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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 * It should be considered a slave, with no callbacks. Callbacks
24 * are evil.
25 */
26
27#include <linux/module.h>
28#include <linux/moduleparam.h>
29#include <linux/string.h>
30#include <linux/bitops.h>
31#include <linux/slab.h>
32#include <linux/interrupt.h> /* for in_interrupt() */
33#include <linux/kmod.h>
34#include <linux/init.h>
35#include <linux/spinlock.h>
36#include <linux/errno.h>
37#include <linux/usb.h>
38#include <linux/usb/hcd.h>
39#include <linux/mutex.h>
40#include <linux/workqueue.h>
41#include <linux/debugfs.h>
42#include <linux/usb/of.h>
43
44#include <asm/io.h>
45#include <linux/scatterlist.h>
46#include <linux/mm.h>
47#include <linux/dma-mapping.h>
48
49#include "hub.h"
50
51const char *usbcore_name = "usbcore";
52
53static bool nousb; /* Disable USB when built into kernel image */
54
55module_param(nousb, bool, 0444);
56
57/*
58 * for external read access to <nousb>
59 */
60int usb_disabled(void)
61{
62 return nousb;
63}
64EXPORT_SYMBOL_GPL(usb_disabled);
65
66#ifdef CONFIG_PM
67/* Default delay value, in seconds */
68static int usb_autosuspend_delay = CONFIG_USB_AUTOSUSPEND_DELAY;
69module_param_named(autosuspend, usb_autosuspend_delay, int, 0644);
70MODULE_PARM_DESC(autosuspend, "default autosuspend delay");
71
72#else
73#define usb_autosuspend_delay 0
74#endif
75
76static bool match_endpoint(struct usb_endpoint_descriptor *epd,
77 struct usb_endpoint_descriptor **bulk_in,
78 struct usb_endpoint_descriptor **bulk_out,
79 struct usb_endpoint_descriptor **int_in,
80 struct usb_endpoint_descriptor **int_out)
81{
82 switch (usb_endpoint_type(epd)) {
83 case USB_ENDPOINT_XFER_BULK:
84 if (usb_endpoint_dir_in(epd)) {
85 if (bulk_in && !*bulk_in) {
86 *bulk_in = epd;
87 break;
88 }
89 } else {
90 if (bulk_out && !*bulk_out) {
91 *bulk_out = epd;
92 break;
93 }
94 }
95
96 return false;
97 case USB_ENDPOINT_XFER_INT:
98 if (usb_endpoint_dir_in(epd)) {
99 if (int_in && !*int_in) {
100 *int_in = epd;
101 break;
102 }
103 } else {
104 if (int_out && !*int_out) {
105 *int_out = epd;
106 break;
107 }
108 }
109
110 return false;
111 default:
112 return false;
113 }
114
115 return (!bulk_in || *bulk_in) && (!bulk_out || *bulk_out) &&
116 (!int_in || *int_in) && (!int_out || *int_out);
117}
118
119/**
120 * usb_find_common_endpoints() -- look up common endpoint descriptors
121 * @alt: alternate setting to search
122 * @bulk_in: pointer to descriptor pointer, or NULL
123 * @bulk_out: pointer to descriptor pointer, or NULL
124 * @int_in: pointer to descriptor pointer, or NULL
125 * @int_out: pointer to descriptor pointer, or NULL
126 *
127 * Search the alternate setting's endpoint descriptors for the first bulk-in,
128 * bulk-out, interrupt-in and interrupt-out endpoints and return them in the
129 * provided pointers (unless they are NULL).
130 *
131 * If a requested endpoint is not found, the corresponding pointer is set to
132 * NULL.
133 *
134 * Return: Zero if all requested descriptors were found, or -ENXIO otherwise.
135 */
136int usb_find_common_endpoints(struct usb_host_interface *alt,
137 struct usb_endpoint_descriptor **bulk_in,
138 struct usb_endpoint_descriptor **bulk_out,
139 struct usb_endpoint_descriptor **int_in,
140 struct usb_endpoint_descriptor **int_out)
141{
142 struct usb_endpoint_descriptor *epd;
143 int i;
144
145 if (bulk_in)
146 *bulk_in = NULL;
147 if (bulk_out)
148 *bulk_out = NULL;
149 if (int_in)
150 *int_in = NULL;
151 if (int_out)
152 *int_out = NULL;
153
154 for (i = 0; i < alt->desc.bNumEndpoints; ++i) {
155 epd = &alt->endpoint[i].desc;
156
157 if (match_endpoint(epd, bulk_in, bulk_out, int_in, int_out))
158 return 0;
159 }
160
161 return -ENXIO;
162}
163EXPORT_SYMBOL_GPL(usb_find_common_endpoints);
164
165/**
166 * usb_find_common_endpoints_reverse() -- look up common endpoint descriptors
167 * @alt: alternate setting to search
168 * @bulk_in: pointer to descriptor pointer, or NULL
169 * @bulk_out: pointer to descriptor pointer, or NULL
170 * @int_in: pointer to descriptor pointer, or NULL
171 * @int_out: pointer to descriptor pointer, or NULL
172 *
173 * Search the alternate setting's endpoint descriptors for the last bulk-in,
174 * bulk-out, interrupt-in and interrupt-out endpoints and return them in the
175 * provided pointers (unless they are NULL).
176 *
177 * If a requested endpoint is not found, the corresponding pointer is set to
178 * NULL.
179 *
180 * Return: Zero if all requested descriptors were found, or -ENXIO otherwise.
181 */
182int usb_find_common_endpoints_reverse(struct usb_host_interface *alt,
183 struct usb_endpoint_descriptor **bulk_in,
184 struct usb_endpoint_descriptor **bulk_out,
185 struct usb_endpoint_descriptor **int_in,
186 struct usb_endpoint_descriptor **int_out)
187{
188 struct usb_endpoint_descriptor *epd;
189 int i;
190
191 if (bulk_in)
192 *bulk_in = NULL;
193 if (bulk_out)
194 *bulk_out = NULL;
195 if (int_in)
196 *int_in = NULL;
197 if (int_out)
198 *int_out = NULL;
199
200 for (i = alt->desc.bNumEndpoints - 1; i >= 0; --i) {
201 epd = &alt->endpoint[i].desc;
202
203 if (match_endpoint(epd, bulk_in, bulk_out, int_in, int_out))
204 return 0;
205 }
206
207 return -ENXIO;
208}
209EXPORT_SYMBOL_GPL(usb_find_common_endpoints_reverse);
210
211/**
212 * usb_find_alt_setting() - Given a configuration, find the alternate setting
213 * for the given interface.
214 * @config: the configuration to search (not necessarily the current config).
215 * @iface_num: interface number to search in
216 * @alt_num: alternate interface setting number to search for.
217 *
218 * Search the configuration's interface cache for the given alt setting.
219 *
220 * Return: The alternate setting, if found. %NULL otherwise.
