xref: /openbmc/linux/drivers/usb/core/driver.c (revision 9d11b134)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * drivers/usb/core/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  */
usb_store_new_id(struct usb_dynids * dynids,const struct usb_device_id * id_table,struct device_driver * driver,const char * buf,size_t count)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 
usb_show_dynids(struct usb_dynids * dynids,char * buf)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 
new_id_show(struct device_driver * driver,char * buf)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 
new_id_store(struct device_driver * driver,const char * buf,size_t count)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  */
remove_id_store(struct device_driver * driver,const char * buf,size_t count)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 
remove_id_show(struct device_driver * driver,char * buf)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 
usb_create_newid_files(struct usb_driver * usb_drv)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 
usb_remove_newid_files(struct usb_driver * usb_drv)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 
usb_free_dynids(struct usb_driver * usb_drv)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 
usb_match_dynamic_id(struct usb_interface * intf,struct usb_driver * drv)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 */
usb_probe_device(struct device * dev)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 	/* Probe the USB device with the driver in hand, but only
273 	 * defer to a generic driver in case the current USB
274 	 * device driver has an id_table or a match function; i.e.,
275 	 * when the device driver was explicitly matched against
276 	 * a device.
277 	 *
278 	 * If the device driver does not have either of these,
279 	 * then we assume that it can bind to any device and is
280 	 * not truly a more specialized/non-generic driver, so a
281 	 * return value of -ENODEV should not force the device
282 	 * to be handled by the generic USB driver, as there
283 	 * can still be another, more specialized, device driver.
284 	 *
285 	 * This accommodates the usbip driver.
286 	 *
287 	 * TODO: What if, in the future, there are multiple
288 	 * specialized USB device drivers for a particular device?
289 	 * In such cases, there is a need to try all matching
290 	 * specialised device drivers prior to setting the
291 	 * use_generic_driver bit.
292 	 */
293 	error = udriver->probe(udev);
294 	if (error == -ENODEV && udriver != &usb_generic_driver &&
295 	    (udriver->id_table || udriver->match)) {
296 		udev->use_generic_driver = 1;
297 		return -EPROBE_DEFER;
298 	}
299 	return error;
300 }
301 
302 /* called from driver core with dev locked */
usb_unbind_device(struct device * dev)303 static int usb_unbind_device(struct device *dev)
304 {
305 	struct usb_device *udev = to_usb_device(dev);
306 	struct usb_device_driver *udriver = to_usb_device_driver(dev->driver);
307 
308 	if (udriver->disconnect)
309 		udriver->disconnect(udev);
310 	if (udriver->generic_subclass)
311 		usb_generic_driver_disconnect(udev);
312 	if (!udriver->supports_autosuspend)
313 		usb_autosuspend_device(udev);
314 	return 0;
315 }
316 
317 /* called from driver core with dev locked */
usb_probe_interface(struct device * dev)318 static int usb_probe_interface(struct device *dev)
319 {
320 	struct usb_driver *driver = to_usb_driver(dev->driver);
321 	struct usb_interface *intf = to_usb_interface(dev);
322 	struct usb_device *udev = interface_to_usbdev(intf);
323 	const struct usb_device_id *id;
324 	int error = -ENODEV;
325 	int lpm_disable_error = -ENODEV;
326 
327 	dev_dbg(dev, "%s\n", __func__);
328 
329 	intf->needs_binding = 0;
330 
331 	if (usb_device_is_owned(udev))
332 		return error;
333 
334 	if (udev->authorized == 0) {
335 		dev_err(&intf->dev, "Device is not authorized for usage\n");
336 		return error;
337 	} else if (intf->authorized == 0) {
338 		dev_err(&intf->dev, "Interface %d is not authorized for usage\n",
339 				intf->altsetting->desc.bInterfaceNumber);
340 		return error;
341 	}
342 
343 	id = usb_match_dynamic_id(intf, driver);
344 	if (!id)
345 		id = usb_match_id(intf, driver->id_table);
346 	if (!id)
347 		return error;
348 
349 	dev_dbg(dev, "%s - got id\n", __func__);
350 
351 	error = usb_autoresume_device(udev);
352 	if (error)
353 		return error;
354 
355 	intf->condition = USB_INTERFACE_BINDING;
356 
357 	/* Probed interfaces are initially active.  They are
358 	 * runtime-PM-enabled only if the driver has autosuspend support.
359 	 * They are sensitive to their children's power states.
360 	 */
361 	pm_runtime_set_active(dev);
362 	pm_suspend_ignore_children(dev, false);
363 	if (driver->supports_autosuspend)
364 		pm_runtime_enable(dev);
365 
366 	/* If the new driver doesn't allow hub-initiated LPM, and we can't
367 	 * disable hub-initiated LPM, then fail the probe.
368 	 *
369 	 * Otherwise, leaving LPM enabled should be harmless, because the
370 	 * endpoint intervals should remain the same, and the U1/U2 timeouts
371 	 * should remain the same.
372 	 *
373 	 * If we need to install alt setting 0 before probe, or another alt
374 	 * setting during probe, that should also be fine.  usb_set_interface()
375 	 * will attempt to disable LPM, and fail if it can't disable it.
376 	 */
377 	if (driver->disable_hub_initiated_lpm) {
378 		lpm_disable_error = usb_unlocked_disable_lpm(udev);
379 		if (lpm_disable_error) {
380 			dev_err(&intf->dev, "%s Failed to disable LPM for driver %s\n",
381 				__func__, driver->name);
382 			error = lpm_disable_error;
383 			goto err;
384 		}
385 	}
386 
387 	/* Carry out a deferred switch to altsetting 0 */
388 	if (intf->needs_altsetting0) {
389 		error = usb_set_interface(udev, intf->altsetting[0].
390 				desc.bInterfaceNumber, 0);
391 		if (error < 0)
392 			goto err;
393 		intf->needs_altsetting0 = 0;
394 	}
395 
396 	error = driver->probe(intf, id);
397 	if (error)
398 		goto err;
399 
400 	intf->condition = USB_INTERFACE_BOUND;
401 
402 	/* If the LPM disable succeeded, balance the ref counts. */
403 	if (!lpm_disable_error)
404 		usb_unlocked_enable_lpm(udev);
405 
406 	usb_autosuspend_device(udev);
407 	return error;
408 
409  err:
410 	usb_set_intfdata(intf, NULL);
411 	intf->needs_remote_wakeup = 0;
412 	intf->condition = USB_INTERFACE_UNBOUND;
413 
414 	/* If the LPM disable succeeded, balance the ref counts. */
415 	if (!lpm_disable_error)
416 		usb_unlocked_enable_lpm(udev);
417 
418 	/* Unbound interfaces are always runtime-PM-disabled and -suspended */
419 	if (driver->supports_autosuspend)
420 		pm_runtime_disable(dev);
421 	pm_runtime_set_suspended(dev);
422 
423 	usb_autosuspend_device(udev);
424 	return error;
425 }
426 
427 /* called from driver core with dev locked */
usb_unbind_interface(struct device * dev)428 static int usb_unbind_interface(struct device *dev)
429 {
430 	struct usb_driver *driver = to_usb_driver(dev->driver);
431 	struct usb_interface *intf = to_usb_interface(dev);
432 	struct usb_host_endpoint *ep, **eps = NULL;
433 	struct usb_device *udev;
434 	int i, j, error, r;
435 	int lpm_disable_error = -ENODEV;
436 
437 	intf->condition = USB_INTERFACE_UNBINDING;
438 
439 	/* Autoresume for set_interface call below */
440 	udev = interface_to_usbdev(intf);
441 	error = usb_autoresume_device(udev);
442 
443 	/* If hub-initiated LPM policy may change, attempt to disable LPM until
444 	 * the driver is unbound.  If LPM isn't disabled, that's fine because it
445 	 * wouldn't be enabled unless all the bound interfaces supported
446 	 * hub-initiated LPM.
447 	 */
448 	if (driver->disable_hub_initiated_lpm)
449 		lpm_disable_error = usb_unlocked_disable_lpm(udev);
450 
451 	/*
452 	 * Terminate all URBs for this interface unless the driver
453 	 * supports "soft" unbinding and the device is still present.
454 	 */
455 	if (!driver->soft_unbind || udev->state == USB_STATE_NOTATTACHED)
456 		usb_disable_interface(udev, intf, false);
457 
458 	driver->disconnect(intf);
459 
460 	/* Free streams */
461 	for (i = 0, j = 0; i < intf->cur_altsetting->desc.bNumEndpoints; i++) {
462 		ep = &intf->cur_altsetting->endpoint[i];
463 		if (ep->streams == 0)
464 			continue;
465 		if (j == 0) {
466 			eps = kmalloc_array(USB_MAXENDPOINTS, sizeof(void *),
467 				      GFP_KERNEL);
468 			if (!eps)
469 				break;
470 		}
471 		eps[j++] = ep;
472 	}
473 	if (j) {
474 		usb_free_streams(intf, eps, j, GFP_KERNEL);
475 		kfree(eps);
476 	}
477 
478 	/* Reset other interface state.
