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 */
42ssize_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(size: sizeof(*dynid), GFP_KERNEL);
61 if (!dynid)
62 return -ENOMEM;
63
64 INIT_LIST_HEAD(list: &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(lock: &dynids->lock);
99 list_add_tail(new: &dynid->node, head: &dynids->list);
100 spin_unlock(lock: &dynids->lock);
101
102 retval = driver_attach(drv: driver);
103
104 if (retval)
105 return retval;
106 return count;
107
108fail:
109 kfree(objp: dynid);
110 return retval;
111}
112EXPORT_SYMBOL_GPL(usb_store_new_id);
113
114ssize_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: &buf[count], PAGE_SIZE - count, fmt: "%04x %04x %02x\n",
122 dynid->id.idVendor, dynid->id.idProduct,
123 dynid->id.bInterfaceClass);
124 else
125 count += scnprintf(buf: &buf[count], PAGE_SIZE - count, fmt: "%04x %04x\n",
126 dynid->id.idVendor, dynid->id.idProduct);
127 return count;
128}
129EXPORT_SYMBOL_GPL(usb_show_dynids);
130
131static 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
138static 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}
145static DRIVER_ATTR_RW(new_id);
146
147/*
148 * Remove a USB device ID from this driver
149 */
150static 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(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(entry: &dynid->node);
170 kfree(objp: dynid);
171 break;
172 }
173 }
174 spin_unlock(lock: &usb_driver->dynids.lock);
175 return count;
176}
177
178static ssize_t remove_id_show(struct device_driver *driver, char *buf)
179{
180 return new_id_show(driver, buf);
181}
182static DRIVER_ATTR_RW(remove_id);
183
184static 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(driver: &usb_drv->driver,
193 attr: &driver_attr_new_id);
194 if (error == 0) {
195 error = driver_create_file(driver: &usb_drv->driver,
196 attr: &driver_attr_remove_id);
197 if (error)
198 driver_remove_file(driver: &usb_drv->driver,
199 attr: &driver_attr_new_id);
200 }
201 }
202exit:
203 return error;
204}
205
206static 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(driver: &usb_drv->driver,
213 attr: &driver_attr_remove_id);
214 driver_remove_file(driver: &usb_drv->driver,
215 attr: &driver_attr_new_id);
216 }
217}
218
219static void usb_free_dynids(struct usb_driver *usb_drv)
220{
221 struct usb_dynid *dynid, *n;
222
223 spin_lock(lock: &usb_drv->dynids.lock);
224 list_for_each_entry_safe(dynid, n, &usb_drv->dynids.list, node) {
225 list_del(entry: &dynid->node);
226 kfree(objp: dynid);
227 }
228 spin_unlock(lock: &usb_drv->dynids.lock);
229}
230
231static 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(lock: &drv->dynids.lock);
237 list_for_each_entry(dynid, &drv->dynids.list, node) {
238 if (usb_match_one_id(interface: intf, id: &dynid->id)) {
239 spin_unlock(lock: &drv->dynids.lock);
240 return &dynid->id;
241 }
242 }
243 spin_unlock(lock: &drv->dynids.lock);
244 return NULL;
245}
246
247
248/* called from driver core with dev locked */
249static 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 if (udriver->probe)
294 error = udriver->probe(udev);
295 else if (!udriver->generic_subclass)
296 error = -EINVAL;
297 if (error == -ENODEV && udriver != &usb_generic_driver &&
298 (udriver->id_table || udriver->match)) {
299 udev->use_generic_driver = 1;
300 return -EPROBE_DEFER;
301 }
302 return error;
303}
304
305/* called from driver core with dev locked */
306static int usb_unbind_device(struct device *dev)
307{
308 struct usb_device *udev = to_usb_device(dev);
309 struct usb_device_driver *udriver = to_usb_device_driver(dev->driver);
310
311 if (udriver->disconnect)
312 udriver->disconnect(udev);
313 if (udriver->generic_subclass)
314 usb_generic_driver_disconnect(udev);
315 if (!udriver->supports_autosuspend)
316 usb_autosuspend_device(udev);
317 return 0;
318}
319
320/* called from driver core with dev locked */
321static int usb_probe_interface(struct device *dev)
322{
323 struct usb_driver *driver = to_usb_driver(dev->driver);
324 struct usb_interface *intf = to_usb_interface(dev);
325 struct usb_device *udev = interface_to_usbdev(intf);
326 const struct usb_device_id *id;
327 int error = -ENODEV;
328 int lpm_disable_error = -ENODEV;
329
330 dev_dbg(dev, "%s\n", __func__);
331
332 intf->needs_binding = 0;
333
334 if (usb_device_is_owned(udev))
335 return error;
336
337 if (udev->authorized == 0) {
338 dev_err(&intf->dev, "Device is not authorized for usage\n");
339 return error;
340 } else if (intf->authorized == 0) {
341 dev_err(&intf->dev, "Interface %d is not authorized for usage\n",
342 intf->altsetting->desc.bInterfaceNumber);
343 return error;
344 }
345
346 id = usb_match_dynamic_id(intf, drv: driver);
347 if (!id)
348 id = usb_match_id(interface: intf, id: driver->id_table);
349 if (!id)
350 return error;
351
352 dev_dbg(dev, "%s - got id\n", __func__);
353
354 error = usb_autoresume_device(udev);
355 if (error)
356 return error;
357
358 intf->condition = USB_INTERFACE_BINDING;
359
360 /* Probed interfaces are initially active. They are
361 * runtime-PM-enabled only if the driver has autosuspend support.
362 * They are sensitive to their children's power states.
363 */
364 pm_runtime_set_active(dev);
365 pm_suspend_ignore_children(dev, enable: false);
366 if (driver->supports_autosuspend)
367 pm_runtime_enable(dev);
368
369 /* If the new driver doesn't allow hub-initiated LPM, and we can't
370 * disable hub-initiated LPM, then fail the probe.
371 *
372 * Otherwise, leaving LPM enabled should be harmless, because the
373 * endpoint intervals should remain the same, and the U1/U2 timeouts
374 * should remain the same.
375 *
376 * If we need to install alt setting 0 before probe, or another alt
377 * setting during probe, that should also be fine. usb_set_interface()
378 * will attempt to disable LPM, and fail if it can't disable it.
379 */
380 if (driver->disable_hub_initiated_lpm) {
381 lpm_disable_error = usb_unlocked_disable_lpm(udev);
382 if (lpm_disable_error) {
383 dev_err(&intf->dev, "%s Failed to disable LPM for driver %s\n",
384 __func__, driver->name);
385 error = lpm_disable_error;
386 goto err;
387 }
388 }
389
390 /* Carry out a deferred switch to altsetting 0 */
391 if (intf->needs_altsetting0) {
392 error = usb_set_interface(dev: udev, ifnum: intf->altsetting[0].
393 desc.bInterfaceNumber, alternate: 0);
394 if (error < 0)
395 goto err;
396 intf->needs_altsetting0 = 0;
397 }
398
399 error = driver->probe(intf, id);
400 if (error)
401 goto err;
402
403 intf->condition = USB_INTERFACE_BOUND;
404
405 /* If the LPM disable succeeded, balance the ref counts. */
406 if (!lpm_disable_error)
407 usb_unlocked_enable_lpm(udev);
408
409 usb_autosuspend_device(udev);
410 return error;
411
412 err:
413 usb_set_intfdata(intf, NULL);
414 intf->needs_remote_wakeup = 0;
415 intf->condition = USB_INTERFACE_UNBOUND;
416
417 /* If the LPM disable succeeded, balance the ref counts. */
418 if (!lpm_disable_error)
419 usb_unlocked_enable_lpm(udev);
420
421 /* Unbound interfaces are always runtime-PM-disabled and -suspended */
422 if (driver->supports_autosuspend)
423 pm_runtime_disable(dev);
424 pm_runtime_set_suspended(dev);
425
426 usb_autosuspend_device(udev);
427 return error;
428}
429
430/* called from driver core with dev locked */
431static int usb_unbind_interface(struct device *dev)
432{
433 struct usb_driver *driver = to_usb_driver(dev->driver);
434 struct usb_interface *intf = to_usb_interface(dev);
435 struct usb_host_endpoint *ep, **eps = NULL;
436 struct usb_device *udev;
437 int i, j, error, r;
438 int lpm_disable_error = -ENODEV;
439
440 intf->condition = USB_INTERFACE_UNBINDING;
441
442 /* Autoresume for set_interface call below */
443 udev = interface_to_usbdev(intf);
444 error = usb_autoresume_device(udev);
445
446 /* If hub-initiated LPM policy may change, attempt to disable LPM until
447 * the driver is unbound. If LPM isn't disabled, that's fine because it
448 * wouldn't be enabled unless all the bound interfaces supported
449 * hub-initiated LPM.
