 * added, allowing the new driver to attach to any recognized devices.
884 * Return: A negative error code on failure and 0 on success.
886 int usb_register_device_driver(struct usb_device_driver *new_udriver,
887 struct module *owner)
889 int retval = 0;
891 if (usb_disabled())
892 return -ENODEV;
894 new_udriver->drvwrap.for_devices = 1;
895 new_udriver->drvwrap.driver.name = new_udriver->name;
896 new_udriver->drvwrap.driver.bus = &usb_bus_type;
897 new_udriver->drvwrap.driver.probe = usb_probe_device;
898 new_udriver->drvwrap.driver.remove = usb_unbind_device;
899 new_udriver->drvwrap.driver.owner = owner;
901 retval = driver_register(&new_udriver->drvwrap.driver);
903 if (!retval)
904 pr_info("%s: registered new device driver %s\n",
905 usbcore_name, new_udriver->name);
906 else
907 printk(KERN_ERR "%s: error %d registering device "
908 " driver %s\n",
909 usbcore_name, retval, new_udriver->name);
911 return retval;
913 EXPORT_SYMBOL_GPL(usb_register_device_driver);
916 * usb_deregister_device_driver - unregister a USB device (not interface) driver
917 * @udriver: USB operations of the device driver to unregister
918 * Context: must be able to sleep
920 * Unlinks the specified driver from the internal USB driver list.
922 void usb_deregister_device_driver(struct usb_device_driver *udriver)
924 pr_info("%s: deregistering device driver %s\n",
925 usbcore_name, udriver->name);
927 driver_unregister(&udriver->drvwrap.driver);
929 EXPORT_SYMBOL_GPL(usb_deregister_device_driver);
932 * usb_register_driver - register a USB interface driver
933 * @new_driver: USB operations for the interface driver
934 * @owner: module owner of this driver.
935 * @mod_name: module name string
937 * Registers a USB interface driver with the USB core. The list of
938 * unattached interfaces will be rescanned whenever a new driver is
939 * added, allowing the new driver to attach to any recognized interfaces.
941 * Return: A negative error code on failure and 0 on success.
943 * NOTE: if you want your driver to use the USB major number, you must call
944 * usb_register_dev() to enable that functionality. This function no longer
945 * takes care of that.
947 int usb_register_driver(struct usb_driver *new_driver, struct module *owner,
948 const char *mod_name)
950 int retval = 0;
952 if (usb_disabled())
953 return -ENODEV;
955 new_driver->drvwrap.for_devices = 0;
956 new_driver->drvwrap.driver.name = new_driver->name;
957 new_driver->drvwrap.driver.bus = &usb_bus_type;
958 new_driver->drvwrap.driver.probe = usb_probe_interface;
959 new_driver->drvwrap.driver.remove = usb_unbind_interface;
960 new_driver->drvwrap.driver.owner = owner;
961 new_driver->drvwrap.driver.mod_name = mod_name;
962 spin_lock_init(&new_driver->dynids.lock);
963 INIT_LIST_HEAD(&new_driver->dynids.list);
965 retval = driver_register(&new_driver->drvwrap.driver);
966 if (retval)
967 goto out;
969 retval = usb_create_newid_files(new_driver);
970 if (retval)
971 goto out_newid;
973 pr_info("%s: registered new interface driver %s\n",
974 usbcore_name, new_driver->name);
976 out:
977 return retval;
979 out_newid:
980 driver_unregister(&new_driver->drvwrap.driver);
982 printk(KERN_ERR "%s: error %d registering interface "
983 " driver %s\n",
984 usbcore_name, retval, new_driver->name);
985 goto out;
987 EXPORT_SYMBOL_GPL(usb_register_driver);
990 * usb_deregister - unregister a USB interface driver
991 * @driver: USB operations of the interface driver to unregister
992 * Context: must be able to sleep
994 * Unlinks the specified driver from the internal USB driver list.
996 * NOTE: If you called usb_register_dev(), you still need to call
997 * usb_deregister_dev() to clean up your driver's allocated minor numbers,
998 * this * call will no longer do it for you.
1000 void usb_deregister(struct usb_driver *driver)
1002 pr_info("%s: deregistering interface driver %s\n",
1003 usbcore_name, driver->name);
1005 usb_remove_newid_files(driver);
1006 driver_unregister(&driver->drvwrap.driver);
1007 usb_free_dynids(driver);
1009 EXPORT_SYMBOL_GPL(usb_deregister);
1011 /* Forced unbinding of a USB interface driver, either because
1012 * it doesn't support pre_reset/post_reset/reset_resume or
1013 * because it doesn't support suspend/resume.
