xref: /openbmc/linux/drivers/usb/core/driver.c (revision f97769fd)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * drivers/usb/driver.c - most of the driver model stuff for usb
4  *
5  * (C) Copyright 2005 Greg Kroah-Hartman <gregkh@suse.de>
6  *
7  * based on drivers/usb/usb.c which had the following copyrights:
8  *	(C) Copyright Linus Torvalds 1999
9  *	(C) Copyright Johannes Erdfelt 1999-2001
10  *	(C) Copyright Andreas Gal 1999
11  *	(C) Copyright Gregory P. Smith 1999
12  *	(C) Copyright Deti Fliegl 1999 (new USB architecture)
13  *	(C) Copyright Randy Dunlap 2000
14  *	(C) Copyright David Brownell 2000-2004
15  *	(C) Copyright Yggdrasil Computing, Inc. 2000
16  *		(usb_device_id matching changes by Adam J. Richter)
17  *	(C) Copyright Greg Kroah-Hartman 2002-2003
18  *
19  * Released under the GPLv2 only.
20  *
21  * NOTE! This is not actually a driver at all, rather this is
22  * just a collection of helper routines that implement the
23  * matching, probing, releasing, suspending and resuming for
24  * real drivers.
25  *
26  */
27 
28 #include <linux/device.h>
29 #include <linux/slab.h>
30 #include <linux/export.h>
31 #include <linux/usb.h>
32 #include <linux/usb/quirks.h>
33 #include <linux/usb/hcd.h>
34 
35 #include "usb.h"
36 
37 
38 /*
39  * Adds a new dynamic USBdevice ID to this driver,
40  * and cause the driver to probe for all devices again.
41  */
42 ssize_t usb_store_new_id(struct usb_dynids *dynids,
43 			 const struct usb_device_id *id_table,
44 			 struct device_driver *driver,
45 			 const char *buf, size_t count)
46 {
47 	struct usb_dynid *dynid;
48 	u32 idVendor = 0;
49 	u32 idProduct = 0;
50 	unsigned int bInterfaceClass = 0;
51 	u32 refVendor, refProduct;
52 	int fields = 0;
53 	int retval = 0;
54 
55 	fields = sscanf(buf, "%x %x %x %x %x", &idVendor, &idProduct,
56 			&bInterfaceClass, &refVendor, &refProduct);
57 	if (fields < 2)
58 		return -EINVAL;
59 
60 	dynid = kzalloc(sizeof(*dynid), GFP_KERNEL);
61 	if (!dynid)
62 		return -ENOMEM;
63 
64 	INIT_LIST_HEAD(&dynid->node);
65 	dynid->id.idVendor = idVendor;
66 	dynid->id.idProduct = idProduct;
67 	dynid->id.match_flags = USB_DEVICE_ID_MATCH_DEVICE;
68 	if (fields > 2 && bInterfaceClass) {
69 		if (bInterfaceClass > 255) {
70 			retval = -EINVAL;
71 			goto fail;
72 		}
73 
74 		dynid->id.bInterfaceClass = (u8)bInterfaceClass;
75 		dynid->id.match_flags |= USB_DEVICE_ID_MATCH_INT_CLASS;
76 	}
77 
78 	if (fields > 4) {
79 		const struct usb_device_id *id = id_table;
80 
81 		if (!id) {
82 			retval = -ENODEV;
83 			goto fail;
84 		}
85 
86 		for (; id->match_flags; id++)
87 			if (id->idVendor == refVendor && id->idProduct == refProduct)
88 				break;
89 
90 		if (id->match_flags) {
91 			dynid->id.driver_info = id->driver_info;
92 		} else {
93 			retval = -ENODEV;
94 			goto fail;
95 		}
96 	}
97 
98 	spin_lock(&dynids->lock);
99 	list_add_tail(&dynid->node, &dynids->list);
100 	spin_unlock(&dynids->lock);
101 
102 	retval = driver_attach(driver);
103 
104 	if (retval)
105 		return retval;
106 	return count;
107 
108 fail:
109 	kfree(dynid);
110 	return retval;
111 }
112 EXPORT_SYMBOL_GPL(usb_store_new_id);
113 
114 ssize_t usb_show_dynids(struct usb_dynids *dynids, char *buf)
115 {
116 	struct usb_dynid *dynid;
117 	size_t count = 0;
118 
119 	list_for_each_entry(dynid, &dynids->list, node)
120 		if (dynid->id.bInterfaceClass != 0)
121 			count += scnprintf(&buf[count], PAGE_SIZE - count, "%04x %04x %02x\n",
122 					   dynid->id.idVendor, dynid->id.idProduct,
123 					   dynid->id.bInterfaceClass);
124 		else
125 			count += scnprintf(&buf[count], PAGE_SIZE - count, "%04x %04x\n",
126 					   dynid->id.idVendor, dynid->id.idProduct);
127 	return count;
128 }
129 EXPORT_SYMBOL_GPL(usb_show_dynids);
130 
131 static ssize_t new_id_show(struct device_driver *driver, char *buf)
132 {
133 	struct usb_driver *usb_drv = to_usb_driver(driver);
134 
135 	return usb_show_dynids(&usb_drv->dynids, buf);
136 }
137 
138 static ssize_t new_id_store(struct device_driver *driver,
139 			    const char *buf, size_t count)
140 {
141 	struct usb_driver *usb_drv = to_usb_driver(driver);
142 
143 	return usb_store_new_id(&usb_drv->dynids, usb_drv->id_table, driver, buf, count);
144 }
145 static DRIVER_ATTR_RW(new_id);
146 
147 /*
148  * Remove a USB device ID from this driver
149  */
150 static ssize_t remove_id_store(struct device_driver *driver, const char *buf,
151 			       size_t count)
152 {
153 	struct usb_dynid *dynid, *n;
154 	struct usb_driver *usb_driver = to_usb_driver(driver);
155 	u32 idVendor;
156 	u32 idProduct;
157 	int fields;
158 
159 	fields = sscanf(buf, "%x %x", &idVendor, &idProduct);
160 	if (fields < 2)
161 		return -EINVAL;
162 
163 	spin_lock(&usb_driver->dynids.lock);
164 	list_for_each_entry_safe(dynid, n, &usb_driver->dynids.list, node) {
165 		struct usb_device_id *id = &dynid->id;
166 
167 		if ((id->idVendor == idVendor) &&
168 		    (id->idProduct == idProduct)) {
169 			list_del(&dynid->node);
170 			kfree(dynid);
171 			break;
172 		}
173 	}
174 	spin_unlock(&usb_driver->dynids.lock);
175 	return count;
176 }
177 
178 static ssize_t remove_id_show(struct device_driver *driver, char *buf)
179 {
180 	return new_id_show(driver, buf);
181 }
182 static DRIVER_ATTR_RW(remove_id);
183 
184 static int usb_create_newid_files(struct usb_driver *usb_drv)
185 {
186 	int error = 0;
187 
188 	if (usb_drv->no_dynamic_id)
189 		goto exit;
190 
191 	if (usb_drv->probe != NULL) {
192 		error = driver_create_file(&usb_drv->drvwrap.driver,
193 					   &driver_attr_new_id);
194 		if (error == 0) {
195 			error = driver_create_file(&usb_drv->drvwrap.driver,
196 					&driver_attr_remove_id);
197 			if (error)
198 				driver_remove_file(&usb_drv->drvwrap.driver,
199 						&driver_attr_new_id);
200 		}
201 	}
202 exit:
203 	return error;
204 }
205 
206 static void usb_remove_newid_files(struct usb_driver *usb_drv)
207 {
208 	if (usb_drv->no_dynamic_id)
209 		return;
210 
211 	if (usb_drv->probe != NULL) {
212 		driver_remove_file(&usb_drv->drvwrap.driver,
213 				&driver_attr_remove_id);
214 		driver_remove_file(&usb_drv->drvwrap.driver,
215 				   &driver_attr_new_id);
216 	}
217 }
218 
219 static void usb_free_dynids(struct usb_driver *usb_drv)
220 {
221 	struct usb_dynid *dynid, *n;
222 
223 	spin_lock(&usb_drv->dynids.lock);
224 	list_for_each_entry_safe(dynid, n, &usb_drv->dynids.list, node) {
225 		list_del(&dynid->node);
226 		kfree(dynid);
227 	}
228 	spin_unlock(&usb_drv->dynids.lock);
229 }
230 
231 static const struct usb_device_id *usb_match_dynamic_id(struct usb_interface *intf,
232 							struct usb_driver *drv)
233 {
234 	struct usb_dynid *dynid;
235 
236 	spin_lock(&drv->dynids.lock);
237 	list_for_each_entry(dynid, &drv->dynids.list, node) {
238 		if (usb_match_one_id(intf, &dynid->id)) {
239 			spin_unlock(&drv->dynids.lock);
240 			return &dynid->id;
241 		}
242 	}
243 	spin_unlock(&drv->dynids.lock);
244 	return NULL;
245 }
246 
247 
248 /* called from driver core with dev locked */
249 static int usb_probe_device(struct device *dev)
250 {
251 	struct usb_device_driver *udriver = to_usb_device_driver(dev->driver);
252 	struct usb_device *udev = to_usb_device(dev);
253 	int error = 0;
254 
255 	dev_dbg(dev, "%s\n", __func__);
256 
257 	/* TODO: Add real matching code */
258 
259 	/* The device should always appear to be in use
260 	 * unless the driver supports autosuspend.
