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