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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * drivers/usb/core/usb.c
4 *
5 * (C) Copyright Linus Torvalds 1999
6 * (C) Copyright Johannes Erdfelt 1999-2001
7 * (C) Copyright Andreas Gal 1999
8 * (C) Copyright Gregory P. Smith 1999
9 * (C) Copyright Deti Fliegl 1999 (new USB architecture)
10 * (C) Copyright Randy Dunlap 2000
11 * (C) Copyright David Brownell 2000-2004
12 * (C) Copyright Yggdrasil Computing, Inc. 2000
13 * (usb_device_id matching changes by Adam J. Richter)
14 * (C) Copyright Greg Kroah-Hartman 2002-2003
15 *
16 * Released under the GPLv2 only.
17 *
18 * NOTE! This is not actually a driver at all, rather this is
19 * just a collection of helper routines that implement the
20 * generic USB things that the real drivers can use..
21 *
22 * Think of this as a "USB library" rather than anything else,
23 * with no callbacks. Callbacks are evil.
24 */
25
26#include <linux/module.h>
27#include <linux/moduleparam.h>
28#include <linux/string.h>
29#include <linux/bitops.h>
30#include <linux/slab.h>
31#include <linux/kmod.h>
32#include <linux/init.h>
33#include <linux/spinlock.h>
34#include <linux/errno.h>
35#include <linux/usb.h>
36#include <linux/usb/hcd.h>
37#include <linux/mutex.h>
38#include <linux/workqueue.h>
39#include <linux/debugfs.h>
40#include <linux/usb/of.h>
41
42#include <asm/io.h>
43#include <linux/scatterlist.h>
44#include <linux/mm.h>
45#include <linux/dma-mapping.h>
46
47#include "hub.h"
48
49const char *usbcore_name = "usbcore";
50
51static bool nousb; /* Disable USB when built into kernel image */
52
53module_param(nousb, bool, 0444);
54
55/*
56 * for external read access to <nousb>
57 */
58int usb_disabled(void)
59{
60 return nousb;
61}
62EXPORT_SYMBOL_GPL(usb_disabled);
63
64#ifdef CONFIG_PM
65/* Default delay value, in seconds */
66static int usb_autosuspend_delay = CONFIG_USB_AUTOSUSPEND_DELAY;
67module_param_named(autosuspend, usb_autosuspend_delay, int, 0644);
68MODULE_PARM_DESC(autosuspend, "default autosuspend delay");
69
70#else
71#define usb_autosuspend_delay 0
72#endif
73
74static bool match_endpoint(struct usb_endpoint_descriptor *epd,
75 struct usb_endpoint_descriptor **bulk_in,
76 struct usb_endpoint_descriptor **bulk_out,
77 struct usb_endpoint_descriptor **int_in,
78 struct usb_endpoint_descriptor **int_out)
79{
80 switch (usb_endpoint_type(epd)) {
81 case USB_ENDPOINT_XFER_BULK:
82 if (usb_endpoint_dir_in(epd)) {
83 if (bulk_in && !*bulk_in) {
84 *bulk_in = epd;
85 break;
86 }
87 } else {
88 if (bulk_out && !*bulk_out) {
89 *bulk_out = epd;
90 break;
91 }
92 }
93
94 return false;
95 case USB_ENDPOINT_XFER_INT:
96 if (usb_endpoint_dir_in(epd)) {
97 if (int_in && !*int_in) {
98 *int_in = epd;
99 break;
100 }
101 } else {
102 if (int_out && !*int_out) {
103 *int_out = epd;
104 break;
105 }
106 }
107
108 return false;
109 default:
110 return false;
111 }
112
113 return (!bulk_in || *bulk_in) && (!bulk_out || *bulk_out) &&
114 (!int_in || *int_in) && (!int_out || *int_out);
115}
116
117/**
118 * usb_find_common_endpoints() -- look up common endpoint descriptors
119 * @alt: alternate setting to search
120 * @bulk_in: pointer to descriptor pointer, or NULL
121 * @bulk_out: pointer to descriptor pointer, or NULL
122 * @int_in: pointer to descriptor pointer, or NULL
123 * @int_out: pointer to descriptor pointer, or NULL
124 *
125 * Search the alternate setting's endpoint descriptors for the first bulk-in,
126 * bulk-out, interrupt-in and interrupt-out endpoints and return them in the
127 * provided pointers (unless they are NULL).
128 *
129 * If a requested endpoint is not found, the corresponding pointer is set to
130 * NULL.
131 *
132 * Return: Zero if all requested descriptors were found, or -ENXIO otherwise.
133 */
134int usb_find_common_endpoints(struct usb_host_interface *alt,
135 struct usb_endpoint_descriptor **bulk_in,
136 struct usb_endpoint_descriptor **bulk_out,
137 struct usb_endpoint_descriptor **int_in,
138 struct usb_endpoint_descriptor **int_out)
139{
140 struct usb_endpoint_descriptor *epd;
141 int i;
142
143 if (bulk_in)
144 *bulk_in = NULL;
145 if (bulk_out)
146 *bulk_out = NULL;
147 if (int_in)
148 *int_in = NULL;
149 if (int_out)
150 *int_out = NULL;
151
152 for (i = 0; i < alt->desc.bNumEndpoints; ++i) {
153 epd = &alt->endpoint[i].desc;
154
155 if (match_endpoint(epd, bulk_in, bulk_out, int_in, int_out))
156 return 0;
157 }
158
159 return -ENXIO;
160}
161EXPORT_SYMBOL_GPL(usb_find_common_endpoints);
162
163/**
164 * usb_find_common_endpoints_reverse() -- look up common endpoint descriptors
165 * @alt: alternate setting to search
166 * @bulk_in: pointer to descriptor pointer, or NULL
167 * @bulk_out: pointer to descriptor pointer, or NULL
168 * @int_in: pointer to descriptor pointer, or NULL
169 * @int_out: pointer to descriptor pointer, or NULL
170 *
171 * Search the alternate setting's endpoint descriptors for the last bulk-in,
172 * bulk-out, interrupt-in and interrupt-out endpoints and return them in the
173 * provided pointers (unless they are NULL).
174 *
175 * If a requested endpoint is not found, the corresponding pointer is set to
176 * NULL.
177 *
178 * Return: Zero if all requested descriptors were found, or -ENXIO otherwise.
179 */
180int usb_find_common_endpoints_reverse(struct usb_host_interface *alt,
181 struct usb_endpoint_descriptor **bulk_in,
182 struct usb_endpoint_descriptor **bulk_out,
183 struct usb_endpoint_descriptor **int_in,
184 struct usb_endpoint_descriptor **int_out)
185{
186 struct usb_endpoint_descriptor *epd;
187 int i;
188
189 if (bulk_in)
190 *bulk_in = NULL;
191 if (bulk_out)
192 *bulk_out = NULL;
193 if (int_in)
194 *int_in = NULL;
195 if (int_out)
196 *int_out = NULL;
197
198 for (i = alt->desc.bNumEndpoints - 1; i >= 0; --i) {
199 epd = &alt->endpoint[i].desc;
200
201 if (match_endpoint(epd, bulk_in, bulk_out, int_in, int_out))
202 return 0;
203 }
204
205 return -ENXIO;
206}
207EXPORT_SYMBOL_GPL(usb_find_common_endpoints_reverse);
208
209/**
210 * usb_find_alt_setting() - Given a configuration, find the alternate setting
211 * for the given interface.
212 * @config: the configuration to search (not necessarily the current config).
213 * @iface_num: interface number to search in
214 * @alt_num: alternate interface setting number to search for.
215 *
216 * Search the configuration's interface cache for the given alt setting.
217 *
218 * Return: The alternate setting, if found. %NULL otherwise.
219 */
220struct usb_host_interface *usb_find_alt_setting(
221 struct usb_host_config *config,
222 unsigned int iface_num,
223 unsigned int alt_num)
224{
225 struct usb_interface_cache *intf_cache = NULL;
226 int i;
227
228 if (!config)
229 return NULL;
230 for (i = 0; i < config->desc.bNumInterfaces; i++) {
231 if (config->intf_cache[i]->altsetting[0].desc.bInterfaceNumber
232 == iface_num) {
233 intf_cache = config->intf_cache[i];
234 break;
235 }
236 }
237 if (!intf_cache)
238 return NULL;
239 for (i = 0; i < intf_cache->num_altsetting; i++)
240 if (intf_cache->altsetting[i].desc.bAlternateSetting == alt_num)
241 return &intf_cache->altsetting[i];
242
243 printk(KERN_DEBUG "Did not find alt setting %u for intf %u, "
244 "config %u\n", alt_num, iface_num,
245 config->desc.bConfigurationValue);
246 return NULL;
247}
248EXPORT_SYMBOL_GPL(usb_find_alt_setting);
249
250/**
251 * usb_ifnum_to_if - get the interface object with a given interface number
252 * @dev: the device whose current configuration is considered
253 * @ifnum: the desired interface
254 *
255 * This walks the device descriptor for the currently active configuration
256 * to find the interface object with the particular interface number.
257 *
258 * Note that configuration descriptors are not required to assign interface
259 * numbers sequentially, so that it would be incorrect to assume that
260 * the first interface in that descriptor corresponds to interface zero.
261 * This routine helps device drivers avoid such mistakes.
262 * However, you should make sure that you do the right thing with any
263 * alternate settings available for this interfaces.
264 *
265 * Don't call this function unless you are bound to one of the interfaces
266 * on this device or you have locked the device!
267 *
268 * Return: A pointer to the interface that has @ifnum as interface number,
269 * if found. %NULL otherwise.