221 */
222struct usb_host_interface *usb_find_alt_setting(
223 struct usb_host_config *config,
224 unsigned int iface_num,
225 unsigned int alt_num)
226{
227 struct usb_interface_cache *intf_cache = NULL;
228 int i;
229
230 if (!config)
231 return NULL;
232 for (i = 0; i < config->desc.bNumInterfaces; i++) {
233 if (config->intf_cache[i]->altsetting[0].desc.bInterfaceNumber
234 == iface_num) {
235 intf_cache = config->intf_cache[i];
236 break;
237 }
238 }
239 if (!intf_cache)
240 return NULL;
241 for (i = 0; i < intf_cache->num_altsetting; i++)
242 if (intf_cache->altsetting[i].desc.bAlternateSetting == alt_num)
243 return &intf_cache->altsetting[i];
244
245 printk(KERN_DEBUG "Did not find alt setting %u for intf %u, "
246 "config %u\n", alt_num, iface_num,
247 config->desc.bConfigurationValue);
248 return NULL;
249}
250EXPORT_SYMBOL_GPL(usb_find_alt_setting);
251
252/**
253 * usb_ifnum_to_if - get the interface object with a given interface number
254 * @dev: the device whose current configuration is considered
255 * @ifnum: the desired interface
256 *
257 * This walks the device descriptor for the currently active configuration
258 * to find the interface object with the particular interface number.
259 *
260 * Note that configuration descriptors are not required to assign interface
261 * numbers sequentially, so that it would be incorrect to assume that
262 * the first interface in that descriptor corresponds to interface zero.
263 * This routine helps device drivers avoid such mistakes.
264 * However, you should make sure that you do the right thing with any
265 * alternate settings available for this interfaces.
266 *
267 * Don't call this function unless you are bound to one of the interfaces
268 * on this device or you have locked the device!
269 *
270 * Return: A pointer to the interface that has @ifnum as interface number,
271 * if found. %NULL otherwise.
272 */
273struct usb_interface *usb_ifnum_to_if(const struct usb_device *dev,
274 unsigned ifnum)
275{
276 struct usb_host_config *config = dev->actconfig;
277 int i;
278
279 if (!config)
280 return NULL;
281 for (i = 0; i < config->desc.bNumInterfaces; i++)
282 if (config->interface[i]->altsetting[0]
283 .desc.bInterfaceNumber == ifnum)
284 return config->interface[i];
285
286 return NULL;
287}
288EXPORT_SYMBOL_GPL(usb_ifnum_to_if);
289
290/**
291 * usb_altnum_to_altsetting - get the altsetting structure with a given alternate setting number.
292 * @intf: the interface containing the altsetting in question
293 * @altnum: the desired alternate setting number
294 *
295 * This searches the altsetting array of the specified interface for
296 * an entry with the correct bAlternateSetting value.
297 *
298 * Note that altsettings need not be stored sequentially by number, so
299 * it would be incorrect to assume that the first altsetting entry in
300 * the array corresponds to altsetting zero. This routine helps device
301 * drivers avoid such mistakes.
302 *
303 * Don't call this function unless you are bound to the intf interface
304 * or you have locked the device!
305 *
306 * Return: A pointer to the entry of the altsetting array of @intf that
307 * has @altnum as the alternate setting number. %NULL if not found.
308 */
309struct usb_host_interface *usb_altnum_to_altsetting(
310 const struct usb_interface *intf,
311 unsigned int altnum)
312{
313 int i;
314
315 for (i = 0; i < intf->num_altsetting; i++) {
316 if (intf->altsetting[i].desc.bAlternateSetting == altnum)
317 return &intf->altsetting[i];
318 }
319 return NULL;
320}
321EXPORT_SYMBOL_GPL(usb_altnum_to_altsetting);
322
323struct find_interface_arg {
324 int minor;
325 struct device_driver *drv;
326};
327
328static int __find_interface(struct device *dev, const void *data)
329{
330 const struct find_interface_arg *arg = data;
331 struct usb_interface *intf;
332
333 if (!is_usb_interface(dev))
334 return 0;
335
336 if (dev->driver != arg->drv)
337 return 0;
338 intf = to_usb_interface(dev);
339 return intf->minor == arg->minor;
340}
341
342/**
343 * usb_find_interface - find usb_interface pointer for driver and device
344 * @drv: the driver whose current configuration is considered
345 * @minor: the minor number of the desired device
346 *
347 * This walks the bus device list and returns a pointer to the interface
348 * with the matching minor and driver. Note, this only works for devices
349 * that share the USB major number.
350 *
351 * Return: A pointer to the interface with the matching major and @minor.
352 */
353struct usb_interface *usb_find_interface(struct usb_driver *drv, int minor)
354{
355 struct find_interface_arg argb;
356 struct device *dev;
357
358 argb.minor = minor;
359 argb.drv = &drv->drvwrap.driver;
360
361 dev = bus_find_device(&usb_bus_type, NULL, &argb, __find_interface);
362
363 /* Drop reference count from bus_find_device */
364 put_device(dev);
365
366 return dev ? to_usb_interface(dev) : NULL;
367}
368EXPORT_SYMBOL_GPL(usb_find_interface);
369
370struct each_dev_arg {
371 void *data;
372 int (*fn)(struct usb_device *, void *);
373};
374
375static int __each_dev(struct device *dev, void *data)
376{
377 struct each_dev_arg *arg = (struct each_dev_arg *)data;
378
379 /* There are struct usb_interface on the same bus, filter them out */
380 if (!is_usb_device(dev))
381 return 0;
382
383 return arg->fn(to_usb_device(dev), arg->data);
384}
385
386/**
387 * usb_for_each_dev - iterate over all USB devices in the system
388 * @data: data pointer that will be handed to the callback function
389 * @fn: callback function to be called for each USB device
390 *
391 * Iterate over all USB devices and call @fn for each, passing it @data. If it
392 * returns anything other than 0, we break the iteration prematurely and return
393 * that value.
394 */
395int usb_for_each_dev(void *data, int (*fn)(struct usb_device *, void *))
396{
397 struct each_dev_arg arg = {data, fn};
398
399 return bus_for_each_dev(&usb_bus_type, NULL, &arg, __each_dev);
400}
401EXPORT_SYMBOL_GPL(usb_for_each_dev);
402
403/**
404 * usb_release_dev - free a usb device structure when all users of it are finished.
405 * @dev: device that's been disconnected
406 *
407 * Will be called only by the device core when all users of this usb device are
408 * done.
409 */
410static void usb_release_dev(struct device *dev)
411{
412 struct usb_device *udev;
413 struct usb_hcd *hcd;
414
415 udev = to_usb_device(dev);
416 hcd = bus_to_hcd(udev->bus);
417
418 usb_destroy_configuration(udev);
419 usb_release_bos_descriptor(udev);
420 of_node_put(dev->of_node);
421 usb_put_hcd(hcd);
422 kfree(udev->product);
423 kfree(udev->manufacturer);
424 kfree(udev->serial);
425 kfree(udev);
426}
427
428static int usb_dev_uevent(struct device *dev, struct kobj_uevent_env *env)
429{
430 struct usb_device *usb_dev;
431
432 usb_dev = to_usb_device(dev);
433
434 if (add_uevent_var(env, "BUSNUM=%03d", usb_dev->bus->busnum))
435 return -ENOMEM;
436
437 if (add_uevent_var(env, "DEVNUM=%03d", usb_dev->devnum))
438 return -ENOMEM;
439
440 return 0;
441}
442
443#ifdef CONFIG_PM
444
445/* USB device Power-Management thunks.