1015 * The caller must hold @intf's device's lock, but not @intf's lock.
1017 void usb_forced_unbind_intf(struct usb_interface *intf)
1019 struct usb_driver *driver = to_usb_driver(intf->dev.driver);
1021 dev_dbg(&intf->dev, "forced unbind\n");
1022 usb_driver_release_interface(driver, intf);
1024 /* Mark the interface for later rebinding */
1025 intf->needs_binding = 1;
1029 * Unbind drivers for @udev's marked interfaces. These interfaces have
1030 * the needs_binding flag set, for example by usb_resume_interface().
1032 * The caller must hold @udev's device lock.
1034 static void unbind_marked_interfaces(struct usb_device *udev)
1036 struct usb_host_config *config;
1037 int i;
1038 struct usb_interface *intf;
1040 config = udev->actconfig;
1041 if (config) {
1042 for (i = 0; i < config->desc.bNumInterfaces; ++i) {
1043 intf = config->interface[i];
1044 if (intf->dev.driver && intf->needs_binding)
1045 usb_forced_unbind_intf(intf);
1050 /* Delayed forced unbinding of a USB interface driver and scan
1051 * for rebinding.
1053 * The caller must hold @intf's device's lock, but not @intf's lock.
1055 * Note: Rebinds will be skipped if a system sleep transition is in
1056 * progress and the PM "complete" callback hasn't occurred yet.
1058 static void usb_rebind_intf(struct usb_interface *intf)
1060 int rc;
1062 /* Delayed unbind of an existing driver */
1063 if (intf->dev.driver)
1064 usb_forced_unbind_intf(intf);
1066 /* Try to rebind the interface */
1067 if (!intf->dev.power.is_prepared) {
1068 intf->needs_binding = 0;
1069 rc = device_attach(&intf->dev);
1070 if (rc < 0)
1071 dev_warn(&intf->dev, "rebind failed: %d\n", rc);
1076 * Rebind drivers to @udev's marked interfaces. These interfaces have
1077 * the needs_binding flag set.
1079 * The caller must hold @udev's device lock.
1081 static void rebind_marked_interfaces(struct usb_device *udev)
1083 struct usb_host_config *config;
1084 int i;
1085 struct usb_interface *intf;
1087 config = udev->actconfig;
1088 if (config) {
1089 for (i = 0; i < config->desc.bNumInterfaces; ++i) {
1090 intf = config->interface[i];
1091 if (intf->needs_binding)
1092 usb_rebind_intf(intf);
1098 * Unbind all of @udev's marked interfaces and then rebind all of them.
1099 * This ordering is necessary because some drivers claim several interfaces
1100 * when they are first probed.
1102 * The caller must hold @udev's device lock.
1104 void usb_unbind_and_rebind_marked_interfaces(struct usb_device *udev)
1106 unbind_marked_interfaces(udev);
1107 rebind_marked_interfaces(udev);
1110 #ifdef CONFIG_PM
1112 /* Unbind drivers for @udev's interfaces that don't support suspend/resume
1113 * There is no check for reset_resume here because it can be determined
1114 * only during resume whether reset_resume is needed.
1116 * The caller must hold @udev's device lock.
1118 static void unbind_no_pm_drivers_interfaces(struct usb_device *udev)
1120 struct usb_host_config *config;
1121 int i;
1122 struct usb_interface *intf;
1123 struct usb_driver *drv;
1125 config = udev->actconfig;
1126 if (config) {
1127 for (i = 0; i < config->desc.bNumInterfaces; ++i) {
1128 intf = config->interface[i];
1130 if (intf->dev.driver) {
1131 drv = to_usb_driver(intf->dev.driver);
1132 if (!drv->suspend || !drv->resume)
1133 usb_forced_unbind_intf(intf);
1139 static int usb_suspend_device(struct usb_device *udev, pm_message_t msg)
1141 struct usb_device_driver *udriver;
1142 int status = 0;
1144 if (udev->state == USB_STATE_NOTATTACHED ||
1145 udev->state == USB_STATE_SUSPENDED)
1146 goto done;
1148 /* For devices that don't have a driver, we do a generic suspend. */
1149 if (udev->dev.driver)
1150 udriver = to_usb_device_driver(udev->dev.driver);
1151 else {
1152 udev->do_remote_wakeup = 0;
1153 udriver = &usb_generic_driver;
1155 status = udriver->suspend(udev, msg);
1157 done:
1158 dev_vdbg(&udev->dev, "%s: status %d\n", __func__, status);
1159 return status;
1162 static int usb_resume_device(struct usb_device *udev, pm_message_t msg)
1164 struct usb_device_driver *udriver;
1165 int status = 0;
1167 if (udev->state == USB_STATE_NOTATTACHED)
1168 goto done;
1170 /* Can't resume it if it doesn't have a driver. */
1171 if (udev->dev.driver == NULL) {
1172 status = -ENOTCONN;
1173 goto done;
1176 /* Non-root devices on a full/low-speed bus must wait for their
1177 * companion high-speed root hub, in case a handoff is needed.