261 	 */
262 	if (!udriver->supports_autosuspend)
263 		error = usb_autoresume_device(udev);
264 	if (error)
265 		return error;
266 
267 	if (udriver->generic_subclass)
268 		error = usb_generic_driver_probe(udev);
269 	if (error)
270 		return error;
271 
272 	error = udriver->probe(udev);
273 	if (error == -ENODEV && udriver != &usb_generic_driver) {
274 		udev->use_generic_driver = 1;
275 		return -EPROBE_DEFER;
276 	}
277 	return error;
278 }
279 
280 /* called from driver core with dev locked */
281 static int usb_unbind_device(struct device *dev)
282 {
283 	struct usb_device *udev = to_usb_device(dev);
284 	struct usb_device_driver *udriver = to_usb_device_driver(dev->driver);
285 
286 	if (udriver->disconnect)
287 		udriver->disconnect(udev);
288 	if (udriver->generic_subclass)
289 		usb_generic_driver_disconnect(udev);
290 	if (!udriver->supports_autosuspend)
291 		usb_autosuspend_device(udev);
292 	return 0;
293 }
294 
295 /* called from driver core with dev locked */
296 static int usb_probe_interface(struct device *dev)
297 {
298 	struct usb_driver *driver = to_usb_driver(dev->driver);
299 	struct usb_interface *intf = to_usb_interface(dev);
300 	struct usb_device *udev = interface_to_usbdev(intf);
301 	const struct usb_device_id *id;
302 	int error = -ENODEV;
303 	int lpm_disable_error = -ENODEV;
304 
305 	dev_dbg(dev, "%s\n", __func__);
306 
307 	intf->needs_binding = 0;
308 
309 	if (usb_device_is_owned(udev))
310 		return error;
311 
312 	if (udev->authorized == 0) {
313 		dev_err(&intf->dev, "Device is not authorized for usage\n");
314 		return error;
315 	} else if (intf->authorized == 0) {
316 		dev_err(&intf->dev, "Interface %d is not authorized for usage\n",
317 				intf->altsetting->desc.bInterfaceNumber);
318 		return error;
319 	}
320 
321 	id = usb_match_dynamic_id(intf, driver);
322 	if (!id)
323 		id = usb_match_id(intf, driver->id_table);
324 	if (!id)
325 		return error;
326 
327 	dev_dbg(dev, "%s - got id\n", __func__);
328 
329 	error = usb_autoresume_device(udev);
330 	if (error)
331 		return error;
332 
333 	intf->condition = USB_INTERFACE_BINDING;
334 
335 	/* Probed interfaces are initially active.  They are
336 	 * runtime-PM-enabled only if the driver has autosuspend support.
337 	 * They are sensitive to their children's power states.
338 	 */
339 	pm_runtime_set_active(dev);
340 	pm_suspend_ignore_children(dev, false);
341 	if (driver->supports_autosuspend)
342 		pm_runtime_enable(dev);
343 
344 	/* If the new driver doesn't allow hub-initiated LPM, and we can't
345 	 * disable hub-initiated LPM, then fail the probe.
346 	 *
347 	 * Otherwise, leaving LPM enabled should be harmless, because the
348 	 * endpoint intervals should remain the same, and the U1/U2 timeouts
349 	 * should remain the same.
350 	 *
351 	 * If we need to install alt setting 0 before probe, or another alt
352 	 * setting during probe, that should also be fine.  usb_set_interface()
353 	 * will attempt to disable LPM, and fail if it can't disable it.
354 	 */
355 	if (driver->disable_hub_initiated_lpm) {
356 		lpm_disable_error = usb_unlocked_disable_lpm(udev);
357 		if (lpm_disable_error) {
358 			dev_err(&intf->dev, "%s Failed to disable LPM for driver %s\n",
359 				__func__, driver->name);
360 			error = lpm_disable_error;
361 			goto err;
362 		}
363 	}
364 
365 	/* Carry out a deferred switch to altsetting 0 */
366 	if (intf->needs_altsetting0) {
367 		error = usb_set_interface(udev, intf->altsetting[0].
368 				desc.bInterfaceNumber, 0);
369 		if (error < 0)
370 			goto err;
371 		intf->needs_altsetting0 = 0;
372 	}
373 
374 	error = driver->probe(intf, id);
375 	if (error)
376 		goto err;
377 
378 	intf->condition = USB_INTERFACE_BOUND;
379 
380 	/* If the LPM disable succeeded, balance the ref counts. */
381 	if (!lpm_disable_error)
382 		usb_unlocked_enable_lpm(udev);
383 
384 	usb_autosuspend_device(udev);
385 	return error;
386 
387  err:
388 	usb_set_intfdata(intf, NULL);
389 	intf->needs_remote_wakeup = 0;
390 	intf->condition = USB_INTERFACE_UNBOUND;
391 
392 	/* If the LPM disable succeeded, balance the ref counts. */
393 	if (!lpm_disable_error)
394 		usb_unlocked_enable_lpm(udev);
395 
396 	/* Unbound interfaces are always runtime-PM-disabled and -suspended */
397 	if (driver->supports_autosuspend)
398 		pm_runtime_disable(dev);
399 	pm_runtime_set_suspended(dev);
400 
401 	usb_autosuspend_device(udev);
402 	return error;
403 }
404 
405 /* called from driver core with dev locked */
406 static int usb_unbind_interface(struct device *dev)
407 {
408 	struct usb_driver *driver = to_usb_driver(dev->driver);
409 	struct usb_interface *intf = to_usb_interface(dev);
410 	struct usb_host_endpoint *ep, **eps = NULL;
411 	struct usb_device *udev;
412 	int i, j, error, r;
413 	int lpm_disable_error = -ENODEV;
414 
415 	intf->condition = USB_INTERFACE_UNBINDING;
416 
417 	/* Autoresume for set_interface call below */
418 	udev = interface_to_usbdev(intf);
419 	error = usb_autoresume_device(udev);
420 
421 	/* If hub-initiated LPM policy may change, attempt to disable LPM until
422 	 * the driver is unbound.  If LPM isn't disabled, that's fine because it
423 	 * wouldn't be enabled unless all the bound interfaces supported
424 	 * hub-initiated LPM.
425 	 */
426 	if (driver->disable_hub_initiated_lpm)
427 		lpm_disable_error = usb_unlocked_disable_lpm(udev);
428 
429 	/*
430 	 * Terminate all URBs for this interface unless the driver
431 	 * supports "soft" unbinding and the device is still present.
432 	 */
433 	if (!driver->soft_unbind || udev->state == USB_STATE_NOTATTACHED)
434 		usb_disable_interface(udev, intf, false);
435 
436 	driver->disconnect(intf);
437 
438 	/* Free streams */
439 	for (i = 0, j = 0; i < intf->cur_altsetting->desc.bNumEndpoints; i++) {
440 		ep = &intf->cur_altsetting->endpoint[i];
441 		if (ep->streams == 0)
442 			continue;
443 		if (j == 0) {
444 			eps = kmalloc_array(USB_MAXENDPOINTS, sizeof(void *),
445 				      GFP_KERNEL);
446 			if (!eps)
447 				break;
448 		}
449 		eps[j++] = ep;
450 	}
451 	if (j) {
452 		usb_free_streams(intf, eps, j, GFP_KERNEL);
453 		kfree(eps);
454 	}
455 
456 	/* Reset other interface state.
457 	 * We cannot do a Set-Interface if the device is suspended or
458 	 * if it is prepared for a system sleep (since installing a new
459 	 * altsetting means creating new endpoint device entries).
460 	 * When either of these happens, defer the Set-Interface.
461 	 */
462 	if (intf->cur_altsetting->desc.bAlternateSetting == 0) {
463 		/* Already in altsetting 0 so skip Set-Interface.
464 		 * Just re-enable it without affecting the endpoint toggles.
465 		 */
466 		usb_enable_interface(udev, intf, false);
467 	} else if (!error && !intf->dev.power.is_prepared) {
468 		r = usb_set_interface(udev, intf->altsetting[0].
469 				desc.bInterfaceNumber, 0);
470 		if (r < 0)
471 			intf->needs_altsetting0 = 1;
472 	} else {
473 		intf->needs_altsetting0 = 1;
474 	}
475 	usb_set_intfdata(intf, NULL);
476 
477 	intf->condition = USB_INTERFACE_UNBOUND;
478 	intf->needs_remote_wakeup = 0;
479 
480 	/* Attempt to re-enable USB3 LPM, if the disable succeeded. */
481 	if (!lpm_disable_error)
482 		usb_unlocked_enable_lpm(udev);
483 
484 	/* Unbound interfaces are always runtime-PM-disabled and -suspended */
485 	if (driver->supports_autosuspend)
486 		pm_runtime_disable(dev);
487 	pm_runtime_set_suspended(dev);
488 
489 	if (!error)
490 		usb_autosuspend_device(udev);
491 
492 	return 0;
493 }
494 
495 /**
496  * usb_driver_claim_interface - bind a driver to an interface
497  * @driver: the driver to be bound
498  * @iface: the interface to which it will be bound; must be in the
499  *	usb device's active configuration
500  * @priv: driver data associated with that interface
501  *
502  * This is used by usb device drivers that need to claim more than one
503  * interface on a device when probing (audio and acm are current examples).
504  * No device driver should directly modify internal usb_interface or
505  * usb_device structure members.
506  *
507  * Few drivers should need to use this routine, since the most natural
508  * way to bind to an interface is to return the private data from
509  * the driver's probe() method.
510  *
511  * Callers must own the device lock, so driver probe() entries don't need
512  * extra locking, but other call contexts may need to explicitly claim that
513  * lock.
514  *
515  * Return: 0 on success.