446 * There's no need to distinguish here between quiescing a USB device
447 * and powering it down; the generic_suspend() routine takes care of
448 * it by skipping the usb_port_suspend() call for a quiesce. And for
449 * USB interfaces there's no difference at all.
450 */
451
452static int usb_dev_prepare(struct device *dev)
453{
454 return 0; /* Implement eventually? */
455}
456
457static void usb_dev_complete(struct device *dev)
458{
459 /* Currently used only for rebinding interfaces */
460 usb_resume_complete(dev);
461}
462
463static int usb_dev_suspend(struct device *dev)
464{
465 return usb_suspend(dev, PMSG_SUSPEND);
466}
467
468static int usb_dev_resume(struct device *dev)
469{
470 return usb_resume(dev, PMSG_RESUME);
471}
472
473static int usb_dev_freeze(struct device *dev)
474{
475 return usb_suspend(dev, PMSG_FREEZE);
476}
477
478static int usb_dev_thaw(struct device *dev)
479{
480 return usb_resume(dev, PMSG_THAW);
481}
482
483static int usb_dev_poweroff(struct device *dev)
484{
485 return usb_suspend(dev, PMSG_HIBERNATE);
486}
487
488static int usb_dev_restore(struct device *dev)
489{
490 return usb_resume(dev, PMSG_RESTORE);
491}
492
493static const struct dev_pm_ops usb_device_pm_ops = {
494 .prepare = usb_dev_prepare,
495 .complete = usb_dev_complete,
496 .suspend = usb_dev_suspend,
497 .resume = usb_dev_resume,
498 .freeze = usb_dev_freeze,
499 .thaw = usb_dev_thaw,
500 .poweroff = usb_dev_poweroff,
501 .restore = usb_dev_restore,
502 .runtime_suspend = usb_runtime_suspend,
503 .runtime_resume = usb_runtime_resume,
504 .runtime_idle = usb_runtime_idle,
505};
506
507#endif /* CONFIG_PM */
508
509
510static char *usb_devnode(struct device *dev,
511 umode_t *mode, kuid_t *uid, kgid_t *gid)
512{
513 struct usb_device *usb_dev;
514
515 usb_dev = to_usb_device(dev);
516 return kasprintf(GFP_KERNEL, "bus/usb/%03d/%03d",
517 usb_dev->bus->busnum, usb_dev->devnum);
518}
519
520struct device_type usb_device_type = {
521 .name = "usb_device",
522 .release = usb_release_dev,
523 .uevent = usb_dev_uevent,
524 .devnode = usb_devnode,
525#ifdef CONFIG_PM
526 .pm = &usb_device_pm_ops,
527#endif
528};
529
530
531/* Returns 1 if @usb_bus is WUSB, 0 otherwise */
532static unsigned usb_bus_is_wusb(struct usb_bus *bus)
533{
534 struct usb_hcd *hcd = bus_to_hcd(bus);
535 return hcd->wireless;
536}
537
538static bool usb_dev_authorized(struct usb_device *dev, struct usb_hcd *hcd)
539{
540 struct usb_hub *hub;
541
542 if (!dev->parent)
543 return true; /* Root hub always ok [and always wired] */
544
545 switch (hcd->dev_policy) {
546 case USB_DEVICE_AUTHORIZE_NONE:
547 default:
548 return false;
549
550 case USB_DEVICE_AUTHORIZE_ALL:
551 return true;
552
553 case USB_DEVICE_AUTHORIZE_INTERNAL:
554 hub = usb_hub_to_struct_hub(dev->parent);
555 return hub->ports[dev->portnum - 1]->connect_type ==
556 USB_PORT_CONNECT_TYPE_HARD_WIRED;
557 }
558}
559
560/**
561 * usb_alloc_dev - usb device constructor (usbcore-internal)
562 * @parent: hub to which device is connected; null to allocate a root hub
563 * @bus: bus used to access the device
564 * @port1: one-based index of port; ignored for root hubs
565 * Context: !in_interrupt()
566 *
567 * Only hub drivers (including virtual root hub drivers for host
568 * controllers) should ever call this.
569 *
570 * This call may not be used in a non-sleeping context.
571 *
572 * Return: On success, a pointer to the allocated usb device. %NULL on
573 * failure.
574 */
575struct usb_device *usb_alloc_dev(struct usb_device *parent,
576 struct usb_bus *bus, unsigned port1)
577{
578 struct usb_device *dev;
579 struct usb_hcd *usb_hcd = bus_to_hcd(bus);
580 unsigned root_hub = 0;
581 unsigned raw_port = port1;
582
583 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
584 if (!dev)
585 return NULL;
586
587 if (!usb_get_hcd(usb_hcd)) {
588 kfree(dev);
589 return NULL;
590 }
591 /* Root hubs aren't true devices, so don't allocate HCD resources */
592 if (usb_hcd->driver->alloc_dev && parent &&
593 !usb_hcd->driver->alloc_dev(usb_hcd, dev)) {
594 usb_put_hcd(bus_to_hcd(bus));
595 kfree(dev);
596 return NULL;
597 }
598
599 device_initialize(&dev->dev);
600 dev->dev.bus = &usb_bus_type;
601 dev->dev.type = &usb_device_type;
602 dev->dev.groups = usb_device_groups;
603 /*
604 * Fake a dma_mask/offset for the USB device:
605 * We cannot really use the dma-mapping API (dma_alloc_* and
606 * dma_map_*) for USB devices but instead need to use
607 * usb_alloc_coherent and pass data in 'urb's, but some subsystems
608 * manually look into the mask/offset pair to determine whether
609 * they need bounce buffers.
610 * Note: calling dma_set_mask() on a USB device would set the
611 * mask for the entire HCD, so don't do that.
612 */
613 dev->dev.dma_mask = bus->sysdev->dma_mask;
614 dev->dev.dma_pfn_offset = bus->sysdev->dma_pfn_offset;
615 set_dev_node(&dev->dev, dev_to_node(bus->sysdev));
616 dev->state = USB_STATE_ATTACHED;
617 dev->lpm_disable_count = 1;
618 atomic_set(&dev->urbnum, 0);
619
620 INIT_LIST_HEAD(&dev->ep0.urb_list);
621 dev->ep0.desc.bLength = USB_DT_ENDPOINT_SIZE;
622 dev->ep0.desc.bDescriptorType = USB_DT_ENDPOINT;
623 /* ep0 maxpacket comes later, from device descriptor */
624 usb_enable_endpoint(dev, &dev->ep0, false);
625 dev->can_submit = 1;
626
627 /* Save readable and stable topology id, distinguishing devices
628 * by location for diagnostics, tools, driver model, etc. The
629 * string is a path along hub ports, from the root. Each device's
630 * dev->devpath will be stable until USB is re-cabled, and hubs
631 * are often labeled with these port numbers. The name isn't
632 * as stable: bus->busnum changes easily from modprobe order,
633 * cardbus or pci hotplugging, and so on.