479 	 * We cannot do a Set-Interface if the device is suspended or
480 	 * if it is prepared for a system sleep (since installing a new
481 	 * altsetting means creating new endpoint device entries).
482 	 * When either of these happens, defer the Set-Interface.
483 	 */
484 	if (intf->cur_altsetting->desc.bAlternateSetting == 0) {
485 		/* Already in altsetting 0 so skip Set-Interface.
486 		 * Just re-enable it without affecting the endpoint toggles.
487 		 */
488 		usb_enable_interface(udev, intf, false);
489 	} else if (!error && !intf->dev.power.is_prepared) {
490 		r = usb_set_interface(udev, intf->altsetting[0].
491 				desc.bInterfaceNumber, 0);
492 		if (r < 0)
493 			intf->needs_altsetting0 = 1;
494 	} else {
495 		intf->needs_altsetting0 = 1;
496 	}
497 	usb_set_intfdata(intf, NULL);
498 
499 	intf->condition = USB_INTERFACE_UNBOUND;
500 	intf->needs_remote_wakeup = 0;
501 
502 	/* Attempt to re-enable USB3 LPM, if the disable succeeded. */
503 	if (!lpm_disable_error)
504 		usb_unlocked_enable_lpm(udev);
505 
506 	/* Unbound interfaces are always runtime-PM-disabled and -suspended */
507 	if (driver->supports_autosuspend)
508 		pm_runtime_disable(dev);
509 	pm_runtime_set_suspended(dev);
510 
511 	if (!error)
512 		usb_autosuspend_device(udev);
513 
514 	return 0;
515 }
516 
517 /**
518  * usb_driver_claim_interface - bind a driver to an interface
519  * @driver: the driver to be bound
520  * @iface: the interface to which it will be bound; must be in the
521  *	usb device's active configuration
522  * @data: driver data associated with that interface
523  *
524  * This is used by usb device drivers that need to claim more than one
525  * interface on a device when probing (audio and acm are current examples).
526  * No device driver should directly modify internal usb_interface or
527  * usb_device structure members.
528  *
529  * Callers must own the device lock, so driver probe() entries don't need
530  * extra locking, but other call contexts may need to explicitly claim that
531  * lock.
532  *
533  * Return: 0 on success.
534  */
usb_driver_claim_interface(struct usb_driver * driver,struct usb_interface * iface,void * data)535 int usb_driver_claim_interface(struct usb_driver *driver,
536 				struct usb_interface *iface, void *data)
537 {
538 	struct device *dev;
539 	int retval = 0;
540 
541 	if (!iface)
542 		return -ENODEV;
543 
544 	dev = &iface->dev;
545 	if (dev->driver)
546 		return -EBUSY;
547 
548 	/* reject claim if interface is not authorized */
549 	if (!iface->authorized)
550 		return -ENODEV;
551 
552 	dev->driver = &driver->drvwrap.driver;
553 	usb_set_intfdata(iface, data);
554 	iface->needs_binding = 0;
555 
556 	iface->condition = USB_INTERFACE_BOUND;
557 
558 	/* Claimed interfaces are initially inactive (suspended) and
559 	 * runtime-PM-enabled, but only if the driver has autosuspend
560 	 * support.  Otherwise they are marked active, to prevent the
561 	 * device from being autosuspended, but left disabled.  In either
562 	 * case they are sensitive to their children's power states.
563 	 */
564 	pm_suspend_ignore_children(dev, false);
565 	if (driver->supports_autosuspend)
566 		pm_runtime_enable(dev);
567 	else
568 		pm_runtime_set_active(dev);
569 
570 	/* if interface was already added, bind now; else let
571 	 * the future device_add() bind it, bypassing probe()
572 	 */
573 	if (device_is_registered(dev))
574 		retval = device_bind_driver(dev);
575 
576 	if (retval) {
577 		dev->driver = NULL;
578 		usb_set_intfdata(iface, NULL);
579 		iface->needs_remote_wakeup = 0;
580 		iface->condition = USB_INTERFACE_UNBOUND;
581 
582 		/*
583 		 * Unbound interfaces are always runtime-PM-disabled
584 		 * and runtime-PM-suspended
585 		 */
586 		if (driver->supports_autosuspend)
587 			pm_runtime_disable(dev);
588 		pm_runtime_set_suspended(dev);
589 	}
590 
591 	return retval;
592 }
593 EXPORT_SYMBOL_GPL(usb_driver_claim_interface);
594 
595 /**
596  * usb_driver_release_interface - unbind a driver from an interface
597  * @driver: the driver to be unbound
598  * @iface: the interface from which it will be unbound
599  *
600  * This can be used by drivers to release an interface without waiting
601  * for their disconnect() methods to be called.  In typical cases this
602  * also causes the driver disconnect() method to be called.
603  *
604  * This call is synchronous, and may not be used in an interrupt context.
605  * Callers must own the device lock, so driver disconnect() entries don't
606  * need extra locking, but other call contexts may need to explicitly claim
607  * that lock.
608  */
usb_driver_release_interface(struct usb_driver * driver,struct usb_interface * iface)609 void usb_driver_release_interface(struct usb_driver *driver,
610 					struct usb_interface *iface)
611 {
612 	struct device *dev = &iface->dev;
613 
614 	/* this should never happen, don't release something that's not ours */
615 	if (!dev->driver || dev->driver != &driver->drvwrap.driver)
616 		return;
617 
618 	/* don't release from within disconnect() */
619 	if (iface->condition != USB_INTERFACE_BOUND)
620 		return;
621 	iface->condition = USB_INTERFACE_UNBINDING;
622 
623 	/* Release via the driver core only if the interface
624 	 * has already been registered
625 	 */
626 	if (device_is_registered(dev)) {
627 		device_release_driver(dev);
628 	} else {
629 		device_lock(dev);
630 		usb_unbind_interface(dev);
631 		dev->driver = NULL;
632 		device_unlock(dev);
633 	}
634 }
635 EXPORT_SYMBOL_GPL(usb_driver_release_interface);
636 
637 /* returns 0 if no match, 1 if match */
usb_match_device(struct usb_device * dev,const struct usb_device_id * id)638 int usb_match_device(struct usb_device *dev, const struct usb_device_id *id)
639 {
640 	if ((id->match_flags & USB_DEVICE_ID_MATCH_VENDOR) &&
641 	    id->idVendor != le16_to_cpu(dev->descriptor.idVendor))
642 		return 0;
643 
644 	if ((id->match_flags & USB_DEVICE_ID_MATCH_PRODUCT) &&
645 	    id->idProduct != le16_to_cpu(dev->descriptor.idProduct))
646 		return 0;
647 
648 	/* No need to test id->bcdDevice_lo != 0, since 0 is never
649 	   greater than any unsigned number. */
650 	if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_LO) &&
651 	    (id->bcdDevice_lo > le16_to_cpu(dev->descriptor.bcdDevice)))
652 		return 0;
653 
654 	if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_HI) &&
655 	    (id->bcdDevice_hi < le16_to_cpu(dev->descriptor.bcdDevice)))
656 		return 0;
657 
658 	if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_CLASS) &&
659 	    (id->bDeviceClass != dev->descriptor.bDeviceClass))
660 		return 0;
661 
662 	if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_SUBCLASS) &&
663 	    (id->bDeviceSubClass != dev->descriptor.bDeviceSubClass))
664 		return 0;
665 
666 	if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_PROTOCOL) &&
667 	    (id->bDeviceProtocol != dev->descriptor.bDeviceProtocol))
668 		return 0;
669 
670 	return 1;
671 }
672 
673 /* returns 0 if no match, 1 if match */
usb_match_one_id_intf(struct usb_device * dev,struct usb_host_interface * intf,const struct usb_device_id * id)674 int usb_match_one_id_intf(struct usb_device *dev,
675 			  struct usb_host_interface *intf,
676 			  const struct usb_device_id *id)
677 {
678 	/* The interface class, subclass, protocol and number should never be
679 	 * checked for a match if the device class is Vendor Specific,
680 	 * unless the match record specifies the Vendor ID. */
681 	if (dev->descriptor.bDeviceClass == USB_CLASS_VENDOR_SPEC &&
682 			!(id->match_flags & USB_DEVICE_ID_MATCH_VENDOR) &&
683 			(id->match_flags & (USB_DEVICE_ID_MATCH_INT_CLASS |
684 				USB_DEVICE_ID_MATCH_INT_SUBCLASS |
685 				USB_DEVICE_ID_MATCH_INT_PROTOCOL |
686 				USB_DEVICE_ID_MATCH_INT_NUMBER)))
687 		return 0;
688 
689 	if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_CLASS) &&
690 	    (id->bInterfaceClass != intf->desc.bInterfaceClass))
691 		return 0;
692 
693 	if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_SUBCLASS) &&
694 	    (id->bInterfaceSubClass != intf->desc.bInterfaceSubClass))
695 		return 0;
696 
697 	if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_PROTOCOL) &&
698 	    (id->bInterfaceProtocol != intf->desc.bInterfaceProtocol))
699 		return 0;
700 
701 	if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_NUMBER) &&
702 	    (id->bInterfaceNumber != intf->desc.bInterfaceNumber))
703 		return 0;
704 
705 	return 1;
706 }
707 
708 /* returns 0 if no match, 1 if match */
usb_match_one_id(struct usb_interface * interface,const struct usb_device_id * id)709 int usb_match_one_id(struct usb_interface *interface,
710 		     const struct usb_device_id *id)
711 {
712 	struct usb_host_interface *intf;
713 	struct usb_device *dev;
714 
715 	/* proc_connectinfo in devio.c may call us with id == NULL. */
716 	if (id == NULL)
717 		return 0;
718 
719 	intf = interface->cur_altsetting;
720 	dev = interface_to_usbdev(interface);
721 
722 	if (!usb_match_device(dev, id))
723 		return 0;
724 
725 	return usb_match_one_id_intf(dev, intf, id);
726 }
727 EXPORT_SYMBOL_GPL(usb_match_one_id);
728 
729 /**
730  * usb_match_id - find first usb_device_id matching device or interface
731  * @interface: the interface of interest
732  * @id: array of usb_device_id structures, terminated by zero entry
733  *
734  * usb_match_id searches an array of usb_device_id's and returns
735  * the first one matching the device or interface, or null.