270 */
271struct usb_interface *usb_ifnum_to_if(const struct usb_device *dev,
272 unsigned ifnum)
273{
274 struct usb_host_config *config = dev->actconfig;
275 int i;
276
277 if (!config)
278 return NULL;
279 for (i = 0; i < config->desc.bNumInterfaces; i++)
280 if (config->interface[i]->altsetting[0]
281 .desc.bInterfaceNumber == ifnum)
282 return config->interface[i];
283
284 return NULL;
285}
286EXPORT_SYMBOL_GPL(usb_ifnum_to_if);
287
288/**
289 * usb_altnum_to_altsetting - get the altsetting structure with a given alternate setting number.
290 * @intf: the interface containing the altsetting in question
291 * @altnum: the desired alternate setting number
292 *
293 * This searches the altsetting array of the specified interface for
294 * an entry with the correct bAlternateSetting value.
295 *
296 * Note that altsettings need not be stored sequentially by number, so
297 * it would be incorrect to assume that the first altsetting entry in
298 * the array corresponds to altsetting zero. This routine helps device
299 * drivers avoid such mistakes.
300 *
301 * Don't call this function unless you are bound to the intf interface
302 * or you have locked the device!
303 *
304 * Return: A pointer to the entry of the altsetting array of @intf that
305 * has @altnum as the alternate setting number. %NULL if not found.
306 */
307struct usb_host_interface *usb_altnum_to_altsetting(
308 const struct usb_interface *intf,
309 unsigned int altnum)
310{
311 int i;
312
313 for (i = 0; i < intf->num_altsetting; i++) {
314 if (intf->altsetting[i].desc.bAlternateSetting == altnum)
315 return &intf->altsetting[i];
316 }
317 return NULL;
318}
319EXPORT_SYMBOL_GPL(usb_altnum_to_altsetting);
320
321struct find_interface_arg {
322 int minor;
323 struct device_driver *drv;
324};
325
326static int __find_interface(struct device *dev, const void *data)
327{
328 const struct find_interface_arg *arg = data;
329 struct usb_interface *intf;
330
331 if (!is_usb_interface(dev))
332 return 0;
333
334 if (dev->driver != arg->drv)
335 return 0;
336 intf = to_usb_interface(dev);
337 return intf->minor == arg->minor;
338}
339
340/**
341 * usb_find_interface - find usb_interface pointer for driver and device
342 * @drv: the driver whose current configuration is considered
343 * @minor: the minor number of the desired device
344 *
345 * This walks the bus device list and returns a pointer to the interface
346 * with the matching minor and driver. Note, this only works for devices
347 * that share the USB major number.
348 *
349 * Return: A pointer to the interface with the matching major and @minor.
350 */
351struct usb_interface *usb_find_interface(struct usb_driver *drv, int minor)
352{
353 struct find_interface_arg argb;
354 struct device *dev;
355
356 argb.minor = minor;
357 argb.drv = &drv->drvwrap.driver;
358
359 dev = bus_find_device(&usb_bus_type, NULL, &argb, __find_interface);
360
361 /* Drop reference count from bus_find_device */
362 put_device(dev);
363
364 return dev ? to_usb_interface(dev) : NULL;
365}
366EXPORT_SYMBOL_GPL(usb_find_interface);
367
368struct each_dev_arg {
369 void *data;
370 int (*fn)(struct usb_device *, void *);
371};
372
373static int __each_dev(struct device *dev, void *data)
374{
375 struct each_dev_arg *arg = (struct each_dev_arg *)data;
376
377 /* There are struct usb_interface on the same bus, filter them out */
378 if (!is_usb_device(dev))
379 return 0;
380
381 return arg->fn(to_usb_device(dev), arg->data);
382}
383
384/**
385 * usb_for_each_dev - iterate over all USB devices in the system
386 * @data: data pointer that will be handed to the callback function
387 * @fn: callback function to be called for each USB device
388 *
389 * Iterate over all USB devices and call @fn for each, passing it @data. If it
390 * returns anything other than 0, we break the iteration prematurely and return
391 * that value.
392 */
393int usb_for_each_dev(void *data, int (*fn)(struct usb_device *, void *))
394{
395 struct each_dev_arg arg = {data, fn};
396
397 return bus_for_each_dev(&usb_bus_type, NULL, &arg, __each_dev);
398}
399EXPORT_SYMBOL_GPL(usb_for_each_dev);
400
401/**
402 * usb_release_dev - free a usb device structure when all users of it are finished.
403 * @dev: device that's been disconnected
404 *
405 * Will be called only by the device core when all users of this usb device are
406 * done.
407 */
408static void usb_release_dev(struct device *dev)
409{
410 struct usb_device *udev;
411 struct usb_hcd *hcd;
412
413 udev = to_usb_device(dev);
414 hcd = bus_to_hcd(udev->bus);
415
416 usb_destroy_configuration(udev);
417 usb_release_bos_descriptor(udev);
418 of_node_put(dev->of_node);
419 usb_put_hcd(hcd);
420 kfree(udev->product);
421 kfree(udev->manufacturer);
422 kfree(udev->serial);
423 kfree(udev);
424}
425
426static int usb_dev_uevent(struct device *dev, struct kobj_uevent_env *env)
427{
428 struct usb_device *usb_dev;
429
430 usb_dev = to_usb_device(dev);
431
432 if (add_uevent_var(env, "BUSNUM=%03d", usb_dev->bus->busnum))
433 return -ENOMEM;
434
435 if (add_uevent_var(env, "DEVNUM=%03d", usb_dev->devnum))
436 return -ENOMEM;
437
438 return 0;
439}
440
441#ifdef CONFIG_PM
442
443/* USB device Power-Management thunks.
444 * There's no need to distinguish here between quiescing a USB device
445 * and powering it down; the generic_suspend() routine takes care of
446 * it by skipping the usb_port_suspend() call for a quiesce. And for
447 * USB interfaces there's no difference at all.
448 */
449
450static int usb_dev_prepare(struct device *dev)
451{
452 return 0; /* Implement eventually? */
453}
454
455static void usb_dev_complete(struct device *dev)
456{
457 /* Currently used only for rebinding interfaces */
458 usb_resume_complete(dev);
459}
460
461static int usb_dev_suspend(struct device *dev)
462{
463 return usb_suspend(dev, PMSG_SUSPEND);
464}
465
466static int usb_dev_resume(struct device *dev)
467{
468 return usb_resume(dev, PMSG_RESUME);
469}
470
471static int usb_dev_freeze(struct device *dev)
472{
473 return usb_suspend(dev, PMSG_FREEZE);
474}
475
476static int usb_dev_thaw(struct device *dev)
477{
478 return usb_resume(dev, PMSG_THAW);
479}
480
481static int usb_dev_poweroff(struct device *dev)
482{
483 return usb_suspend(dev, PMSG_HIBERNATE);
484}
485
486static int usb_dev_restore(struct device *dev)
487{
488 return usb_resume(dev, PMSG_RESTORE);
489}
490
491static const struct dev_pm_ops usb_device_pm_ops = {
492 .prepare = usb_dev_prepare,
493 .complete = usb_dev_complete,
494 .suspend = usb_dev_suspend,
495 .resume = usb_dev_resume,
496 .freeze = usb_dev_freeze,
497 .thaw = usb_dev_thaw,
498 .poweroff = usb_dev_poweroff,
499 .restore = usb_dev_restore,
500 .runtime_suspend = usb_runtime_suspend,
501 .runtime_resume = usb_runtime_resume,
502 .runtime_idle = usb_runtime_idle,
503};
504
505#endif /* CONFIG_PM */
506
507
508static char *usb_devnode(struct device *dev,
509 umode_t *mode, kuid_t *uid, kgid_t *gid)
510{
511 struct usb_device *usb_dev;
512
513 usb_dev = to_usb_device(dev);
514 return kasprintf(GFP_KERNEL, "bus/usb/%03d/%03d",
515 usb_dev->bus->busnum, usb_dev->devnum);
516}
517
518struct device_type usb_device_type = {
519 .name = "usb_device",
520 .release = usb_release_dev,
521 .uevent = usb_dev_uevent,
522 .devnode = usb_devnode,
523#ifdef CONFIG_PM
524 .pm = &usb_device_pm_ops,
525#endif
526};
527
528
529/* Returns 1 if @usb_bus is WUSB, 0 otherwise */
530static unsigned usb_bus_is_wusb(struct usb_bus *bus)
531{
532 struct usb_hcd *hcd = bus_to_hcd(bus);
533 return hcd->wireless;
534}
535
536static bool usb_dev_authorized(struct usb_device *dev, struct usb_hcd *hcd)
537{
538 struct usb_hub *hub;
539
540 if (!dev->parent)
541 return true; /* Root hub always ok [and always wired] */
542
543 switch (hcd->dev_policy) {
544 case USB_DEVICE_AUTHORIZE_NONE:
545 default:
546 return false;
547
548 case USB_DEVICE_AUTHORIZE_ALL:
549 return true;
550
551 case USB_DEVICE_AUTHORIZE_INTERNAL:
552 hub = usb_hub_to_struct_hub(dev->parent);
553 return hub->ports[dev->portnum - 1]->connect_type ==
554 USB_PORT_CONNECT_TYPE_HARD_WIRED;
555 }
556}
557
558/**
559 * usb_alloc_dev - usb device constructor (usbcore-internal)
560 * @parent: hub to which device is connected; null to allocate a root hub
561 * @bus: bus used to access the device
562 * @port1: one-based index of port; ignored for root hubs
563 *
564 * Context: task context, might sleep.
565 *
566 * Only hub drivers (including virtual root hub drivers for host
567 * controllers) should ever call this.