634 */
635 if (unlikely(!parent)) {
636 dev->devpath[0] = '0';
637 dev->route = 0;
638
639 dev->dev.parent = bus->controller;
640 device_set_of_node_from_dev(&dev->dev, bus->sysdev);
641 dev_set_name(&dev->dev, "usb%d", bus->busnum);
642 root_hub = 1;
643 } else {
644 /* match any labeling on the hubs; it's one-based */
645 if (parent->devpath[0] == '0') {
646 snprintf(dev->devpath, sizeof dev->devpath,
647 "%d", port1);
648 /* Root ports are not counted in route string */
649 dev->route = 0;
650 } else {
651 snprintf(dev->devpath, sizeof dev->devpath,
652 "%s.%d", parent->devpath, port1);
653 /* Route string assumes hubs have less than 16 ports */
654 if (port1 < 15)
655 dev->route = parent->route +
656 (port1 << ((parent->level - 1)*4));
657 else
658 dev->route = parent->route +
659 (15 << ((parent->level - 1)*4));
660 }
661
662 dev->dev.parent = &parent->dev;
663 dev_set_name(&dev->dev, "%d-%s", bus->busnum, dev->devpath);
664
665 if (!parent->parent) {
666 /* device under root hub's port */
667 raw_port = usb_hcd_find_raw_port_number(usb_hcd,
668 port1);
669 }
670 dev->dev.of_node = usb_of_get_device_node(parent, raw_port);
671
672 /* hub driver sets up TT records */
673 }
674
675 dev->portnum = port1;
676 dev->bus = bus;
677 dev->parent = parent;
678 INIT_LIST_HEAD(&dev->filelist);
679
680#ifdef CONFIG_PM
681 pm_runtime_set_autosuspend_delay(&dev->dev,
682 usb_autosuspend_delay * 1000);
683 dev->connect_time = jiffies;
684 dev->active_duration = -jiffies;
685#endif
686
687 dev->authorized = usb_dev_authorized(dev, usb_hcd);
688 if (!root_hub)
689 dev->wusb = usb_bus_is_wusb(bus) ? 1 : 0;
690
691 return dev;
692}
693EXPORT_SYMBOL_GPL(usb_alloc_dev);
694
695/**
696 * usb_get_dev - increments the reference count of the usb device structure
697 * @dev: the device being referenced
698 *
699 * Each live reference to a device should be refcounted.
700 *
701 * Drivers for USB interfaces should normally record such references in
702 * their probe() methods, when they bind to an interface, and release
703 * them by calling usb_put_dev(), in their disconnect() methods.
704 *
705 * Return: A pointer to the device with the incremented reference counter.
706 */
707struct usb_device *usb_get_dev(struct usb_device *dev)
708{
709 if (dev)
710 get_device(&dev->dev);
711 return dev;
712}
713EXPORT_SYMBOL_GPL(usb_get_dev);
714
715/**
716 * usb_put_dev - release a use of the usb device structure
717 * @dev: device that's been disconnected
718 *
719 * Must be called when a user of a device is finished with it. When the last
720 * user of the device calls this function, the memory of the device is freed.
721 */
722void usb_put_dev(struct usb_device *dev)
723{
724 if (dev)
725 put_device(&dev->dev);
726}
727EXPORT_SYMBOL_GPL(usb_put_dev);
728
729/**
730 * usb_get_intf - increments the reference count of the usb interface structure
731 * @intf: the interface being referenced
732 *
733 * Each live reference to a interface must be refcounted.
734 *
735 * Drivers for USB interfaces should normally record such references in
736 * their probe() methods, when they bind to an interface, and release
737 * them by calling usb_put_intf(), in their disconnect() methods.
738 *
739 * Return: A pointer to the interface with the incremented reference counter.
740 */
741struct usb_interface *usb_get_intf(struct usb_interface *intf)
742{
743 if (intf)
744 get_device(&intf->dev);
745 return intf;
746}
747EXPORT_SYMBOL_GPL(usb_get_intf);
748
749/**
750 * usb_put_intf - release a use of the usb interface structure
751 * @intf: interface that's been decremented
752 *
753 * Must be called when a user of an interface is finished with it. When the
754 * last user of the interface calls this function, the memory of the interface
755 * is freed.
756 */
757void usb_put_intf(struct usb_interface *intf)
758{
759 if (intf)
760 put_device(&intf->dev);
761}
762EXPORT_SYMBOL_GPL(usb_put_intf);
763
764/* USB device locking
765 *
766 * USB devices and interfaces are locked using the semaphore in their
767 * embedded struct device. The hub driver guarantees that whenever a
768 * device is connected or disconnected, drivers are called with the
769 * USB device locked as well as their particular interface.
770 *
771 * Complications arise when several devices are to be locked at the same
772 * time. Only hub-aware drivers that are part of usbcore ever have to
773 * do this; nobody else needs to worry about it. The rule for locking
774 * is simple:
775 *
776 * When locking both a device and its parent, always lock the
777 * the parent first.
778 */
779
780/**
781 * usb_lock_device_for_reset - cautiously acquire the lock for a usb device structure
782 * @udev: device that's being locked
783 * @iface: interface bound to the driver making the request (optional)
784 *
785 * Attempts to acquire the device lock, but fails if the device is
786 * NOTATTACHED or SUSPENDED, or if iface is specified and the interface
787 * is neither BINDING nor BOUND. Rather than sleeping to wait for the
788 * lock, the routine polls repeatedly. This is to prevent deadlock with
789 * disconnect; in some drivers (such as usb-storage) the disconnect()
790 * or suspend() method will block waiting for a device reset to complete.
791 *
792 * Return: A negative error code for failure, otherwise 0.
793 */
794int usb_lock_device_for_reset(struct usb_device *udev,
795 const struct usb_interface *iface)
796{
797 unsigned long jiffies_expire = jiffies + HZ;
798
799 if (udev->state == USB_STATE_NOTATTACHED)
800 return -ENODEV;
801 if (udev->state == USB_STATE_SUSPENDED)
802 return -EHOSTUNREACH;
803 if (iface && (iface->condition == USB_INTERFACE_UNBINDING ||
804 iface->condition == USB_INTERFACE_UNBOUND))
805 return -EINTR;
806
807 while (!usb_trylock_device(udev)) {
808
809 /* If we can't acquire the lock after waiting one second,
810 * we're probably deadlocked */
811 if (time_after(jiffies, jiffies_expire))
812 return -EBUSY;
813
814 msleep(15);
815 if (udev->state == USB_STATE_NOTATTACHED)
816 return -ENODEV;
817 if (udev->state == USB_STATE_SUSPENDED)
818 return -EHOSTUNREACH;
819 if (iface && (iface->condition == USB_INTERFACE_UNBINDING ||
820 iface->condition == USB_INTERFACE_UNBOUND))
821 return -EINTR;
822 }
823 return 0;
824}
825EXPORT_SYMBOL_GPL(usb_lock_device_for_reset);
826
827/**
828 * usb_get_current_frame_number - return current bus frame number
829 * @dev: the device whose bus is being queried
830 *
831 * Return: The current frame number for the USB host controller used
832 * with the given USB device. This can be used when scheduling
833 * isochronous requests.
834 *
835 * Note: Different kinds of host controller have different "scheduling
836 * horizons". While one type might support scheduling only 32 frames
837 * into the future, others could support scheduling up to 1024 frames
838 * into the future.