1179 if (!PMSG_IS_AUTO(msg) && udev->parent && udev->bus->hs_companion)
1180 device_pm_wait_for_dev(&udev->dev,
1181 &udev->bus->hs_companion->root_hub->dev);
1183 if (udev->quirks & USB_QUIRK_RESET_RESUME)
1184 udev->reset_resume = 1;
1186 udriver = to_usb_device_driver(udev->dev.driver);
1187 status = udriver->resume(udev, msg);
1189 done:
1190 dev_vdbg(&udev->dev, "%s: status %d\n", __func__, status);
1191 return status;
1194 static int usb_suspend_interface(struct usb_device *udev,
1195 struct usb_interface *intf, pm_message_t msg)
1197 struct usb_driver *driver;
1198 int status = 0;
1200 if (udev->state == USB_STATE_NOTATTACHED ||
1201 intf->condition == USB_INTERFACE_UNBOUND)
1202 goto done;
1203 driver = to_usb_driver(intf->dev.driver);
1205 /* at this time we know the driver supports suspend */
1206 status = driver->suspend(intf, msg);
1207 if (status && !PMSG_IS_AUTO(msg))
1208 dev_err(&intf->dev, "suspend error %d\n", status);
1210 done:
1211 dev_vdbg(&intf->dev, "%s: status %d\n", __func__, status);
1212 return status;
1215 static int usb_resume_interface(struct usb_device *udev,
1216 struct usb_interface *intf, pm_message_t msg, int reset_resume)
1218 struct usb_driver *driver;
1219 int status = 0;
1221 if (udev->state == USB_STATE_NOTATTACHED)
1222 goto done;
1224 /* Don't let autoresume interfere with unbinding */
1225 if (intf->condition == USB_INTERFACE_UNBINDING)
1226 goto done;
1228 /* Can't resume it if it doesn't have a driver. */
1229 if (intf->condition == USB_INTERFACE_UNBOUND) {
1231 /* Carry out a deferred switch to altsetting 0 */
1232 if (intf->needs_altsetting0 && !intf->dev.power.is_prepared) {
1233 usb_set_interface(udev, intf->altsetting[0].
1234 desc.bInterfaceNumber, 0);
1235 intf->needs_altsetting0 = 0;
1237 goto done;
1240 /* Don't resume if the interface is marked for rebinding */
1241 if (intf->needs_binding)
1242 goto done;
1243 driver = to_usb_driver(intf->dev.driver);
1245 if (reset_resume) {
1246 if (driver->reset_resume) {
1247 status = driver->reset_resume(intf);
1248 if (status)
1249 dev_err(&intf->dev, "%s error %d\n",
1250 "reset_resume", status);
1251 } else {
1252 intf->needs_binding = 1;
1253 dev_dbg(&intf->dev, "no reset_resume for driver %s?\n",
1254 driver->name);
1256 } else {
1257 status = driver->resume(intf);
1258 if (status)
1259 dev_err(&intf->dev, "resume error %d\n", status);
1262 done:
1263 dev_vdbg(&intf->dev, "%s: status %d\n", __func__, status);
1265 /* Later we will unbind the driver and/or reprobe, if necessary */
1266 return status;
1270 * usb_suspend_both - suspend a USB device and its interfaces
1271 * @udev: the usb_device to suspend
1272 * @msg: Power Management message describing this state transition
1274 * This is the central routine for suspending USB devices. It calls the
1275 * suspend methods for all the interface drivers in @udev and then calls
1276 * the suspend method for @udev itself. When the routine is called in
1277 * autosuspend, if an error occurs at any stage, all the interfaces
1278 * which were suspended are resumed so that they remain in the same
1279 * state as the device, but when called from system sleep, all error
1280 * from suspend methods of interfaces and the non-root-hub device itself
1281 * are simply ignored, so all suspended interfaces are only resumed
1282 * to the device's state when @udev is root-hub and its suspend method
1283 * returns failure.