736  * This is used when binding (or rebinding) a driver to an interface.
737  * Most USB device drivers will use this indirectly, through the usb core,
738  * but some layered driver frameworks use it directly.
739  * These device tables are exported with MODULE_DEVICE_TABLE, through
740  * modutils, to support the driver loading functionality of USB hotplugging.
741  *
742  * Return: The first matching usb_device_id, or %NULL.
743  *
744  * What Matches:
745  *
746  * The "match_flags" element in a usb_device_id controls which
747  * members are used.  If the corresponding bit is set, the
748  * value in the device_id must match its corresponding member
749  * in the device or interface descriptor, or else the device_id
750  * does not match.
751  *
752  * "driver_info" is normally used only by device drivers,
753  * but you can create a wildcard "matches anything" usb_device_id
754  * as a driver's "modules.usbmap" entry if you provide an id with
755  * only a nonzero "driver_info" field.  If you do this, the USB device
756  * driver's probe() routine should use additional intelligence to
757  * decide whether to bind to the specified interface.
758  *
759  * What Makes Good usb_device_id Tables:
760  *
761  * The match algorithm is very simple, so that intelligence in
762  * driver selection must come from smart driver id records.
763  * Unless you have good reasons to use another selection policy,
764  * provide match elements only in related groups, and order match
765  * specifiers from specific to general.  Use the macros provided
766  * for that purpose if you can.
767  *
768  * The most specific match specifiers use device descriptor
769  * data.  These are commonly used with product-specific matches;
770  * the USB_DEVICE macro lets you provide vendor and product IDs,
771  * and you can also match against ranges of product revisions.
772  * These are widely used for devices with application or vendor
773  * specific bDeviceClass values.
774  *
775  * Matches based on device class/subclass/protocol specifications
776  * are slightly more general; use the USB_DEVICE_INFO macro, or
777  * its siblings.  These are used with single-function devices
778  * where bDeviceClass doesn't specify that each interface has
779  * its own class.
780  *
781  * Matches based on interface class/subclass/protocol are the
782  * most general; they let drivers bind to any interface on a
783  * multiple-function device.  Use the USB_INTERFACE_INFO
784  * macro, or its siblings, to match class-per-interface style
785  * devices (as recorded in bInterfaceClass).
786  *
787  * Note that an entry created by USB_INTERFACE_INFO won't match
788  * any interface if the device class is set to Vendor-Specific.
789  * This is deliberate; according to the USB spec the meanings of
790  * the interface class/subclass/protocol for these devices are also
791  * vendor-specific, and hence matching against a standard product
792  * class wouldn't work anyway.  If you really want to use an
793  * interface-based match for such a device, create a match record
794  * that also specifies the vendor ID.  (Unforunately there isn't a
795  * standard macro for creating records like this.)
796  *
797  * Within those groups, remember that not all combinations are
798  * meaningful.  For example, don't give a product version range
799  * without vendor and product IDs; or specify a protocol without
800  * its associated class and subclass.
801  */
usb_match_id(struct usb_interface * interface,const struct usb_device_id * id)802 const struct usb_device_id *usb_match_id(struct usb_interface *interface,
803 					 const struct usb_device_id *id)
804 {
805 	/* proc_connectinfo in devio.c may call us with id == NULL. */
806 	if (id == NULL)
807 		return NULL;
808 
809 	/* It is important to check that id->driver_info is nonzero,
810 	   since an entry that is all zeroes except for a nonzero
811 	   id->driver_info is the way to create an entry that
812 	   indicates that the driver want to examine every
813 	   device and interface. */
814 	for (; id->idVendor || id->idProduct || id->bDeviceClass ||
815 	       id->bInterfaceClass || id->driver_info; id++) {
816 		if (usb_match_one_id(interface, id))
817 			return id;
818 	}
819 
820 	return NULL;
821 }
822 EXPORT_SYMBOL_GPL(usb_match_id);
823 
usb_device_match_id(struct usb_device * udev,const struct usb_device_id * id)824 const struct usb_device_id *usb_device_match_id(struct usb_device *udev,
825 				const struct usb_device_id *id)
826 {
827 	if (!id)
828 		return NULL;
829 
830 	for (; id->idVendor || id->idProduct ; id++) {
831 		if (usb_match_device(udev, id))
832 			return id;
833 	}
834 
835 	return NULL;
836 }
837 EXPORT_SYMBOL_GPL(usb_device_match_id);
838 
usb_driver_applicable(struct usb_device * udev,struct usb_device_driver * udrv)839 bool usb_driver_applicable(struct usb_device *udev,
840 			   struct usb_device_driver *udrv)
841 {
842 	if (udrv->id_table && udrv->match)
843 		return usb_device_match_id(udev, udrv->id_table) != NULL &&
844 		       udrv->match(udev);
845 
846 	if (udrv->id_table)
847 		return usb_device_match_id(udev, udrv->id_table) != NULL;
848 
849 	if (udrv->match)
850 		return udrv->match(udev);
851 
852 	return false;
853 }
854 
usb_device_match(struct device * dev,struct device_driver * drv)855 static int usb_device_match(struct device *dev, struct device_driver *drv)
856 {
857 	/* devices and interfaces are handled separately */
858 	if (is_usb_device(dev)) {
859 		struct usb_device *udev;
860 		struct usb_device_driver *udrv;
861 
862 		/* interface drivers never match devices */
863 		if (!is_usb_device_driver(drv))
864 			return 0;
865 
866 		udev = to_usb_device(dev);
867 		udrv = to_usb_device_driver(drv);
868 
869 		/* If the device driver under consideration does not have a
870 		 * id_table or a match function, then let the driver's probe
871 		 * function decide.
872 		 */
873 		if (!udrv->id_table && !udrv->match)
874 			return 1;
875 
876 		return usb_driver_applicable(udev, udrv);
877 
878 	} else if (is_usb_interface(dev)) {
879 		struct usb_interface *intf;
880 		struct usb_driver *usb_drv;
881 		const struct usb_device_id *id;
882 
883 		/* device drivers never match interfaces */
884 		if (is_usb_device_driver(drv))
885 			return 0;
886 
887 		intf = to_usb_interface(dev);
888 		usb_drv = to_usb_driver(drv);
889 
890 		id = usb_match_id(intf, usb_drv->id_table);
891 		if (id)
892 			return 1;
893 
894 		id = usb_match_dynamic_id(intf, usb_drv);
895 		if (id)
896 			return 1;
897 	}
898 
899 	return 0;
900 }
901 
usb_uevent(const struct device * dev,struct kobj_uevent_env * env)902 static int usb_uevent(const struct device *dev, struct kobj_uevent_env *env)
903 {
904 	const struct usb_device *usb_dev;
905 
906 	if (is_usb_device(dev)) {
907 		usb_dev = to_usb_device(dev);
908 	} else if (is_usb_interface(dev)) {
909 		const struct usb_interface *intf = to_usb_interface(dev);
910 
911 		usb_dev = interface_to_usbdev(intf);
912 	} else {
913 		return 0;
914 	}
915 
916 	if (usb_dev->devnum < 0) {
917 		/* driver is often null here; dev_dbg() would oops */
918 		pr_debug("usb %s: already deleted?\n", dev_name(dev));
919 		return -ENODEV;
920 	}
921 	if (!usb_dev->bus) {
922 		pr_debug("usb %s: bus removed?\n", dev_name(dev));
923 		return -ENODEV;
924 	}
925 
926 	/* per-device configurations are common */
927 	if (add_uevent_var(env, "PRODUCT=%x/%x/%x",
928 			   le16_to_cpu(usb_dev->descriptor.idVendor),
929 			   le16_to_cpu(usb_dev->descriptor.idProduct),
930 			   le16_to_cpu(usb_dev->descriptor.bcdDevice)))
931 		return -ENOMEM;
932 
933 	/* class-based driver binding models */
934 	if (add_uevent_var(env, "TYPE=%d/%d/%d",
935 			   usb_dev->descriptor.bDeviceClass,
936 			   usb_dev->descriptor.bDeviceSubClass,
937 			   usb_dev->descriptor.bDeviceProtocol))
938 		return -ENOMEM;
939 
940 	return 0;
941 }
942 
__usb_bus_reprobe_drivers(struct device * dev,void * data)943 static int __usb_bus_reprobe_drivers(struct device *dev, void *data)
944 {
945 	struct usb_device_driver *new_udriver = data;
946 	struct usb_device *udev;
947 	int ret;
948 
949 	/* Don't reprobe if current driver isn't usb_generic_driver */
950 	if (dev->driver != &usb_generic_driver.drvwrap.driver)
951 		return 0;
952 
953 	udev = to_usb_device(dev);
954 	if (!usb_driver_applicable(udev, new_udriver))
955 		return 0;
956 
957 	ret = device_reprobe(dev);
958 	if (ret && ret != -EPROBE_DEFER)
959 		dev_err(dev, "Failed to reprobe device (error %d)\n", ret);
960 
961 	return 0;
962 }
963 
964 /**
965  * usb_register_device_driver - register a USB device (not interface) driver
966  * @new_udriver: USB operations for the device driver
967  * @owner: module owner of this driver.