839 *
840 */
841int usb_get_current_frame_number(struct usb_device *dev)
842{
843 return usb_hcd_get_frame_number(dev);
844}
845EXPORT_SYMBOL_GPL(usb_get_current_frame_number);
846
847/*-------------------------------------------------------------------*/
848/*
849 * __usb_get_extra_descriptor() finds a descriptor of specific type in the
850 * extra field of the interface and endpoint descriptor structs.
851 */
852
853int __usb_get_extra_descriptor(char *buffer, unsigned size,
854 unsigned char type, void **ptr, size_t minsize)
855{
856 struct usb_descriptor_header *header;
857
858 while (size >= sizeof(struct usb_descriptor_header)) {
859 header = (struct usb_descriptor_header *)buffer;
860
861 if (header->bLength < 2 || header->bLength > size) {
862 printk(KERN_ERR
863 "%s: bogus descriptor, type %d length %d\n",
864 usbcore_name,
865 header->bDescriptorType,
866 header->bLength);
867 return -1;
868 }
869
870 if (header->bDescriptorType == type && header->bLength >= minsize) {
871 *ptr = header;
872 return 0;
873 }
874
875 buffer += header->bLength;
876 size -= header->bLength;
877 }
878 return -1;
879}
880EXPORT_SYMBOL_GPL(__usb_get_extra_descriptor);
881
882/**
883 * usb_alloc_coherent - allocate dma-consistent buffer for URB_NO_xxx_DMA_MAP
884 * @dev: device the buffer will be used with
885 * @size: requested buffer size
886 * @mem_flags: affect whether allocation may block
887 * @dma: used to return DMA address of buffer
888 *
889 * Return: Either null (indicating no buffer could be allocated), or the
890 * cpu-space pointer to a buffer that may be used to perform DMA to the
891 * specified device. Such cpu-space buffers are returned along with the DMA
892 * address (through the pointer provided).
893 *
894 * Note:
895 * These buffers are used with URB_NO_xxx_DMA_MAP set in urb->transfer_flags
896 * to avoid behaviors like using "DMA bounce buffers", or thrashing IOMMU
897 * hardware during URB completion/resubmit. The implementation varies between
898 * platforms, depending on details of how DMA will work to this device.
899 * Using these buffers also eliminates cacheline sharing problems on
900 * architectures where CPU caches are not DMA-coherent. On systems without
901 * bus-snooping caches, these buffers are uncached.
902 *
903 * When the buffer is no longer used, free it with usb_free_coherent().
904 */
905void *usb_alloc_coherent(struct usb_device *dev, size_t size, gfp_t mem_flags,
906 dma_addr_t *dma)
907{
908 if (!dev || !dev->bus)
909 return NULL;
910 return hcd_buffer_alloc(dev->bus, size, mem_flags, dma);
911}
912EXPORT_SYMBOL_GPL(usb_alloc_coherent);
913
914/**
915 * usb_free_coherent - free memory allocated with usb_alloc_coherent()
916 * @dev: device the buffer was used with
917 * @size: requested buffer size
918 * @addr: CPU address of buffer
919 * @dma: DMA address of buffer
920 *
921 * This reclaims an I/O buffer, letting it be reused. The memory must have
922 * been allocated using usb_alloc_coherent(), and the parameters must match
923 * those provided in that allocation request.
924 */
925void usb_free_coherent(struct usb_device *dev, size_t size, void *addr,
926 dma_addr_t dma)
927{
928 if (!dev || !dev->bus)
929 return;
930 if (!addr)
931 return;
932 hcd_buffer_free(dev->bus, size, addr, dma);
933}
934EXPORT_SYMBOL_GPL(usb_free_coherent);
935
936/*
937 * Notifications of device and interface registration
938 */
939static int usb_bus_notify(struct notifier_block *nb, unsigned long action,
940 void *data)
941{
942 struct device *dev = data;
943
944 switch (action) {
945 case BUS_NOTIFY_ADD_DEVICE:
946 if (dev->type == &usb_device_type)
947 (void) usb_create_sysfs_dev_files(to_usb_device(dev));
948 else if (dev->type == &usb_if_device_type)
949 usb_create_sysfs_intf_files(to_usb_interface(dev));
950 break;
951
952 case BUS_NOTIFY_DEL_DEVICE:
953 if (dev->type == &usb_device_type)
954 usb_remove_sysfs_dev_files(to_usb_device(dev));
955 else if (dev->type == &usb_if_device_type)
956 usb_remove_sysfs_intf_files(to_usb_interface(dev));
957 break;
958 }
959 return 0;
960}
961
962static struct notifier_block usb_bus_nb = {
963 .notifier_call = usb_bus_notify,
964};
965
966static struct dentry *usb_devices_root;
967
968static void usb_debugfs_init(void)
969{
970 usb_devices_root = debugfs_create_file("devices", 0444, usb_debug_root,
971 NULL, &usbfs_devices_fops);
972}
973
974static void usb_debugfs_cleanup(void)
975{
976 debugfs_remove(usb_devices_root);
977}
978
979/*
980 * Init
981 */
982static int __init usb_init(void)
983{
984 int retval;
985 if (usb_disabled()) {
986 pr_info("%s: USB support disabled\n", usbcore_name);
987 return 0;
988 }
989 usb_init_pool_max();
990
991 usb_debugfs_init();
992
993 usb_acpi_register();
994 retval = bus_register(&usb_bus_type);
995 if (retval)
996 goto bus_register_failed;
997 retval = bus_register_notifier(&usb_bus_type, &usb_bus_nb);
998 if (retval)
999 goto bus_notifier_failed;
1000 retval = usb_major_init();
1001 if (retval)
1002 goto major_init_failed;
1003 retval = usb_register(&usbfs_driver);
1004 if (retval)
1005 goto driver_register_failed;
1006 retval = usb_devio_init();
1007 if (retval)
1008 goto usb_devio_init_failed;
1009 retval = usb_hub_init();
1010 if (retval)
1011 goto hub_init_failed;
1012 retval = usb_register_device_driver(&usb_generic_driver, THIS_MODULE);
1013 if (!retval)
1014 goto out;
1015
1016 usb_hub_cleanup();
1017hub_init_failed:
1018 usb_devio_cleanup();
1019usb_devio_init_failed:
1020 usb_deregister(&usbfs_driver);
1021driver_register_failed:
1022 usb_major_cleanup();
1023major_init_failed:
1024 bus_unregister_notifier(&usb_bus_type, &usb_bus_nb);
1025bus_notifier_failed:
1026 bus_unregister(&usb_bus_type);
1027bus_register_failed:
1028 usb_acpi_unregister();
1029 usb_debugfs_cleanup();
1030out:
1031 return retval;
1032}
1033
1034/*
1035 * Cleanup
1036 */
1037static void __exit usb_exit(void)
1038{
1039 /* This will matter if shutdown/reboot does exitcalls. */
1040 if (usb_disabled())
1041 return;
1042
1043 usb_release_quirk_list();
1044 usb_deregister_device_driver(&usb_generic_driver);
1045 usb_major_cleanup();
1046 usb_deregister(&usbfs_driver);
1047 usb_devio_cleanup();
1048 usb_hub_cleanup();
1049 bus_unregister_notifier(&usb_bus_type, &usb_bus_nb);
1050 bus_unregister(&usb_bus_type);
1051 usb_acpi_unregister();
1052 usb_debugfs_cleanup();
1053 idr_destroy(&usb_bus_idr);
1054}
1055
1056subsys_initcall(usb_init);
1057module_exit(usb_exit);
1058MODULE_LICENSE("GPL");
1/*
2 * drivers/usb/core/usb.c
3 *
4 * (C) Copyright Linus Torvalds 1999
5 * (C) Copyright Johannes Erdfelt 1999-2001
6 * (C) Copyright Andreas Gal 1999
7 * (C) Copyright Gregory P. Smith 1999
8 * (C) Copyright Deti Fliegl 1999 (new USB architecture)
9 * (C) Copyright Randy Dunlap 2000
10 * (C) Copyright David Brownell 2000-2004
11 * (C) Copyright Yggdrasil Computing, Inc. 2000
12 * (usb_device_id matching changes by Adam J. Richter)
13 * (C) Copyright Greg Kroah-Hartman 2002-2003
14 *
15 * Released under the GPLv2 only.