568 *
569 * This call may not be used in a non-sleeping context.
570 *
571 * Return: On success, a pointer to the allocated usb device. %NULL on
572 * failure.
573 */
574struct usb_device *usb_alloc_dev(struct usb_device *parent,
575 struct usb_bus *bus, unsigned port1)
576{
577 struct usb_device *dev;
578 struct usb_hcd *usb_hcd = bus_to_hcd(bus);
579 unsigned root_hub = 0;
580 unsigned raw_port = port1;
581
582 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
583 if (!dev)
584 return NULL;
585
586 if (!usb_get_hcd(usb_hcd)) {
587 kfree(dev);
588 return NULL;
589 }
590 /* Root hubs aren't true devices, so don't allocate HCD resources */
591 if (usb_hcd->driver->alloc_dev && parent &&
592 !usb_hcd->driver->alloc_dev(usb_hcd, dev)) {
593 usb_put_hcd(bus_to_hcd(bus));
594 kfree(dev);
595 return NULL;
596 }
597
598 device_initialize(&dev->dev);
599 dev->dev.bus = &usb_bus_type;
600 dev->dev.type = &usb_device_type;
601 dev->dev.groups = usb_device_groups;
602 set_dev_node(&dev->dev, dev_to_node(bus->sysdev));
603 dev->state = USB_STATE_ATTACHED;
604 dev->lpm_disable_count = 1;
605 atomic_set(&dev->urbnum, 0);
606
607 INIT_LIST_HEAD(&dev->ep0.urb_list);
608 dev->ep0.desc.bLength = USB_DT_ENDPOINT_SIZE;
609 dev->ep0.desc.bDescriptorType = USB_DT_ENDPOINT;
610 /* ep0 maxpacket comes later, from device descriptor */
611 usb_enable_endpoint(dev, &dev->ep0, false);
612 dev->can_submit = 1;
613
614 /* Save readable and stable topology id, distinguishing devices
615 * by location for diagnostics, tools, driver model, etc. The
616 * string is a path along hub ports, from the root. Each device's
617 * dev->devpath will be stable until USB is re-cabled, and hubs
618 * are often labeled with these port numbers. The name isn't
619 * as stable: bus->busnum changes easily from modprobe order,
620 * cardbus or pci hotplugging, and so on.
621 */
622 if (unlikely(!parent)) {
623 dev->devpath[0] = '0';
624 dev->route = 0;
625
626 dev->dev.parent = bus->controller;
627 device_set_of_node_from_dev(&dev->dev, bus->sysdev);
628 dev_set_name(&dev->dev, "usb%d", bus->busnum);
629 root_hub = 1;
630 } else {
631 /* match any labeling on the hubs; it's one-based */
632 if (parent->devpath[0] == '0') {
633 snprintf(dev->devpath, sizeof dev->devpath,
634 "%d", port1);
635 /* Root ports are not counted in route string */
636 dev->route = 0;
637 } else {
638 snprintf(dev->devpath, sizeof dev->devpath,
639 "%s.%d", parent->devpath, port1);
640 /* Route string assumes hubs have less than 16 ports */
641 if (port1 < 15)
642 dev->route = parent->route +
643 (port1 << ((parent->level - 1)*4));
644 else
645 dev->route = parent->route +
646 (15 << ((parent->level - 1)*4));
647 }
648
649 dev->dev.parent = &parent->dev;
650 dev_set_name(&dev->dev, "%d-%s", bus->busnum, dev->devpath);
651
652 if (!parent->parent) {
653 /* device under root hub's port */
654 raw_port = usb_hcd_find_raw_port_number(usb_hcd,
655 port1);
656 }
657 dev->dev.of_node = usb_of_get_device_node(parent, raw_port);
658
659 /* hub driver sets up TT records */
660 }
661
662 dev->portnum = port1;
663 dev->bus = bus;
664 dev->parent = parent;
665 INIT_LIST_HEAD(&dev->filelist);
666
667#ifdef CONFIG_PM
668 pm_runtime_set_autosuspend_delay(&dev->dev,
669 usb_autosuspend_delay * 1000);
670 dev->connect_time = jiffies;
671 dev->active_duration = -jiffies;
672#endif
673
674 dev->authorized = usb_dev_authorized(dev, usb_hcd);
675 if (!root_hub)
676 dev->wusb = usb_bus_is_wusb(bus) ? 1 : 0;
677
678 return dev;
679}
680EXPORT_SYMBOL_GPL(usb_alloc_dev);
681
682/**
683 * usb_get_dev - increments the reference count of the usb device structure
684 * @dev: the device being referenced
685 *
686 * Each live reference to a device should be refcounted.
687 *
688 * Drivers for USB interfaces should normally record such references in
689 * their probe() methods, when they bind to an interface, and release
690 * them by calling usb_put_dev(), in their disconnect() methods.
691 * However, if a driver does not access the usb_device structure after
692 * its disconnect() method returns then refcounting is not necessary,
693 * because the USB core guarantees that a usb_device will not be
694 * deallocated until after all of its interface drivers have been unbound.
695 *
696 * Return: A pointer to the device with the incremented reference counter.
697 */
698struct usb_device *usb_get_dev(struct usb_device *dev)
699{
700 if (dev)
701 get_device(&dev->dev);
702 return dev;
703}
704EXPORT_SYMBOL_GPL(usb_get_dev);
705
706/**
707 * usb_put_dev - release a use of the usb device structure
708 * @dev: device that's been disconnected
709 *
710 * Must be called when a user of a device is finished with it. When the last
711 * user of the device calls this function, the memory of the device is freed.
712 */
713void usb_put_dev(struct usb_device *dev)
714{
715 if (dev)
716 put_device(&dev->dev);
717}
718EXPORT_SYMBOL_GPL(usb_put_dev);
719
720/**
721 * usb_get_intf - increments the reference count of the usb interface structure
722 * @intf: the interface being referenced
723 *
724 * Each live reference to a interface must be refcounted.
725 *
726 * Drivers for USB interfaces should normally record such references in
727 * their probe() methods, when they bind to an interface, and release
728 * them by calling usb_put_intf(), in their disconnect() methods.
729 * However, if a driver does not access the usb_interface structure after
730 * its disconnect() method returns then refcounting is not necessary,
731 * because the USB core guarantees that a usb_interface will not be
732 * deallocated until after its driver has been unbound.
733 *
734 * Return: A pointer to the interface with the incremented reference counter.
735 */
736struct usb_interface *usb_get_intf(struct usb_interface *intf)
737{
738 if (intf)
739 get_device(&intf->dev);
740 return intf;
741}
742EXPORT_SYMBOL_GPL(usb_get_intf);
743
744/**
745 * usb_put_intf - release a use of the usb interface structure
746 * @intf: interface that's been decremented
747 *
748 * Must be called when a user of an interface is finished with it. When the
749 * last user of the interface calls this function, the memory of the interface
750 * is freed.
751 */
752void usb_put_intf(struct usb_interface *intf)
753{
754 if (intf)
755 put_device(&intf->dev);
756}
757EXPORT_SYMBOL_GPL(usb_put_intf);
758
759/**
760 * usb_intf_get_dma_device - acquire a reference on the usb interface's DMA endpoint
761 * @intf: the usb interface
762 *
763 * While a USB device cannot perform DMA operations by itself, many USB
764 * controllers can. A call to usb_intf_get_dma_device() returns the DMA endpoint
765 * for the given USB interface, if any. The returned device structure must be
766 * released with put_device().
767 *
768 * See also usb_get_dma_device().
769 *
770 * Returns: A reference to the usb interface's DMA endpoint; or NULL if none
771 * exists.
772 */
773struct device *usb_intf_get_dma_device(struct usb_interface *intf)
774{
775 struct usb_device *udev = interface_to_usbdev(intf);
776 struct device *dmadev;
777
778 if (!udev->bus)
779 return NULL;
780
781 dmadev = get_device(udev->bus->sysdev);
782 if (!dmadev || !dmadev->dma_mask) {
783 put_device(dmadev);
784 return NULL;
785 }
786
787 return dmadev;
788}
789EXPORT_SYMBOL_GPL(usb_intf_get_dma_device);
790
791/* USB device locking
792 *
793 * USB devices and interfaces are locked using the semaphore in their
794 * embedded struct device. The hub driver guarantees that whenever a
795 * device is connected or disconnected, drivers are called with the
796 * USB device locked as well as their particular interface.
797 *
798 * Complications arise when several devices are to be locked at the same
799 * time. Only hub-aware drivers that are part of usbcore ever have to
800 * do this; nobody else needs to worry about it. The rule for locking
801 * is simple:
802 *
803 * When locking both a device and its parent, always lock the
804 * parent first.
805 */
806
807/**
808 * usb_lock_device_for_reset - cautiously acquire the lock for a usb device structure
809 * @udev: device that's being locked
810 * @iface: interface bound to the driver making the request (optional)
811 *
812 * Attempts to acquire the device lock, but fails if the device is
813 * NOTATTACHED or SUSPENDED, or if iface is specified and the interface
814 * is neither BINDING nor BOUND. Rather than sleeping to wait for the
815 * lock, the routine polls repeatedly. This is to prevent deadlock with
816 * disconnect; in some drivers (such as usb-storage) the disconnect()
817 * or suspend() method will block waiting for a device reset to complete.
818 *
819 * Return: A negative error code for failure, otherwise 0.