516  */
517 int usb_driver_claim_interface(struct usb_driver *driver,
518 				struct usb_interface *iface, void *priv)
519 {
520 	struct device *dev;
521 	int retval = 0;
522 
523 	if (!iface)
524 		return -ENODEV;
525 
526 	dev = &iface->dev;
527 	if (dev->driver)
528 		return -EBUSY;
529 
530 	/* reject claim if interface is not authorized */
531 	if (!iface->authorized)
532 		return -ENODEV;
533 
534 	dev->driver = &driver->drvwrap.driver;
535 	usb_set_intfdata(iface, priv);
536 	iface->needs_binding = 0;
537 
538 	iface->condition = USB_INTERFACE_BOUND;
539 
540 	/* Claimed interfaces are initially inactive (suspended) and
541 	 * runtime-PM-enabled, but only if the driver has autosuspend
542 	 * support.  Otherwise they are marked active, to prevent the
543 	 * device from being autosuspended, but left disabled.  In either
544 	 * case they are sensitive to their children's power states.
545 	 */
546 	pm_suspend_ignore_children(dev, false);
547 	if (driver->supports_autosuspend)
548 		pm_runtime_enable(dev);
549 	else
550 		pm_runtime_set_active(dev);
551 
552 	/* if interface was already added, bind now; else let
553 	 * the future device_add() bind it, bypassing probe()
554 	 */
555 	if (device_is_registered(dev))
556 		retval = device_bind_driver(dev);
557 
558 	if (retval) {
559 		dev->driver = NULL;
560 		usb_set_intfdata(iface, NULL);
561 		iface->needs_remote_wakeup = 0;
562 		iface->condition = USB_INTERFACE_UNBOUND;
563 
564 		/*
565 		 * Unbound interfaces are always runtime-PM-disabled
566 		 * and runtime-PM-suspended
567 		 */
568 		if (driver->supports_autosuspend)
569 			pm_runtime_disable(dev);
570 		pm_runtime_set_suspended(dev);
571 	}
572 
573 	return retval;
574 }
575 EXPORT_SYMBOL_GPL(usb_driver_claim_interface);
576 
577 /**
578  * usb_driver_release_interface - unbind a driver from an interface
579  * @driver: the driver to be unbound
580  * @iface: the interface from which it will be unbound
581  *
582  * This can be used by drivers to release an interface without waiting
583  * for their disconnect() methods to be called.  In typical cases this
584  * also causes the driver disconnect() method to be called.
585  *
586  * This call is synchronous, and may not be used in an interrupt context.
587  * Callers must own the device lock, so driver disconnect() entries don't
588  * need extra locking, but other call contexts may need to explicitly claim
589  * that lock.
590  */
591 void usb_driver_release_interface(struct usb_driver *driver,
592 					struct usb_interface *iface)
593 {
594 	struct device *dev = &iface->dev;
595 
596 	/* this should never happen, don't release something that's not ours */
597 	if (!dev->driver || dev->driver != &driver->drvwrap.driver)
598 		return;
599 
600 	/* don't release from within disconnect() */
601 	if (iface->condition != USB_INTERFACE_BOUND)
602 		return;
603 	iface->condition = USB_INTERFACE_UNBINDING;
604 
605 	/* Release via the driver core only if the interface
606 	 * has already been registered
607 	 */
608 	if (device_is_registered(dev)) {
609 		device_release_driver(dev);
610 	} else {
611 		device_lock(dev);
612 		usb_unbind_interface(dev);
613 		dev->driver = NULL;
614 		device_unlock(dev);
615 	}
616 }
617 EXPORT_SYMBOL_GPL(usb_driver_release_interface);
618 
619 /* returns 0 if no match, 1 if match */
620 int usb_match_device(struct usb_device *dev, const struct usb_device_id *id)
621 {
622 	if ((id->match_flags & USB_DEVICE_ID_MATCH_VENDOR) &&
623 	    id->idVendor != le16_to_cpu(dev->descriptor.idVendor))
624 		return 0;
625 
626 	if ((id->match_flags & USB_DEVICE_ID_MATCH_PRODUCT) &&
627 	    id->idProduct != le16_to_cpu(dev->descriptor.idProduct))
628 		return 0;
629 
630 	/* No need to test id->bcdDevice_lo != 0, since 0 is never
631 	   greater than any unsigned number. */
632 	if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_LO) &&
633 	    (id->bcdDevice_lo > le16_to_cpu(dev->descriptor.bcdDevice)))
634 		return 0;
635 
636 	if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_HI) &&
637 	    (id->bcdDevice_hi < le16_to_cpu(dev->descriptor.bcdDevice)))
638 		return 0;
639 
640 	if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_CLASS) &&
641 	    (id->bDeviceClass != dev->descriptor.bDeviceClass))
642 		return 0;
643 
644 	if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_SUBCLASS) &&
645 	    (id->bDeviceSubClass != dev->descriptor.bDeviceSubClass))
646 		return 0;
647 
648 	if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_PROTOCOL) &&
649 	    (id->bDeviceProtocol != dev->descriptor.bDeviceProtocol))
650 		return 0;
651 
652 	return 1;
653 }
654 
655 /* returns 0 if no match, 1 if match */
656 int usb_match_one_id_intf(struct usb_device *dev,
657 			  struct usb_host_interface *intf,
658 			  const struct usb_device_id *id)
659 {
660 	/* The interface class, subclass, protocol and number should never be
661 	 * checked for a match if the device class is Vendor Specific,
662 	 * unless the match record specifies the Vendor ID. */
663 	if (dev->descriptor.bDeviceClass == USB_CLASS_VENDOR_SPEC &&
664 			!(id->match_flags & USB_DEVICE_ID_MATCH_VENDOR) &&
665 			(id->match_flags & (USB_DEVICE_ID_MATCH_INT_CLASS |
666 				USB_DEVICE_ID_MATCH_INT_SUBCLASS |
667 				USB_DEVICE_ID_MATCH_INT_PROTOCOL |
668 				USB_DEVICE_ID_MATCH_INT_NUMBER)))
669 		return 0;
670 
671 	if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_CLASS) &&
672 	    (id->bInterfaceClass != intf->desc.bInterfaceClass))
673 		return 0;
674 
675 	if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_SUBCLASS) &&
676 	    (id->bInterfaceSubClass != intf->desc.bInterfaceSubClass))
677 		return 0;
678 
679 	if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_PROTOCOL) &&
680 	    (id->bInterfaceProtocol != intf->desc.bInterfaceProtocol))
681 		return 0;
682 
683 	if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_NUMBER) &&
684 	    (id->bInterfaceNumber != intf->desc.bInterfaceNumber))
685 		return 0;
686 
687 	return 1;
688 }
689 
690 /* returns 0 if no match, 1 if match */
691 int usb_match_one_id(struct usb_interface *interface,
692 		     const struct usb_device_id *id)
693 {
694 	struct usb_host_interface *intf;
695 	struct usb_device *dev;
696 
697 	/* proc_connectinfo in devio.c may call us with id == NULL. */
698 	if (id == NULL)
699 		return 0;
700 
701 	intf = interface->cur_altsetting;
702 	dev = interface_to_usbdev(interface);
703 
704 	if (!usb_match_device(dev, id))
705 		return 0;
706 
707 	return usb_match_one_id_intf(dev, intf, id);
708 }
709 EXPORT_SYMBOL_GPL(usb_match_one_id);
710 
711 /**
712  * usb_match_id - find first usb_device_id matching device or interface
713  * @interface: the interface of interest
714  * @id: array of usb_device_id structures, terminated by zero entry
715  *
716  * usb_match_id searches an array of usb_device_id's and returns
717  * the first one matching the device or interface, or null.
718  * This is used when binding (or rebinding) a driver to an interface.
719  * Most USB device drivers will use this indirectly, through the usb core,
720  * but some layered driver frameworks use it directly.
721  * These device tables are exported with MODULE_DEVICE_TABLE, through
722  * modutils, to support the driver loading functionality of USB hotplugging.
723  *
724  * Return: The first matching usb_device_id, or %NULL.
725  *
726  * What Matches:
727  *
728  * The "match_flags" element in a usb_device_id controls which
729  * members are used.  If the corresponding bit is set, the
730  * value in the device_id must match its corresponding member
731  * in the device or interface descriptor, or else the device_id
732  * does not match.
733  *
734  * "driver_info" is normally used only by device drivers,
735  * but you can create a wildcard "matches anything" usb_device_id
736  * as a driver's "modules.usbmap" entry if you provide an id with
737  * only a nonzero "driver_info" field.  If you do this, the USB device
738  * driver's probe() routine should use additional intelligence to
739  * decide whether to bind to the specified interface.
740  *
741  * What Makes Good usb_device_id Tables:
742  *
743  * The match algorithm is very simple, so that intelligence in
744  * driver selection must come from smart driver id records.
745  * Unless you have good reasons to use another selection policy,
746  * provide match elements only in related groups, and order match
747  * specifiers from specific to general.  Use the macros provided
748  * for that purpose if you can.
749  *
750  * The most specific match specifiers use device descriptor
751  * data.  These are commonly used with product-specific matches;
752  * the USB_DEVICE macro lets you provide vendor and product IDs,
753  * and you can also match against ranges of product revisions.
754  * These are widely used for devices with application or vendor
755  * specific bDeviceClass values.
756  *
757  * Matches based on device class/subclass/protocol specifications
758  * are slightly more general; use the USB_DEVICE_INFO macro, or
759  * its siblings.  These are used with single-function devices
760  * where bDeviceClass doesn't specify that each interface has
761  * its own class.
762  *
763  * Matches based on interface class/subclass/protocol are the
764  * most general; they let drivers bind to any interface on a
765  * multiple-function device.  Use the USB_INTERFACE_INFO
766  * macro, or its siblings, to match class-per-interface style
767  * devices (as recorded in bInterfaceClass).