16 * SPDX-License-Identifier: GPL-2.0
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 * It should be considered a slave, with no callbacks. Callbacks
24 * are evil.
25 */
26
27#include <linux/module.h>
28#include <linux/moduleparam.h>
29#include <linux/string.h>
30#include <linux/bitops.h>
31#include <linux/slab.h>
32#include <linux/interrupt.h> /* for in_interrupt() */
33#include <linux/kmod.h>
34#include <linux/init.h>
35#include <linux/spinlock.h>
36#include <linux/errno.h>
37#include <linux/usb.h>
38#include <linux/usb/hcd.h>
39#include <linux/mutex.h>
40#include <linux/workqueue.h>
41#include <linux/debugfs.h>
42#include <linux/usb/of.h>
43
44#include <asm/io.h>
45#include <linux/scatterlist.h>
46#include <linux/mm.h>
47#include <linux/dma-mapping.h>
48
49#include "usb.h"
50
51
52const char *usbcore_name = "usbcore";
53
54static bool nousb; /* Disable USB when built into kernel image */
55
56module_param(nousb, bool, 0444);
57
58/*
59 * for external read access to <nousb>
60 */
61int usb_disabled(void)
62{
63 return nousb;
64}
65EXPORT_SYMBOL_GPL(usb_disabled);
66
67#ifdef CONFIG_PM
68static int usb_autosuspend_delay = 2; /* Default delay value,
69 * in seconds */
70module_param_named(autosuspend, usb_autosuspend_delay, int, 0644);
71MODULE_PARM_DESC(autosuspend, "default autosuspend delay");
72
73#else
74#define usb_autosuspend_delay 0
75#endif
76
77
78/**
79 * usb_find_alt_setting() - Given a configuration, find the alternate setting
80 * for the given interface.
81 * @config: the configuration to search (not necessarily the current config).
82 * @iface_num: interface number to search in
83 * @alt_num: alternate interface setting number to search for.
84 *
85 * Search the configuration's interface cache for the given alt setting.
86 *
87 * Return: The alternate setting, if found. %NULL otherwise.
88 */
89struct usb_host_interface *usb_find_alt_setting(
90 struct usb_host_config *config,
91 unsigned int iface_num,
92 unsigned int alt_num)
93{
94 struct usb_interface_cache *intf_cache = NULL;
95 int i;
96
97 for (i = 0; i < config->desc.bNumInterfaces; i++) {
98 if (config->intf_cache[i]->altsetting[0].desc.bInterfaceNumber
99 == iface_num) {
100 intf_cache = config->intf_cache[i];
101 break;
102 }
103 }
104 if (!intf_cache)
105 return NULL;
106 for (i = 0; i < intf_cache->num_altsetting; i++)
107 if (intf_cache->altsetting[i].desc.bAlternateSetting == alt_num)
108 return &intf_cache->altsetting[i];
109
110 printk(KERN_DEBUG "Did not find alt setting %u for intf %u, "
111 "config %u\n", alt_num, iface_num,
112 config->desc.bConfigurationValue);
113 return NULL;
114}
115EXPORT_SYMBOL_GPL(usb_find_alt_setting);
116
117/**
118 * usb_ifnum_to_if - get the interface object with a given interface number
119 * @dev: the device whose current configuration is considered
120 * @ifnum: the desired interface
121 *
122 * This walks the device descriptor for the currently active configuration
123 * to find the interface object with the particular interface number.
124 *
125 * Note that configuration descriptors are not required to assign interface
126 * numbers sequentially, so that it would be incorrect to assume that
127 * the first interface in that descriptor corresponds to interface zero.
128 * This routine helps device drivers avoid such mistakes.
129 * However, you should make sure that you do the right thing with any
130 * alternate settings available for this interfaces.
131 *
132 * Don't call this function unless you are bound to one of the interfaces
133 * on this device or you have locked the device!
134 *
135 * Return: A pointer to the interface that has @ifnum as interface number,
136 * if found. %NULL otherwise.
137 */
138struct usb_interface *usb_ifnum_to_if(const struct usb_device *dev,
139 unsigned ifnum)
140{
141 struct usb_host_config *config = dev->actconfig;
142 int i;
143
144 if (!config)
145 return NULL;
146 for (i = 0; i < config->desc.bNumInterfaces; i++)
147 if (config->interface[i]->altsetting[0]
148 .desc.bInterfaceNumber == ifnum)
149 return config->interface[i];
150
151 return NULL;
152}
153EXPORT_SYMBOL_GPL(usb_ifnum_to_if);
154
155/**
156 * usb_altnum_to_altsetting - get the altsetting structure with a given alternate setting number.
157 * @intf: the interface containing the altsetting in question
158 * @altnum: the desired alternate setting number
159 *
160 * This searches the altsetting array of the specified interface for
161 * an entry with the correct bAlternateSetting value.
162 *
163 * Note that altsettings need not be stored sequentially by number, so
164 * it would be incorrect to assume that the first altsetting entry in
165 * the array corresponds to altsetting zero. This routine helps device
166 * drivers avoid such mistakes.
167 *
168 * Don't call this function unless you are bound to the intf interface
169 * or you have locked the device!
170 *
171 * Return: A pointer to the entry of the altsetting array of @intf that
172 * has @altnum as the alternate setting number. %NULL if not found.
173 */
174struct usb_host_interface *usb_altnum_to_altsetting(
175 const struct usb_interface *intf,
176 unsigned int altnum)
177{
178 int i;
179
180 for (i = 0; i < intf->num_altsetting; i++) {
181 if (intf->altsetting[i].desc.bAlternateSetting == altnum)
182 return &intf->altsetting[i];
183 }
184 return NULL;
185}
186EXPORT_SYMBOL_GPL(usb_altnum_to_altsetting);
187
188struct find_interface_arg {
189 int minor;
190 struct device_driver *drv;
191};
192
193static int __find_interface(struct device *dev, void *data)
194{
195 struct find_interface_arg *arg = data;
196 struct usb_interface *intf;
197
198 if (!is_usb_interface(dev))
199 return 0;
200
201 if (dev->driver != arg->drv)
202 return 0;
203 intf = to_usb_interface(dev);
204 return intf->minor == arg->minor;
205}
206
207/**
208 * usb_find_interface - find usb_interface pointer for driver and device
209 * @drv: the driver whose current configuration is considered
210 * @minor: the minor number of the desired device
211 *
212 * This walks the bus device list and returns a pointer to the interface
213 * with the matching minor and driver. Note, this only works for devices
214 * that share the USB major number.