1285 * Autosuspend requests originating from a child device or an interface
1286 * driver may be made without the protection of @udev's device lock, but
1287 * all other suspend calls will hold the lock. Usbcore will insure that
1288 * method calls do not arrive during bind, unbind, or reset operations.
1289 * However drivers must be prepared to handle suspend calls arriving at
1290 * unpredictable times.
1292 * This routine can run only in process context.
1294 * Return: 0 if the suspend succeeded.
1296 static int usb_suspend_both(struct usb_device *udev, pm_message_t msg)
1298 int status = 0;
1299 int i = 0, n = 0;
1300 struct usb_interface *intf;
1302 if (udev->state == USB_STATE_NOTATTACHED ||
1303 udev->state == USB_STATE_SUSPENDED)
1304 goto done;
1306 /* Suspend all the interfaces and then udev itself */
1307 if (udev->actconfig) {
1308 n = udev->actconfig->desc.bNumInterfaces;
1309 for (i = n - 1; i >= 0; --i) {
1310 intf = udev->actconfig->interface[i];
1311 status = usb_suspend_interface(udev, intf, msg);
1313 /* Ignore errors during system sleep transitions */
1314 if (!PMSG_IS_AUTO(msg))
1315 status = 0;
1316 if (status != 0)
1317 break;
1320 if (status == 0) {
1321 status = usb_suspend_device(udev, msg);
1324 * Ignore errors from non-root-hub devices during
1325 * system sleep transitions. For the most part,
1326 * these devices should go to low power anyway when
1327 * the entire bus is suspended.
1329 if (udev->parent && !PMSG_IS_AUTO(msg))
1330 status = 0;
1333 * If the device is inaccessible, don't try to resume
1334 * suspended interfaces and just return the error.
1336 if (status && status != -EBUSY) {
1337 int err;
1338 u16 devstat;
1340 err = usb_get_status(udev, USB_RECIP_DEVICE, 0,
1341 &devstat);
1342 if (err) {
1343 dev_err(&udev->dev,
1344 "Failed to suspend device, error %d\n",
1345 status);
1346 goto done;
1351 /* If the suspend failed, resume interfaces that did get suspended */
1352 if (status != 0) {
1353 if (udev->actconfig) {
1354 msg.event ^= (PM_EVENT_SUSPEND | PM_EVENT_RESUME);
1355 while (++i < n) {
1356 intf = udev->actconfig->interface[i];
1357 usb_resume_interface(udev, intf, msg, 0);
1361 /* If the suspend succeeded then prevent any more URB submissions
1362 * and flush any outstanding URBs.
1364 } else {
1365 udev->can_submit = 0;
1366 for (i = 0; i < 16; ++i) {
1367 usb_hcd_flush_endpoint(udev, udev->ep_out[i]);
1368 usb_hcd_flush_endpoint(udev, udev->ep_in[i]);
1372 done:
1373 dev_vdbg(&udev->dev, "%s: status %d\n", __func__, status);
1374 return status;
1378 * usb_resume_both - resume a USB device and its interfaces
1379 * @udev: the usb_device to resume
1380 * @msg: Power Management message describing this state transition
1382 * This is the central routine for resuming USB devices. It calls the
1383 * the resume method for @udev and then calls the resume methods for all
1384 * the interface drivers in @udev.
1386 * Autoresume requests originating from a child device or an interface
1387 * driver may be made without the protection of @udev's device lock, but
1388 * all other resume calls will hold the lock. Usbcore will insure that
1389 * method calls do not arrive during bind, unbind, or reset operations.
1390 * However drivers must be prepared to handle resume calls arriving at
1391 * unpredictable times.
1393 * This routine can run only in process context.
1395 * Return: 0 on success.