768  *
769  * Note that an entry created by USB_INTERFACE_INFO won't match
770  * any interface if the device class is set to Vendor-Specific.
771  * This is deliberate; according to the USB spec the meanings of
772  * the interface class/subclass/protocol for these devices are also
773  * vendor-specific, and hence matching against a standard product
774  * class wouldn't work anyway.  If you really want to use an
775  * interface-based match for such a device, create a match record
776  * that also specifies the vendor ID.  (Unforunately there isn't a
777  * standard macro for creating records like this.)
778  *
779  * Within those groups, remember that not all combinations are
780  * meaningful.  For example, don't give a product version range
781  * without vendor and product IDs; or specify a protocol without
782  * its associated class and subclass.
783  */
784 const struct usb_device_id *usb_match_id(struct usb_interface *interface,
785 					 const struct usb_device_id *id)
786 {
787 	/* proc_connectinfo in devio.c may call us with id == NULL. */
788 	if (id == NULL)
789 		return NULL;
790 
791 	/* It is important to check that id->driver_info is nonzero,
792 	   since an entry that is all zeroes except for a nonzero
793 	   id->driver_info is the way to create an entry that
794 	   indicates that the driver want to examine every
795 	   device and interface. */
796 	for (; id->idVendor || id->idProduct || id->bDeviceClass ||
797 	       id->bInterfaceClass || id->driver_info; id++) {
798 		if (usb_match_one_id(interface, id))
799 			return id;
800 	}
801 
802 	return NULL;
803 }
804 EXPORT_SYMBOL_GPL(usb_match_id);
805 
806 const struct usb_device_id *usb_device_match_id(struct usb_device *udev,
807 				const struct usb_device_id *id)
808 {
809 	if (!id)
810 		return NULL;
811 
812 	for (; id->idVendor || id->idProduct ; id++) {
813 		if (usb_match_device(udev, id))
814 			return id;
815 	}
816 
817 	return NULL;
818 }
819 
820 static int usb_device_match(struct device *dev, struct device_driver *drv)
821 {
822 	/* devices and interfaces are handled separately */
823 	if (is_usb_device(dev)) {
824 		struct usb_device *udev;
825 		struct usb_device_driver *udrv;
826 
827 		/* interface drivers never match devices */
828 		if (!is_usb_device_driver(drv))
829 			return 0;
830 
831 		udev = to_usb_device(dev);
832 		udrv = to_usb_device_driver(drv);
833 
834 		if (udrv->id_table &&
835 		    usb_device_match_id(udev, udrv->id_table) != NULL) {
836 			return 1;
837 		}
838 
839 		if (udrv->match)
840 			return udrv->match(udev);
841 		return 0;
842 
843 	} else if (is_usb_interface(dev)) {
844 		struct usb_interface *intf;
845 		struct usb_driver *usb_drv;
846 		const struct usb_device_id *id;
847 
848 		/* device drivers never match interfaces */
849 		if (is_usb_device_driver(drv))
850 			return 0;
851 
852 		intf = to_usb_interface(dev);
853 		usb_drv = to_usb_driver(drv);
854 
855 		id = usb_match_id(intf, usb_drv->id_table);
856 		if (id)
857 			return 1;
858 
859 		id = usb_match_dynamic_id(intf, usb_drv);
860 		if (id)
861 			return 1;
862 	}
863 
864 	return 0;
865 }
866 
867 static int usb_uevent(struct device *dev, struct kobj_uevent_env *env)
868 {
869 	struct usb_device *usb_dev;
870 
871 	if (is_usb_device(dev)) {
872 		usb_dev = to_usb_device(dev);
873 	} else if (is_usb_interface(dev)) {
874 		struct usb_interface *intf = to_usb_interface(dev);
875 
876 		usb_dev = interface_to_usbdev(intf);
877 	} else {
878 		return 0;
879 	}
880 
881 	if (usb_dev->devnum < 0) {
882 		/* driver is often null here; dev_dbg() would oops */
883 		pr_debug("usb %s: already deleted?\n", dev_name(dev));
884 		return -ENODEV;
885 	}
886 	if (!usb_dev->bus) {
887 		pr_debug("usb %s: bus removed?\n", dev_name(dev));
888 		return -ENODEV;
889 	}
890 
891 	/* per-device configurations are common */
892 	if (add_uevent_var(env, "PRODUCT=%x/%x/%x",
893 			   le16_to_cpu(usb_dev->descriptor.idVendor),
894 			   le16_to_cpu(usb_dev->descriptor.idProduct),
895 			   le16_to_cpu(usb_dev->descriptor.bcdDevice)))
896 		return -ENOMEM;
897 
898 	/* class-based driver binding models */
899 	if (add_uevent_var(env, "TYPE=%d/%d/%d",
900 			   usb_dev->descriptor.bDeviceClass,
901 			   usb_dev->descriptor.bDeviceSubClass,
902 			   usb_dev->descriptor.bDeviceProtocol))
903 		return -ENOMEM;
904 
905 	return 0;
906 }
907 
908 static bool is_dev_usb_generic_driver(struct device *dev)
909 {
910 	struct usb_device_driver *udd = dev->driver ?
911 		to_usb_device_driver(dev->driver) : NULL;
912 
913 	return udd == &usb_generic_driver;
914 }
915 
916 static int __usb_bus_reprobe_drivers(struct device *dev, void *data)
917 {
918 	struct usb_device_driver *new_udriver = data;
919 	struct usb_device *udev;
920 	int ret;
921 
922 	if (!is_dev_usb_generic_driver(dev))
923 		return 0;
924 
925 	udev = to_usb_device(dev);
926 	if (usb_device_match_id(udev, new_udriver->id_table) == NULL &&
927 	    (!new_udriver->match || new_udriver->match(udev) != 0))
928 		return 0;
929 
930 	ret = device_reprobe(dev);
931 	if (ret && ret != -EPROBE_DEFER)
932 		dev_err(dev, "Failed to reprobe device (error %d)\n", ret);
933 
934 	return 0;
935 }
936 
937 /**
938  * usb_register_device_driver - register a USB device (not interface) driver
939  * @new_udriver: USB operations for the device driver
940  * @owner: module owner of this driver.
941  *
942  * Registers a USB device driver with the USB core.  The list of
943  * unattached devices will be rescanned whenever a new driver is
944  * added, allowing the new driver to attach to any recognized devices.
945  *
946  * Return: A negative error code on failure and 0 on success.
947  */
948 int usb_register_device_driver(struct usb_device_driver *new_udriver,
949 		struct module *owner)
950 {
951 	int retval = 0;
952 
953 	if (usb_disabled())
954 		return -ENODEV;
955 
956 	new_udriver->drvwrap.for_devices = 1;
957 	new_udriver->drvwrap.driver.name = new_udriver->name;
958 	new_udriver->drvwrap.driver.bus = &usb_bus_type;
959 	new_udriver->drvwrap.driver.probe = usb_probe_device;
960 	new_udriver->drvwrap.driver.remove = usb_unbind_device;
961 	new_udriver->drvwrap.driver.owner = owner;
962 	new_udriver->drvwrap.driver.dev_groups = new_udriver->dev_groups;
963 
964 	retval = driver_register(&new_udriver->drvwrap.driver);
965 
966 	if (!retval) {
967 		pr_info("%s: registered new device driver %s\n",
968 			usbcore_name, new_udriver->name);
969 		/*
970 		 * Check whether any device could be better served with
971 		 * this new driver
972 		 */
973 		bus_for_each_dev(&usb_bus_type, NULL, new_udriver,
974 				 __usb_bus_reprobe_drivers);
975 	} else {
976 		printk(KERN_ERR "%s: error %d registering device "
977 			"	driver %s\n",
978 			usbcore_name, retval, new_udriver->name);
979 	}
980 
981 	return retval;
982 }
983 EXPORT_SYMBOL_GPL(usb_register_device_driver);
984 
985 /**
986  * usb_deregister_device_driver - unregister a USB device (not interface) driver
987  * @udriver: USB operations of the device driver to unregister
988  * Context: must be able to sleep
989  *
990  * Unlinks the specified driver from the internal USB driver list.
991  */
992 void usb_deregister_device_driver(struct usb_device_driver *udriver)
993 {
994 	pr_info("%s: deregistering device driver %s\n",
995 			usbcore_name, udriver->name);
996 
997 	driver_unregister(&udriver->drvwrap.driver);
998 }
999 EXPORT_SYMBOL_GPL(usb_deregister_device_driver);
1000 
1001 /**
1002  * usb_register_driver - register a USB interface driver
1003  * @new_driver: USB operations for the interface driver
1004  * @owner: module owner of this driver.
1005  * @mod_name: module name string
1006  *
1007  * Registers a USB interface driver with the USB core.  The list of
1008  * unattached interfaces will be rescanned whenever a new driver is
1009  * added, allowing the new driver to attach to any recognized interfaces.
1010  *
1011  * Return: A negative error code on failure and 0 on success.
1012  *
1013  * NOTE: if you want your driver to use the USB major number, you must call
1014  * usb_register_dev() to enable that functionality.  This function no longer
1015  * takes care of that.