820 */
821int usb_lock_device_for_reset(struct usb_device *udev,
822 const struct usb_interface *iface)
823{
824 unsigned long jiffies_expire = jiffies + HZ;
825
826 if (udev->state == USB_STATE_NOTATTACHED)
827 return -ENODEV;
828 if (udev->state == USB_STATE_SUSPENDED)
829 return -EHOSTUNREACH;
830 if (iface && (iface->condition == USB_INTERFACE_UNBINDING ||
831 iface->condition == USB_INTERFACE_UNBOUND))
832 return -EINTR;
833
834 while (!usb_trylock_device(udev)) {
835
836 /* If we can't acquire the lock after waiting one second,
837 * we're probably deadlocked */
838 if (time_after(jiffies, jiffies_expire))
839 return -EBUSY;
840
841 msleep(15);
842 if (udev->state == USB_STATE_NOTATTACHED)
843 return -ENODEV;
844 if (udev->state == USB_STATE_SUSPENDED)
845 return -EHOSTUNREACH;
846 if (iface && (iface->condition == USB_INTERFACE_UNBINDING ||
847 iface->condition == USB_INTERFACE_UNBOUND))
848 return -EINTR;
849 }
850 return 0;
851}
852EXPORT_SYMBOL_GPL(usb_lock_device_for_reset);
853
854/**
855 * usb_get_current_frame_number - return current bus frame number
856 * @dev: the device whose bus is being queried
857 *
858 * Return: The current frame number for the USB host controller used
859 * with the given USB device. This can be used when scheduling
860 * isochronous requests.
861 *
862 * Note: Different kinds of host controller have different "scheduling
863 * horizons". While one type might support scheduling only 32 frames
864 * into the future, others could support scheduling up to 1024 frames
865 * into the future.
866 *
867 */
868int usb_get_current_frame_number(struct usb_device *dev)
869{
870 return usb_hcd_get_frame_number(dev);
871}
872EXPORT_SYMBOL_GPL(usb_get_current_frame_number);
873
874/*-------------------------------------------------------------------*/
875/*
876 * __usb_get_extra_descriptor() finds a descriptor of specific type in the
877 * extra field of the interface and endpoint descriptor structs.
878 */
879
880int __usb_get_extra_descriptor(char *buffer, unsigned size,
881 unsigned char type, void **ptr, size_t minsize)
882{
883 struct usb_descriptor_header *header;
884
885 while (size >= sizeof(struct usb_descriptor_header)) {
886 header = (struct usb_descriptor_header *)buffer;
887
888 if (header->bLength < 2 || header->bLength > size) {
889 printk(KERN_ERR
890 "%s: bogus descriptor, type %d length %d\n",
891 usbcore_name,
892 header->bDescriptorType,
893 header->bLength);
894 return -1;
895 }
896
897 if (header->bDescriptorType == type && header->bLength >= minsize) {
898 *ptr = header;
899 return 0;
900 }
901
902 buffer += header->bLength;
903 size -= header->bLength;
904 }
905 return -1;
906}
907EXPORT_SYMBOL_GPL(__usb_get_extra_descriptor);
908
909/**
910 * usb_alloc_coherent - allocate dma-consistent buffer for URB_NO_xxx_DMA_MAP
911 * @dev: device the buffer will be used with
912 * @size: requested buffer size
913 * @mem_flags: affect whether allocation may block
914 * @dma: used to return DMA address of buffer
915 *
916 * Return: Either null (indicating no buffer could be allocated), or the
917 * cpu-space pointer to a buffer that may be used to perform DMA to the
918 * specified device. Such cpu-space buffers are returned along with the DMA
919 * address (through the pointer provided).
920 *
921 * Note:
922 * These buffers are used with URB_NO_xxx_DMA_MAP set in urb->transfer_flags
923 * to avoid behaviors like using "DMA bounce buffers", or thrashing IOMMU
924 * hardware during URB completion/resubmit. The implementation varies between
925 * platforms, depending on details of how DMA will work to this device.
926 * Using these buffers also eliminates cacheline sharing problems on
927 * architectures where CPU caches are not DMA-coherent. On systems without
928 * bus-snooping caches, these buffers are uncached.
929 *
930 * When the buffer is no longer used, free it with usb_free_coherent().
931 */
932void *usb_alloc_coherent(struct usb_device *dev, size_t size, gfp_t mem_flags,
933 dma_addr_t *dma)
934{
935 if (!dev || !dev->bus)
936 return NULL;
937 return hcd_buffer_alloc(dev->bus, size, mem_flags, dma);
938}
939EXPORT_SYMBOL_GPL(usb_alloc_coherent);
940
941/**
942 * usb_free_coherent - free memory allocated with usb_alloc_coherent()
943 * @dev: device the buffer was used with
944 * @size: requested buffer size
945 * @addr: CPU address of buffer
946 * @dma: DMA address of buffer
947 *
948 * This reclaims an I/O buffer, letting it be reused. The memory must have
949 * been allocated using usb_alloc_coherent(), and the parameters must match
950 * those provided in that allocation request.
951 */
952void usb_free_coherent(struct usb_device *dev, size_t size, void *addr,
953 dma_addr_t dma)
954{
955 if (!dev || !dev->bus)
956 return;
957 if (!addr)
958 return;
959 hcd_buffer_free(dev->bus, size, addr, dma);
960}
961EXPORT_SYMBOL_GPL(usb_free_coherent);
962
963/*
964 * Notifications of device and interface registration
965 */
966static int usb_bus_notify(struct notifier_block *nb, unsigned long action,
967 void *data)
968{
969 struct device *dev = data;
970
971 switch (action) {
972 case BUS_NOTIFY_ADD_DEVICE:
973 if (dev->type == &usb_device_type)
974 (void) usb_create_sysfs_dev_files(to_usb_device(dev));
975 else if (dev->type == &usb_if_device_type)
976 usb_create_sysfs_intf_files(to_usb_interface(dev));
977 break;
978
979 case BUS_NOTIFY_DEL_DEVICE:
980 if (dev->type == &usb_device_type)
981 usb_remove_sysfs_dev_files(to_usb_device(dev));
982 else if (dev->type == &usb_if_device_type)
983 usb_remove_sysfs_intf_files(to_usb_interface(dev));
984 break;
985 }
986 return 0;
987}
988
989static struct notifier_block usb_bus_nb = {
990 .notifier_call = usb_bus_notify,
991};
992
993static void usb_debugfs_init(void)
994{
995 debugfs_create_file("devices", 0444, usb_debug_root, NULL,
996 &usbfs_devices_fops);
997}
998
999static void usb_debugfs_cleanup(void)
1000{
1001 debugfs_remove(debugfs_lookup("devices", usb_debug_root));
1002}
1003
1004/*
1005 * Init
1006 */
1007static int __init usb_init(void)
1008{
1009 int retval;
1010 if (usb_disabled()) {
1011 pr_info("%s: USB support disabled\n", usbcore_name);
1012 return 0;
1013 }
1014 usb_init_pool_max();
1015
1016 usb_debugfs_init();
1017
1018 usb_acpi_register();
1019 retval = bus_register(&usb_bus_type);
1020 if (retval)
1021 goto bus_register_failed;
1022 retval = bus_register_notifier(&usb_bus_type, &usb_bus_nb);
1023 if (retval)
1024 goto bus_notifier_failed;
1025 retval = usb_major_init();
1026 if (retval)
1027 goto major_init_failed;
1028 retval = usb_register(&usbfs_driver);
1029 if (retval)
1030 goto driver_register_failed;
1031 retval = usb_devio_init();
1032 if (retval)
1033 goto usb_devio_init_failed;
1034 retval = usb_hub_init();
1035 if (retval)
1036 goto hub_init_failed;
1037 retval = usb_register_device_driver(&usb_generic_driver, THIS_MODULE);
1038 if (!retval)
1039 goto out;
1040
1041 usb_hub_cleanup();
1042hub_init_failed:
1043 usb_devio_cleanup();
1044usb_devio_init_failed:
1045 usb_deregister(&usbfs_driver);
1046driver_register_failed:
1047 usb_major_cleanup();
1048major_init_failed:
1049 bus_unregister_notifier(&usb_bus_type, &usb_bus_nb);
1050bus_notifier_failed:
1051 bus_unregister(&usb_bus_type);
1052bus_register_failed:
1053 usb_acpi_unregister();
1054 usb_debugfs_cleanup();
1055out:
1056 return retval;
1057}
1058
1059/*
1060 * Cleanup
1061 */
1062static void __exit usb_exit(void)
1063{
1064 /* This will matter if shutdown/reboot does exitcalls. */
1065 if (usb_disabled())
1066 return;
1067
1068 usb_release_quirk_list();
1069 usb_deregister_device_driver(&usb_generic_driver);
1070 usb_major_cleanup();
1071 usb_deregister(&usbfs_driver);
1072 usb_devio_cleanup();
1073 usb_hub_cleanup();
1074 bus_unregister_notifier(&usb_bus_type, &usb_bus_nb);
1075 bus_unregister(&usb_bus_type);
1076 usb_acpi_unregister();
1077 usb_debugfs_cleanup();
1078 idr_destroy(&usb_bus_idr);
1079}
1080
1081subsys_initcall(usb_init);
1082module_exit(usb_exit);
1083MODULE_LICENSE("GPL");
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * drivers/usb/core/usb.c
4 *
5 * (C) Copyright Linus Torvalds 1999
6 * (C) Copyright Johannes Erdfelt 1999-2001
7 * (C) Copyright Andreas Gal 1999
8 * (C) Copyright Gregory P. Smith 1999
9 * (C) Copyright Deti Fliegl 1999 (new USB architecture)
10 * (C) Copyright Randy Dunlap 2000
11 * (C) Copyright David Brownell 2000-2004
12 * (C) Copyright Yggdrasil Computing, Inc. 2000
13 * (usb_device_id matching changes by Adam J. Richter)
14 * (C) Copyright Greg Kroah-Hartman 2002-2003
15 *
16 * Released under the GPLv2 only.