1397 static int usb_resume_both(struct usb_device *udev, pm_message_t msg)
1399 int status = 0;
1400 int i;
1401 struct usb_interface *intf;
1403 if (udev->state == USB_STATE_NOTATTACHED) {
1404 status = -ENODEV;
1405 goto done;
1407 udev->can_submit = 1;
1409 /* Resume the device */
1410 if (udev->state == USB_STATE_SUSPENDED || udev->reset_resume)
1411 status = usb_resume_device(udev, msg);
1413 /* Resume the interfaces */
1414 if (status == 0 && udev->actconfig) {
1415 for (i = 0; i < udev->actconfig->desc.bNumInterfaces; i++) {
1416 intf = udev->actconfig->interface[i];
1417 usb_resume_interface(udev, intf, msg,
1418 udev->reset_resume);
1421 usb_mark_last_busy(udev);
1423 done:
1424 dev_vdbg(&udev->dev, "%s: status %d\n", __func__, status);
1425 if (!status)
1426 udev->reset_resume = 0;
1427 return status;
1430 static void choose_wakeup(struct usb_device *udev, pm_message_t msg)
1432 int w;
1434 /* Remote wakeup is needed only when we actually go to sleep.
1435 * For things like FREEZE and QUIESCE, if the device is already
1436 * autosuspended then its current wakeup setting is okay.
1438 if (msg.event == PM_EVENT_FREEZE || msg.event == PM_EVENT_QUIESCE) {
1439 if (udev->state != USB_STATE_SUSPENDED)
1440 udev->do_remote_wakeup = 0;
1441 return;
1444 /* Enable remote wakeup if it is allowed, even if no interface drivers
1445 * actually want it.
1447 w = device_may_wakeup(&udev->dev);
1449 /* If the device is autosuspended with the wrong wakeup setting,
1450 * autoresume now so the setting can be changed.
1452 if (udev->state == USB_STATE_SUSPENDED && w != udev->do_remote_wakeup)
1453 pm_runtime_resume(&udev->dev);
1454 udev->do_remote_wakeup = w;
1457 /* The device lock is held by the PM core */
1458 int usb_suspend(struct device *dev, pm_message_t msg)
1460 struct usb_device *udev = to_usb_device(dev);
1462 unbind_no_pm_drivers_interfaces(udev);
1464 /* From now on we are sure all drivers support suspend/resume
1465 * but not necessarily reset_resume()
1466 * so we may still need to unbind and rebind upon resume
1468 choose_wakeup(udev, msg);
1469 return usb_suspend_both(udev, msg);
1472 /* The device lock is held by the PM core */
1473 int usb_resume_complete(struct device *dev)
1475 struct usb_device *udev = to_usb_device(dev);
1477 /* For PM complete calls, all we do is rebind interfaces
1478 * whose needs_binding flag is set
1480 if (udev->state != USB_STATE_NOTATTACHED)
1481 rebind_marked_interfaces(udev);
1482 return 0;
1485 /* The device lock is held by the PM core */
1486 int usb_resume(struct device *dev, pm_message_t msg)
1488 struct usb_device *udev = to_usb_device(dev);
1489 int status;
1491 /* For all calls, take the device back to full power and
1492 * tell the PM core in case it was autosuspended previously.
1493 * Unbind the interfaces that will need rebinding later,
1494 * because they fail to support reset_resume.
1495 * (This can't be done in usb_resume_interface()
1496 * above because it doesn't own the right set of locks.)
1498 status = usb_resume_both(udev, msg);
1499 if (status == 0) {
1500 pm_runtime_disable(dev);
1501 pm_runtime_set_active(dev);
1502 pm_runtime_enable(dev);
1503 unbind_marked_interfaces(udev);
1506 /* Avoid PM error messages for devices disconnected while suspended
1507 * as we'll display regular disconnect messages just a bit later.
1509 if (status == -ENODEV || status == -ESHUTDOWN)
1510 status = 0;
1511 return status;
1515 * usb_enable_autosuspend - allow a USB device to be autosuspended
1516 * @udev: the USB device which may be autosuspended
1518 * This routine allows @udev to be autosuspended. An autosuspend won't
1519 * take place until the autosuspend_delay has elapsed and all the other
1520 * necessary conditions are satisfied.
1522 * The caller must hold @udev's device lock.
1524 void usb_enable_autosuspend(struct usb_device *udev)
1526 pm_runtime_allow(&udev->dev);
1528 EXPORT_SYMBOL_GPL(usb_enable_autosuspend);
1531 * usb_disable_autosuspend - prevent a USB device from being autosuspended
1532 * @udev: the USB device which may not be autosuspended
1534 * This routine prevents @udev from being autosuspended and wakes it up
1535 * if it is already autosuspended.
1537 * The caller must hold @udev's device lock.