1016  */
1017 int usb_register_driver(struct usb_driver *new_driver, struct module *owner,
1018 			const char *mod_name)
1019 {
1020 	int retval = 0;
1021 
1022 	if (usb_disabled())
1023 		return -ENODEV;
1024 
1025 	new_driver->drvwrap.for_devices = 0;
1026 	new_driver->drvwrap.driver.name = new_driver->name;
1027 	new_driver->drvwrap.driver.bus = &usb_bus_type;
1028 	new_driver->drvwrap.driver.probe = usb_probe_interface;
1029 	new_driver->drvwrap.driver.remove = usb_unbind_interface;
1030 	new_driver->drvwrap.driver.owner = owner;
1031 	new_driver->drvwrap.driver.mod_name = mod_name;
1032 	new_driver->drvwrap.driver.dev_groups = new_driver->dev_groups;
1033 	spin_lock_init(&new_driver->dynids.lock);
1034 	INIT_LIST_HEAD(&new_driver->dynids.list);
1035 
1036 	retval = driver_register(&new_driver->drvwrap.driver);
1037 	if (retval)
1038 		goto out;
1039 
1040 	retval = usb_create_newid_files(new_driver);
1041 	if (retval)
1042 		goto out_newid;
1043 
1044 	pr_info("%s: registered new interface driver %s\n",
1045 			usbcore_name, new_driver->name);
1046 
1047 out:
1048 	return retval;
1049 
1050 out_newid:
1051 	driver_unregister(&new_driver->drvwrap.driver);
1052 
1053 	printk(KERN_ERR "%s: error %d registering interface "
1054 			"	driver %s\n",
1055 			usbcore_name, retval, new_driver->name);
1056 	goto out;
1057 }
1058 EXPORT_SYMBOL_GPL(usb_register_driver);
1059 
1060 /**
1061  * usb_deregister - unregister a USB interface driver
1062  * @driver: USB operations of the interface driver to unregister
1063  * Context: must be able to sleep
1064  *
1065  * Unlinks the specified driver from the internal USB driver list.
1066  *
1067  * NOTE: If you called usb_register_dev(), you still need to call
1068  * usb_deregister_dev() to clean up your driver's allocated minor numbers,
1069  * this * call will no longer do it for you.
1070  */
1071 void usb_deregister(struct usb_driver *driver)
1072 {
1073 	pr_info("%s: deregistering interface driver %s\n",
1074 			usbcore_name, driver->name);
1075 
1076 	usb_remove_newid_files(driver);
1077 	driver_unregister(&driver->drvwrap.driver);
1078 	usb_free_dynids(driver);
1079 }
1080 EXPORT_SYMBOL_GPL(usb_deregister);
1081 
1082 /* Forced unbinding of a USB interface driver, either because
1083  * it doesn't support pre_reset/post_reset/reset_resume or
1084  * because it doesn't support suspend/resume.
1085  *
1086  * The caller must hold @intf's device's lock, but not @intf's lock.
1087  */
1088 void usb_forced_unbind_intf(struct usb_interface *intf)
1089 {
1090 	struct usb_driver *driver = to_usb_driver(intf->dev.driver);
1091 
1092 	dev_dbg(&intf->dev, "forced unbind\n");
1093 	usb_driver_release_interface(driver, intf);
1094 
1095 	/* Mark the interface for later rebinding */
1096 	intf->needs_binding = 1;
1097 }
1098 
1099 /*
1100  * Unbind drivers for @udev's marked interfaces.  These interfaces have
1101  * the needs_binding flag set, for example by usb_resume_interface().
1102  *
1103  * The caller must hold @udev's device lock.
1104  */
1105 static void unbind_marked_interfaces(struct usb_device *udev)
1106 {
1107 	struct usb_host_config	*config;
1108 	int			i;
1109 	struct usb_interface	*intf;
1110 
1111 	config = udev->actconfig;
1112 	if (config) {
1113 		for (i = 0; i < config->desc.bNumInterfaces; ++i) {
1114 			intf = config->interface[i];
1115 			if (intf->dev.driver && intf->needs_binding)
1116 				usb_forced_unbind_intf(intf);
1117 		}
1118 	}
1119 }
1120 
1121 /* Delayed forced unbinding of a USB interface driver and scan
1122  * for rebinding.
1123  *
1124  * The caller must hold @intf's device's lock, but not @intf's lock.
1125  *
1126  * Note: Rebinds will be skipped if a system sleep transition is in
1127  * progress and the PM "complete" callback hasn't occurred yet.
1128  */
1129 static void usb_rebind_intf(struct usb_interface *intf)
1130 {
1131 	int rc;
1132 
1133 	/* Delayed unbind of an existing driver */
1134 	if (intf->dev.driver)
1135 		usb_forced_unbind_intf(intf);
1136 
1137 	/* Try to rebind the interface */
1138 	if (!intf->dev.power.is_prepared) {
1139 		intf->needs_binding = 0;
1140 		rc = device_attach(&intf->dev);
1141 		if (rc < 0 && rc != -EPROBE_DEFER)
1142 			dev_warn(&intf->dev, "rebind failed: %d\n", rc);
1143 	}
1144 }
1145 
1146 /*
1147  * Rebind drivers to @udev's marked interfaces.  These interfaces have
1148  * the needs_binding flag set.
1149  *
1150  * The caller must hold @udev's device lock.
1151  */
1152 static void rebind_marked_interfaces(struct usb_device *udev)
1153 {
1154 	struct usb_host_config	*config;
1155 	int			i;
1156 	struct usb_interface	*intf;
1157 
1158 	config = udev->actconfig;
1159 	if (config) {
1160 		for (i = 0; i < config->desc.bNumInterfaces; ++i) {
1161 			intf = config->interface[i];
1162 			if (intf->needs_binding)
1163 				usb_rebind_intf(intf);
1164 		}
1165 	}
1166 }
1167 
1168 /*
1169  * Unbind all of @udev's marked interfaces and then rebind all of them.
1170  * This ordering is necessary because some drivers claim several interfaces
1171  * when they are first probed.
1172  *
1173  * The caller must hold @udev's device lock.
1174  */
1175 void usb_unbind_and_rebind_marked_interfaces(struct usb_device *udev)
1176 {
1177 	unbind_marked_interfaces(udev);
1178 	rebind_marked_interfaces(udev);
1179 }
1180 
1181 #ifdef CONFIG_PM
1182 
1183 /* Unbind drivers for @udev's interfaces that don't support suspend/resume
1184  * There is no check for reset_resume here because it can be determined
1185  * only during resume whether reset_resume is needed.
1186  *
1187  * The caller must hold @udev's device lock.
1188  */
1189 static void unbind_no_pm_drivers_interfaces(struct usb_device *udev)
1190 {
1191 	struct usb_host_config	*config;
1192 	int			i;
1193 	struct usb_interface	*intf;
1194 	struct usb_driver	*drv;
1195 
1196 	config = udev->actconfig;
1197 	if (config) {
1198 		for (i = 0; i < config->desc.bNumInterfaces; ++i) {
1199 			intf = config->interface[i];
1200 
1201 			if (intf->dev.driver) {
1202 				drv = to_usb_driver(intf->dev.driver);
1203 				if (!drv->suspend || !drv->resume)
1204 					usb_forced_unbind_intf(intf);
1205 			}
1206 		}
1207 	}
1208 }
1209 
1210 static int usb_suspend_device(struct usb_device *udev, pm_message_t msg)
1211 {
1212 	struct usb_device_driver	*udriver;
1213 	int				status = 0;
1214 
1215 	if (udev->state == USB_STATE_NOTATTACHED ||
1216 			udev->state == USB_STATE_SUSPENDED)
1217 		goto done;
1218 
1219 	/* For devices that don't have a driver, we do a generic suspend. */
1220 	if (udev->dev.driver)
1221 		udriver = to_usb_device_driver(udev->dev.driver);
1222 	else {
1223 		udev->do_remote_wakeup = 0;
1224 		udriver = &usb_generic_driver;
1225 	}
1226 	if (udriver->suspend)
1227 		status = udriver->suspend(udev, msg);
1228 	if (status == 0 && udriver->generic_subclass)
1229 		status = usb_generic_driver_suspend(udev, msg);
1230 
1231  done:
1232 	dev_vdbg(&udev->dev, "%s: status %d\n", __func__, status);
1233 	return status;
1234 }
1235 
1236 static int usb_resume_device(struct usb_device *udev, pm_message_t msg)
1237 {
1238 	struct usb_device_driver	*udriver;
1239 	int				status = 0;
1240 
1241 	if (udev->state == USB_STATE_NOTATTACHED)
1242 		goto done;
1243 
1244 	/* Can't resume it if it doesn't have a driver. */
1245 	if (udev->dev.driver == NULL) {
1246 		status = -ENOTCONN;
1247 		goto done;
1248 	}
1249 
1250 	/* Non-root devices on a full/low-speed bus must wait for their
1251 	 * companion high-speed root hub, in case a handoff is needed.
1252 	 */
1253 	if (!PMSG_IS_AUTO(msg) && udev->parent && udev->bus->hs_companion)
1254 		device_pm_wait_for_dev(&udev->dev,
1255 				&udev->bus->hs_companion->root_hub->dev);
1256 
1257 	if (udev->quirks & USB_QUIRK_RESET_RESUME)
1258 		udev->reset_resume = 1;
1259 
1260 	udriver = to_usb_device_driver(udev->dev.driver);
1261 	if (udriver->generic_subclass)
1262 		status = usb_generic_driver_resume(udev, msg);
1263 	if (status == 0 && udriver->resume)
1264 		status = udriver->resume(udev, msg);
1265 
1266  done:
1267 	dev_vdbg(&udev->dev, "%s: status %d\n", __func__, status);
1268 	return status;
1269 }
1270 
1271 static int usb_suspend_interface(struct usb_device *udev,
1272 		struct usb_interface *intf, pm_message_t msg)
1273 {
1274 	struct usb_driver	*driver;
1275 	int			status = 0;
1276 
1277 	if (udev->state == USB_STATE_NOTATTACHED ||
1278 			intf->condition == USB_INTERFACE_UNBOUND)
1279 		goto done;
1280 	driver = to_usb_driver(intf->dev.driver);
1281 
1282 	/* at this time we know the driver supports suspend */
1283 	status = driver->suspend(intf, msg);
1284 	if (status && !PMSG_IS_AUTO(msg))
1285 		dev_err(&intf->dev, "suspend error %d\n", status);
1286 
1287  done:
1288 	dev_vdbg(&intf->dev, "%s: status %d\n", __func__, status);
1289 	return status;
1290 }
1291 
1292 static int usb_resume_interface(struct usb_device *udev,
1293 		struct usb_interface *intf, pm_message_t msg, int reset_resume)
1294 {
1295 	struct usb_driver	*driver;
1296 	int			status = 0;
1297 
1298 	if (udev->state == USB_STATE_NOTATTACHED)
1299 		goto done;
1300 
1301 	/* Don't let autoresume interfere with unbinding */
1302 	if (intf->condition == USB_INTERFACE_UNBINDING)
1303 		goto done;
1304 
1305 	/* Can't resume it if it doesn't have a driver. */
1306 	if (intf->condition == USB_INTERFACE_UNBOUND) {
1307 
1308 		/* Carry out a deferred switch to altsetting 0 */
1309 		if (intf->needs_altsetting0 && !intf->dev.power.is_prepared) {
1310 			usb_set_interface(udev, intf->altsetting[0].