450 */
451 if (driver->disable_hub_initiated_lpm)
452 lpm_disable_error = usb_unlocked_disable_lpm(udev);
453
454 /*
455 * Terminate all URBs for this interface unless the driver
456 * supports "soft" unbinding and the device is still present.
457 */
458 if (!driver->soft_unbind || udev->state == USB_STATE_NOTATTACHED)
459 usb_disable_interface(dev: udev, intf, reset_hardware: false);
460
461 driver->disconnect(intf);
462
463 /* Free streams */
464 for (i = 0, j = 0; i < intf->cur_altsetting->desc.bNumEndpoints; i++) {
465 ep = &intf->cur_altsetting->endpoint[i];
466 if (ep->streams == 0)
467 continue;
468 if (j == 0) {
469 eps = kmalloc_array(USB_MAXENDPOINTS, size: sizeof(void *),
470 GFP_KERNEL);
471 if (!eps)
472 break;
473 }
474 eps[j++] = ep;
475 }
476 if (j) {
477 usb_free_streams(interface: intf, eps, num_eps: j, GFP_KERNEL);
478 kfree(objp: eps);
479 }
480
481 /* Reset other interface state.
482 * We cannot do a Set-Interface if the device is suspended or
483 * if it is prepared for a system sleep (since installing a new
484 * altsetting means creating new endpoint device entries).
485 * When either of these happens, defer the Set-Interface.
486 */
487 if (intf->cur_altsetting->desc.bAlternateSetting == 0) {
488 /* Already in altsetting 0 so skip Set-Interface.
489 * Just re-enable it without affecting the endpoint toggles.
490 */
491 usb_enable_interface(dev: udev, intf, reset_toggles: false);
492 } else if (!error && !intf->dev.power.is_prepared) {
493 r = usb_set_interface(dev: udev, ifnum: intf->altsetting[0].
494 desc.bInterfaceNumber, alternate: 0);
495 if (r < 0)
496 intf->needs_altsetting0 = 1;
497 } else {
498 intf->needs_altsetting0 = 1;
499 }
500 usb_set_intfdata(intf, NULL);
501
502 intf->condition = USB_INTERFACE_UNBOUND;
503 intf->needs_remote_wakeup = 0;
504
505 /* Attempt to re-enable USB3 LPM, if the disable succeeded. */
506 if (!lpm_disable_error)
507 usb_unlocked_enable_lpm(udev);
508
509 /* Unbound interfaces are always runtime-PM-disabled and -suspended */
510 if (driver->supports_autosuspend)
511 pm_runtime_disable(dev);
512 pm_runtime_set_suspended(dev);
513
514 if (!error)
515 usb_autosuspend_device(udev);
516
517 return 0;
518}
519
520/**
521 * usb_driver_claim_interface - bind a driver to an interface
522 * @driver: the driver to be bound
523 * @iface: the interface to which it will be bound; must be in the
524 * usb device's active configuration
525 * @data: driver data associated with that interface
526 *
527 * This is used by usb device drivers that need to claim more than one
528 * interface on a device when probing (audio and acm are current examples).
529 * No device driver should directly modify internal usb_interface or
530 * usb_device structure members.
531 *
532 * Callers must own the device lock, so driver probe() entries don't need
533 * extra locking, but other call contexts may need to explicitly claim that
534 * lock.
535 *
536 * Return: 0 on success.
537 */
538int usb_driver_claim_interface(struct usb_driver *driver,
539 struct usb_interface *iface, void *data)
540{
541 struct device *dev;
542 int retval = 0;
543
544 if (!iface)
545 return -ENODEV;
546
547 dev = &iface->dev;
548 if (dev->driver)
549 return -EBUSY;
550
551 /* reject claim if interface is not authorized */
552 if (!iface->authorized)
553 return -ENODEV;
554
555 dev->driver = &driver->driver;
556 usb_set_intfdata(intf: iface, data);
557 iface->needs_binding = 0;
558
559 iface->condition = USB_INTERFACE_BOUND;
560
561 /* Claimed interfaces are initially inactive (suspended) and
562 * runtime-PM-enabled, but only if the driver has autosuspend
563 * support. Otherwise they are marked active, to prevent the
564 * device from being autosuspended, but left disabled. In either
565 * case they are sensitive to their children's power states.
566 */
567 pm_suspend_ignore_children(dev, enable: false);
568 if (driver->supports_autosuspend)
569 pm_runtime_enable(dev);
570 else
571 pm_runtime_set_active(dev);
572
573 /* if interface was already added, bind now; else let
574 * the future device_add() bind it, bypassing probe()
575 */
576 if (device_is_registered(dev))
577 retval = device_bind_driver(dev);
578
579 if (retval) {
580 dev->driver = NULL;
581 usb_set_intfdata(intf: iface, NULL);
582 iface->needs_remote_wakeup = 0;
583 iface->condition = USB_INTERFACE_UNBOUND;
584
585 /*
586 * Unbound interfaces are always runtime-PM-disabled
587 * and runtime-PM-suspended
588 */
589 if (driver->supports_autosuspend)
590 pm_runtime_disable(dev);
591 pm_runtime_set_suspended(dev);
592 }
593
594 return retval;
595}
596EXPORT_SYMBOL_GPL(usb_driver_claim_interface);
597
598/**
599 * usb_driver_release_interface - unbind a driver from an interface
600 * @driver: the driver to be unbound
601 * @iface: the interface from which it will be unbound
602 *
603 * This can be used by drivers to release an interface without waiting
604 * for their disconnect() methods to be called. In typical cases this
605 * also causes the driver disconnect() method to be called.
606 *
607 * This call is synchronous, and may not be used in an interrupt context.
608 * Callers must own the device lock, so driver disconnect() entries don't
609 * need extra locking, but other call contexts may need to explicitly claim
610 * that lock.