215 *
216 * Return: A pointer to the interface with the matching major and @minor.
217 */
218struct usb_interface *usb_find_interface(struct usb_driver *drv, int minor)
219{
220 struct find_interface_arg argb;
221 struct device *dev;
222
223 argb.minor = minor;
224 argb.drv = &drv->drvwrap.driver;
225
226 dev = bus_find_device(&usb_bus_type, NULL, &argb, __find_interface);
227
228 /* Drop reference count from bus_find_device */
229 put_device(dev);
230
231 return dev ? to_usb_interface(dev) : NULL;
232}
233EXPORT_SYMBOL_GPL(usb_find_interface);
234
235struct each_dev_arg {
236 void *data;
237 int (*fn)(struct usb_device *, void *);
238};
239
240static int __each_dev(struct device *dev, void *data)
241{
242 struct each_dev_arg *arg = (struct each_dev_arg *)data;
243
244 /* There are struct usb_interface on the same bus, filter them out */
245 if (!is_usb_device(dev))
246 return 0;
247
248 return arg->fn(to_usb_device(dev), arg->data);
249}
250
251/**
252 * usb_for_each_dev - iterate over all USB devices in the system
253 * @data: data pointer that will be handed to the callback function
254 * @fn: callback function to be called for each USB device
255 *
256 * Iterate over all USB devices and call @fn for each, passing it @data. If it
257 * returns anything other than 0, we break the iteration prematurely and return
258 * that value.
259 */
260int usb_for_each_dev(void *data, int (*fn)(struct usb_device *, void *))
261{
262 struct each_dev_arg arg = {data, fn};
263
264 return bus_for_each_dev(&usb_bus_type, NULL, &arg, __each_dev);
265}
266EXPORT_SYMBOL_GPL(usb_for_each_dev);
267
268/**
269 * usb_release_dev - free a usb device structure when all users of it are finished.
270 * @dev: device that's been disconnected
271 *
272 * Will be called only by the device core when all users of this usb device are
273 * done.
274 */
275static void usb_release_dev(struct device *dev)
276{
277 struct usb_device *udev;
278 struct usb_hcd *hcd;
279
280 udev = to_usb_device(dev);
281 hcd = bus_to_hcd(udev->bus);
282
283 usb_destroy_configuration(udev);
284 usb_release_bos_descriptor(udev);
285 usb_put_hcd(hcd);
286 kfree(udev->product);
287 kfree(udev->manufacturer);
288 kfree(udev->serial);
289 kfree(udev);
290}
291
292static int usb_dev_uevent(struct device *dev, struct kobj_uevent_env *env)
293{
294 struct usb_device *usb_dev;
295
296 usb_dev = to_usb_device(dev);
297
298 if (add_uevent_var(env, "BUSNUM=%03d", usb_dev->bus->busnum))
299 return -ENOMEM;
300
301 if (add_uevent_var(env, "DEVNUM=%03d", usb_dev->devnum))
302 return -ENOMEM;
303
304 return 0;
305}
306
307#ifdef CONFIG_PM
308
309/* USB device Power-Management thunks.
310 * There's no need to distinguish here between quiescing a USB device
311 * and powering it down; the generic_suspend() routine takes care of
312 * it by skipping the usb_port_suspend() call for a quiesce. And for
313 * USB interfaces there's no difference at all.
314 */
315
316static int usb_dev_prepare(struct device *dev)
317{
318 return 0; /* Implement eventually? */
319}
320
321static void usb_dev_complete(struct device *dev)
322{
323 /* Currently used only for rebinding interfaces */
324 usb_resume_complete(dev);
325}
326
327static int usb_dev_suspend(struct device *dev)
328{
329 return usb_suspend(dev, PMSG_SUSPEND);
330}
331
332static int usb_dev_resume(struct device *dev)
333{
334 return usb_resume(dev, PMSG_RESUME);
335}
336
337static int usb_dev_freeze(struct device *dev)
338{
339 return usb_suspend(dev, PMSG_FREEZE);
340}
341
342static int usb_dev_thaw(struct device *dev)
343{
344 return usb_resume(dev, PMSG_THAW);
345}
346
347static int usb_dev_poweroff(struct device *dev)
348{
349 return usb_suspend(dev, PMSG_HIBERNATE);
350}
351
352static int usb_dev_restore(struct device *dev)
353{
354 return usb_resume(dev, PMSG_RESTORE);
355}
356
357static const struct dev_pm_ops usb_device_pm_ops = {
358 .prepare = usb_dev_prepare,
359 .complete = usb_dev_complete,
360 .suspend = usb_dev_suspend,
361 .resume = usb_dev_resume,
362 .freeze = usb_dev_freeze,
363 .thaw = usb_dev_thaw,
364 .poweroff = usb_dev_poweroff,
365 .restore = usb_dev_restore,
366 .runtime_suspend = usb_runtime_suspend,
367 .runtime_resume = usb_runtime_resume,
368 .runtime_idle = usb_runtime_idle,
369};
370
371#endif /* CONFIG_PM */
372
373
374static char *usb_devnode(struct device *dev,
375 umode_t *mode, kuid_t *uid, kgid_t *gid)
376{
377 struct usb_device *usb_dev;
378
379 usb_dev = to_usb_device(dev);
380 return kasprintf(GFP_KERNEL, "bus/usb/%03d/%03d",
381 usb_dev->bus->busnum, usb_dev->devnum);
382}
383
384struct device_type usb_device_type = {
385 .name = "usb_device",
386 .release = usb_release_dev,
387 .uevent = usb_dev_uevent,
388 .devnode = usb_devnode,
389#ifdef CONFIG_PM
390 .pm = &usb_device_pm_ops,
391#endif
392};
393
394
395/* Returns 1 if @usb_bus is WUSB, 0 otherwise */
396static unsigned usb_bus_is_wusb(struct usb_bus *bus)
397{
398 struct usb_hcd *hcd = bus_to_hcd(bus);
399 return hcd->wireless;
400}
401
402
403/**
404 * usb_alloc_dev - usb device constructor (usbcore-internal)
405 * @parent: hub to which device is connected; null to allocate a root hub
406 * @bus: bus used to access the device
407 * @port1: one-based index of port; ignored for root hubs
408 * Context: !in_interrupt()
409 *
410 * Only hub drivers (including virtual root hub drivers for host
411 * controllers) should ever call this.
412 *
413 * This call may not be used in a non-sleeping context.
414 *
415 * Return: On success, a pointer to the allocated usb device. %NULL on
416 * failure.