1311 					desc.bInterfaceNumber, 0);
1312 			intf->needs_altsetting0 = 0;
1313 		}
1314 		goto done;
1315 	}
1316 
1317 	/* Don't resume if the interface is marked for rebinding */
1318 	if (intf->needs_binding)
1319 		goto done;
1320 	driver = to_usb_driver(intf->dev.driver);
1321 
1322 	if (reset_resume) {
1323 		if (driver->reset_resume) {
1324 			status = driver->reset_resume(intf);
1325 			if (status)
1326 				dev_err(&intf->dev, "%s error %d\n",
1327 						"reset_resume", status);
1328 		} else {
1329 			intf->needs_binding = 1;
1330 			dev_dbg(&intf->dev, "no reset_resume for driver %s?\n",
1331 					driver->name);
1332 		}
1333 	} else {
1334 		status = driver->resume(intf);
1335 		if (status)
1336 			dev_err(&intf->dev, "resume error %d\n", status);
1337 	}
1338 
1339 done:
1340 	dev_vdbg(&intf->dev, "%s: status %d\n", __func__, status);
1341 
1342 	/* Later we will unbind the driver and/or reprobe, if necessary */
1343 	return status;
1344 }
1345 
1346 /**
1347  * usb_suspend_both - suspend a USB device and its interfaces
1348  * @udev: the usb_device to suspend
1349  * @msg: Power Management message describing this state transition
1350  *
1351  * This is the central routine for suspending USB devices.  It calls the
1352  * suspend methods for all the interface drivers in @udev and then calls
1353  * the suspend method for @udev itself.  When the routine is called in
1354  * autosuspend, if an error occurs at any stage, all the interfaces
1355  * which were suspended are resumed so that they remain in the same
1356  * state as the device, but when called from system sleep, all error
1357  * from suspend methods of interfaces and the non-root-hub device itself
1358  * are simply ignored, so all suspended interfaces are only resumed
1359  * to the device's state when @udev is root-hub and its suspend method
1360  * returns failure.
1361  *
1362  * Autosuspend requests originating from a child device or an interface
1363  * driver may be made without the protection of @udev's device lock, but
1364  * all other suspend calls will hold the lock.  Usbcore will insure that
1365  * method calls do not arrive during bind, unbind, or reset operations.
1366  * However drivers must be prepared to handle suspend calls arriving at
1367  * unpredictable times.
1368  *
1369  * This routine can run only in process context.
1370  *
1371  * Return: 0 if the suspend succeeded.
1372  */
1373 static int usb_suspend_both(struct usb_device *udev, pm_message_t msg)
1374 {
1375 	int			status = 0;
1376 	int			i = 0, n = 0;
1377 	struct usb_interface	*intf;
1378 
1379 	if (udev->state == USB_STATE_NOTATTACHED ||
1380 			udev->state == USB_STATE_SUSPENDED)
1381 		goto done;
1382 
1383 	/* Suspend all the interfaces and then udev itself */
1384 	if (udev->actconfig) {
1385 		n = udev->actconfig->desc.bNumInterfaces;
1386 		for (i = n - 1; i >= 0; --i) {
1387 			intf = udev->actconfig->interface[i];
1388 			status = usb_suspend_interface(udev, intf, msg);
1389 
1390 			/* Ignore errors during system sleep transitions */
1391 			if (!PMSG_IS_AUTO(msg))
1392 				status = 0;
1393 			if (status != 0)
1394 				break;
1395 		}
1396 	}
1397 	if (status == 0) {
1398 		status = usb_suspend_device(udev, msg);
1399 
1400 		/*
1401 		 * Ignore errors from non-root-hub devices during
1402 		 * system sleep transitions.  For the most part,
1403 		 * these devices should go to low power anyway when
1404 		 * the entire bus is suspended.
1405 		 */
1406 		if (udev->parent && !PMSG_IS_AUTO(msg))
1407 			status = 0;
1408 
1409 		/*
1410 		 * If the device is inaccessible, don't try to resume
1411 		 * suspended interfaces and just return the error.
1412 		 */
1413 		if (status && status != -EBUSY) {
1414 			int err;
1415 			u16 devstat;
1416 
1417 			err = usb_get_std_status(udev, USB_RECIP_DEVICE, 0,
1418 						 &devstat);
1419 			if (err) {
1420 				dev_err(&udev->dev,
1421 					"Failed to suspend device, error %d\n",
1422 					status);
1423 				goto done;
1424 			}
1425 		}
1426 	}
1427 
1428 	/* If the suspend failed, resume interfaces that did get suspended */
1429 	if (status != 0) {
1430 		if (udev->actconfig) {
1431 			msg.event ^= (PM_EVENT_SUSPEND | PM_EVENT_RESUME);
1432 			while (++i < n) {
1433 				intf = udev->actconfig->interface[i];
1434 				usb_resume_interface(udev, intf, msg, 0);
1435 			}
1436 		}
1437 
1438 	/* If the suspend succeeded then prevent any more URB submissions
1439 	 * and flush any outstanding URBs.
1440 	 */
1441 	} else {
1442 		udev->can_submit = 0;
1443 		for (i = 0; i < 16; ++i) {
1444 			usb_hcd_flush_endpoint(udev, udev->ep_out[i]);
1445 			usb_hcd_flush_endpoint(udev, udev->ep_in[i]);
1446 		}
1447 	}
1448 
1449  done:
1450 	dev_vdbg(&udev->dev, "%s: status %d\n", __func__, status);
1451 	return status;
1452 }
1453 
1454 /**
1455  * usb_resume_both - resume a USB device and its interfaces
1456  * @udev: the usb_device to resume
1457  * @msg: Power Management message describing this state transition
1458  *
1459  * This is the central routine for resuming USB devices.  It calls the
1460  * the resume method for @udev and then calls the resume methods for all
1461  * the interface drivers in @udev.
1462  *
1463  * Autoresume requests originating from a child device or an interface
1464  * driver may be made without the protection of @udev's device lock, but
1465  * all other resume calls will hold the lock.  Usbcore will insure that
1466  * method calls do not arrive during bind, unbind, or reset operations.
1467  * However drivers must be prepared to handle resume calls arriving at
1468  * unpredictable times.
1469  *
1470  * This routine can run only in process context.
1471  *
1472  * Return: 0 on success.
1473  */
1474 static int usb_resume_both(struct usb_device *udev, pm_message_t msg)
1475 {
1476 	int			status = 0;
1477 	int			i;
1478 	struct usb_interface	*intf;
1479 
1480 	if (udev->state == USB_STATE_NOTATTACHED) {
1481 		status = -ENODEV;
1482 		goto done;
1483 	}
1484 	udev->can_submit = 1;
1485 
1486 	/* Resume the device */
1487 	if (udev->state == USB_STATE_SUSPENDED || udev->reset_resume)
1488 		status = usb_resume_device(udev, msg);
1489 
1490 	/* Resume the interfaces */
1491 	if (status == 0 && udev->actconfig) {
1492 		for (i = 0; i < udev->actconfig->desc.bNumInterfaces; i++) {
1493 			intf = udev->actconfig->interface[i];
1494 			usb_resume_interface(udev, intf, msg,
1495 					udev->reset_resume);
1496 		}
1497 	}
1498 	usb_mark_last_busy(udev);
1499 
1500  done:
1501 	dev_vdbg(&udev->dev, "%s: status %d\n", __func__, status);
1502 	if (!status)
1503 		udev->reset_resume = 0;
1504 	return status;
1505 }
1506 
1507 static void choose_wakeup(struct usb_device *udev, pm_message_t msg)
1508 {
1509 	int	w;
1510 
1511 	/* Remote wakeup is needed only when we actually go to sleep.
1512 	 * For things like FREEZE and QUIESCE, if the device is already
1513 	 * autosuspended then its current wakeup setting is okay.
1514 	 */
1515 	if (msg.event == PM_EVENT_FREEZE || msg.event == PM_EVENT_QUIESCE) {
1516 		if (udev->state != USB_STATE_SUSPENDED)
1517 			udev->do_remote_wakeup = 0;
1518 		return;
1519 	}
1520 
1521 	/* Enable remote wakeup if it is allowed, even if no interface drivers
1522 	 * actually want it.
1523 	 */
1524 	w = device_may_wakeup(&udev->dev);
1525 
1526 	/* If the device is autosuspended with the wrong wakeup setting,
1527 	 * autoresume now so the setting can be changed.