1539 void usb_disable_autosuspend(struct usb_device *udev)
1541 pm_runtime_forbid(&udev->dev);
1543 EXPORT_SYMBOL_GPL(usb_disable_autosuspend);
1546 * usb_autosuspend_device - delayed autosuspend of a USB device and its interfaces
1547 * @udev: the usb_device to autosuspend
1549 * This routine should be called when a core subsystem is finished using
1550 * @udev and wants to allow it to autosuspend. Examples would be when
1551 * @udev's device file in usbfs is closed or after a configuration change.
1553 * @udev's usage counter is decremented; if it drops to 0 and all the
1554 * interfaces are inactive then a delayed autosuspend will be attempted.
1555 * The attempt may fail (see autosuspend_check()).
1557 * The caller must hold @udev's device lock.
1559 * This routine can run only in process context.
1561 void usb_autosuspend_device(struct usb_device *udev)
1563 int status;
1565 usb_mark_last_busy(udev);
1566 status = pm_runtime_put_sync_autosuspend(&udev->dev);
1567 dev_vdbg(&udev->dev, "%s: cnt %d -> %d\n",
1568 __func__, atomic_read(&udev->dev.power.usage_count),
1569 status);
1573 * usb_autoresume_device - immediately autoresume a USB device and its interfaces
1574 * @udev: the usb_device to autoresume
1576 * This routine should be called when a core subsystem wants to use @udev
1577 * and needs to guarantee that it is not suspended. No autosuspend will
1578 * occur until usb_autosuspend_device() is called. (Note that this will
1579 * not prevent suspend events originating in the PM core.) Examples would
1580 * be when @udev's device file in usbfs is opened or when a remote-wakeup
1581 * request is received.
1583 * @udev's usage counter is incremented to prevent subsequent autosuspends.
1584 * However if the autoresume fails then the usage counter is re-decremented.
1586 * The caller must hold @udev's device lock.
1588 * This routine can run only in process context.
1590 * Return: 0 on success. A negative error code otherwise.
1592 int usb_autoresume_device(struct usb_device *udev)
1594 int status;
1596 status = pm_runtime_get_sync(&udev->dev);
1597 if (status < 0)
1598 pm_runtime_put_sync(&udev->dev);
1599 dev_vdbg(&udev->dev, "%s: cnt %d -> %d\n",
1600 __func__, atomic_read(&udev->dev.power.usage_count),
1601 status);
1602 if (status > 0)
1603 status = 0;
1604 return status;
1608 * usb_autopm_put_interface - decrement a USB interface's PM-usage counter
1609 * @intf: the usb_interface whose counter should be decremented
1611 * This routine should be called by an interface driver when it is
1612 * finished using @intf and wants to allow it to autosuspend. A typical
1613 * example would be a character-device driver when its device file is
1614 * closed.
1616 * The routine decrements @intf's usage counter. When the counter reaches
1617 * 0, a delayed autosuspend request for @intf's device is attempted. The
1618 * attempt may fail (see autosuspend_check()).
1620 * This routine can run only in process context.
1622 void usb_autopm_put_interface(struct usb_interface *intf)
1624 struct usb_device *udev = interface_to_usbdev(intf);
1625 int status;
1627 usb_mark_last_busy(udev);
1628 atomic_dec(&intf->pm_usage_cnt);
1629 status = pm_runtime_put_sync(&intf->dev);
1630 dev_vdbg(&intf->dev, "%s: cnt %d -> %d\n",
1631 __func__, atomic_read(&intf->dev.power.usage_count),
1632 status);
1634 EXPORT_SYMBOL_GPL(usb_autopm_put_interface);
1637 * usb_autopm_put_interface_async - decrement a USB interface's PM-usage counter
1638 * @intf: the usb_interface whose counter should be decremented
1640 * This routine does much the same thing as usb_autopm_put_interface():
1641 * It decrements @intf's usage counter and schedules a delayed
1642 * autosuspend request if the counter is <= 0. The difference is that it
1643 * does not perform any synchronization; callers should hold a private
1644 * lock and handle all synchronization issues themselves.
1646 * Typically a driver would call this routine during an URB's completion
1647 * handler, if no more URBs were pending.
1649 * This routine can run in atomic context.
1651 void usb_autopm_put_interface_async(struct usb_interface *intf)
1653 struct usb_device *udev = interface_to_usbdev(intf);
1654 int status;
1656 usb_mark_last_busy(udev);
1657 atomic_dec(&intf->pm_usage_cnt);
1658 status = pm_runtime_put(&intf->dev);
1659 dev_vdbg(&intf->dev, "%s: cnt %d -> %d\n",
1660 __func__, atomic_read(&intf->dev.power.usage_count),
1661 status);
1663 EXPORT_SYMBOL_GPL(usb_autopm_put_interface_async);
1666 * usb_autopm_put_interface_no_suspend - decrement a USB interface's PM-usage counter
1667 * @intf: the usb_interface whose counter should be decremented
1669 * This routine decrements @intf's usage counter but does not carry out an
1670 * autosuspend.
