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