1528 	 */
1529 	if (udev->state == USB_STATE_SUSPENDED && w != udev->do_remote_wakeup)
1530 		pm_runtime_resume(&udev->dev);
1531 	udev->do_remote_wakeup = w;
1532 }
1533 
1534 /* The device lock is held by the PM core */
1535 int usb_suspend(struct device *dev, pm_message_t msg)
1536 {
1537 	struct usb_device	*udev = to_usb_device(dev);
1538 	int r;
1539 
1540 	unbind_no_pm_drivers_interfaces(udev);
1541 
1542 	/* From now on we are sure all drivers support suspend/resume
1543 	 * but not necessarily reset_resume()
1544 	 * so we may still need to unbind and rebind upon resume
1545 	 */
1546 	choose_wakeup(udev, msg);
1547 	r = usb_suspend_both(udev, msg);
1548 	if (r)
1549 		return r;
1550 
1551 	if (udev->quirks & USB_QUIRK_DISCONNECT_SUSPEND)
1552 		usb_port_disable(udev);
1553 
1554 	return 0;
1555 }
1556 
1557 /* The device lock is held by the PM core */
1558 int usb_resume_complete(struct device *dev)
1559 {
1560 	struct usb_device *udev = to_usb_device(dev);
1561 
1562 	/* For PM complete calls, all we do is rebind interfaces
1563 	 * whose needs_binding flag is set
1564 	 */
1565 	if (udev->state != USB_STATE_NOTATTACHED)
1566 		rebind_marked_interfaces(udev);
1567 	return 0;
1568 }
1569 
1570 /* The device lock is held by the PM core */
1571 int usb_resume(struct device *dev, pm_message_t msg)
1572 {
1573 	struct usb_device	*udev = to_usb_device(dev);
1574 	int			status;
1575 
1576 	/* For all calls, take the device back to full power and
1577 	 * tell the PM core in case it was autosuspended previously.
1578 	 * Unbind the interfaces that will need rebinding later,
1579 	 * because they fail to support reset_resume.
1580 	 * (This can't be done in usb_resume_interface()
1581 	 * above because it doesn't own the right set of locks.)
1582 	 */
1583 	status = usb_resume_both(udev, msg);
1584 	if (status == 0) {
1585 		pm_runtime_disable(dev);
1586 		pm_runtime_set_active(dev);
1587 		pm_runtime_enable(dev);
1588 		unbind_marked_interfaces(udev);
1589 	}
1590 
1591 	/* Avoid PM error messages for devices disconnected while suspended
1592 	 * as we'll display regular disconnect messages just a bit later.
1593 	 */
1594 	if (status == -ENODEV || status == -ESHUTDOWN)
1595 		status = 0;
1596 	return status;
1597 }
1598 
1599 /**
1600  * usb_enable_autosuspend - allow a USB device to be autosuspended
1601  * @udev: the USB device which may be autosuspended
1602  *
1603  * This routine allows @udev to be autosuspended.  An autosuspend won't
1604  * take place until the autosuspend_delay has elapsed and all the other
1605  * necessary conditions are satisfied.
1606  *
1607  * The caller must hold @udev's device lock.
1608  */
1609 void usb_enable_autosuspend(struct usb_device *udev)
1610 {
1611 	pm_runtime_allow(&udev->dev);
1612 }
1613 EXPORT_SYMBOL_GPL(usb_enable_autosuspend);
1614 
1615 /**
1616  * usb_disable_autosuspend - prevent a USB device from being autosuspended
1617  * @udev: the USB device which may not be autosuspended
1618  *
1619  * This routine prevents @udev from being autosuspended and wakes it up
1620  * if it is already autosuspended.
1621  *
1622  * The caller must hold @udev's device lock.
1623  */
1624 void usb_disable_autosuspend(struct usb_device *udev)
1625 {
1626 	pm_runtime_forbid(&udev->dev);
1627 }
1628 EXPORT_SYMBOL_GPL(usb_disable_autosuspend);
1629 
1630 /**
1631  * usb_autosuspend_device - delayed autosuspend of a USB device and its interfaces
1632  * @udev: the usb_device to autosuspend
1633  *
1634  * This routine should be called when a core subsystem is finished using
1635  * @udev and wants to allow it to autosuspend.  Examples would be when
1636  * @udev's device file in usbfs is closed or after a configuration change.
1637  *
1638  * @udev's usage counter is decremented; if it drops to 0 and all the
1639  * interfaces are inactive then a delayed autosuspend will be attempted.
1640  * The attempt may fail (see autosuspend_check()).
1641  *
1642  * The caller must hold @udev's device lock.
1643  *
1644  * This routine can run only in process context.
1645  */
1646 void usb_autosuspend_device(struct usb_device *udev)
1647 {
1648 	int	status;
1649 
1650 	usb_mark_last_busy(udev);
1651 	status = pm_runtime_put_sync_autosuspend(&udev->dev);
1652 	dev_vdbg(&udev->dev, "%s: cnt %d -> %d\n",
1653 			__func__, atomic_read(&udev->dev.power.usage_count),
1654 			status);
1655 }
1656 
1657 /**
1658  * usb_autoresume_device - immediately autoresume a USB device and its interfaces
1659  * @udev: the usb_device to autoresume
1660  *
1661  * This routine should be called when a core subsystem wants to use @udev
1662  * and needs to guarantee that it is not suspended.  No autosuspend will
1663  * occur until usb_autosuspend_device() is called.  (Note that this will
1664  * not prevent suspend events originating in the PM core.)  Examples would
1665  * be when @udev's device file in usbfs is opened or when a remote-wakeup
1666  * request is received.
1667  *
1668  * @udev's usage counter is incremented to prevent subsequent autosuspends.
1669  * However if the autoresume fails then the usage counter is re-decremented.
1670  *
1671  * The caller must hold @udev's device lock.
1672  *
1673  * This routine can run only in process context.
1674  *
1675  * Return: 0 on success. A negative error code otherwise.
1676  */
1677 int usb_autoresume_device(struct usb_device *udev)
1678 {
1679 	int	status;
1680 
1681 	status = pm_runtime_get_sync(&udev->dev);
1682 	if (status < 0)
1683 		pm_runtime_put_sync(&udev->dev);
1684 	dev_vdbg(&udev->dev, "%s: cnt %d -> %d\n",
1685 			__func__, atomic_read(&udev->dev.power.usage_count),
1686 			status);
1687 	if (status > 0)
1688 		status = 0;
1689 	return status;
1690 }
1691 
1692 /**
1693  * usb_autopm_put_interface - decrement a USB interface's PM-usage counter
1694  * @intf: the usb_interface whose counter should be decremented
1695  *
1696  * This routine should be called by an interface driver when it is
1697  * finished using @intf and wants to allow it to autosuspend.  A typical
1698  * example would be a character-device driver when its device file is
1699  * closed.
1700  *
1701  * The routine decrements @intf's usage counter.  When the counter reaches
1702  * 0, a delayed autosuspend request for @intf's device is attempted.  The
1703  * attempt may fail (see autosuspend_check()).
1704  *
1705  * This routine can run only in process context.
1706  */
1707 void usb_autopm_put_interface(struct usb_interface *intf)
1708 {
1709 	struct usb_device	*udev = interface_to_usbdev(intf);
1710 	int			status;
1711 
1712 	usb_mark_last_busy(udev);
1713 	status = pm_runtime_put_sync(&intf->dev);
1714 	dev_vdbg(&intf->dev, "%s: cnt %d -> %d\n",
1715 			__func__, atomic_read(&intf->dev.power.usage_count),
1716 			status);
1717 }
1718 EXPORT_SYMBOL_GPL(usb_autopm_put_interface);
1719 
1720 /**
1721  * usb_autopm_put_interface_async - decrement a USB interface's PM-usage counter
1722  * @intf: the usb_interface whose counter should be decremented
1723  *
1724  * This routine does much the same thing as usb_autopm_put_interface():
1725  * It decrements @intf's usage counter and schedules a delayed
1726  * autosuspend request if the counter is <= 0.  The difference is that it
1727  * does not perform any synchronization; callers should hold a private
1728  * lock and handle all synchronization issues themselves.
1729  *
1730  * Typically a driver would call this routine during an URB's completion
1731  * handler, if no more URBs were pending.
1732  *
1733  * This routine can run in atomic context.
1734  */
1735 void usb_autopm_put_interface_async(struct usb_interface *intf)
1736 {
1737 	struct usb_device	*udev = interface_to_usbdev(intf);
1738 	int			status;
1739 
1740 	usb_mark_last_busy(udev);
1741 	status = pm_runtime_put(&intf->dev);
1742 	dev_vdbg(&intf->dev, "%s: cnt %d -> %d\n",
1743 			__func__, atomic_read(&intf->dev.power.usage_count),
1744 			status);
1745 }
1746 EXPORT_SYMBOL_GPL(usb_autopm_put_interface_async);
1747 
1748 /**
1749  * usb_autopm_put_interface_no_suspend - decrement a USB interface's PM-usage counter
1750  * @intf: the usb_interface whose counter should be decremented
1751  *
1752  * This routine decrements @intf's usage counter but does not carry out an
1753  * autosuspend.
1754  *
1755  * This routine can run in atomic context.
1756  */
1757 void usb_autopm_put_interface_no_suspend(struct usb_interface *intf)
1758 {
1759 	struct usb_device	*udev = interface_to_usbdev(intf);
1760 
1761 	usb_mark_last_busy(udev);
1762 	pm_runtime_put_noidle(&intf->dev);
1763 }
1764 EXPORT_SYMBOL_GPL(usb_autopm_put_interface_no_suspend);
1765 
1766 /**
1767  * usb_autopm_get_interface - increment a USB interface's PM-usage counter
1768  * @intf: the usb_interface whose counter should be incremented
1769  *
1770  * This routine should be called by an interface driver when it wants to
1771  * use @intf and needs to guarantee that it is not suspended.  In addition,
1772  * the routine prevents @intf from being autosuspended subsequently.  (Note
1773  * that this will not prevent suspend events originating in the PM core.)