611 */
612void usb_driver_release_interface(struct usb_driver *driver,
613 struct usb_interface *iface)
614{
615 struct device *dev = &iface->dev;
616
617 /* this should never happen, don't release something that's not ours */
618 if (!dev->driver || dev->driver != &driver->driver)
619 return;
620
621 /* don't release from within disconnect() */
622 if (iface->condition != USB_INTERFACE_BOUND)
623 return;
624 iface->condition = USB_INTERFACE_UNBINDING;
625
626 /* Release via the driver core only if the interface
627 * has already been registered
628 */
629 if (device_is_registered(dev)) {
630 device_release_driver(dev);
631 } else {
632 device_lock(dev);
633 usb_unbind_interface(dev);
634 dev->driver = NULL;
635 device_unlock(dev);
636 }
637}
638EXPORT_SYMBOL_GPL(usb_driver_release_interface);
639
640/* returns 0 if no match, 1 if match */
641int usb_match_device(struct usb_device *dev, const struct usb_device_id *id)
642{
643 if ((id->match_flags & USB_DEVICE_ID_MATCH_VENDOR) &&
644 id->idVendor != le16_to_cpu(dev->descriptor.idVendor))
645 return 0;
646
647 if ((id->match_flags & USB_DEVICE_ID_MATCH_PRODUCT) &&
648 id->idProduct != le16_to_cpu(dev->descriptor.idProduct))
649 return 0;
650
651 /* No need to test id->bcdDevice_lo != 0, since 0 is never
652 greater than any unsigned number. */
653 if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_LO) &&
654 (id->bcdDevice_lo > le16_to_cpu(dev->descriptor.bcdDevice)))
655 return 0;
656
657 if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_HI) &&
658 (id->bcdDevice_hi < le16_to_cpu(dev->descriptor.bcdDevice)))
659 return 0;
660
661 if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_CLASS) &&
662 (id->bDeviceClass != dev->descriptor.bDeviceClass))
663 return 0;
664
665 if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_SUBCLASS) &&
666 (id->bDeviceSubClass != dev->descriptor.bDeviceSubClass))
667 return 0;
668
669 if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_PROTOCOL) &&
670 (id->bDeviceProtocol != dev->descriptor.bDeviceProtocol))
671 return 0;
672
673 return 1;
674}
675
676/* returns 0 if no match, 1 if match */
677int usb_match_one_id_intf(struct usb_device *dev,
678 struct usb_host_interface *intf,
679 const struct usb_device_id *id)
680{
681 /* The interface class, subclass, protocol and number should never be
682 * checked for a match if the device class is Vendor Specific,
683 * unless the match record specifies the Vendor ID. */
684 if (dev->descriptor.bDeviceClass == USB_CLASS_VENDOR_SPEC &&
685 !(id->match_flags & USB_DEVICE_ID_MATCH_VENDOR) &&
686 (id->match_flags & (USB_DEVICE_ID_MATCH_INT_CLASS |
687 USB_DEVICE_ID_MATCH_INT_SUBCLASS |
688 USB_DEVICE_ID_MATCH_INT_PROTOCOL |
689 USB_DEVICE_ID_MATCH_INT_NUMBER)))
690 return 0;
691
692 if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_CLASS) &&
693 (id->bInterfaceClass != intf->desc.bInterfaceClass))
694 return 0;
695
696 if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_SUBCLASS) &&
697 (id->bInterfaceSubClass != intf->desc.bInterfaceSubClass))
698 return 0;
699
700 if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_PROTOCOL) &&
701 (id->bInterfaceProtocol != intf->desc.bInterfaceProtocol))
702 return 0;
703
704 if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_NUMBER) &&
705 (id->bInterfaceNumber != intf->desc.bInterfaceNumber))
706 return 0;
707
708 return 1;
709}
710
711/* returns 0 if no match, 1 if match */
712int usb_match_one_id(struct usb_interface *interface,
713 const struct usb_device_id *id)
714{
715 struct usb_host_interface *intf;
716 struct usb_device *dev;
717
718 /* proc_connectinfo in devio.c may call us with id == NULL. */
719 if (id == NULL)
720 return 0;
721
722 intf = interface->cur_altsetting;
723 dev = interface_to_usbdev(interface);
724
725 if (!usb_match_device(dev, id))
726 return 0;
727
728 return usb_match_one_id_intf(dev, intf, id);
729}
730EXPORT_SYMBOL_GPL(usb_match_one_id);
731
732/**
733 * usb_match_id - find first usb_device_id matching device or interface
734 * @interface: the interface of interest
735 * @id: array of usb_device_id structures, terminated by zero entry
736 *
737 * usb_match_id searches an array of usb_device_id's and returns
738 * the first one matching the device or interface, or null.
739 * This is used when binding (or rebinding) a driver to an interface.
740 * Most USB device drivers will use this indirectly, through the usb core,
741 * but some layered driver frameworks use it directly.
742 * These device tables are exported with MODULE_DEVICE_TABLE, through
743 * modutils, to support the driver loading functionality of USB hotplugging.
744 *
745 * Return: The first matching usb_device_id, or %NULL.
746 *
747 * What Matches:
748 *
749 * The "match_flags" element in a usb_device_id controls which
750 * members are used. If the corresponding bit is set, the
751 * value in the device_id must match its corresponding member
752 * in the device or interface descriptor, or else the device_id
753 * does not match.
754 *
755 * "driver_info" is normally used only by device drivers,
756 * but you can create a wildcard "matches anything" usb_device_id
757 * as a driver's "modules.usbmap" entry if you provide an id with
758 * only a nonzero "driver_info" field. If you do this, the USB device
759 * driver's probe() routine should use additional intelligence to
760 * decide whether to bind to the specified interface.
761 *
762 * What Makes Good usb_device_id Tables:
763 *
764 * The match algorithm is very simple, so that intelligence in
765 * driver selection must come from smart driver id records.
766 * Unless you have good reasons to use another selection policy,
767 * provide match elements only in related groups, and order match
768 * specifiers from specific to general. Use the macros provided
769 * for that purpose if you can.
770 *
771 * The most specific match specifiers use device descriptor
772 * data. These are commonly used with product-specific matches;
773 * the USB_DEVICE macro lets you provide vendor and product IDs,
774 * and you can also match against ranges of product revisions.
775 * These are widely used for devices with application or vendor
776 * specific bDeviceClass values.
777 *
778 * Matches based on device class/subclass/protocol specifications
779 * are slightly more general; use the USB_DEVICE_INFO macro, or
780 * its siblings. These are used with single-function devices
781 * where bDeviceClass doesn't specify that each interface has
782 * its own class.
783 *
784 * Matches based on interface class/subclass/protocol are the
785 * most general; they let drivers bind to any interface on a
786 * multiple-function device. Use the USB_INTERFACE_INFO
787 * macro, or its siblings, to match class-per-interface style
788 * devices (as recorded in bInterfaceClass).
789 *
790 * Note that an entry created by USB_INTERFACE_INFO won't match
791 * any interface if the device class is set to Vendor-Specific.
792 * This is deliberate; according to the USB spec the meanings of
793 * the interface class/subclass/protocol for these devices are also
794 * vendor-specific, and hence matching against a standard product
795 * class wouldn't work anyway. If you really want to use an
796 * interface-based match for such a device, create a match record
797 * that also specifies the vendor ID. (Unforunately there isn't a
798 * standard macro for creating records like this.)
799 *
800 * Within those groups, remember that not all combinations are
801 * meaningful. For example, don't give a product version range
802 * without vendor and product IDs; or specify a protocol without
803 * its associated class and subclass.
804 */
805const struct usb_device_id *usb_match_id(struct usb_interface *interface,
806 const struct usb_device_id *id)
807{
808 /* proc_connectinfo in devio.c may call us with id == NULL. */
809 if (id == NULL)
810 return NULL;
811
812 /* It is important to check that id->driver_info is nonzero,
813 since an entry that is all zeroes except for a nonzero
814 id->driver_info is the way to create an entry that
815 indicates that the driver want to examine every
816 device and interface. */
817 for (; id->idVendor || id->idProduct || id->bDeviceClass ||
818 id->bInterfaceClass || id->driver_info; id++) {
819 if (usb_match_one_id(interface, id))
820 return id;
821 }
822
823 return NULL;
824}
825EXPORT_SYMBOL_GPL(usb_match_id);
826
827const struct usb_device_id *usb_device_match_id(struct usb_device *udev,
828 const struct usb_device_id *id)
829{
830 if (!id)
831 return NULL;
832
833 for (; id->idVendor || id->idProduct ; id++) {
834 if (usb_match_device(dev: udev, id))
835 return id;
836 }
837
838 return NULL;
839}
840EXPORT_SYMBOL_GPL(usb_device_match_id);
841
842bool usb_driver_applicable(struct usb_device *udev,
843 struct usb_device_driver *udrv)
844{
845 if (udrv->id_table && udrv->match)
846 return usb_device_match_id(udev, udrv->id_table) != NULL &&
847 udrv->match(udev);
848
849 if (udrv->id_table)
850 return usb_device_match_id(udev, udrv->id_table) != NULL;
851
852 if (udrv->match)
853 return udrv->match(udev);
854
855 return false;
856}
857
858static int usb_device_match(struct device *dev, struct device_driver *drv)
859{
860 /* devices and interfaces are handled separately */
861 if (is_usb_device(dev)) {
862 struct usb_device *udev;
863 struct usb_device_driver *udrv;
864
865 /* interface drivers never match devices */
866 if (!is_usb_device_driver(drv))
867 return 0;
868
869 udev = to_usb_device(dev);
870 udrv = to_usb_device_driver(drv);
871
872 /* If the device driver under consideration does not have a
873 * id_table or a match function, then let the driver's probe
874 * function decide.