17 *
18 * NOTE! This is not actually a driver at all, rather this is
19 * just a collection of helper routines that implement the
20 * generic USB things that the real drivers can use..
21 *
22 * Think of this as a "USB library" rather than anything else,
23 * with no callbacks. Callbacks are evil.
24 */
25
26#include <linux/module.h>
27#include <linux/moduleparam.h>
28#include <linux/string.h>
29#include <linux/bitops.h>
30#include <linux/slab.h>
31#include <linux/kmod.h>
32#include <linux/init.h>
33#include <linux/spinlock.h>
34#include <linux/errno.h>
35#include <linux/usb.h>
36#include <linux/usb/hcd.h>
37#include <linux/mutex.h>
38#include <linux/workqueue.h>
39#include <linux/debugfs.h>
40#include <linux/usb/of.h>
41
42#include <asm/io.h>
43#include <linux/scatterlist.h>
44#include <linux/mm.h>
45#include <linux/dma-mapping.h>
46
47#include "hub.h"
48
49const char *usbcore_name = "usbcore";
50
51static bool nousb; /* Disable USB when built into kernel image */
52
53module_param(nousb, bool, 0444);
54
55/*
56 * for external read access to <nousb>
57 */
58int usb_disabled(void)
59{
60 return nousb;
61}
62EXPORT_SYMBOL_GPL(usb_disabled);
63
64#ifdef CONFIG_PM
65/* Default delay value, in seconds */
66static int usb_autosuspend_delay = CONFIG_USB_AUTOSUSPEND_DELAY;
67module_param_named(autosuspend, usb_autosuspend_delay, int, 0644);
68MODULE_PARM_DESC(autosuspend, "default autosuspend delay");
69
70#else
71#define usb_autosuspend_delay 0
72#endif
73
74static bool match_endpoint(struct usb_endpoint_descriptor *epd,
75 struct usb_endpoint_descriptor **bulk_in,
76 struct usb_endpoint_descriptor **bulk_out,
77 struct usb_endpoint_descriptor **int_in,
78 struct usb_endpoint_descriptor **int_out)
79{
80 switch (usb_endpoint_type(epd)) {
81 case USB_ENDPOINT_XFER_BULK:
82 if (usb_endpoint_dir_in(epd)) {
83 if (bulk_in && !*bulk_in) {
84 *bulk_in = epd;
85 break;
86 }
87 } else {
88 if (bulk_out && !*bulk_out) {
89 *bulk_out = epd;
90 break;
91 }
92 }
93
94 return false;
95 case USB_ENDPOINT_XFER_INT:
96 if (usb_endpoint_dir_in(epd)) {
97 if (int_in && !*int_in) {
98 *int_in = epd;
99 break;
100 }
101 } else {
102 if (int_out && !*int_out) {
103 *int_out = epd;
104 break;
105 }
106 }
107
108 return false;
109 default:
110 return false;
111 }
112
113 return (!bulk_in || *bulk_in) && (!bulk_out || *bulk_out) &&
114 (!int_in || *int_in) && (!int_out || *int_out);
115}
116
117/**
118 * usb_find_common_endpoints() -- look up common endpoint descriptors
119 * @alt: alternate setting to search
120 * @bulk_in: pointer to descriptor pointer, or NULL
121 * @bulk_out: pointer to descriptor pointer, or NULL
122 * @int_in: pointer to descriptor pointer, or NULL
123 * @int_out: pointer to descriptor pointer, or NULL
124 *
125 * Search the alternate setting's endpoint descriptors for the first bulk-in,
126 * bulk-out, interrupt-in and interrupt-out endpoints and return them in the
127 * provided pointers (unless they are NULL).
128 *
129 * If a requested endpoint is not found, the corresponding pointer is set to
130 * NULL.
131 *
132 * Return: Zero if all requested descriptors were found, or -ENXIO otherwise.
133 */
134int usb_find_common_endpoints(struct usb_host_interface *alt,
135 struct usb_endpoint_descriptor **bulk_in,
136 struct usb_endpoint_descriptor **bulk_out,
137 struct usb_endpoint_descriptor **int_in,
138 struct usb_endpoint_descriptor **int_out)
139{
140 struct usb_endpoint_descriptor *epd;
141 int i;
142
143 if (bulk_in)
144 *bulk_in = NULL;
145 if (bulk_out)
146 *bulk_out = NULL;
147 if (int_in)
148 *int_in = NULL;
149 if (int_out)
150 *int_out = NULL;
151
152 for (i = 0; i < alt->desc.bNumEndpoints; ++i) {
153 epd = &alt->endpoint[i].desc;
154
155 if (match_endpoint(epd, bulk_in, bulk_out, int_in, int_out))
156 return 0;
157 }
158
159 return -ENXIO;
160}
161EXPORT_SYMBOL_GPL(usb_find_common_endpoints);
162
163/**
164 * usb_find_common_endpoints_reverse() -- look up common endpoint descriptors
165 * @alt: alternate setting to search
166 * @bulk_in: pointer to descriptor pointer, or NULL
167 * @bulk_out: pointer to descriptor pointer, or NULL
168 * @int_in: pointer to descriptor pointer, or NULL
169 * @int_out: pointer to descriptor pointer, or NULL
170 *
171 * Search the alternate setting's endpoint descriptors for the last bulk-in,
172 * bulk-out, interrupt-in and interrupt-out endpoints and return them in the
173 * provided pointers (unless they are NULL).
174 *
175 * If a requested endpoint is not found, the corresponding pointer is set to
176 * NULL.
177 *
178 * Return: Zero if all requested descriptors were found, or -ENXIO otherwise.
179 */
180int usb_find_common_endpoints_reverse(struct usb_host_interface *alt,
181 struct usb_endpoint_descriptor **bulk_in,
182 struct usb_endpoint_descriptor **bulk_out,
183 struct usb_endpoint_descriptor **int_in,
184 struct usb_endpoint_descriptor **int_out)
185{
186 struct usb_endpoint_descriptor *epd;
187 int i;
188
189 if (bulk_in)
190 *bulk_in = NULL;
191 if (bulk_out)
192 *bulk_out = NULL;
193 if (int_in)
194 *int_in = NULL;
195 if (int_out)
196 *int_out = NULL;
197
198 for (i = alt->desc.bNumEndpoints - 1; i >= 0; --i) {
199 epd = &alt->endpoint[i].desc;
200
201 if (match_endpoint(epd, bulk_in, bulk_out, int_in, int_out))
202 return 0;
203 }
204
205 return -ENXIO;
206}
207EXPORT_SYMBOL_GPL(usb_find_common_endpoints_reverse);
208
209/**
210 * usb_find_alt_setting() - Given a configuration, find the alternate setting
211 * for the given interface.
212 * @config: the configuration to search (not necessarily the current config).
213 * @iface_num: interface number to search in
214 * @alt_num: alternate interface setting number to search for.
215 *
216 * Search the configuration's interface cache for the given alt setting.
217 *
218 * Return: The alternate setting, if found. %NULL otherwise.
219 */
220struct usb_host_interface *usb_find_alt_setting(
221 struct usb_host_config *config,
222 unsigned int iface_num,
223 unsigned int alt_num)
224{
225 struct usb_interface_cache *intf_cache = NULL;
226 int i;
227
228 if (!config)
229 return NULL;
230 for (i = 0; i < config->desc.bNumInterfaces; i++) {
231 if (config->intf_cache[i]->altsetting[0].desc.bInterfaceNumber
232 == iface_num) {
233 intf_cache = config->intf_cache[i];
234 break;
235 }
236 }
237 if (!intf_cache)
238 return NULL;
239 for (i = 0; i < intf_cache->num_altsetting; i++)
240 if (intf_cache->altsetting[i].desc.bAlternateSetting == alt_num)
241 return &intf_cache->altsetting[i];
242
243 printk(KERN_DEBUG "Did not find alt setting %u for intf %u, "
244 "config %u\n", alt_num, iface_num,
245 config->desc.bConfigurationValue);
246 return NULL;
247}
248EXPORT_SYMBOL_GPL(usb_find_alt_setting);
249
250/**
251 * usb_ifnum_to_if - get the interface object with a given interface number
252 * @dev: the device whose current configuration is considered
253 * @ifnum: the desired interface
254 *
255 * This walks the device descriptor for the currently active configuration
256 * to find the interface object with the particular interface number.
257 *
258 * Note that configuration descriptors are not required to assign interface
259 * numbers sequentially, so that it would be incorrect to assume that
260 * the first interface in that descriptor corresponds to interface zero.
261 * This routine helps device drivers avoid such mistakes.
262 * However, you should make sure that you do the right thing with any
263 * alternate settings available for this interfaces.
264 *
265 * Don't call this function unless you are bound to one of the interfaces
266 * on this device or you have locked the device!
267 *
268 * Return: A pointer to the interface that has @ifnum as interface number,
269 * if found. %NULL otherwise.
270 */
271struct usb_interface *usb_ifnum_to_if(const struct usb_device *dev,
272 unsigned ifnum)
273{
274 struct usb_host_config *config = dev->actconfig;
275 int i;
276
277 if (!config)
278 return NULL;
279 for (i = 0; i < config->desc.bNumInterfaces; i++)
280 if (config->interface[i]->altsetting[0]
281 .desc.bInterfaceNumber == ifnum)
282 return config->interface[i];
283
284 return NULL;
285}
286EXPORT_SYMBOL_GPL(usb_ifnum_to_if);
287
288/**
289 * usb_altnum_to_altsetting - get the altsetting structure with a given alternate setting number.