968  *
969  * Registers a USB device driver with the USB core.  The list of
970  * unattached devices will be rescanned whenever a new driver is
971  * added, allowing the new driver to attach to any recognized devices.
972  *
973  * Return: A negative error code on failure and 0 on success.
974  */
usb_register_device_driver(struct usb_device_driver * new_udriver,struct module * owner)975 int usb_register_device_driver(struct usb_device_driver *new_udriver,
976 		struct module *owner)
977 {
978 	int retval = 0;
979 
980 	if (usb_disabled())
981 		return -ENODEV;
982 
983 	new_udriver->drvwrap.for_devices = 1;
984 	new_udriver->drvwrap.driver.name = new_udriver->name;
985 	new_udriver->drvwrap.driver.bus = &usb_bus_type;
986 	new_udriver->drvwrap.driver.probe = usb_probe_device;
987 	new_udriver->drvwrap.driver.remove = usb_unbind_device;
988 	new_udriver->drvwrap.driver.owner = owner;
989 	new_udriver->drvwrap.driver.dev_groups = new_udriver->dev_groups;
990 
991 	retval = driver_register(&new_udriver->drvwrap.driver);
992 
993 	if (!retval) {
994 		pr_info("%s: registered new device driver %s\n",
995 			usbcore_name, new_udriver->name);
996 		/*
997 		 * Check whether any device could be better served with
998 		 * this new driver
999 		 */
1000 		bus_for_each_dev(&usb_bus_type, NULL, new_udriver,
1001 				 __usb_bus_reprobe_drivers);
1002 	} else {
1003 		pr_err("%s: error %d registering device driver %s\n",
1004 			usbcore_name, retval, new_udriver->name);
1005 	}
1006 
1007 	return retval;
1008 }
1009 EXPORT_SYMBOL_GPL(usb_register_device_driver);
1010 
1011 /**
1012  * usb_deregister_device_driver - unregister a USB device (not interface) driver
1013  * @udriver: USB operations of the device driver to unregister
1014  * Context: must be able to sleep
1015  *
1016  * Unlinks the specified driver from the internal USB driver list.
1017  */
usb_deregister_device_driver(struct usb_device_driver * udriver)1018 void usb_deregister_device_driver(struct usb_device_driver *udriver)
1019 {
1020 	pr_info("%s: deregistering device driver %s\n",
1021 			usbcore_name, udriver->name);
1022 
1023 	driver_unregister(&udriver->drvwrap.driver);
1024 }
1025 EXPORT_SYMBOL_GPL(usb_deregister_device_driver);
1026 
1027 /**
1028  * usb_register_driver - register a USB interface driver
1029  * @new_driver: USB operations for the interface driver
1030  * @owner: module owner of this driver.
1031  * @mod_name: module name string
1032  *
1033  * Registers a USB interface driver with the USB core.  The list of
1034  * unattached interfaces will be rescanned whenever a new driver is
1035  * added, allowing the new driver to attach to any recognized interfaces.
1036  *
1037  * Return: A negative error code on failure and 0 on success.
1038  *
1039  * NOTE: if you want your driver to use the USB major number, you must call
1040  * usb_register_dev() to enable that functionality.  This function no longer
1041  * takes care of that.
1042  */
usb_register_driver(struct usb_driver * new_driver,struct module * owner,const char * mod_name)1043 int usb_register_driver(struct usb_driver *new_driver, struct module *owner,
1044 			const char *mod_name)
1045 {
1046 	int retval = 0;
1047 
1048 	if (usb_disabled())
1049 		return -ENODEV;
1050 
1051 	new_driver->drvwrap.for_devices = 0;
1052 	new_driver->drvwrap.driver.name = new_driver->name;
1053 	new_driver->drvwrap.driver.bus = &usb_bus_type;
1054 	new_driver->drvwrap.driver.probe = usb_probe_interface;
1055 	new_driver->drvwrap.driver.remove = usb_unbind_interface;
1056 	new_driver->drvwrap.driver.owner = owner;
1057 	new_driver->drvwrap.driver.mod_name = mod_name;
1058 	new_driver->drvwrap.driver.dev_groups = new_driver->dev_groups;
1059 	spin_lock_init(&new_driver->dynids.lock);
1060 	INIT_LIST_HEAD(&new_driver->dynids.list);
1061 
1062 	retval = driver_register(&new_driver->drvwrap.driver);
1063 	if (retval)
1064 		goto out;
1065 
1066 	retval = usb_create_newid_files(new_driver);
1067 	if (retval)
1068 		goto out_newid;
1069 
1070 	pr_info("%s: registered new interface driver %s\n",
1071 			usbcore_name, new_driver->name);
1072 
1073 out:
1074 	return retval;
1075 
1076 out_newid:
1077 	driver_unregister(&new_driver->drvwrap.driver);
1078 
1079 	pr_err("%s: error %d registering interface driver %s\n",
1080 		usbcore_name, retval, new_driver->name);
1081 	goto out;
1082 }
1083 EXPORT_SYMBOL_GPL(usb_register_driver);
1084 
1085 /**
1086  * usb_deregister - unregister a USB interface driver
1087  * @driver: USB operations of the interface driver to unregister
1088  * Context: must be able to sleep
1089  *
1090  * Unlinks the specified driver from the internal USB driver list.
1091  *
1092  * NOTE: If you called usb_register_dev(), you still need to call
1093  * usb_deregister_dev() to clean up your driver's allocated minor numbers,
1094  * this * call will no longer do it for you.
1095  */
usb_deregister(struct usb_driver * driver)1096 void usb_deregister(struct usb_driver *driver)
1097 {
1098 	pr_info("%s: deregistering interface driver %s\n",
1099 			usbcore_name, driver->name);
1100 
1101 	usb_remove_newid_files(driver);
1102 	driver_unregister(&driver->drvwrap.driver);
1103 	usb_free_dynids(driver);
1104 }
1105 EXPORT_SYMBOL_GPL(usb_deregister);
1106 
1107 /* Forced unbinding of a USB interface driver, either because
1108  * it doesn't support pre_reset/post_reset/reset_resume or
1109  * because it doesn't support suspend/resume.
1110  *
1111  * The caller must hold @intf's device's lock, but not @intf's lock.
1112  */
usb_forced_unbind_intf(struct usb_interface * intf)1113 void usb_forced_unbind_intf(struct usb_interface *intf)
1114 {
1115 	struct usb_driver *driver = to_usb_driver(intf->dev.driver);
1116 
1117 	dev_dbg(&intf->dev, "forced unbind\n");
1118 	usb_driver_release_interface(driver, intf);
1119 
1120 	/* Mark the interface for later rebinding */
1121 	intf->needs_binding = 1;
1122 }
1123 
1124 /*
1125  * Unbind drivers for @udev's marked interfaces.  These interfaces have
1126  * the needs_binding flag set, for example by usb_resume_interface().
1127  *
1128  * The caller must hold @udev's device lock.
1129  */
unbind_marked_interfaces(struct usb_device * udev)1130 static void unbind_marked_interfaces(struct usb_device *udev)
1131 {
1132 	struct usb_host_config	*config;
1133 	int			i;
1134 	struct usb_interface	*intf;
1135 
1136 	config = udev->actconfig;
1137 	if (config) {
1138 		for (i = 0; i < config->desc.bNumInterfaces; ++i) {
1139 			intf = config->interface[i];
1140 			if (intf->dev.driver && intf->needs_binding)
1141 				usb_forced_unbind_intf(intf);
1142 		}
1143 	}
1144 }
1145 
1146 /* Delayed forced unbinding of a USB interface driver and scan
1147  * for rebinding.
1148  *
1149  * The caller must hold @intf's device's lock, but not @intf's lock.
1150  *
1151  * Note: Rebinds will be skipped if a system sleep transition is in
1152  * progress and the PM "complete" callback hasn't occurred yet.