875 */
876 if (!udrv->id_table && !udrv->match)
877 return 1;
878
879 return usb_driver_applicable(udev, udrv);
880
881 } else if (is_usb_interface(dev)) {
882 struct usb_interface *intf;
883 struct usb_driver *usb_drv;
884 const struct usb_device_id *id;
885
886 /* device drivers never match interfaces */
887 if (is_usb_device_driver(drv))
888 return 0;
889
890 intf = to_usb_interface(dev);
891 usb_drv = to_usb_driver(drv);
892
893 id = usb_match_id(intf, usb_drv->id_table);
894 if (id)
895 return 1;
896
897 id = usb_match_dynamic_id(intf, drv: usb_drv);
898 if (id)
899 return 1;
900 }
901
902 return 0;
903}
904
905static int usb_uevent(const struct device *dev, struct kobj_uevent_env *env)
906{
907 const struct usb_device *usb_dev;
908
909 if (is_usb_device(dev)) {
910 usb_dev = to_usb_device(dev);
911 } else if (is_usb_interface(dev)) {
912 const struct usb_interface *intf = to_usb_interface(dev);
913
914 usb_dev = interface_to_usbdev(intf);
915 } else {
916 return 0;
917 }
918
919 if (usb_dev->devnum < 0) {
920 /* driver is often null here; dev_dbg() would oops */
921 pr_debug("usb %s: already deleted?\n", dev_name(dev));
922 return -ENODEV;
923 }
924 if (!usb_dev->bus) {
925 pr_debug("usb %s: bus removed?\n", dev_name(dev));
926 return -ENODEV;
927 }
928
929 /* per-device configurations are common */
930 if (add_uevent_var(env, format: "PRODUCT=%x/%x/%x",
931 le16_to_cpu(usb_dev->descriptor.idVendor),
932 le16_to_cpu(usb_dev->descriptor.idProduct),
933 le16_to_cpu(usb_dev->descriptor.bcdDevice)))
934 return -ENOMEM;
935
936 /* class-based driver binding models */
937 if (add_uevent_var(env, format: "TYPE=%d/%d/%d",
938 usb_dev->descriptor.bDeviceClass,
939 usb_dev->descriptor.bDeviceSubClass,
940 usb_dev->descriptor.bDeviceProtocol))
941 return -ENOMEM;
942
943 return 0;
944}
945
946static int __usb_bus_reprobe_drivers(struct device *dev, void *data)
947{
948 struct usb_device_driver *new_udriver = data;
949 struct usb_device *udev;
950 int ret;
951
952 /* Don't reprobe if current driver isn't usb_generic_driver */
953 if (dev->driver != &usb_generic_driver.driver)
954 return 0;
955
956 udev = to_usb_device(dev);
957 if (!usb_driver_applicable(udev, udrv: new_udriver))
958 return 0;
959
960 ret = device_reprobe(dev);
961 if (ret && ret != -EPROBE_DEFER)
962 dev_err(dev, "Failed to reprobe device (error %d)\n", ret);
963
964 return 0;
965}
966
967bool is_usb_device_driver(const struct device_driver *drv)
968{
969 return drv->probe == usb_probe_device;
970}
971
972/**
973 * usb_register_device_driver - register a USB device (not interface) driver
974 * @new_udriver: USB operations for the device driver
975 * @owner: module owner of this driver.
976 *
977 * Registers a USB device driver with the USB core. The list of
978 * unattached devices will be rescanned whenever a new driver is
979 * added, allowing the new driver to attach to any recognized devices.
980 *
981 * Return: A negative error code on failure and 0 on success.
982 */
983int usb_register_device_driver(struct usb_device_driver *new_udriver,
984 struct module *owner)
985{
986 int retval = 0;
987
988 if (usb_disabled())
989 return -ENODEV;
990
991 new_udriver->driver.name = new_udriver->name;
992 new_udriver->driver.bus = &usb_bus_type;
993 new_udriver->driver.probe = usb_probe_device;
994 new_udriver->driver.remove = usb_unbind_device;
995 new_udriver->driver.owner = owner;
996 new_udriver->driver.dev_groups = new_udriver->dev_groups;
997
998 retval = driver_register(drv: &new_udriver->driver);
999
1000 if (!retval) {
1001 pr_info("%s: registered new device driver %s\n",
1002 usbcore_name, new_udriver->name);
1003 /*
1004 * Check whether any device could be better served with
1005 * this new driver
1006 */
1007 bus_for_each_dev(bus: &usb_bus_type, NULL, data: new_udriver,
1008 fn: __usb_bus_reprobe_drivers);
1009 } else {
1010 pr_err("%s: error %d registering device driver %s\n",
1011 usbcore_name, retval, new_udriver->name);
1012 }
1013
1014 return retval;
1015}
1016EXPORT_SYMBOL_GPL(usb_register_device_driver);
1017
1018/**
1019 * usb_deregister_device_driver - unregister a USB device (not interface) driver
1020 * @udriver: USB operations of the device driver to unregister
1021 * Context: must be able to sleep
1022 *
1023 * Unlinks the specified driver from the internal USB driver list.
1024 */
1025void usb_deregister_device_driver(struct usb_device_driver *udriver)
1026{
1027 pr_info("%s: deregistering device driver %s\n",
1028 usbcore_name, udriver->name);
1029
1030 driver_unregister(drv: &udriver->driver);
1031}
1032EXPORT_SYMBOL_GPL(usb_deregister_device_driver);
1033
1034/**
1035 * usb_register_driver - register a USB interface driver
1036 * @new_driver: USB operations for the interface driver
1037 * @owner: module owner of this driver.
1038 * @mod_name: module name string
1039 *
1040 * Registers a USB interface driver with the USB core. The list of
1041 * unattached interfaces will be rescanned whenever a new driver is
1042 * added, allowing the new driver to attach to any recognized interfaces.
1043 *
1044 * Return: A negative error code on failure and 0 on success.
1045 *
1046 * NOTE: if you want your driver to use the USB major number, you must call
1047 * usb_register_dev() to enable that functionality. This function no longer
1048 * takes care of that.
1049 */
1050int usb_register_driver(struct usb_driver *new_driver, struct module *owner,
1051 const char *mod_name)
1052{
1053 int retval = 0;
1054
1055 if (usb_disabled())
1056 return -ENODEV;
1057
1058 new_driver->driver.name = new_driver->name;
1059 new_driver->driver.bus = &usb_bus_type;
1060 new_driver->driver.probe = usb_probe_interface;
1061 new_driver->driver.remove = usb_unbind_interface;
1062 new_driver->driver.owner = owner;
1063 new_driver->driver.mod_name = mod_name;
1064 new_driver->driver.dev_groups = new_driver->dev_groups;
1065 spin_lock_init(&new_driver->dynids.lock);
1066 INIT_LIST_HEAD(list: &new_driver->dynids.list);
1067
1068 retval = driver_register(drv: &new_driver->driver);
1069 if (retval)
1070 goto out;
1071
1072 retval = usb_create_newid_files(usb_drv: new_driver);
1073 if (retval)
1074 goto out_newid;
1075
1076 pr_info("%s: registered new interface driver %s\n",
1077 usbcore_name, new_driver->name);
1078
1079out:
1080 return retval;
1081
1082out_newid:
1083 driver_unregister(drv: &new_driver->driver);
1084
1085 pr_err("%s: error %d registering interface driver %s\n",
1086 usbcore_name, retval, new_driver->name);
1087 goto out;
1088}
1089EXPORT_SYMBOL_GPL(usb_register_driver);
1090
1091/**
1092 * usb_deregister - unregister a USB interface driver
1093 * @driver: USB operations of the interface driver to unregister
1094 * Context: must be able to sleep
1095 *
1096 * Unlinks the specified driver from the internal USB driver list.
1097 *
1098 * NOTE: If you called usb_register_dev(), you still need to call
1099 * usb_deregister_dev() to clean up your driver's allocated minor numbers,
1100 * this * call will no longer do it for you.
1101 */
1102void usb_deregister(struct usb_driver *driver)
1103{
1104 pr_info("%s: deregistering interface driver %s\n",
1105 usbcore_name, driver->name);
1106
1107 usb_remove_newid_files(usb_drv: driver);
1108 driver_unregister(drv: &driver->driver);
1109 usb_free_dynids(usb_drv: driver);
1110}
1111EXPORT_SYMBOL_GPL(usb_deregister);
1112
1113/* Forced unbinding of a USB interface driver, either because
1114 * it doesn't support pre_reset/post_reset/reset_resume or
1115 * because it doesn't support suspend/resume.
1116 *
1117 * The caller must hold @intf's device's lock, but not @intf's lock.
1118 */
1119void usb_forced_unbind_intf(struct usb_interface *intf)
1120{
1121 struct usb_driver *driver = to_usb_driver(intf->dev.driver);
1122
1123 dev_dbg(&intf->dev, "forced unbind\n");
1124 usb_driver_release_interface(driver, intf);
1125
1126 /* Mark the interface for later rebinding */
1127 intf->needs_binding = 1;
1128}
1129
1130/*
1131 * Unbind drivers for @udev's marked interfaces. These interfaces have
1132 * the needs_binding flag set, for example by usb_resume_interface().
1133 *
1134 * The caller must hold @udev's device lock.