290 * @intf: the interface containing the altsetting in question
291 * @altnum: the desired alternate setting number
292 *
293 * This searches the altsetting array of the specified interface for
294 * an entry with the correct bAlternateSetting value.
295 *
296 * Note that altsettings need not be stored sequentially by number, so
297 * it would be incorrect to assume that the first altsetting entry in
298 * the array corresponds to altsetting zero. This routine helps device
299 * drivers avoid such mistakes.
300 *
301 * Don't call this function unless you are bound to the intf interface
302 * or you have locked the device!
303 *
304 * Return: A pointer to the entry of the altsetting array of @intf that
305 * has @altnum as the alternate setting number. %NULL if not found.
306 */
307struct usb_host_interface *usb_altnum_to_altsetting(
308 const struct usb_interface *intf,
309 unsigned int altnum)
310{
311 int i;
312
313 for (i = 0; i < intf->num_altsetting; i++) {
314 if (intf->altsetting[i].desc.bAlternateSetting == altnum)
315 return &intf->altsetting[i];
316 }
317 return NULL;
318}
319EXPORT_SYMBOL_GPL(usb_altnum_to_altsetting);
320
321struct find_interface_arg {
322 int minor;
323 struct device_driver *drv;
324};
325
326static int __find_interface(struct device *dev, const void *data)
327{
328 const struct find_interface_arg *arg = data;
329 struct usb_interface *intf;
330
331 if (!is_usb_interface(dev))
332 return 0;
333
334 if (dev->driver != arg->drv)
335 return 0;
336 intf = to_usb_interface(dev);
337 return intf->minor == arg->minor;
338}
339
340/**
341 * usb_find_interface - find usb_interface pointer for driver and device
342 * @drv: the driver whose current configuration is considered
343 * @minor: the minor number of the desired device
344 *
345 * This walks the bus device list and returns a pointer to the interface
346 * with the matching minor and driver. Note, this only works for devices
347 * that share the USB major number.
348 *
349 * Return: A pointer to the interface with the matching major and @minor.
350 */
351struct usb_interface *usb_find_interface(struct usb_driver *drv, int minor)
352{
353 struct find_interface_arg argb;
354 struct device *dev;
355
356 argb.minor = minor;
357 argb.drv = &drv->drvwrap.driver;
358
359 dev = bus_find_device(&usb_bus_type, NULL, &argb, __find_interface);
360
361 /* Drop reference count from bus_find_device */
362 put_device(dev);
363
364 return dev ? to_usb_interface(dev) : NULL;
365}
366EXPORT_SYMBOL_GPL(usb_find_interface);
367
368struct each_dev_arg {
369 void *data;
370 int (*fn)(struct usb_device *, void *);
371};
372
373static int __each_dev(struct device *dev, void *data)
374{
375 struct each_dev_arg *arg = (struct each_dev_arg *)data;
376
377 /* There are struct usb_interface on the same bus, filter them out */
378 if (!is_usb_device(dev))
379 return 0;
380
381 return arg->fn(to_usb_device(dev), arg->data);
382}
383
384/**
385 * usb_for_each_dev - iterate over all USB devices in the system
386 * @data: data pointer that will be handed to the callback function
387 * @fn: callback function to be called for each USB device
388 *
389 * Iterate over all USB devices and call @fn for each, passing it @data. If it
390 * returns anything other than 0, we break the iteration prematurely and return
391 * that value.
392 */
393int usb_for_each_dev(void *data, int (*fn)(struct usb_device *, void *))
394{
395 struct each_dev_arg arg = {data, fn};
396
397 return bus_for_each_dev(&usb_bus_type, NULL, &arg, __each_dev);
398}
399EXPORT_SYMBOL_GPL(usb_for_each_dev);
400
401struct each_hub_arg {
402 void *data;
403 int (*fn)(struct device *, void *);
404};
405
406static int __each_hub(struct usb_device *hdev, void *data)
407{
408 struct each_hub_arg *arg = (struct each_hub_arg *)data;
409 struct usb_hub *hub;
410 int ret = 0;
411 int i;
412
413 hub = usb_hub_to_struct_hub(hdev);
414 if (!hub)
415 return 0;
416
417 mutex_lock(&usb_port_peer_mutex);
418
419 for (i = 0; i < hdev->maxchild; i++) {
420 ret = arg->fn(&hub->ports[i]->dev, arg->data);
421 if (ret)
422 break;
423 }
424
425 mutex_unlock(&usb_port_peer_mutex);
426
427 return ret;
428}
429
430/**
431 * usb_for_each_port - interate over all USB ports in the system
432 * @data: data pointer that will be handed to the callback function
433 * @fn: callback function to be called for each USB port
434 *
435 * Iterate over all USB ports and call @fn for each, passing it @data. If it
436 * returns anything other than 0, we break the iteration prematurely and return
437 * that value.
438 */
439int usb_for_each_port(void *data, int (*fn)(struct device *, void *))
440{
441 struct each_hub_arg arg = {data, fn};
442
443 return usb_for_each_dev(&arg, __each_hub);
444}
445EXPORT_SYMBOL_GPL(usb_for_each_port);
446
447/**
448 * usb_release_dev - free a usb device structure when all users of it are finished.
449 * @dev: device that's been disconnected
450 *
451 * Will be called only by the device core when all users of this usb device are
452 * done.
453 */
454static void usb_release_dev(struct device *dev)
455{
456 struct usb_device *udev;
457 struct usb_hcd *hcd;
458
459 udev = to_usb_device(dev);
460 hcd = bus_to_hcd(udev->bus);
461
462 usb_destroy_configuration(udev);
463 usb_release_bos_descriptor(udev);
464 of_node_put(dev->of_node);
465 usb_put_hcd(hcd);
466 kfree(udev->product);
467 kfree(udev->manufacturer);
468 kfree(udev->serial);
469 kfree(udev);
470}
471
472static int usb_dev_uevent(struct device *dev, struct kobj_uevent_env *env)
473{
474 struct usb_device *usb_dev;
475
476 usb_dev = to_usb_device(dev);
477
478 if (add_uevent_var(env, "BUSNUM=%03d", usb_dev->bus->busnum))
479 return -ENOMEM;
480
481 if (add_uevent_var(env, "DEVNUM=%03d", usb_dev->devnum))
482 return -ENOMEM;
483
484 return 0;
485}
486
487#ifdef CONFIG_PM
488
489/* USB device Power-Management thunks.
490 * There's no need to distinguish here between quiescing a USB device
491 * and powering it down; the generic_suspend() routine takes care of
492 * it by skipping the usb_port_suspend() call for a quiesce. And for
493 * USB interfaces there's no difference at all.
494 */
495
496static int usb_dev_prepare(struct device *dev)
497{
498 return 0; /* Implement eventually? */
499}
500
501static void usb_dev_complete(struct device *dev)
502{
503 /* Currently used only for rebinding interfaces */
504 usb_resume_complete(dev);
505}
506
507static int usb_dev_suspend(struct device *dev)
508{
509 return usb_suspend(dev, PMSG_SUSPEND);
510}
511
512static int usb_dev_resume(struct device *dev)
513{
514 return usb_resume(dev, PMSG_RESUME);
515}
516
517static int usb_dev_freeze(struct device *dev)
518{
519 return usb_suspend(dev, PMSG_FREEZE);
520}
521
522static int usb_dev_thaw(struct device *dev)
523{
524 return usb_resume(dev, PMSG_THAW);
525}
526
527static int usb_dev_poweroff(struct device *dev)
528{
529 return usb_suspend(dev, PMSG_HIBERNATE);
530}
531
532static int usb_dev_restore(struct device *dev)
533{
534 return usb_resume(dev, PMSG_RESTORE);
535}
536
537static const struct dev_pm_ops usb_device_pm_ops = {
538 .prepare = usb_dev_prepare,
539 .complete = usb_dev_complete,
540 .suspend = usb_dev_suspend,
541 .resume = usb_dev_resume,
542 .freeze = usb_dev_freeze,
543 .thaw = usb_dev_thaw,
544 .poweroff = usb_dev_poweroff,
545 .restore = usb_dev_restore,
546 .runtime_suspend = usb_runtime_suspend,
547 .runtime_resume = usb_runtime_resume,
548 .runtime_idle = usb_runtime_idle,
549};
550
551#endif /* CONFIG_PM */
552
553
554static char *usb_devnode(struct device *dev,
555 umode_t *mode, kuid_t *uid, kgid_t *gid)
556{
557 struct usb_device *usb_dev;
558
559 usb_dev = to_usb_device(dev);
560 return kasprintf(GFP_KERNEL, "bus/usb/%03d/%03d",
561 usb_dev->bus->busnum, usb_dev->devnum);
562}
563
564struct device_type usb_device_type = {
565 .name = "usb_device",
566 .release = usb_release_dev,
567 .uevent = usb_dev_uevent,
568 .devnode = usb_devnode,
569#ifdef CONFIG_PM
570 .pm = &usb_device_pm_ops,
571#endif
572};
573
574
575/* Returns 1 if @usb_bus is WUSB, 0 otherwise */
576static unsigned usb_bus_is_wusb(struct usb_bus *bus)
577{
578 struct usb_hcd *hcd = bus_to_hcd(bus);
579 return hcd->wireless;
580}
581
582static bool usb_dev_authorized(struct usb_device *dev, struct usb_hcd *hcd)
583{
584 struct usb_hub *hub;
585
586 if (!dev->parent)
587 return true; /* Root hub always ok [and always wired] */
588
589 switch (hcd->dev_policy) {
590 case USB_DEVICE_AUTHORIZE_NONE:
591 default:
592 return false;
593
594 case USB_DEVICE_AUTHORIZE_ALL:
595 return true;
596
597 case USB_DEVICE_AUTHORIZE_INTERNAL:
598 hub = usb_hub_to_struct_hub(dev->parent);
599 return hub->ports[dev->portnum - 1]->connect_type ==
600 USB_PORT_CONNECT_TYPE_HARD_WIRED;
601 }
602}
603
604/**
605 * usb_alloc_dev - usb device constructor (usbcore-internal)
606 * @parent: hub to which device is connected; null to allocate a root hub
607 * @bus: bus used to access the device
608 * @port1: one-based index of port; ignored for root hubs
609 *
610 * Context: task context, might sleep.