1153  */
usb_rebind_intf(struct usb_interface * intf)1154 static void usb_rebind_intf(struct usb_interface *intf)
1155 {
1156 	int rc;
1157 
1158 	/* Delayed unbind of an existing driver */
1159 	if (intf->dev.driver)
1160 		usb_forced_unbind_intf(intf);
1161 
1162 	/* Try to rebind the interface */
1163 	if (!intf->dev.power.is_prepared) {
1164 		intf->needs_binding = 0;
1165 		rc = device_attach(&intf->dev);
1166 		if (rc < 0 && rc != -EPROBE_DEFER)
1167 			dev_warn(&intf->dev, "rebind failed: %d\n", rc);
1168 	}
1169 }
1170 
1171 /*
1172  * Rebind drivers to @udev's marked interfaces.  These interfaces have
1173  * the needs_binding flag set.
1174  *
1175  * The caller must hold @udev's device lock.
1176  */
rebind_marked_interfaces(struct usb_device * udev)1177 static void rebind_marked_interfaces(struct usb_device *udev)
1178 {
1179 	struct usb_host_config	*config;
1180 	int			i;
1181 	struct usb_interface	*intf;
1182 
1183 	config = udev->actconfig;
1184 	if (config) {
1185 		for (i = 0; i < config->desc.bNumInterfaces; ++i) {
1186 			intf = config->interface[i];
1187 			if (intf->needs_binding)
1188 				usb_rebind_intf(intf);
1189 		}
1190 	}
1191 }
1192 
1193 /*
1194  * Unbind all of @udev's marked interfaces and then rebind all of them.
1195  * This ordering is necessary because some drivers claim several interfaces
1196  * when they are first probed.
1197  *
1198  * The caller must hold @udev's device lock.
1199  */
usb_unbind_and_rebind_marked_interfaces(struct usb_device * udev)1200 void usb_unbind_and_rebind_marked_interfaces(struct usb_device *udev)
1201 {
1202 	unbind_marked_interfaces(udev);
1203 	rebind_marked_interfaces(udev);
1204 }
1205 
1206 #ifdef CONFIG_PM
1207 
1208 /* Unbind drivers for @udev's interfaces that don't support suspend/resume
1209  * There is no check for reset_resume here because it can be determined
1210  * only during resume whether reset_resume is needed.
1211  *
1212  * The caller must hold @udev's device lock.
1213  */
unbind_no_pm_drivers_interfaces(struct usb_device * udev)1214 static void unbind_no_pm_drivers_interfaces(struct usb_device *udev)
1215 {
1216 	struct usb_host_config	*config;
1217 	int			i;
1218 	struct usb_interface	*intf;
1219 	struct usb_driver	*drv;
1220 
1221 	config = udev->actconfig;
1222 	if (config) {
1223 		for (i = 0; i < config->desc.bNumInterfaces; ++i) {
1224 			intf = config->interface[i];
1225 
1226 			if (intf->dev.driver) {
1227 				drv = to_usb_driver(intf->dev.driver);
1228 				if (!drv->suspend || !drv->resume)
1229 					usb_forced_unbind_intf(intf);
1230 			}
1231 		}
1232 	}
1233 }
1234 
usb_suspend_device(struct usb_device * udev,pm_message_t msg)1235 static int usb_suspend_device(struct usb_device *udev, pm_message_t msg)
1236 {
1237 	struct usb_device_driver	*udriver;
1238 	int				status = 0;
1239 
1240 	if (udev->state == USB_STATE_NOTATTACHED ||
1241 			udev->state == USB_STATE_SUSPENDED)
1242 		goto done;
1243 
1244 	/* For devices that don't have a driver, we do a generic suspend. */
1245 	if (udev->dev.driver)
1246 		udriver = to_usb_device_driver(udev->dev.driver);
1247 	else {
1248 		udev->do_remote_wakeup = 0;
1249 		udriver = &usb_generic_driver;
1250 	}
1251 	if (udriver->suspend)
1252 		status = udriver->suspend(udev, msg);
1253 	if (status == 0 && udriver->generic_subclass)
1254 		status = usb_generic_driver_suspend(udev, msg);
1255 
1256  done:
1257 	dev_vdbg(&udev->dev, "%s: status %d\n", __func__, status);
1258 	return status;
1259 }
1260 
usb_resume_device(struct usb_device * udev,pm_message_t msg)1261 static int usb_resume_device(struct usb_device *udev, pm_message_t msg)
1262 {
1263 	struct usb_device_driver	*udriver;
1264 	int				status = 0;
1265 
1266 	if (udev->state == USB_STATE_NOTATTACHED)
1267 		goto done;
1268 
1269 	/* Can't resume it if it doesn't have a driver. */
1270 	if (udev->dev.driver == NULL) {
1271 		status = -ENOTCONN;
1272 		goto done;
1273 	}
1274 
1275 	/* Non-root devices on a full/low-speed bus must wait for their
1276 	 * companion high-speed root hub, in case a handoff is needed.
1277 	 */
1278 	if (!PMSG_IS_AUTO(msg) && udev->parent && udev->bus->hs_companion)
1279 		device_pm_wait_for_dev(&udev->dev,
1280 				&udev->bus->hs_companion->root_hub->dev);
1281 
1282 	if (udev->quirks & USB_QUIRK_RESET_RESUME)
1283 		udev->reset_resume = 1;
1284 
1285 	udriver = to_usb_device_driver(udev->dev.driver);
1286 	if (udriver->generic_subclass)
1287 		status = usb_generic_driver_resume(udev, msg);
1288 	if (status == 0 && udriver->resume)
1289 		status = udriver->resume(udev, msg);
1290 
1291  done:
1292 	dev_vdbg(&udev->dev, "%s: status %d\n", __func__, status);
1293 	return status;
1294 }
1295 
usb_suspend_interface(struct usb_device * udev,struct usb_interface * intf,pm_message_t msg)1296 static int usb_suspend_interface(struct usb_device *udev,
1297 		struct usb_interface *intf, pm_message_t msg)
1298 {
1299 	struct usb_driver	*driver;
1300 	int			status = 0;
1301 
1302 	if (udev->state == USB_STATE_NOTATTACHED ||
1303 			intf->condition == USB_INTERFACE_UNBOUND)
1304 		goto done;
1305 	driver = to_usb_driver(intf->dev.driver);
1306 
1307 	/* at this time we know the driver supports suspend */
1308 	status = driver->suspend(intf, msg);
1309 	if (status && !PMSG_IS_AUTO(msg))
1310 		dev_err(&intf->dev, "suspend error %d\n", status);
1311 
1312  done:
1313 	dev_vdbg(&intf->dev, "%s: status %d\n", __func__, status);
1314 	return status;
1315 }
1316 
usb_resume_interface(struct usb_device * udev,struct usb_interface * intf,pm_message_t msg,int reset_resume)1317 static int usb_resume_interface(struct usb_device *udev,
1318 		struct usb_interface *intf, pm_message_t msg, int reset_resume)
1319 {
1320 	struct usb_driver	*driver;
1321 	int			status = 0;
1322 
1323 	if (udev->state == USB_STATE_NOTATTACHED)
1324 		goto done;
1325 
1326 	/* Don't let autoresume interfere with unbinding */
1327 	if (intf->condition == USB_INTERFACE_UNBINDING)
1328 		goto done;
1329 
1330 	/* Can't resume it if it doesn't have a driver. */
1331 	if (intf->condition == USB_INTERFACE_UNBOUND) {
1332 
1333 		/* Carry out a deferred switch to altsetting 0 */
1334 		if (intf->needs_altsetting0 && !intf->dev.power.is_prepared) {
1335 			usb_set_interface(udev, intf->altsetting[0].
1336 					desc.bInterfaceNumber, 0);
1337 			intf->needs_altsetting0 = 0;
1338 		}
1339 		goto done;
1340 	}
1341 
1342 	/* Don't resume if the interface is marked for rebinding */
1343 	if (intf->needs_binding)
1344 		goto done;
1345 	driver = to_usb_driver(intf->dev.driver);
1346 
1347 	if (reset_resume) {
1348 		if (driver->reset_resume) {
1349 			status = driver->reset_resume(intf);
1350 			if (status)
1351 				dev_err(&intf->dev, "%s error %d\n",
1352 						"reset_resume", status);
1353 		} else {
1354 			intf->needs_binding = 1;
1355 			dev_dbg(&intf->dev, "no reset_resume for driver %s?\n",
1356 					driver->name);
1357 		}
1358 	} else {
1359 		status = driver->resume(intf);
1360 		if (status)
1361 			dev_err(&intf->dev, "resume error %d\n", status);
1362 	}
1363 
1364 done:
1365 	dev_vdbg(&intf->dev, "%s: status %d\n", __func__, status);
1366 
1367 	/* Later we will unbind the driver and/or reprobe, if necessary */
1368 	return status;
1369 }
1370 
1371 /**
1372  * usb_suspend_both - suspend a USB device and its interfaces
1373  * @udev: the usb_device to suspend
1374  * @msg: Power Management message describing this state transition
1375  *
1376  * This is the central routine for suspending USB devices.  It calls the
1377  * suspend methods for all the interface drivers in @udev and then calls
1378  * the suspend method for @udev itself.  When the routine is called in
1379  * autosuspend, if an error occurs at any stage, all the interfaces
1380  * which were suspended are resumed so that they remain in the same
1381  * state as the device, but when called from system sleep, all error
1382  * from suspend methods of interfaces and the non-root-hub device itself
1383  * are simply ignored, so all suspended interfaces are only resumed
1384  * to the device's state when @udev is root-hub and its suspend method
1385  * returns failure.