1135 */
1136static void unbind_marked_interfaces(struct usb_device *udev)
1137{
1138 struct usb_host_config *config;
1139 int i;
1140 struct usb_interface *intf;
1141
1142 config = udev->actconfig;
1143 if (config) {
1144 for (i = 0; i < config->desc.bNumInterfaces; ++i) {
1145 intf = config->interface[i];
1146 if (intf->dev.driver && intf->needs_binding)
1147 usb_forced_unbind_intf(intf);
1148 }
1149 }
1150}
1151
1152/* Delayed forced unbinding of a USB interface driver and scan
1153 * for rebinding.
1154 *
1155 * The caller must hold @intf's device's lock, but not @intf's lock.
1156 *
1157 * Note: Rebinds will be skipped if a system sleep transition is in
1158 * progress and the PM "complete" callback hasn't occurred yet.
1159 */
1160static void usb_rebind_intf(struct usb_interface *intf)
1161{
1162 int rc;
1163
1164 /* Delayed unbind of an existing driver */
1165 if (intf->dev.driver)
1166 usb_forced_unbind_intf(intf);
1167
1168 /* Try to rebind the interface */
1169 if (!intf->dev.power.is_prepared) {
1170 intf->needs_binding = 0;
1171 rc = device_attach(dev: &intf->dev);
1172 if (rc < 0 && rc != -EPROBE_DEFER)
1173 dev_warn(&intf->dev, "rebind failed: %d\n", rc);
1174 }
1175}
1176
1177/*
1178 * Rebind drivers to @udev's marked interfaces. These interfaces have
1179 * the needs_binding flag set.
1180 *
1181 * The caller must hold @udev's device lock.
1182 */
1183static void rebind_marked_interfaces(struct usb_device *udev)
1184{
1185 struct usb_host_config *config;
1186 int i;
1187 struct usb_interface *intf;
1188
1189 config = udev->actconfig;
1190 if (config) {
1191 for (i = 0; i < config->desc.bNumInterfaces; ++i) {
1192 intf = config->interface[i];
1193 if (intf->needs_binding)
1194 usb_rebind_intf(intf);
1195 }
1196 }
1197}
1198
1199/*
1200 * Unbind all of @udev's marked interfaces and then rebind all of them.
1201 * This ordering is necessary because some drivers claim several interfaces
1202 * when they are first probed.
1203 *
1204 * The caller must hold @udev's device lock.
1205 */
1206void usb_unbind_and_rebind_marked_interfaces(struct usb_device *udev)
1207{
1208 unbind_marked_interfaces(udev);
1209 rebind_marked_interfaces(udev);
1210}
1211
1212#ifdef CONFIG_PM
1213
1214/* Unbind drivers for @udev's interfaces that don't support suspend/resume
1215 * There is no check for reset_resume here because it can be determined
1216 * only during resume whether reset_resume is needed.
1217 *
1218 * The caller must hold @udev's device lock.
1219 */
1220static void unbind_no_pm_drivers_interfaces(struct usb_device *udev)
1221{
1222 struct usb_host_config *config;
1223 int i;
1224 struct usb_interface *intf;
1225 struct usb_driver *drv;
1226
1227 config = udev->actconfig;
1228 if (config) {
1229 for (i = 0; i < config->desc.bNumInterfaces; ++i) {
1230 intf = config->interface[i];
1231
1232 if (intf->dev.driver) {
1233 drv = to_usb_driver(intf->dev.driver);
1234 if (!drv->suspend || !drv->resume)
1235 usb_forced_unbind_intf(intf);
1236 }
1237 }
1238 }
1239}
1240
1241static int usb_suspend_device(struct usb_device *udev, pm_message_t msg)
1242{
1243 struct usb_device_driver *udriver;
1244 int status = 0;
1245
1246 if (udev->state == USB_STATE_NOTATTACHED ||
1247 udev->state == USB_STATE_SUSPENDED)
1248 goto done;
1249
1250 /* For devices that don't have a driver, we do a generic suspend. */
1251 if (udev->dev.driver)
1252 udriver = to_usb_device_driver(udev->dev.driver);
1253 else {
1254 udev->do_remote_wakeup = 0;
1255 udriver = &usb_generic_driver;
1256 }
1257 if (udriver->suspend)
1258 status = udriver->suspend(udev, msg);
1259 if (status == 0 && udriver->generic_subclass)
1260 status = usb_generic_driver_suspend(udev, msg);
1261
1262 done:
1263 dev_vdbg(&udev->dev, "%s: status %d\n", __func__, status);
1264 return status;
1265}
1266
1267static int usb_resume_device(struct usb_device *udev, pm_message_t msg)
1268{
1269 struct usb_device_driver *udriver;
1270 int status = 0;
1271
1272 if (udev->state == USB_STATE_NOTATTACHED)
1273 goto done;
1274
1275 /* Can't resume it if it doesn't have a driver. */
1276 if (udev->dev.driver == NULL) {
1277 status = -ENOTCONN;
1278 goto done;
1279 }
1280
1281 /* Non-root devices on a full/low-speed bus must wait for their
1282 * companion high-speed root hub, in case a handoff is needed.
1283 */
1284 if (!PMSG_IS_AUTO(msg) && udev->parent && udev->bus->hs_companion)
1285 device_pm_wait_for_dev(sub: &udev->dev,
1286 dev: &udev->bus->hs_companion->root_hub->dev);
1287
1288 if (udev->quirks & USB_QUIRK_RESET_RESUME)
1289 udev->reset_resume = 1;
1290
1291 udriver = to_usb_device_driver(udev->dev.driver);
1292 if (udriver->generic_subclass)
1293 status = usb_generic_driver_resume(udev, msg);
1294 if (status == 0 && udriver->resume)
1295 status = udriver->resume(udev, msg);
1296
1297 done:
1298 dev_vdbg(&udev->dev, "%s: status %d\n", __func__, status);
1299 return status;
1300}
1301
1302static int usb_suspend_interface(struct usb_device *udev,
1303 struct usb_interface *intf, pm_message_t msg)
1304{
1305 struct usb_driver *driver;
1306 int status = 0;
1307
1308 if (udev->state == USB_STATE_NOTATTACHED ||
1309 intf->condition == USB_INTERFACE_UNBOUND)
1310 goto done;
1311 driver = to_usb_driver(intf->dev.driver);
1312
1313 /* at this time we know the driver supports suspend */
1314 status = driver->suspend(intf, msg);
1315 if (status && !PMSG_IS_AUTO(msg))
1316 dev_err(&intf->dev, "suspend error %d\n", status);
1317
1318 done:
1319 dev_vdbg(&intf->dev, "%s: status %d\n", __func__, status);
1320 return status;
1321}
1322
1323static int usb_resume_interface(struct usb_device *udev,
1324 struct usb_interface *intf, pm_message_t msg, int reset_resume)
1325{
1326 struct usb_driver *driver;
1327 int status = 0;
1328
1329 if (udev->state == USB_STATE_NOTATTACHED)
1330 goto done;
1331
1332 /* Don't let autoresume interfere with unbinding */
1333 if (intf->condition == USB_INTERFACE_UNBINDING)
1334 goto done;
1335
1336 /* Can't resume it if it doesn't have a driver. */
1337 if (intf->condition == USB_INTERFACE_UNBOUND) {
1338
1339 /* Carry out a deferred switch to altsetting 0 */
1340 if (intf->needs_altsetting0 && !intf->dev.power.is_prepared) {
1341 usb_set_interface(dev: udev, ifnum: intf->altsetting[0].
1342 desc.bInterfaceNumber, alternate: 0);
1343 intf->needs_altsetting0 = 0;
1344 }
1345 goto done;
1346 }
1347
1348 /* Don't resume if the interface is marked for rebinding */
1349 if (intf->needs_binding)
1350 goto done;
1351 driver = to_usb_driver(intf->dev.driver);
1352
1353 if (reset_resume) {
1354 if (driver->reset_resume) {
1355 status = driver->reset_resume(intf);
1356 if (status)
1357 dev_err(&intf->dev, "%s error %d\n",
1358 "reset_resume", status);
1359 } else {
1360 intf->needs_binding = 1;
1361 dev_dbg(&intf->dev, "no reset_resume for driver %s?\n",
1362 driver->name);
1363 }
1364 } else {
1365 status = driver->resume(intf);
1366 if (status)
1367 dev_err(&intf->dev, "resume error %d\n", status);
1368 }
1369
1370done:
1371 dev_vdbg(&intf->dev, "%s: status %d\n", __func__, status);
1372
1373 /* Later we will unbind the driver and/or reprobe, if necessary */
1374 return status;
1375}
1376
1377/**
1378 * usb_suspend_both - suspend a USB device and its interfaces
1379 * @udev: the usb_device to suspend
1380 * @msg: Power Management message describing this state transition
1381 *
1382 * This is the central routine for suspending USB devices. It calls the
1383 * suspend methods for all the interface drivers in @udev and then calls
1384 * the suspend method for @udev itself. When the routine is called in
1385 * autosuspend, if an error occurs at any stage, all the interfaces
1386 * which were suspended are resumed so that they remain in the same
1387 * state as the device, but when called from system sleep, all error
1388 * from suspend methods of interfaces and the non-root-hub device itself
1389 * are simply ignored, so all suspended interfaces are only resumed
1390 * to the device's state when @udev is root-hub and its suspend method
1391 * returns failure.