611 *
612 * Only hub drivers (including virtual root hub drivers for host
613 * controllers) should ever call this.
614 *
615 * This call may not be used in a non-sleeping context.
616 *
617 * Return: On success, a pointer to the allocated usb device. %NULL on
618 * failure.
619 */
620struct usb_device *usb_alloc_dev(struct usb_device *parent,
621 struct usb_bus *bus, unsigned port1)
622{
623 struct usb_device *dev;
624 struct usb_hcd *usb_hcd = bus_to_hcd(bus);
625 unsigned root_hub = 0;
626 unsigned raw_port = port1;
627
628 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
629 if (!dev)
630 return NULL;
631
632 if (!usb_get_hcd(usb_hcd)) {
633 kfree(dev);
634 return NULL;
635 }
636 /* Root hubs aren't true devices, so don't allocate HCD resources */
637 if (usb_hcd->driver->alloc_dev && parent &&
638 !usb_hcd->driver->alloc_dev(usb_hcd, dev)) {
639 usb_put_hcd(bus_to_hcd(bus));
640 kfree(dev);
641 return NULL;
642 }
643
644 device_initialize(&dev->dev);
645 dev->dev.bus = &usb_bus_type;
646 dev->dev.type = &usb_device_type;
647 dev->dev.groups = usb_device_groups;
648 set_dev_node(&dev->dev, dev_to_node(bus->sysdev));
649 dev->state = USB_STATE_ATTACHED;
650 dev->lpm_disable_count = 1;
651 atomic_set(&dev->urbnum, 0);
652
653 INIT_LIST_HEAD(&dev->ep0.urb_list);
654 dev->ep0.desc.bLength = USB_DT_ENDPOINT_SIZE;
655 dev->ep0.desc.bDescriptorType = USB_DT_ENDPOINT;
656 /* ep0 maxpacket comes later, from device descriptor */
657 usb_enable_endpoint(dev, &dev->ep0, false);
658 dev->can_submit = 1;
659
660 /* Save readable and stable topology id, distinguishing devices
661 * by location for diagnostics, tools, driver model, etc. The
662 * string is a path along hub ports, from the root. Each device's
663 * dev->devpath will be stable until USB is re-cabled, and hubs
664 * are often labeled with these port numbers. The name isn't
665 * as stable: bus->busnum changes easily from modprobe order,
666 * cardbus or pci hotplugging, and so on.
667 */
668 if (unlikely(!parent)) {
669 dev->devpath[0] = '0';
670 dev->route = 0;
671
672 dev->dev.parent = bus->controller;
673 device_set_of_node_from_dev(&dev->dev, bus->sysdev);
674 dev_set_name(&dev->dev, "usb%d", bus->busnum);
675 root_hub = 1;
676 } else {
677 /* match any labeling on the hubs; it's one-based */
678 if (parent->devpath[0] == '0') {
679 snprintf(dev->devpath, sizeof dev->devpath,
680 "%d", port1);
681 /* Root ports are not counted in route string */
682 dev->route = 0;
683 } else {
684 snprintf(dev->devpath, sizeof dev->devpath,
685 "%s.%d", parent->devpath, port1);
686 /* Route string assumes hubs have less than 16 ports */
687 if (port1 < 15)
688 dev->route = parent->route +
689 (port1 << ((parent->level - 1)*4));
690 else
691 dev->route = parent->route +
692 (15 << ((parent->level - 1)*4));
693 }
694
695 dev->dev.parent = &parent->dev;
696 dev_set_name(&dev->dev, "%d-%s", bus->busnum, dev->devpath);
697
698 if (!parent->parent) {
699 /* device under root hub's port */
700 raw_port = usb_hcd_find_raw_port_number(usb_hcd,
701 port1);
702 }
703 dev->dev.of_node = usb_of_get_device_node(parent, raw_port);
704
705 /* hub driver sets up TT records */
706 }
707
708 dev->portnum = port1;
709 dev->bus = bus;
710 dev->parent = parent;
711 INIT_LIST_HEAD(&dev->filelist);
712
713#ifdef CONFIG_PM
714 pm_runtime_set_autosuspend_delay(&dev->dev,
715 usb_autosuspend_delay * 1000);
716 dev->connect_time = jiffies;
717 dev->active_duration = -jiffies;
718#endif
719
720 dev->authorized = usb_dev_authorized(dev, usb_hcd);
721 if (!root_hub)
722 dev->wusb = usb_bus_is_wusb(bus) ? 1 : 0;
723
724 return dev;
725}
726EXPORT_SYMBOL_GPL(usb_alloc_dev);
727
728/**
729 * usb_get_dev - increments the reference count of the usb device structure
730 * @dev: the device being referenced
731 *
732 * Each live reference to a device should be refcounted.
733 *
734 * Drivers for USB interfaces should normally record such references in
735 * their probe() methods, when they bind to an interface, and release
736 * them by calling usb_put_dev(), in their disconnect() methods.
737 *
738 * Return: A pointer to the device with the incremented reference counter.
739 */
740struct usb_device *usb_get_dev(struct usb_device *dev)
741{
742 if (dev)
743 get_device(&dev->dev);
744 return dev;
745}
746EXPORT_SYMBOL_GPL(usb_get_dev);
747
748/**
749 * usb_put_dev - release a use of the usb device structure
750 * @dev: device that's been disconnected
751 *
752 * Must be called when a user of a device is finished with it. When the last
753 * user of the device calls this function, the memory of the device is freed.
754 */
755void usb_put_dev(struct usb_device *dev)
756{
757 if (dev)
758 put_device(&dev->dev);
759}
760EXPORT_SYMBOL_GPL(usb_put_dev);
761
762/**
763 * usb_get_intf - increments the reference count of the usb interface structure
764 * @intf: the interface being referenced
765 *
766 * Each live reference to a interface must be refcounted.
767 *
768 * Drivers for USB interfaces should normally record such references in
769 * their probe() methods, when they bind to an interface, and release
770 * them by calling usb_put_intf(), in their disconnect() methods.
771 *
772 * Return: A pointer to the interface with the incremented reference counter.
773 */
774struct usb_interface *usb_get_intf(struct usb_interface *intf)
775{
776 if (intf)
777 get_device(&intf->dev);
778 return intf;
779}
780EXPORT_SYMBOL_GPL(usb_get_intf);
781
782/**
783 * usb_put_intf - release a use of the usb interface structure
784 * @intf: interface that's been decremented
785 *
786 * Must be called when a user of an interface is finished with it. When the
787 * last user of the interface calls this function, the memory of the interface
788 * is freed.
789 */
790void usb_put_intf(struct usb_interface *intf)
791{
792 if (intf)
793 put_device(&intf->dev);
794}
795EXPORT_SYMBOL_GPL(usb_put_intf);
796
797/**
798 * usb_intf_get_dma_device - acquire a reference on the usb interface's DMA endpoint
799 * @intf: the usb interface
800 *
801 * While a USB device cannot perform DMA operations by itself, many USB
802 * controllers can. A call to usb_intf_get_dma_device() returns the DMA endpoint
803 * for the given USB interface, if any. The returned device structure must be
804 * released with put_device().
805 *
806 * See also usb_get_dma_device().
807 *
808 * Returns: A reference to the usb interface's DMA endpoint; or NULL if none
809 * exists.
810 */
811struct device *usb_intf_get_dma_device(struct usb_interface *intf)
812{
813 struct usb_device *udev = interface_to_usbdev(intf);
814 struct device *dmadev;
815
816 if (!udev->bus)
817 return NULL;
818
819 dmadev = get_device(udev->bus->sysdev);
820 if (!dmadev || !dmadev->dma_mask) {
821 put_device(dmadev);
822 return NULL;
823 }
824
825 return dmadev;
826}
827EXPORT_SYMBOL_GPL(usb_intf_get_dma_device);
828
829/* USB device locking
830 *
831 * USB devices and interfaces are locked using the semaphore in their
832 * embedded struct device. The hub driver guarantees that whenever a
833 * device is connected or disconnected, drivers are called with the
834 * USB device locked as well as their particular interface.
835 *
836 * Complications arise when several devices are to be locked at the same
837 * time. Only hub-aware drivers that are part of usbcore ever have to
838 * do this; nobody else needs to worry about it. The rule for locking
839 * is simple:
840 *
841 * When locking both a device and its parent, always lock the
842 * the parent first.
843 */
844
845/**
846 * usb_lock_device_for_reset - cautiously acquire the lock for a usb device structure
847 * @udev: device that's being locked
848 * @iface: interface bound to the driver making the request (optional)
849 *
850 * Attempts to acquire the device lock, but fails if the device is
851 * NOTATTACHED or SUSPENDED, or if iface is specified and the interface
852 * is neither BINDING nor BOUND. Rather than sleeping to wait for the
853 * lock, the routine polls repeatedly. This is to prevent deadlock with
854 * disconnect; in some drivers (such as usb-storage) the disconnect()
855 * or suspend() method will block waiting for a device reset to complete.