1386  *
1387  * Autosuspend requests originating from a child device or an interface
1388  * driver may be made without the protection of @udev's device lock, but
1389  * all other suspend calls will hold the lock.  Usbcore will insure that
1390  * method calls do not arrive during bind, unbind, or reset operations.
1391  * However drivers must be prepared to handle suspend calls arriving at
1392  * unpredictable times.
1393  *
1394  * This routine can run only in process context.
1395  *
1396  * Return: 0 if the suspend succeeded.
1397  */
usb_suspend_both(struct usb_device * udev,pm_message_t msg)1398 static int usb_suspend_both(struct usb_device *udev, pm_message_t msg)
1399 {
1400 	int			status = 0;
1401 	int			i = 0, n = 0;
1402 	struct usb_interface	*intf;
1403 
1404 	if (udev->state == USB_STATE_NOTATTACHED ||
1405 			udev->state == USB_STATE_SUSPENDED)
1406 		goto done;
1407 
1408 	/* Suspend all the interfaces and then udev itself */
1409 	if (udev->actconfig) {
1410 		n = udev->actconfig->desc.bNumInterfaces;
1411 		for (i = n - 1; i >= 0; --i) {
1412 			intf = udev->actconfig->interface[i];
1413 			status = usb_suspend_interface(udev, intf, msg);
1414 
1415 			/* Ignore errors during system sleep transitions */
1416 			if (!PMSG_IS_AUTO(msg))
1417 				status = 0;
1418 			if (status != 0)
1419 				break;
1420 		}
1421 	}
1422 	if (status == 0) {
1423 		status = usb_suspend_device(udev, msg);
1424 
1425 		/*
1426 		 * Ignore errors from non-root-hub devices during
1427 		 * system sleep transitions.  For the most part,
1428 		 * these devices should go to low power anyway when
1429 		 * the entire bus is suspended.
1430 		 */
1431 		if (udev->parent && !PMSG_IS_AUTO(msg))
1432 			status = 0;
1433 
1434 		/*
1435 		 * If the device is inaccessible, don't try to resume
1436 		 * suspended interfaces and just return the error.
1437 		 */
1438 		if (status && status != -EBUSY) {
1439 			int err;
1440 			u16 devstat;
1441 
1442 			err = usb_get_std_status(udev, USB_RECIP_DEVICE, 0,
1443 						 &devstat);
1444 			if (err) {
1445 				dev_err(&udev->dev,
1446 					"Failed to suspend device, error %d\n",
1447 					status);
1448 				goto done;
1449 			}
1450 		}
1451 	}
1452 
1453 	/* If the suspend failed, resume interfaces that did get suspended */
1454 	if (status != 0) {
1455 		if (udev->actconfig) {
1456 			msg.event ^= (PM_EVENT_SUSPEND | PM_EVENT_RESUME);
1457 			while (++i < n) {
1458 				intf = udev->actconfig->interface[i];
1459 				usb_resume_interface(udev, intf, msg, 0);
1460 			}
1461 		}
1462 
1463 	/* If the suspend succeeded then prevent any more URB submissions
1464 	 * and flush any outstanding URBs.
1465 	 */
1466 	} else {
1467 		udev->can_submit = 0;
1468 		for (i = 0; i < 16; ++i) {
1469 			usb_hcd_flush_endpoint(udev, udev->ep_out[i]);
1470 			usb_hcd_flush_endpoint(udev, udev->ep_in[i]);
1471 		}
1472 	}
1473 
1474  done:
1475 	dev_vdbg(&udev->dev, "%s: status %d\n", __func__, status);
1476 	return status;
1477 }
1478 
1479 /**
1480  * usb_resume_both - resume a USB device and its interfaces
1481  * @udev: the usb_device to resume
1482  * @msg: Power Management message describing this state transition
1483  *
1484  * This is the central routine for resuming USB devices.  It calls the
1485  * resume method for @udev and then calls the resume methods for all
1486  * the interface drivers in @udev.
1487  *
1488  * Autoresume requests originating from a child device or an interface
1489  * driver may be made without the protection of @udev's device lock, but
1490  * all other resume calls will hold the lock.  Usbcore will insure that
1491  * method calls do not arrive during bind, unbind, or reset operations.
1492  * However drivers must be prepared to handle resume calls arriving at
1493  * unpredictable times.
1494  *
1495  * This routine can run only in process context.
1496  *
1497  * Return: 0 on success.
1498  */
usb_resume_both(struct usb_device * udev,pm_message_t msg)1499 static int usb_resume_both(struct usb_device *udev, pm_message_t msg)
1500 {
1501 	int			status = 0;
1502 	int			i;
1503 	struct usb_interface	*intf;
1504 
1505 	if (udev->state == USB_STATE_NOTATTACHED) {
1506 		status = -ENODEV;
1507 		goto done;
1508 	}
1509 	udev->can_submit = 1;
1510 
1511 	/* Resume the device */
1512 	if (udev->state == USB_STATE_SUSPENDED || udev->reset_resume)
1513 		status = usb_resume_device(udev, msg);
1514 
1515 	/* Resume the interfaces */
1516 	if (status == 0 && udev->actconfig) {
1517 		for (i = 0; i < udev->actconfig->desc.bNumInterfaces; i++) {
1518 			intf = udev->actconfig->interface[i];
1519 			usb_resume_interface(udev, intf, msg,
1520 					udev->reset_resume);
1521 		}
1522 	}
1523 	usb_mark_last_busy(udev);
1524 
1525  done:
1526 	dev_vdbg(&udev->dev, "%s: status %d\n", __func__, status);
1527 	if (!status)
1528 		udev->reset_resume = 0;
1529 	return status;
1530 }
1531 
choose_wakeup(struct usb_device * udev,pm_message_t msg)1532 static void choose_wakeup(struct usb_device *udev, pm_message_t msg)
1533 {
1534 	int	w;
1535 
1536 	/*
1537 	 * For FREEZE/QUIESCE, disable remote wakeups so no interrupts get
1538 	 * generated.
1539 	 */
1540 	if (msg.event == PM_EVENT_FREEZE || msg.event == PM_EVENT_QUIESCE) {
1541 		w = 0;
1542 
1543 	} else {
1544 		/*
1545 		 * Enable remote wakeup if it is allowed, even if no interface
1546 		 * drivers actually want it.
1547 		 */
1548 		w = device_may_wakeup(&udev->dev);
1549 	}
1550 
1551 	/*
1552 	 * If the device is autosuspended with the wrong wakeup setting,
1553 	 * autoresume now so the setting can be changed.
1554 	 */
1555 	if (udev->state == USB_STATE_SUSPENDED && w != udev->do_remote_wakeup)
1556 		pm_runtime_resume(&udev->dev);
1557 	udev->do_remote_wakeup = w;
1558 }
1559 
1560 /* The device lock is held by the PM core */
usb_suspend(struct device * dev,pm_message_t msg)1561 int usb_suspend(struct device *dev, pm_message_t msg)
1562 {
1563 	struct usb_device	*udev = to_usb_device(dev);
1564 	int r;
1565 
1566 	unbind_no_pm_drivers_interfaces(udev);
1567 
1568 	/* From now on we are sure all drivers support suspend/resume
1569 	 * but not necessarily reset_resume()
1570 	 * so we may still need to unbind and rebind upon resume
1571 	 */
1572 	choose_wakeup(udev, msg);
1573 	r = usb_suspend_both(udev, msg);
1574 	if (r)
1575 		return r;
1576 
1577 	if (udev->quirks & USB_QUIRK_DISCONNECT_SUSPEND)
1578 		usb_port_disable(udev);
1579 
1580 	return 0;
1581 }
1582 
1583 /* The device lock is held by the PM core */
usb_resume_complete(struct device * dev)1584 int usb_resume_complete(struct device *dev)
1585 {
1586 	struct usb_device *udev = to_usb_device(dev);
1587 
1588 	/* For PM complete calls, all we do is rebind interfaces
1589 	 * whose needs_binding flag is set
1590 	 */
1591 	if (udev->state != USB_STATE_NOTATTACHED)
1592 		rebind_marked_interfaces(udev);
1593 	return 0;
1594 }
1595 
1596 /* The device lock is held by the PM core */
usb_resume(struct device * dev,pm_message_t msg)1597 int usb_resume(struct device *dev, pm_message_t msg)
1598 {
1599 	struct usb_device	*udev = to_usb_device(dev);
1600 	int			status;
1601 
1602 	/* For all calls, take the device back to full power and
1603 	 * tell the PM core in case it was autosuspended previously.
1604 	 * Unbind the interfaces that will need rebinding later,
1605 	 * because they fail to support reset_resume.
1606 	 * (This can't be done in usb_resume_interface()
1607 	 * above because it doesn't own the right set of locks.)