1392 *
1393 * Autosuspend requests originating from a child device or an interface
1394 * driver may be made without the protection of @udev's device lock, but
1395 * all other suspend calls will hold the lock. Usbcore will insure that
1396 * method calls do not arrive during bind, unbind, or reset operations.
1397 * However drivers must be prepared to handle suspend calls arriving at
1398 * unpredictable times.
1399 *
1400 * This routine can run only in process context.
1401 *
1402 * Return: 0 if the suspend succeeded.
1403 */
1404static int usb_suspend_both(struct usb_device *udev, pm_message_t msg)
1405{
1406 int status = 0;
1407 int i = 0, n = 0;
1408 struct usb_interface *intf;
1409
1410 if (udev->state == USB_STATE_NOTATTACHED ||
1411 udev->state == USB_STATE_SUSPENDED)
1412 goto done;
1413
1414 /* Suspend all the interfaces and then udev itself */
1415 if (udev->actconfig) {
1416 n = udev->actconfig->desc.bNumInterfaces;
1417 for (i = n - 1; i >= 0; --i) {
1418 intf = udev->actconfig->interface[i];
1419 status = usb_suspend_interface(udev, intf, msg);
1420
1421 /* Ignore errors during system sleep transitions */
1422 if (!PMSG_IS_AUTO(msg))
1423 status = 0;
1424 if (status != 0)
1425 break;
1426 }
1427 }
1428 if (status == 0) {
1429 status = usb_suspend_device(udev, msg);
1430
1431 /*
1432 * Ignore errors from non-root-hub devices during
1433 * system sleep transitions. For the most part,
1434 * these devices should go to low power anyway when
1435 * the entire bus is suspended.
1436 */
1437 if (udev->parent && !PMSG_IS_AUTO(msg))
1438 status = 0;
1439
1440 /*
1441 * If the device is inaccessible, don't try to resume
1442 * suspended interfaces and just return the error.
1443 */
1444 if (status && status != -EBUSY) {
1445 int err;
1446 u16 devstat;
1447
1448 err = usb_get_std_status(dev: udev, USB_RECIP_DEVICE, target: 0,
1449 data: &devstat);
1450 if (err) {
1451 dev_err(&udev->dev,
1452 "Failed to suspend device, error %d\n",
1453 status);
1454 goto done;
1455 }
1456 }
1457 }
1458
1459 /* If the suspend failed, resume interfaces that did get suspended */
1460 if (status != 0) {
1461 if (udev->actconfig) {
1462 msg.event ^= (PM_EVENT_SUSPEND | PM_EVENT_RESUME);
1463 while (++i < n) {
1464 intf = udev->actconfig->interface[i];
1465 usb_resume_interface(udev, intf, msg, reset_resume: 0);
1466 }
1467 }
1468
1469 /* If the suspend succeeded then prevent any more URB submissions
1470 * and flush any outstanding URBs.
1471 */
1472 } else {
1473 udev->can_submit = 0;
1474 for (i = 0; i < 16; ++i) {
1475 usb_hcd_flush_endpoint(udev, ep: udev->ep_out[i]);
1476 usb_hcd_flush_endpoint(udev, ep: udev->ep_in[i]);
1477 }
1478 }
1479
1480 done:
1481 dev_vdbg(&udev->dev, "%s: status %d\n", __func__, status);
1482 return status;
1483}
1484
1485/**
1486 * usb_resume_both - resume a USB device and its interfaces
1487 * @udev: the usb_device to resume
1488 * @msg: Power Management message describing this state transition
1489 *
1490 * This is the central routine for resuming USB devices. It calls the
1491 * resume method for @udev and then calls the resume methods for all
1492 * the interface drivers in @udev.
1493 *
1494 * Autoresume requests originating from a child device or an interface
1495 * driver may be made without the protection of @udev's device lock, but
1496 * all other resume calls will hold the lock. Usbcore will insure that
1497 * method calls do not arrive during bind, unbind, or reset operations.
1498 * However drivers must be prepared to handle resume calls arriving at
1499 * unpredictable times.
1500 *
1501 * This routine can run only in process context.
1502 *
1503 * Return: 0 on success.
1504 */
1505static int usb_resume_both(struct usb_device *udev, pm_message_t msg)
1506{
1507 int status = 0;
1508 int i;
1509 struct usb_interface *intf;
1510
1511 if (udev->state == USB_STATE_NOTATTACHED) {
1512 status = -ENODEV;
1513 goto done;
1514 }
1515 udev->can_submit = 1;
1516
1517 /* Resume the device */
1518 if (udev->state == USB_STATE_SUSPENDED || udev->reset_resume)
1519 status = usb_resume_device(udev, msg);
1520
1521 /* Resume the interfaces */
1522 if (status == 0 && udev->actconfig) {
1523 for (i = 0; i < udev->actconfig->desc.bNumInterfaces; i++) {
1524 intf = udev->actconfig->interface[i];
1525 usb_resume_interface(udev, intf, msg,
1526 reset_resume: udev->reset_resume);
1527 }
1528 }
1529 usb_mark_last_busy(udev);
1530
1531 done:
1532 dev_vdbg(&udev->dev, "%s: status %d\n", __func__, status);
1533 if (!status)
1534 udev->reset_resume = 0;
1535 return status;
1536}
1537
1538static void choose_wakeup(struct usb_device *udev, pm_message_t msg)
1539{
1540 int w;
1541
1542 /*
1543 * For FREEZE/QUIESCE, disable remote wakeups so no interrupts get
1544 * generated.
1545 */
1546 if (msg.event == PM_EVENT_FREEZE || msg.event == PM_EVENT_QUIESCE) {
1547 w = 0;
1548
1549 } else {
1550 /*
1551 * Enable remote wakeup if it is allowed, even if no interface
1552 * drivers actually want it.
1553 */
1554 w = device_may_wakeup(dev: &udev->dev);
1555 }
1556
1557 /*
1558 * If the device is autosuspended with the wrong wakeup setting,
1559 * autoresume now so the setting can be changed.
1560 */
1561 if (udev->state == USB_STATE_SUSPENDED && w != udev->do_remote_wakeup)
1562 pm_runtime_resume(dev: &udev->dev);
1563 udev->do_remote_wakeup = w;
1564}
1565
1566/* The device lock is held by the PM core */
1567int usb_suspend(struct device *dev, pm_message_t msg)
1568{
1569 struct usb_device *udev = to_usb_device(dev);
1570 int r;
1571
1572 unbind_no_pm_drivers_interfaces(udev);
1573
1574 /* From now on we are sure all drivers support suspend/resume
1575 * but not necessarily reset_resume()
1576 * so we may still need to unbind and rebind upon resume
1577 */
1578 choose_wakeup(udev, msg);
1579 r = usb_suspend_both(udev, msg);
1580 if (r)
1581 return r;
1582
1583 if (udev->quirks & USB_QUIRK_DISCONNECT_SUSPEND)
1584 usb_port_disable(udev);
1585
1586 return 0;
1587}
1588
1589/* The device lock is held by the PM core */
1590int usb_resume_complete(struct device *dev)
1591{
1592 struct usb_device *udev = to_usb_device(dev);
1593
1594 /* For PM complete calls, all we do is rebind interfaces
1595 * whose needs_binding flag is set
1596 */
1597 if (udev->state != USB_STATE_NOTATTACHED)
1598 rebind_marked_interfaces(udev);
1599 return 0;
1600}
1601
1602/* The device lock is held by the PM core */
1603int usb_resume(struct device *dev, pm_message_t msg)
1604{
1605 struct usb_device *udev = to_usb_device(dev);
1606 int status;
1607
1608 /* For all calls, take the device back to full power and
1609 * tell the PM core in case it was autosuspended previously.