1774  * This prevention will persist until usb_autopm_put_interface() is called
1775  * or @intf is unbound.  A typical example would be a character-device
1776  * driver when its device file is opened.
1777  *
1778  * @intf's usage counter is incremented to prevent subsequent autosuspends.
1779  * However if the autoresume fails then the counter is re-decremented.
1780  *
1781  * This routine can run only in process context.
1782  *
1783  * Return: 0 on success.
1784  */
1785 int usb_autopm_get_interface(struct usb_interface *intf)
1786 {
1787 	int	status;
1788 
1789 	status = pm_runtime_get_sync(&intf->dev);
1790 	if (status < 0)
1791 		pm_runtime_put_sync(&intf->dev);
1792 	dev_vdbg(&intf->dev, "%s: cnt %d -> %d\n",
1793 			__func__, atomic_read(&intf->dev.power.usage_count),
1794 			status);
1795 	if (status > 0)
1796 		status = 0;
1797 	return status;
1798 }
1799 EXPORT_SYMBOL_GPL(usb_autopm_get_interface);
1800 
1801 /**
1802  * usb_autopm_get_interface_async - increment a USB interface's PM-usage counter
1803  * @intf: the usb_interface whose counter should be incremented
1804  *
1805  * This routine does much the same thing as
1806  * usb_autopm_get_interface(): It increments @intf's usage counter and
1807  * queues an autoresume request if the device is suspended.  The
1808  * differences are that it does not perform any synchronization (callers
1809  * should hold a private lock and handle all synchronization issues
1810  * themselves), and it does not autoresume the device directly (it only
1811  * queues a request).  After a successful call, the device may not yet be
1812  * resumed.
1813  *
1814  * This routine can run in atomic context.
1815  *
1816  * Return: 0 on success. A negative error code otherwise.
1817  */
1818 int usb_autopm_get_interface_async(struct usb_interface *intf)
1819 {
1820 	int	status;
1821 
1822 	status = pm_runtime_get(&intf->dev);
1823 	if (status < 0 && status != -EINPROGRESS)
1824 		pm_runtime_put_noidle(&intf->dev);
1825 	dev_vdbg(&intf->dev, "%s: cnt %d -> %d\n",
1826 			__func__, atomic_read(&intf->dev.power.usage_count),
1827 			status);
1828 	if (status > 0 || status == -EINPROGRESS)
1829 		status = 0;
1830 	return status;
1831 }
1832 EXPORT_SYMBOL_GPL(usb_autopm_get_interface_async);
1833 
1834 /**
1835  * usb_autopm_get_interface_no_resume - increment a USB interface's PM-usage counter
1836  * @intf: the usb_interface whose counter should be incremented
1837  *
1838  * This routine increments @intf's usage counter but does not carry out an
1839  * autoresume.
1840  *
1841  * This routine can run in atomic context.
1842  */
1843 void usb_autopm_get_interface_no_resume(struct usb_interface *intf)
1844 {
1845 	struct usb_device	*udev = interface_to_usbdev(intf);
1846 
1847 	usb_mark_last_busy(udev);
1848 	pm_runtime_get_noresume(&intf->dev);
1849 }
1850 EXPORT_SYMBOL_GPL(usb_autopm_get_interface_no_resume);
1851 
1852 /* Internal routine to check whether we may autosuspend a device. */
1853 static int autosuspend_check(struct usb_device *udev)
1854 {
1855 	int			w, i;
1856 	struct usb_interface	*intf;
1857 
1858 	if (udev->state == USB_STATE_NOTATTACHED)
1859 		return -ENODEV;
1860 
1861 	/* Fail if autosuspend is disabled, or any interfaces are in use, or
1862 	 * any interface drivers require remote wakeup but it isn't available.
1863 	 */
1864 	w = 0;
1865 	if (udev->actconfig) {
1866 		for (i = 0; i < udev->actconfig->desc.bNumInterfaces; i++) {
1867 			intf = udev->actconfig->interface[i];
1868 
1869 			/* We don't need to check interfaces that are
1870 			 * disabled for runtime PM.  Either they are unbound
1871 			 * or else their drivers don't support autosuspend
1872 			 * and so they are permanently active.
1873 			 */
1874 			if (intf->dev.power.disable_depth)
1875 				continue;
1876 			if (atomic_read(&intf->dev.power.usage_count) > 0)
1877 				return -EBUSY;
1878 			w |= intf->needs_remote_wakeup;
1879 
1880 			/* Don't allow autosuspend if the device will need
1881 			 * a reset-resume and any of its interface drivers
1882 			 * doesn't include support or needs remote wakeup.
1883 			 */
1884 			if (udev->quirks & USB_QUIRK_RESET_RESUME) {
1885 				struct usb_driver *driver;
1886 
1887 				driver = to_usb_driver(intf->dev.driver);
1888 				if (!driver->reset_resume ||
1889 						intf->needs_remote_wakeup)
1890 					return -EOPNOTSUPP;
1891 			}
1892 		}
1893 	}
1894 	if (w && !device_can_wakeup(&udev->dev)) {
1895 		dev_dbg(&udev->dev, "remote wakeup needed for autosuspend\n");
1896 		return -EOPNOTSUPP;
1897 	}
1898 
1899 	/*
1900 	 * If the device is a direct child of the root hub and the HCD
1901 	 * doesn't handle wakeup requests, don't allow autosuspend when
1902 	 * wakeup is needed.
1903 	 */
1904 	if (w && udev->parent == udev->bus->root_hub &&
1905 			bus_to_hcd(udev->bus)->cant_recv_wakeups) {
1906 		dev_dbg(&udev->dev, "HCD doesn't handle wakeup requests\n");
1907 		return -EOPNOTSUPP;
1908 	}
1909 
1910 	udev->do_remote_wakeup = w;
1911 	return 0;
1912 }
1913 
1914 int usb_runtime_suspend(struct device *dev)
1915 {
1916 	struct usb_device	*udev = to_usb_device(dev);
1917 	int			status;
1918 
1919 	/* A USB device can be suspended if it passes the various autosuspend
1920 	 * checks.  Runtime suspend for a USB device means suspending all the
1921 	 * interfaces and then the device itself.
1922 	 */
1923 	if (autosuspend_check(udev) != 0)
1924 		return -EAGAIN;
1925 
1926 	status = usb_suspend_both(udev, PMSG_AUTO_SUSPEND);
1927 
1928 	/* Allow a retry if autosuspend failed temporarily */
1929 	if (status == -EAGAIN || status == -EBUSY)
1930 		usb_mark_last_busy(udev);
1931 
1932 	/*
1933 	 * The PM core reacts badly unless the return code is 0,
1934 	 * -EAGAIN, or -EBUSY, so always return -EBUSY on an error
1935 	 * (except for root hubs, because they don't suspend through
1936 	 * an upstream port like other USB devices).
1937 	 */
1938 	if (status != 0 && udev->parent)
1939 		return -EBUSY;
1940 	return status;
1941 }
1942 
1943 int usb_runtime_resume(struct device *dev)
1944 {
1945 	struct usb_device	*udev = to_usb_device(dev);
1946 	int			status;
1947 
1948 	/* Runtime resume for a USB device means resuming both the device
1949 	 * and all its interfaces.
1950 	 */
1951 	status = usb_resume_both(udev, PMSG_AUTO_RESUME);
1952 	return status;
1953 }
1954 
1955 int usb_runtime_idle(struct device *dev)
1956 {
1957 	struct usb_device	*udev = to_usb_device(dev);
1958 
1959 	/* An idle USB device can be suspended if it passes the various
1960 	 * autosuspend checks.
1961 	 */
1962 	if (autosuspend_check(udev) == 0)
1963 		pm_runtime_autosuspend(dev);
1964 	/* Tell the core not to suspend it, though. */
1965 	return -EBUSY;
1966 }
1967 
1968 static int usb_set_usb2_hardware_lpm(struct usb_device *udev, int enable)
1969 {
1970 	struct usb_hcd *hcd = bus_to_hcd(udev->bus);
1971 	int ret = -EPERM;
1972 
1973 	if (hcd->driver->set_usb2_hw_lpm) {
1974 		ret = hcd->driver->set_usb2_hw_lpm(hcd, udev, enable);
1975 		if (!ret)
1976 			udev->usb2_hw_lpm_enabled = enable;
1977 	}
1978 
1979 	return ret;
1980 }
1981 
1982 int usb_enable_usb2_hardware_lpm(struct usb_device *udev)
1983 {
1984 	if (!udev->usb2_hw_lpm_capable ||
1985 	    !udev->usb2_hw_lpm_allowed ||
1986 	    udev->usb2_hw_lpm_enabled)
1987 		return 0;
1988 
1989 	return usb_set_usb2_hardware_lpm(udev, 1);
1990 }
1991 
1992 int usb_disable_usb2_hardware_lpm(struct usb_device *udev)
1993 {
1994 	if (!udev->usb2_hw_lpm_enabled)
1995 		return 0;
1996 
1997 	return usb_set_usb2_hardware_lpm(udev, 0);
1998 }
1999 
2000 #endif /* CONFIG_PM */
2001 
2002 struct bus_type usb_bus_type = {
2003 	.name =		"usb",
2004 	.match =	usb_device_match,
2005 	.uevent =	usb_uevent,
2006 	.need_parent_lock =	true,
2007 };
2008