1608 	 */
1609 	status = usb_resume_both(udev, msg);
1610 	if (status == 0) {
1611 		pm_runtime_disable(dev);
1612 		pm_runtime_set_active(dev);
1613 		pm_runtime_enable(dev);
1614 		unbind_marked_interfaces(udev);
1615 	}
1616 
1617 	/* Avoid PM error messages for devices disconnected while suspended
1618 	 * as we'll display regular disconnect messages just a bit later.
1619 	 */
1620 	if (status == -ENODEV || status == -ESHUTDOWN)
1621 		status = 0;
1622 	return status;
1623 }
1624 
1625 /**
1626  * usb_enable_autosuspend - allow a USB device to be autosuspended
1627  * @udev: the USB device which may be autosuspended
1628  *
1629  * This routine allows @udev to be autosuspended.  An autosuspend won't
1630  * take place until the autosuspend_delay has elapsed and all the other
1631  * necessary conditions are satisfied.
1632  *
1633  * The caller must hold @udev's device lock.
1634  */
usb_enable_autosuspend(struct usb_device * udev)1635 void usb_enable_autosuspend(struct usb_device *udev)
1636 {
1637 	pm_runtime_allow(&udev->dev);
1638 }
1639 EXPORT_SYMBOL_GPL(usb_enable_autosuspend);
1640 
1641 /**
1642  * usb_disable_autosuspend - prevent a USB device from being autosuspended
1643  * @udev: the USB device which may not be autosuspended
1644  *
1645  * This routine prevents @udev from being autosuspended and wakes it up
1646  * if it is already autosuspended.
1647  *
1648  * The caller must hold @udev's device lock.
1649  */
usb_disable_autosuspend(struct usb_device * udev)1650 void usb_disable_autosuspend(struct usb_device *udev)
1651 {
1652 	pm_runtime_forbid(&udev->dev);
1653 }
1654 EXPORT_SYMBOL_GPL(usb_disable_autosuspend);
1655 
1656 /**
1657  * usb_autosuspend_device - delayed autosuspend of a USB device and its interfaces
1658  * @udev: the usb_device to autosuspend
1659  *
1660  * This routine should be called when a core subsystem is finished using
1661  * @udev and wants to allow it to autosuspend.  Examples would be when
1662  * @udev's device file in usbfs is closed or after a configuration change.
1663  *
1664  * @udev's usage counter is decremented; if it drops to 0 and all the
1665  * interfaces are inactive then a delayed autosuspend will be attempted.
1666  * The attempt may fail (see autosuspend_check()).
1667  *
1668  * The caller must hold @udev's device lock.
1669  *
1670  * This routine can run only in process context.
1671  */
usb_autosuspend_device(struct usb_device * udev)1672 void usb_autosuspend_device(struct usb_device *udev)
1673 {
1674 	int	status;
1675 
1676 	usb_mark_last_busy(udev);
1677 	status = pm_runtime_put_sync_autosuspend(&udev->dev);
1678 	dev_vdbg(&udev->dev, "%s: cnt %d -> %d\n",
1679 			__func__, atomic_read(&udev->dev.power.usage_count),
1680 			status);
1681 }
1682 
1683 /**
1684  * usb_autoresume_device - immediately autoresume a USB device and its interfaces
1685  * @udev: the usb_device to autoresume
1686  *
1687  * This routine should be called when a core subsystem wants to use @udev
1688  * and needs to guarantee that it is not suspended.  No autosuspend will
1689  * occur until usb_autosuspend_device() is called.  (Note that this will
1690  * not prevent suspend events originating in the PM core.)  Examples would
1691  * be when @udev's device file in usbfs is opened or when a remote-wakeup
1692  * request is received.
1693  *
1694  * @udev's usage counter is incremented to prevent subsequent autosuspends.
1695  * However if the autoresume fails then the usage counter is re-decremented.
1696  *
1697  * The caller must hold @udev's device lock.
1698  *
1699  * This routine can run only in process context.
1700  *
1701  * Return: 0 on success. A negative error code otherwise.
1702  */
usb_autoresume_device(struct usb_device * udev)1703 int usb_autoresume_device(struct usb_device *udev)
1704 {
1705 	int	status;
1706 
1707 	status = pm_runtime_get_sync(&udev->dev);
1708 	if (status < 0)
1709 		pm_runtime_put_sync(&udev->dev);
1710 	dev_vdbg(&udev->dev, "%s: cnt %d -> %d\n",
1711 			__func__, atomic_read(&udev->dev.power.usage_count),
1712 			status);
1713 	if (status > 0)
1714 		status = 0;
1715 	return status;
1716 }
1717 
1718 /**
1719  * usb_autopm_put_interface - decrement a USB interface's PM-usage counter
1720  * @intf: the usb_interface whose counter should be decremented
1721  *
1722  * This routine should be called by an interface driver when it is
1723  * finished using @intf and wants to allow it to autosuspend.  A typical
1724  * example would be a character-device driver when its device file is
1725  * closed.
1726  *
1727  * The routine decrements @intf's usage counter.  When the counter reaches
1728  * 0, a delayed autosuspend request for @intf's device is attempted.  The
1729  * attempt may fail (see autosuspend_check()).
1730  *
1731  * This routine can run only in process context.
1732  */
usb_autopm_put_interface(struct usb_interface * intf)1733 void usb_autopm_put_interface(struct usb_interface *intf)
1734 {
1735 	struct usb_device	*udev = interface_to_usbdev(intf);
1736 	int			status;
1737 
1738 	usb_mark_last_busy(udev);
1739 	status = pm_runtime_put_sync(&intf->dev);
1740 	dev_vdbg(&intf->dev, "%s: cnt %d -> %d\n",
1741 			__func__, atomic_read(&intf->dev.power.usage_count),
1742 			status);
1743 }
1744 EXPORT_SYMBOL_GPL(usb_autopm_put_interface);
1745 
1746 /**
1747  * usb_autopm_put_interface_async - decrement a USB interface's PM-usage counter
1748  * @intf: the usb_interface whose counter should be decremented
1749  *
1750  * This routine does much the same thing as usb_autopm_put_interface():
1751  * It decrements @intf's usage counter and schedules a delayed
1752  * autosuspend request if the counter is <= 0.  The difference is that it
1753  * does not perform any synchronization; callers should hold a private
1754  * lock and handle all synchronization issues themselves.
1755  *
1756  * Typically a driver would call this routine during an URB's completion
1757  * handler, if no more URBs were pending.
1758  *
1759  * This routine can run in atomic context.
1760  */
usb_autopm_put_interface_async(struct usb_interface * intf)1761 void usb_autopm_put_interface_async(struct usb_interface *intf)
1762 {
1763 	struct usb_device	*udev = interface_to_usbdev(intf);
1764 	int			status;
1765 
1766 	usb_mark_last_busy(udev);
1767 	status = pm_runtime_put(&intf->dev);
1768 	dev_vdbg(&intf->dev, "%s: cnt %d -> %d\n",
1769 			__func__, atomic_read(&intf->dev.power.usage_count),
1770 			status);
1771 }
1772 EXPORT_SYMBOL_GPL(usb_autopm_put_interface_async);
1773 
1774 /**
1775  * usb_autopm_put_interface_no_suspend - decrement a USB interface's PM-usage counter
1776  * @intf: the usb_interface whose counter should be decremented
1777  *
1778  * This routine decrements @intf's usage counter but does not carry out an
1779  * autosuspend.
1780  *
1781  * This routine can run in atomic context.
1782  */
usb_autopm_put_interface_no_suspend(struct usb_interface * intf)1783 void usb_autopm_put_interface_no_suspend(struct usb_interface *intf)
1784 {
1785 	struct usb_device	*udev = interface_to_usbdev(intf);
1786 
1787 	usb_mark_last_busy(udev);
1788 	pm_runtime_put_noidle(&intf->dev);
1789 }
1790 EXPORT_SYMBOL_GPL(usb_autopm_put_interface_no_suspend);
1791 
1792 /**
1793  * usb_autopm_get_interface - increment a USB interface's PM-usage counter
1794  * @intf: the usb_interface whose counter should be incremented
1795  *
1796  * This routine should be called by an interface driver when it wants to
1797  * use @intf and needs to guarantee that it is not suspended.  In addition,
1798  * the routine prevents @intf from being autosuspended subsequently.  (Note
1799  * that this will not prevent suspend events originating in the PM core.)
1800  * This prevention will persist until usb_autopm_put_interface() is called
1801  * or @intf is unbound.  A typical example would be a character-device
1802  * driver when its device file is opened.
1803  *
1804  * @intf's usage counter is incremented to prevent subsequent autosuspends.
1805  * However if the autoresume fails then the counter is re-decremented.
1806  *
1807  * This routine can run only in process context.
1808  *
1809  * Return: 0 on success.