1672 * This routine can run in atomic context.
1674 void usb_autopm_put_interface_no_suspend(struct usb_interface *intf)
1676 struct usb_device *udev = interface_to_usbdev(intf);
1678 usb_mark_last_busy(udev);
1679 atomic_dec(&intf->pm_usage_cnt);
1680 pm_runtime_put_noidle(&intf->dev);
1682 EXPORT_SYMBOL_GPL(usb_autopm_put_interface_no_suspend);
1685 * usb_autopm_get_interface - increment a USB interface's PM-usage counter
1686 * @intf: the usb_interface whose counter should be incremented
1688 * This routine should be called by an interface driver when it wants to
1689 * use @intf and needs to guarantee that it is not suspended. In addition,
1690 * the routine prevents @intf from being autosuspended subsequently. (Note
1691 * that this will not prevent suspend events originating in the PM core.)
1692 * This prevention will persist until usb_autopm_put_interface() is called
1693 * or @intf is unbound. A typical example would be a character-device
1694 * driver when its device file is opened.
1696 * @intf's usage counter is incremented to prevent subsequent autosuspends.
1697 * However if the autoresume fails then the counter is re-decremented.
1699 * This routine can run only in process context.
1701 * Return: 0 on success.
1703 int usb_autopm_get_interface(struct usb_interface *intf)
1705 int status;
1707 status = pm_runtime_get_sync(&intf->dev);
1708 if (status < 0)
1709 pm_runtime_put_sync(&intf->dev);
1710 else
1711 atomic_inc(&intf->pm_usage_cnt);
1712 dev_vdbg(&intf->dev, "%s: cnt %d -> %d\n",
1713 __func__, atomic_read(&intf->dev.power.usage_count),
1714 status);
1715 if (status > 0)
1716 status = 0;
1717 return status;
1719 EXPORT_SYMBOL_GPL(usb_autopm_get_interface);
1722 * usb_autopm_get_interface_async - increment a USB interface's PM-usage counter
1723 * @intf: the usb_interface whose counter should be incremented
1725 * This routine does much the same thing as
1726 * usb_autopm_get_interface(): It increments @intf's usage counter and
1727 * queues an autoresume request if the device is suspended. The
1728 * differences are that it does not perform any synchronization (callers
1729 * should hold a private lock and handle all synchronization issues
1730 * themselves), and it does not autoresume the device directly (it only
1731 * queues a request). After a successful call, the device may not yet be
1732 * resumed.
1734 * This routine can run in atomic context.
1736 * Return: 0 on success. A negative error code otherwise.
1738 int usb_autopm_get_interface_async(struct usb_interface *intf)
1740 int status;
1742 status = pm_runtime_get(&intf->dev);
1743 if (status < 0 && status != -EINPROGRESS)
1744 pm_runtime_put_noidle(&intf->dev);
1745 else
1746 atomic_inc(&intf->pm_usage_cnt);
1747 dev_vdbg(&intf->dev, "%s: cnt %d -> %d\n",
1748 __func__, atomic_read(&intf->dev.power.usage_count),
1749 status);
1750 if (status > 0 || status == -EINPROGRESS)
1751 status = 0;
1752 return status;
1754 EXPORT_SYMBOL_GPL(usb_autopm_get_interface_async);
1757 * usb_autopm_get_interface_no_resume - increment a USB interface's PM-usage counter
1758 * @intf: the usb_interface whose counter should be incremented
1760 * This routine increments @intf's usage counter but does not carry out an
1761 * autoresume.
1763 * This routine can run in atomic context.
1765 void usb_autopm_get_interface_no_resume(struct usb_interface *intf)
1767 struct usb_device *udev = interface_to_usbdev(intf);
1769 usb_mark_last_busy(udev);
1770 atomic_inc(&intf->pm_usage_cnt);
1771 pm_runtime_get_noresume(&intf->dev);
1773 EXPORT_SYMBOL_GPL(usb_autopm_get_interface_no_resume);
1775 /* Internal routine to check whether we may autosuspend a device. */
1776 static int autosuspend_check(struct usb_device *udev)
1778 int w, i;
1779 struct usb_interface *intf;
1781 if (udev->state == USB_STATE_NOTATTACHED)
1782 return -ENODEV;
1784 /* Fail if autosuspend is disabled, or any interfaces are in use, or
1785 * any interface drivers require remote wakeup but it isn't available.