856 *
857 * Return: A negative error code for failure, otherwise 0.
858 */
859int usb_lock_device_for_reset(struct usb_device *udev,
860 const struct usb_interface *iface)
861{
862 unsigned long jiffies_expire = jiffies + HZ;
863
864 if (udev->state == USB_STATE_NOTATTACHED)
865 return -ENODEV;
866 if (udev->state == USB_STATE_SUSPENDED)
867 return -EHOSTUNREACH;
868 if (iface && (iface->condition == USB_INTERFACE_UNBINDING ||
869 iface->condition == USB_INTERFACE_UNBOUND))
870 return -EINTR;
871
872 while (!usb_trylock_device(udev)) {
873
874 /* If we can't acquire the lock after waiting one second,
875 * we're probably deadlocked */
876 if (time_after(jiffies, jiffies_expire))
877 return -EBUSY;
878
879 msleep(15);
880 if (udev->state == USB_STATE_NOTATTACHED)
881 return -ENODEV;
882 if (udev->state == USB_STATE_SUSPENDED)
883 return -EHOSTUNREACH;
884 if (iface && (iface->condition == USB_INTERFACE_UNBINDING ||
885 iface->condition == USB_INTERFACE_UNBOUND))
886 return -EINTR;
887 }
888 return 0;
889}
890EXPORT_SYMBOL_GPL(usb_lock_device_for_reset);
891
892/**
893 * usb_get_current_frame_number - return current bus frame number
894 * @dev: the device whose bus is being queried
895 *
896 * Return: The current frame number for the USB host controller used
897 * with the given USB device. This can be used when scheduling
898 * isochronous requests.
899 *
900 * Note: Different kinds of host controller have different "scheduling
901 * horizons". While one type might support scheduling only 32 frames
902 * into the future, others could support scheduling up to 1024 frames
903 * into the future.
904 *
905 */
906int usb_get_current_frame_number(struct usb_device *dev)
907{
908 return usb_hcd_get_frame_number(dev);
909}
910EXPORT_SYMBOL_GPL(usb_get_current_frame_number);
911
912/*-------------------------------------------------------------------*/
913/*
914 * __usb_get_extra_descriptor() finds a descriptor of specific type in the
915 * extra field of the interface and endpoint descriptor structs.
916 */
917
918int __usb_get_extra_descriptor(char *buffer, unsigned size,
919 unsigned char type, void **ptr, size_t minsize)
920{
921 struct usb_descriptor_header *header;
922
923 while (size >= sizeof(struct usb_descriptor_header)) {
924 header = (struct usb_descriptor_header *)buffer;
925
926 if (header->bLength < 2 || header->bLength > size) {
927 printk(KERN_ERR
928 "%s: bogus descriptor, type %d length %d\n",
929 usbcore_name,
930 header->bDescriptorType,
931 header->bLength);
932 return -1;
933 }
934
935 if (header->bDescriptorType == type && header->bLength >= minsize) {
936 *ptr = header;
937 return 0;
938 }
939
940 buffer += header->bLength;
941 size -= header->bLength;
942 }
943 return -1;
944}
945EXPORT_SYMBOL_GPL(__usb_get_extra_descriptor);
946
947/**
948 * usb_alloc_coherent - allocate dma-consistent buffer for URB_NO_xxx_DMA_MAP
949 * @dev: device the buffer will be used with
950 * @size: requested buffer size
951 * @mem_flags: affect whether allocation may block
952 * @dma: used to return DMA address of buffer
953 *
954 * Return: Either null (indicating no buffer could be allocated), or the
955 * cpu-space pointer to a buffer that may be used to perform DMA to the
956 * specified device. Such cpu-space buffers are returned along with the DMA
957 * address (through the pointer provided).
958 *
959 * Note:
960 * These buffers are used with URB_NO_xxx_DMA_MAP set in urb->transfer_flags
961 * to avoid behaviors like using "DMA bounce buffers", or thrashing IOMMU
962 * hardware during URB completion/resubmit. The implementation varies between
963 * platforms, depending on details of how DMA will work to this device.
964 * Using these buffers also eliminates cacheline sharing problems on
965 * architectures where CPU caches are not DMA-coherent. On systems without
966 * bus-snooping caches, these buffers are uncached.
967 *
968 * When the buffer is no longer used, free it with usb_free_coherent().
969 */
970void *usb_alloc_coherent(struct usb_device *dev, size_t size, gfp_t mem_flags,
971 dma_addr_t *dma)
972{
973 if (!dev || !dev->bus)
974 return NULL;
975 return hcd_buffer_alloc(dev->bus, size, mem_flags, dma);
976}
977EXPORT_SYMBOL_GPL(usb_alloc_coherent);
978
979/**
980 * usb_free_coherent - free memory allocated with usb_alloc_coherent()
981 * @dev: device the buffer was used with
982 * @size: requested buffer size
983 * @addr: CPU address of buffer
984 * @dma: DMA address of buffer
985 *
986 * This reclaims an I/O buffer, letting it be reused. The memory must have
987 * been allocated using usb_alloc_coherent(), and the parameters must match
988 * those provided in that allocation request.
989 */
990void usb_free_coherent(struct usb_device *dev, size_t size, void *addr,
991 dma_addr_t dma)
992{
993 if (!dev || !dev->bus)
994 return;
995 if (!addr)
996 return;
997 hcd_buffer_free(dev->bus, size, addr, dma);
998}
999EXPORT_SYMBOL_GPL(usb_free_coherent);
1000
1001/*
1002 * Notifications of device and interface registration
1003 */
1004static int usb_bus_notify(struct notifier_block *nb, unsigned long action,
1005 void *data)
1006{
1007 struct device *dev = data;
1008
1009 switch (action) {
1010 case BUS_NOTIFY_ADD_DEVICE:
1011 if (dev->type == &usb_device_type)
1012 (void) usb_create_sysfs_dev_files(to_usb_device(dev));
1013 else if (dev->type == &usb_if_device_type)
1014 usb_create_sysfs_intf_files(to_usb_interface(dev));
1015 break;
1016
1017 case BUS_NOTIFY_DEL_DEVICE:
1018 if (dev->type == &usb_device_type)
1019 usb_remove_sysfs_dev_files(to_usb_device(dev));
1020 else if (dev->type == &usb_if_device_type)
1021 usb_remove_sysfs_intf_files(to_usb_interface(dev));
1022 break;
1023 }
1024 return 0;
1025}
1026
1027static struct notifier_block usb_bus_nb = {
1028 .notifier_call = usb_bus_notify,
1029};
1030
1031static void usb_debugfs_init(void)
1032{
1033 debugfs_create_file("devices", 0444, usb_debug_root, NULL,
1034 &usbfs_devices_fops);
1035}
1036
1037static void usb_debugfs_cleanup(void)
1038{
1039 debugfs_remove(debugfs_lookup("devices", usb_debug_root));
1040}
1041
1042/*
1043 * Init
1044 */
1045static int __init usb_init(void)
1046{
1047 int retval;
1048 if (usb_disabled()) {
1049 pr_info("%s: USB support disabled\n", usbcore_name);
1050 return 0;
1051 }
1052 usb_init_pool_max();
1053
1054 usb_debugfs_init();
1055
1056 usb_acpi_register();
1057 retval = bus_register(&usb_bus_type);
1058 if (retval)
1059 goto bus_register_failed;
1060 retval = bus_register_notifier(&usb_bus_type, &usb_bus_nb);
1061 if (retval)
1062 goto bus_notifier_failed;
1063 retval = usb_major_init();
1064 if (retval)
1065 goto major_init_failed;
1066 retval = usb_register(&usbfs_driver);
1067 if (retval)
1068 goto driver_register_failed;
1069 retval = usb_devio_init();
1070 if (retval)
1071 goto usb_devio_init_failed;
1072 retval = usb_hub_init();
1073 if (retval)
1074 goto hub_init_failed;
1075 retval = usb_register_device_driver(&usb_generic_driver, THIS_MODULE);
1076 if (!retval)
1077 goto out;
1078
1079 usb_hub_cleanup();
1080hub_init_failed:
1081 usb_devio_cleanup();
1082usb_devio_init_failed:
1083 usb_deregister(&usbfs_driver);
1084driver_register_failed:
1085 usb_major_cleanup();
1086major_init_failed:
1087 bus_unregister_notifier(&usb_bus_type, &usb_bus_nb);
1088bus_notifier_failed:
1089 bus_unregister(&usb_bus_type);
1090bus_register_failed:
1091 usb_acpi_unregister();
1092 usb_debugfs_cleanup();
1093out:
1094 return retval;
1095}
1096
1097/*
1098 * Cleanup
1099 */
1100static void __exit usb_exit(void)
1101{
1102 /* This will matter if shutdown/reboot does exitcalls. */
1103 if (usb_disabled())
1104 return;
1105
1106 usb_release_quirk_list();
1107 usb_deregister_device_driver(&usb_generic_driver);
1108 usb_major_cleanup();
1109 usb_deregister(&usbfs_driver);
1110 usb_devio_cleanup();
1111 usb_hub_cleanup();
1112 bus_unregister_notifier(&usb_bus_type, &usb_bus_nb);
1113 bus_unregister(&usb_bus_type);
1114 usb_acpi_unregister();
1115 usb_debugfs_cleanup();
1116 idr_destroy(&usb_bus_idr);
1117}
1118
1119subsys_initcall(usb_init);
1120module_exit(usb_exit);
1121MODULE_LICENSE("GPL");