1810  */
usb_autopm_get_interface(struct usb_interface * intf)1811 int usb_autopm_get_interface(struct usb_interface *intf)
1812 {
1813 	int	status;
1814 
1815 	status = pm_runtime_get_sync(&intf->dev);
1816 	if (status < 0)
1817 		pm_runtime_put_sync(&intf->dev);
1818 	dev_vdbg(&intf->dev, "%s: cnt %d -> %d\n",
1819 			__func__, atomic_read(&intf->dev.power.usage_count),
1820 			status);
1821 	if (status > 0)
1822 		status = 0;
1823 	return status;
1824 }
1825 EXPORT_SYMBOL_GPL(usb_autopm_get_interface);
1826 
1827 /**
1828  * usb_autopm_get_interface_async - increment a USB interface's PM-usage counter
1829  * @intf: the usb_interface whose counter should be incremented
1830  *
1831  * This routine does much the same thing as
1832  * usb_autopm_get_interface(): It increments @intf's usage counter and
1833  * queues an autoresume request if the device is suspended.  The
1834  * differences are that it does not perform any synchronization (callers
1835  * should hold a private lock and handle all synchronization issues
1836  * themselves), and it does not autoresume the device directly (it only
1837  * queues a request).  After a successful call, the device may not yet be
1838  * resumed.
1839  *
1840  * This routine can run in atomic context.
1841  *
1842  * Return: 0 on success. A negative error code otherwise.
1843  */
usb_autopm_get_interface_async(struct usb_interface * intf)1844 int usb_autopm_get_interface_async(struct usb_interface *intf)
1845 {
1846 	int	status;
1847 
1848 	status = pm_runtime_get(&intf->dev);
1849 	if (status < 0 && status != -EINPROGRESS)
1850 		pm_runtime_put_noidle(&intf->dev);
1851 	dev_vdbg(&intf->dev, "%s: cnt %d -> %d\n",
1852 			__func__, atomic_read(&intf->dev.power.usage_count),
1853 			status);
1854 	if (status > 0 || status == -EINPROGRESS)
1855 		status = 0;
1856 	return status;
1857 }
1858 EXPORT_SYMBOL_GPL(usb_autopm_get_interface_async);
1859 
1860 /**
1861  * usb_autopm_get_interface_no_resume - increment a USB interface's PM-usage counter
1862  * @intf: the usb_interface whose counter should be incremented
1863  *
1864  * This routine increments @intf's usage counter but does not carry out an
1865  * autoresume.
1866  *
1867  * This routine can run in atomic context.
1868  */
usb_autopm_get_interface_no_resume(struct usb_interface * intf)1869 void usb_autopm_get_interface_no_resume(struct usb_interface *intf)
1870 {
1871 	struct usb_device	*udev = interface_to_usbdev(intf);
1872 
1873 	usb_mark_last_busy(udev);
1874 	pm_runtime_get_noresume(&intf->dev);
1875 }
1876 EXPORT_SYMBOL_GPL(usb_autopm_get_interface_no_resume);
1877 
1878 /* Internal routine to check whether we may autosuspend a device. */
autosuspend_check(struct usb_device * udev)1879 static int autosuspend_check(struct usb_device *udev)
1880 {
1881 	int			w, i;
1882 	struct usb_interface	*intf;
1883 
1884 	if (udev->state == USB_STATE_NOTATTACHED)
1885 		return -ENODEV;
1886 
1887 	/* Fail if autosuspend is disabled, or any interfaces are in use, or
1888 	 * any interface drivers require remote wakeup but it isn't available.
1889 	 */
1890 	w = 0;
1891 	if (udev->actconfig) {
1892 		for (i = 0; i < udev->actconfig->desc.bNumInterfaces; i++) {
1893 			intf = udev->actconfig->interface[i];
1894 
1895 			/* We don't need to check interfaces that are
1896 			 * disabled for runtime PM.  Either they are unbound
1897 			 * or else their drivers don't support autosuspend
1898 			 * and so they are permanently active.
1899 			 */
1900 			if (intf->dev.power.disable_depth)
1901 				continue;
1902 			if (atomic_read(&intf->dev.power.usage_count) > 0)
1903 				return -EBUSY;
1904 			w |= intf->needs_remote_wakeup;
1905 
1906 			/* Don't allow autosuspend if the device will need
1907 			 * a reset-resume and any of its interface drivers
1908 			 * doesn't include support or needs remote wakeup.
1909 			 */
1910 			if (udev->quirks & USB_QUIRK_RESET_RESUME) {
1911 				struct usb_driver *driver;
1912 
1913 				driver = to_usb_driver(intf->dev.driver);
1914 				if (!driver->reset_resume ||
1915 						intf->needs_remote_wakeup)
1916 					return -EOPNOTSUPP;
1917 			}
1918 		}
1919 	}
1920 	if (w && !device_can_wakeup(&udev->dev)) {
1921 		dev_dbg(&udev->dev, "remote wakeup needed for autosuspend\n");
1922 		return -EOPNOTSUPP;
1923 	}
1924 
1925 	/*
1926 	 * If the device is a direct child of the root hub and the HCD
1927 	 * doesn't handle wakeup requests, don't allow autosuspend when
1928 	 * wakeup is needed.
1929 	 */
1930 	if (w && udev->parent == udev->bus->root_hub &&
1931 			bus_to_hcd(udev->bus)->cant_recv_wakeups) {
1932 		dev_dbg(&udev->dev, "HCD doesn't handle wakeup requests\n");
1933 		return -EOPNOTSUPP;
1934 	}
1935 
1936 	udev->do_remote_wakeup = w;
1937 	return 0;
1938 }
1939 
usb_runtime_suspend(struct device * dev)1940 int usb_runtime_suspend(struct device *dev)
1941 {
1942 	struct usb_device	*udev = to_usb_device(dev);
1943 	int			status;
1944 
1945 	/* A USB device can be suspended if it passes the various autosuspend
1946 	 * checks.  Runtime suspend for a USB device means suspending all the
1947 	 * interfaces and then the device itself.
1948 	 */
1949 	if (autosuspend_check(udev) != 0)
1950 		return -EAGAIN;
1951 
1952 	status = usb_suspend_both(udev, PMSG_AUTO_SUSPEND);
1953 
1954 	/* Allow a retry if autosuspend failed temporarily */
1955 	if (status == -EAGAIN || status == -EBUSY)
1956 		usb_mark_last_busy(udev);
1957 
1958 	/*
1959 	 * The PM core reacts badly unless the return code is 0,
1960 	 * -EAGAIN, or -EBUSY, so always return -EBUSY on an error
1961 	 * (except for root hubs, because they don't suspend through
1962 	 * an upstream port like other USB devices).
1963 	 */
1964 	if (status != 0 && udev->parent)
1965 		return -EBUSY;
1966 	return status;
1967 }
1968 
usb_runtime_resume(struct device * dev)1969 int usb_runtime_resume(struct device *dev)
1970 {
1971 	struct usb_device	*udev = to_usb_device(dev);
1972 	int			status;
1973 
1974 	/* Runtime resume for a USB device means resuming both the device
1975 	 * and all its interfaces.
1976 	 */
1977 	status = usb_resume_both(udev, PMSG_AUTO_RESUME);
1978 	return status;
1979 }
1980 
usb_runtime_idle(struct device * dev)1981 int usb_runtime_idle(struct device *dev)
1982 {
1983 	struct usb_device	*udev = to_usb_device(dev);
1984 
1985 	/* An idle USB device can be suspended if it passes the various
1986 	 * autosuspend checks.
1987 	 */
1988 	if (autosuspend_check(udev) == 0)
1989 		pm_runtime_autosuspend(dev);
1990 	/* Tell the core not to suspend it, though. */
1991 	return -EBUSY;
1992 }
1993 
usb_set_usb2_hardware_lpm(struct usb_device * udev,int enable)1994 static int usb_set_usb2_hardware_lpm(struct usb_device *udev, int enable)
1995 {
1996 	struct usb_hcd *hcd = bus_to_hcd(udev->bus);
1997 	int ret = -EPERM;
1998 
1999 	if (hcd->driver->set_usb2_hw_lpm) {
2000 		ret = hcd->driver->set_usb2_hw_lpm(hcd, udev, enable);
2001 		if (!ret)
2002 			udev->usb2_hw_lpm_enabled = enable;
2003 	}
2004 
2005 	return ret;
2006 }
2007 
usb_enable_usb2_hardware_lpm(struct usb_device * udev)2008 int usb_enable_usb2_hardware_lpm(struct usb_device *udev)
2009 {
2010 	if (!udev->usb2_hw_lpm_capable ||
2011 	    !udev->usb2_hw_lpm_allowed ||
2012 	    udev->usb2_hw_lpm_enabled)
2013 		return 0;
2014 
2015 	return usb_set_usb2_hardware_lpm(udev, 1);
2016 }
2017 
usb_disable_usb2_hardware_lpm(struct usb_device * udev)2018 int usb_disable_usb2_hardware_lpm(struct usb_device *udev)
2019 {
2020 	if (!udev->usb2_hw_lpm_enabled)
2021 		return 0;
2022 
2023 	return usb_set_usb2_hardware_lpm(udev, 0);
2024 }
2025 
2026 #endif /* CONFIG_PM */
2027 
2028 const struct bus_type usb_bus_type = {
2029 	.name =		"usb",
2030 	.match =	usb_device_match,
2031 	.uevent =	usb_uevent,
2032 	.need_parent_lock =	true,
2033 };
2034