1610 * Unbind the interfaces that will need rebinding later,
1611 * because they fail to support reset_resume.
1612 * (This can't be done in usb_resume_interface()
1613 * above because it doesn't own the right set of locks.)
1614 */
1615 status = usb_resume_both(udev, msg);
1616 if (status == 0) {
1617 pm_runtime_disable(dev);
1618 pm_runtime_set_active(dev);
1619 pm_runtime_enable(dev);
1620 unbind_marked_interfaces(udev);
1621 }
1622
1623 /* Avoid PM error messages for devices disconnected while suspended
1624 * as we'll display regular disconnect messages just a bit later.
1625 */
1626 if (status == -ENODEV || status == -ESHUTDOWN)
1627 status = 0;
1628 return status;
1629}
1630
1631/**
1632 * usb_enable_autosuspend - allow a USB device to be autosuspended
1633 * @udev: the USB device which may be autosuspended
1634 *
1635 * This routine allows @udev to be autosuspended. An autosuspend won't
1636 * take place until the autosuspend_delay has elapsed and all the other
1637 * necessary conditions are satisfied.
1638 *
1639 * The caller must hold @udev's device lock.
1640 */
1641void usb_enable_autosuspend(struct usb_device *udev)
1642{
1643 pm_runtime_allow(dev: &udev->dev);
1644}
1645EXPORT_SYMBOL_GPL(usb_enable_autosuspend);
1646
1647/**
1648 * usb_disable_autosuspend - prevent a USB device from being autosuspended
1649 * @udev: the USB device which may not be autosuspended
1650 *
1651 * This routine prevents @udev from being autosuspended and wakes it up
1652 * if it is already autosuspended.
1653 *
1654 * The caller must hold @udev's device lock.
1655 */
1656void usb_disable_autosuspend(struct usb_device *udev)
1657{
1658 pm_runtime_forbid(dev: &udev->dev);
1659}
1660EXPORT_SYMBOL_GPL(usb_disable_autosuspend);
1661
1662/**
1663 * usb_autosuspend_device - delayed autosuspend of a USB device and its interfaces
1664 * @udev: the usb_device to autosuspend
1665 *
1666 * This routine should be called when a core subsystem is finished using
1667 * @udev and wants to allow it to autosuspend. Examples would be when
1668 * @udev's device file in usbfs is closed or after a configuration change.
1669 *
1670 * @udev's usage counter is decremented; if it drops to 0 and all the
1671 * interfaces are inactive then a delayed autosuspend will be attempted.
1672 * The attempt may fail (see autosuspend_check()).
1673 *
1674 * The caller must hold @udev's device lock.
1675 *
1676 * This routine can run only in process context.
1677 */
1678void usb_autosuspend_device(struct usb_device *udev)
1679{
1680 int status;
1681
1682 usb_mark_last_busy(udev);
1683 status = pm_runtime_put_sync_autosuspend(dev: &udev->dev);
1684 dev_vdbg(&udev->dev, "%s: cnt %d -> %d\n",
1685 __func__, atomic_read(&udev->dev.power.usage_count),
1686 status);
1687}
1688
1689/**
1690 * usb_autoresume_device - immediately autoresume a USB device and its interfaces
1691 * @udev: the usb_device to autoresume
1692 *
1693 * This routine should be called when a core subsystem wants to use @udev
1694 * and needs to guarantee that it is not suspended. No autosuspend will
1695 * occur until usb_autosuspend_device() is called. (Note that this will
1696 * not prevent suspend events originating in the PM core.) Examples would
1697 * be when @udev's device file in usbfs is opened or when a remote-wakeup
1698 * request is received.
1699 *
1700 * @udev's usage counter is incremented to prevent subsequent autosuspends.
1701 * However if the autoresume fails then the usage counter is re-decremented.
1702 *
1703 * The caller must hold @udev's device lock.
1704 *
1705 * This routine can run only in process context.
1706 *
1707 * Return: 0 on success. A negative error code otherwise.
1708 */
1709int usb_autoresume_device(struct usb_device *udev)
1710{
1711 int status;
1712
1713 status = pm_runtime_resume_and_get(dev: &udev->dev);
1714 dev_vdbg(&udev->dev, "%s: cnt %d -> %d\n",
1715 __func__, atomic_read(&udev->dev.power.usage_count),
1716 status);
1717 if (status > 0)
1718 status = 0;
1719 return status;
1720}
1721
1722/**
1723 * usb_autopm_put_interface - decrement a USB interface's PM-usage counter
1724 * @intf: the usb_interface whose counter should be decremented
1725 *
1726 * This routine should be called by an interface driver when it is
1727 * finished using @intf and wants to allow it to autosuspend. A typical
1728 * example would be a character-device driver when its device file is
1729 * closed.
1730 *
1731 * The routine decrements @intf's usage counter. When the counter reaches
1732 * 0, a delayed autosuspend request for @intf's device is attempted. The
1733 * attempt may fail (see autosuspend_check()).
1734 *
1735 * This routine can run only in process context.
1736 */
1737void usb_autopm_put_interface(struct usb_interface *intf)
1738{
1739 struct usb_device *udev = interface_to_usbdev(intf);
1740 int status;
1741
1742 usb_mark_last_busy(udev);
1743 status = pm_runtime_put_sync(dev: &intf->dev);
1744 dev_vdbg(&intf->dev, "%s: cnt %d -> %d\n",
1745 __func__, atomic_read(&intf->dev.power.usage_count),
1746 status);
1747}
1748EXPORT_SYMBOL_GPL(usb_autopm_put_interface);
1749
1750/**
1751 * usb_autopm_put_interface_async - decrement a USB interface's PM-usage counter
1752 * @intf: the usb_interface whose counter should be decremented
1753 *
1754 * This routine does much the same thing as usb_autopm_put_interface():
1755 * It decrements @intf's usage counter and schedules a delayed
1756 * autosuspend request if the counter is <= 0. The difference is that it
1757 * does not perform any synchronization; callers should hold a private
1758 * lock and handle all synchronization issues themselves.
1759 *
1760 * Typically a driver would call this routine during an URB's completion
1761 * handler, if no more URBs were pending.
1762 *
1763 * This routine can run in atomic context.
1764 */
1765void usb_autopm_put_interface_async(struct usb_interface *intf)
1766{
1767 struct usb_device *udev = interface_to_usbdev(intf);
1768 int status;
1769
1770 usb_mark_last_busy(udev);
1771 status = pm_runtime_put(dev: &intf->dev);
1772 dev_vdbg(&intf->dev, "%s: cnt %d -> %d\n",
1773 __func__, atomic_read(&intf->dev.power.usage_count),
1774 status);
1775}
1776EXPORT_SYMBOL_GPL(usb_autopm_put_interface_async);
1777
1778/**
1779 * usb_autopm_put_interface_no_suspend - decrement a USB interface's PM-usage counter
1780 * @intf: the usb_interface whose counter should be decremented
1781 *
1782 * This routine decrements @intf's usage counter but does not carry out an
1783 * autosuspend.
1784 *
1785 * This routine can run in atomic context.
1786 */
1787void usb_autopm_put_interface_no_suspend(struct usb_interface *intf)
1788{
1789 struct usb_device *udev = interface_to_usbdev(intf);
1790
1791 usb_mark_last_busy(udev);
1792 pm_runtime_put_noidle(dev: &intf->dev);
1793}
1794EXPORT_SYMBOL_GPL(usb_autopm_put_interface_no_suspend);
1795
1796/**
1797 * usb_autopm_get_interface - increment a USB interface's PM-usage counter
1798 * @intf: the usb_interface whose counter should be incremented
1799 *
1800 * This routine should be called by an interface driver when it wants to
1801 * use @intf and needs to guarantee that it is not suspended. In addition,
1802 * the routine prevents @intf from being autosuspended subsequently. (Note
1803 * that this will not prevent suspend events originating in the PM core.)
1804 * This prevention will persist until usb_autopm_put_interface() is called
1805 * or @intf is unbound. A typical example would be a character-device
1806 * driver when its device file is opened.
1807 *
1808 * @intf's usage counter is incremented to prevent subsequent autosuspends.
1809 * However if the autoresume fails then the counter is re-decremented.
1810 *
1811 * This routine can run only in process context.