1787 w = 0;
1788 if (udev->actconfig) {
1789 for (i = 0; i < udev->actconfig->desc.bNumInterfaces; i++) {
1790 intf = udev->actconfig->interface[i];
1792 /* We don't need to check interfaces that are
1793 * disabled for runtime PM. Either they are unbound
1794 * or else their drivers don't support autosuspend
1795 * and so they are permanently active.
1797 if (intf->dev.power.disable_depth)
1798 continue;
1799 if (atomic_read(&intf->dev.power.usage_count) > 0)
1800 return -EBUSY;
1801 w |= intf->needs_remote_wakeup;
1803 /* Don't allow autosuspend if the device will need
1804 * a reset-resume and any of its interface drivers
1805 * doesn't include support or needs remote wakeup.
1807 if (udev->quirks & USB_QUIRK_RESET_RESUME) {
1808 struct usb_driver *driver;
1810 driver = to_usb_driver(intf->dev.driver);
1811 if (!driver->reset_resume ||
1812 intf->needs_remote_wakeup)
1813 return -EOPNOTSUPP;
1817 if (w && !device_can_wakeup(&udev->dev)) {
1818 dev_dbg(&udev->dev, "remote wakeup needed for autosuspend\n");
1819 return -EOPNOTSUPP;
1823 * If the device is a direct child of the root hub and the HCD
1824 * doesn't handle wakeup requests, don't allow autosuspend when
1825 * wakeup is needed.
1827 if (w && udev->parent == udev->bus->root_hub &&
1828 bus_to_hcd(udev->bus)->cant_recv_wakeups) {
1829 dev_dbg(&udev->dev, "HCD doesn't handle wakeup requests\n");
1830 return -EOPNOTSUPP;
1833 udev->do_remote_wakeup = w;
1834 return 0;
1837 int usb_runtime_suspend(struct device *dev)
1839 struct usb_device *udev = to_usb_device(dev);
1840 int status;
1842 /* A USB device can be suspended if it passes the various autosuspend
1843 * checks. Runtime suspend for a USB device means suspending all the
1844 * interfaces and then the device itself.
1846 if (autosuspend_check(udev) != 0)
1847 return -EAGAIN;
1849 status = usb_suspend_both(udev, PMSG_AUTO_SUSPEND);
1851 /* Allow a retry if autosuspend failed temporarily */
1852 if (status == -EAGAIN || status == -EBUSY)
1853 usb_mark_last_busy(udev);
1856 * The PM core reacts badly unless the return code is 0,
1857 * -EAGAIN, or -EBUSY, so always return -EBUSY on an error
1858 * (except for root hubs, because they don't suspend through
1859 * an upstream port like other USB devices).
1861 if (status != 0 && udev->parent)
1862 return -EBUSY;
1863 return status;
1866 int usb_runtime_resume(struct device *dev)
1868 struct usb_device *udev = to_usb_device(dev);
1869 int status;
1871 /* Runtime resume for a USB device means resuming both the device
1872 * and all its interfaces.
1874 status = usb_resume_both(udev, PMSG_AUTO_RESUME);
1875 return status;
1878 int usb_runtime_idle(struct device *dev)
1880 struct usb_device *udev = to_usb_device(dev);
1882 /* An idle USB device can be suspended if it passes the various
1883 * autosuspend checks.
1885 if (autosuspend_check(udev) == 0)
1886 pm_runtime_autosuspend(dev);
1887 /* Tell the core not to suspend it, though. */
1888 return -EBUSY;
1891 int usb_set_usb2_hardware_lpm(struct usb_device *udev, int enable)
1893 struct usb_hcd *hcd = bus_to_hcd(udev->bus);
1894 int ret = -EPERM;
1896 if (enable && !udev->usb2_hw_lpm_allowed)
1897 return 0;
1899 if (hcd->driver->set_usb2_hw_lpm) {
1900 ret = hcd->driver->set_usb2_hw_lpm(hcd, udev, enable);
1901 if (!ret)
1902 udev->usb2_hw_lpm_enabled = enable;
1905 return ret;
1908 #endif /* CONFIG_PM */
1910 struct bus_type usb_bus_type = {
1911 .name = "usb",
1912 .match = usb_device_match,
1913 .uevent = usb_uevent,