1812 *
1813 * Return: 0 on success.
1814 */
1815int usb_autopm_get_interface(struct usb_interface *intf)
1816{
1817 int status;
1818
1819 status = pm_runtime_resume_and_get(dev: &intf->dev);
1820 dev_vdbg(&intf->dev, "%s: cnt %d -> %d\n",
1821 __func__, atomic_read(&intf->dev.power.usage_count),
1822 status);
1823 if (status > 0)
1824 status = 0;
1825 return status;
1826}
1827EXPORT_SYMBOL_GPL(usb_autopm_get_interface);
1828
1829/**
1830 * usb_autopm_get_interface_async - increment a USB interface's PM-usage counter
1831 * @intf: the usb_interface whose counter should be incremented
1832 *
1833 * This routine does much the same thing as
1834 * usb_autopm_get_interface(): It increments @intf's usage counter and
1835 * queues an autoresume request if the device is suspended. The
1836 * differences are that it does not perform any synchronization (callers
1837 * should hold a private lock and handle all synchronization issues
1838 * themselves), and it does not autoresume the device directly (it only
1839 * queues a request). After a successful call, the device may not yet be
1840 * resumed.
1841 *
1842 * This routine can run in atomic context.
1843 *
1844 * Return: 0 on success. A negative error code otherwise.
1845 */
1846int usb_autopm_get_interface_async(struct usb_interface *intf)
1847{
1848 int status;
1849
1850 status = pm_runtime_get(dev: &intf->dev);
1851 if (status < 0 && status != -EINPROGRESS)
1852 pm_runtime_put_noidle(dev: &intf->dev);
1853 dev_vdbg(&intf->dev, "%s: cnt %d -> %d\n",
1854 __func__, atomic_read(&intf->dev.power.usage_count),
1855 status);
1856 if (status > 0 || status == -EINPROGRESS)
1857 status = 0;
1858 return status;
1859}
1860EXPORT_SYMBOL_GPL(usb_autopm_get_interface_async);
1861
1862/**
1863 * usb_autopm_get_interface_no_resume - increment a USB interface's PM-usage counter
1864 * @intf: the usb_interface whose counter should be incremented
1865 *
1866 * This routine increments @intf's usage counter but does not carry out an
1867 * autoresume.
1868 *
1869 * This routine can run in atomic context.
1870 */
1871void usb_autopm_get_interface_no_resume(struct usb_interface *intf)
1872{
1873 struct usb_device *udev = interface_to_usbdev(intf);
1874
1875 usb_mark_last_busy(udev);
1876 pm_runtime_get_noresume(dev: &intf->dev);
1877}
1878EXPORT_SYMBOL_GPL(usb_autopm_get_interface_no_resume);
1879
1880/* Internal routine to check whether we may autosuspend a device. */
1881static int autosuspend_check(struct usb_device *udev)
1882{
1883 int w, i;
1884 struct usb_interface *intf;
1885
1886 if (udev->state == USB_STATE_NOTATTACHED)
1887 return -ENODEV;
1888
1889 /* Fail if autosuspend is disabled, or any interfaces are in use, or
1890 * any interface drivers require remote wakeup but it isn't available.
1891 */
1892 w = 0;
1893 if (udev->actconfig) {
1894 for (i = 0; i < udev->actconfig->desc.bNumInterfaces; i++) {
1895 intf = udev->actconfig->interface[i];
1896
1897 /* We don't need to check interfaces that are
1898 * disabled for runtime PM. Either they are unbound
1899 * or else their drivers don't support autosuspend
1900 * and so they are permanently active.
1901 */
1902 if (intf->dev.power.disable_depth)
1903 continue;
1904 if (atomic_read(v: &intf->dev.power.usage_count) > 0)
1905 return -EBUSY;
1906 w |= intf->needs_remote_wakeup;
1907
1908 /* Don't allow autosuspend if the device will need
1909 * a reset-resume and any of its interface drivers
1910 * doesn't include support or needs remote wakeup.
1911 */
1912 if (udev->quirks & USB_QUIRK_RESET_RESUME) {
1913 struct usb_driver *driver;
1914
1915 driver = to_usb_driver(intf->dev.driver);
1916 if (!driver->reset_resume ||
1917 intf->needs_remote_wakeup)
1918 return -EOPNOTSUPP;
1919 }
1920 }
1921 }
1922 if (w && !device_can_wakeup(dev: &udev->dev)) {
1923 dev_dbg(&udev->dev, "remote wakeup needed for autosuspend\n");
1924 return -EOPNOTSUPP;
1925 }
1926
1927 /*
1928 * If the device is a direct child of the root hub and the HCD
1929 * doesn't handle wakeup requests, don't allow autosuspend when
1930 * wakeup is needed.
1931 */
1932 if (w && udev->parent == udev->bus->root_hub &&
1933 bus_to_hcd(bus: udev->bus)->cant_recv_wakeups) {
1934 dev_dbg(&udev->dev, "HCD doesn't handle wakeup requests\n");
1935 return -EOPNOTSUPP;
1936 }
1937
1938 udev->do_remote_wakeup = w;
1939 return 0;
1940}
1941
1942int usb_runtime_suspend(struct device *dev)
1943{
1944 struct usb_device *udev = to_usb_device(dev);
1945 int status;
1946
1947 /* A USB device can be suspended if it passes the various autosuspend
1948 * checks. Runtime suspend for a USB device means suspending all the
1949 * interfaces and then the device itself.
1950 */
1951 if (autosuspend_check(udev) != 0)
1952 return -EAGAIN;
1953
1954 status = usb_suspend_both(udev, PMSG_AUTO_SUSPEND);
1955
1956 /* Allow a retry if autosuspend failed temporarily */
1957 if (status == -EAGAIN || status == -EBUSY)
1958 usb_mark_last_busy(udev);
1959
1960 /*
1961 * The PM core reacts badly unless the return code is 0,
1962 * -EAGAIN, or -EBUSY, so always return -EBUSY on an error
1963 * (except for root hubs, because they don't suspend through
1964 * an upstream port like other USB devices).
1965 */
1966 if (status != 0 && udev->parent)
1967 return -EBUSY;
1968 return status;
1969}
1970
1971int usb_runtime_resume(struct device *dev)
1972{
1973 struct usb_device *udev = to_usb_device(dev);
1974 int status;
1975
1976 /* Runtime resume for a USB device means resuming both the device
1977 * and all its interfaces.
1978 */
1979 status = usb_resume_both(udev, PMSG_AUTO_RESUME);
1980 return status;
1981}
1982
1983int usb_runtime_idle(struct device *dev)
1984{
1985 struct usb_device *udev = to_usb_device(dev);
1986
1987 /* An idle USB device can be suspended if it passes the various
1988 * autosuspend checks.
1989 */
1990 if (autosuspend_check(udev) == 0)
1991 pm_runtime_autosuspend(dev);
1992 /* Tell the core not to suspend it, though. */
1993 return -EBUSY;
1994}
1995
1996static int usb_set_usb2_hardware_lpm(struct usb_device *udev, int enable)
1997{
1998 struct usb_hcd *hcd = bus_to_hcd(bus: udev->bus);
1999 int ret = -EPERM;
2000
2001 if (hcd->driver->set_usb2_hw_lpm) {
2002 ret = hcd->driver->set_usb2_hw_lpm(hcd, udev, enable);
2003 if (!ret)
2004 udev->usb2_hw_lpm_enabled = enable;
2005 }
2006
2007 return ret;
2008}
2009
2010int usb_enable_usb2_hardware_lpm(struct usb_device *udev)
2011{
2012 if (!udev->usb2_hw_lpm_capable ||
2013 !udev->usb2_hw_lpm_allowed ||
2014 udev->usb2_hw_lpm_enabled)
2015 return 0;
2016
2017 return usb_set_usb2_hardware_lpm(udev, enable: 1);
2018}
2019
2020int usb_disable_usb2_hardware_lpm(struct usb_device *udev)
2021{
2022 if (!udev->usb2_hw_lpm_enabled)
2023 return 0;
2024
2025 return usb_set_usb2_hardware_lpm(udev, enable: 0);
2026}
2027
2028#endif /* CONFIG_PM */
2029
2030const struct bus_type usb_bus_type = {
2031 .name = "usb",
2032 .match = usb_device_match,
2033 .uevent = usb_uevent,
2034 .need_parent_lock = true,
2035};
2036

source code of linux/drivers/usb/core/driver.c