417 */
418struct usb_device *usb_alloc_dev(struct usb_device *parent,
419 struct usb_bus *bus, unsigned port1)
420{
421 struct usb_device *dev;
422 struct usb_hcd *usb_hcd = bus_to_hcd(bus);
423 unsigned root_hub = 0;
424 unsigned raw_port = port1;
425
426 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
427 if (!dev)
428 return NULL;
429
430 if (!usb_get_hcd(usb_hcd)) {
431 kfree(dev);
432 return NULL;
433 }
434 /* Root hubs aren't true devices, so don't allocate HCD resources */
435 if (usb_hcd->driver->alloc_dev && parent &&
436 !usb_hcd->driver->alloc_dev(usb_hcd, dev)) {
437 usb_put_hcd(bus_to_hcd(bus));
438 kfree(dev);
439 return NULL;
440 }
441
442 device_initialize(&dev->dev);
443 dev->dev.bus = &usb_bus_type;
444 dev->dev.type = &usb_device_type;
445 dev->dev.groups = usb_device_groups;
446 /*
447 * Fake a dma_mask/offset for the USB device:
448 * We cannot really use the dma-mapping API (dma_alloc_* and
449 * dma_map_*) for USB devices but instead need to use
450 * usb_alloc_coherent and pass data in 'urb's, but some subsystems
451 * manually look into the mask/offset pair to determine whether
452 * they need bounce buffers.
453 * Note: calling dma_set_mask() on a USB device would set the
454 * mask for the entire HCD, so don't do that.
455 */
456 dev->dev.dma_mask = bus->controller->dma_mask;
457 dev->dev.dma_pfn_offset = bus->controller->dma_pfn_offset;
458 set_dev_node(&dev->dev, dev_to_node(bus->controller));
459 dev->state = USB_STATE_ATTACHED;
460 dev->lpm_disable_count = 1;
461 atomic_set(&dev->urbnum, 0);
462
463 INIT_LIST_HEAD(&dev->ep0.urb_list);
464 dev->ep0.desc.bLength = USB_DT_ENDPOINT_SIZE;
465 dev->ep0.desc.bDescriptorType = USB_DT_ENDPOINT;
466 /* ep0 maxpacket comes later, from device descriptor */
467 usb_enable_endpoint(dev, &dev->ep0, false);
468 dev->can_submit = 1;
469
470 /* Save readable and stable topology id, distinguishing devices
471 * by location for diagnostics, tools, driver model, etc. The
472 * string is a path along hub ports, from the root. Each device's
473 * dev->devpath will be stable until USB is re-cabled, and hubs
474 * are often labeled with these port numbers. The name isn't
475 * as stable: bus->busnum changes easily from modprobe order,
476 * cardbus or pci hotplugging, and so on.
477 */
478 if (unlikely(!parent)) {
479 dev->devpath[0] = '0';
480 dev->route = 0;
481
482 dev->dev.parent = bus->controller;
483 dev_set_name(&dev->dev, "usb%d", bus->busnum);
484 root_hub = 1;
485 } else {
486 /* match any labeling on the hubs; it's one-based */
487 if (parent->devpath[0] == '0') {
488 snprintf(dev->devpath, sizeof dev->devpath,
489 "%d", port1);
490 /* Root ports are not counted in route string */
491 dev->route = 0;
492 } else {
493 snprintf(dev->devpath, sizeof dev->devpath,
494 "%s.%d", parent->devpath, port1);
495 /* Route string assumes hubs have less than 16 ports */
496 if (port1 < 15)
497 dev->route = parent->route +
498 (port1 << ((parent->level - 1)*4));
499 else
500 dev->route = parent->route +
501 (15 << ((parent->level - 1)*4));
502 }
503
504 dev->dev.parent = &parent->dev;
505 dev_set_name(&dev->dev, "%d-%s", bus->busnum, dev->devpath);
506
507 if (!parent->parent) {
508 /* device under root hub's port */
509 raw_port = usb_hcd_find_raw_port_number(usb_hcd,
510 port1);
511 }
512 dev->dev.of_node = usb_of_get_child_node(parent->dev.of_node,
513 raw_port);
514
515 /* hub driver sets up TT records */
516 }
517
518 dev->portnum = port1;
519 dev->bus = bus;
520 dev->parent = parent;
521 INIT_LIST_HEAD(&dev->filelist);
522
523#ifdef CONFIG_PM
524 pm_runtime_set_autosuspend_delay(&dev->dev,
525 usb_autosuspend_delay * 1000);
526 dev->connect_time = jiffies;
527 dev->active_duration = -jiffies;
528#endif
529 if (root_hub) /* Root hub always ok [and always wired] */
530 dev->authorized = 1;
531 else {
532 dev->authorized = !!HCD_DEV_AUTHORIZED(usb_hcd);
533 dev->wusb = usb_bus_is_wusb(bus) ? 1 : 0;
534 }
535 return dev;
536}
537EXPORT_SYMBOL_GPL(usb_alloc_dev);
538
539/**
540 * usb_get_dev - increments the reference count of the usb device structure
541 * @dev: the device being referenced
542 *
543 * Each live reference to a device should be refcounted.
544 *
545 * Drivers for USB interfaces should normally record such references in
546 * their probe() methods, when they bind to an interface, and release
547 * them by calling usb_put_dev(), in their disconnect() methods.
548 *
549 * Return: A pointer to the device with the incremented reference counter.
550 */
551struct usb_device *usb_get_dev(struct usb_device *dev)
552{
553 if (dev)
554 get_device(&dev->dev);
555 return dev;
556}
557EXPORT_SYMBOL_GPL(usb_get_dev);
558
559/**
560 * usb_put_dev - release a use of the usb device structure
561 * @dev: device that's been disconnected
562 *
563 * Must be called when a user of a device is finished with it. When the last
564 * user of the device calls this function, the memory of the device is freed.
565 */
566void usb_put_dev(struct usb_device *dev)
567{
568 if (dev)
569 put_device(&dev->dev);
570}
571EXPORT_SYMBOL_GPL(usb_put_dev);
572
573/**
574 * usb_get_intf - increments the reference count of the usb interface structure
575 * @intf: the interface being referenced
576 *
577 * Each live reference to a interface must be refcounted.
578 *
579 * Drivers for USB interfaces should normally record such references in
580 * their probe() methods, when they bind to an interface, and release
581 * them by calling usb_put_intf(), in their disconnect() methods.
582 *
583 * Return: A pointer to the interface with the incremented reference counter.
584 */
585struct usb_interface *usb_get_intf(struct usb_interface *intf)
586{
587 if (intf)
588 get_device(&intf->dev);
589 return intf;
590}
591EXPORT_SYMBOL_GPL(usb_get_intf);
592
593/**
594 * usb_put_intf - release a use of the usb interface structure
595 * @intf: interface that's been decremented
596 *
597 * Must be called when a user of an interface is finished with it. When the
598 * last user of the interface calls this function, the memory of the interface
599 * is freed.
600 */
601void usb_put_intf(struct usb_interface *intf)
602{
603 if (intf)
604 put_device(&intf->dev);
605}
606EXPORT_SYMBOL_GPL(usb_put_intf);
607
608/* USB device locking
609 *
610 * USB devices and interfaces are locked using the semaphore in their
611 * embedded struct device. The hub driver guarantees that whenever a
612 * device is connected or disconnected, drivers are called with the
613 * USB device locked as well as their particular interface.
614 *
615 * Complications arise when several devices are to be locked at the same
616 * time. Only hub-aware drivers that are part of usbcore ever have to
617 * do this; nobody else needs to worry about it. The rule for locking
618 * is simple:
619 *
620 * When locking both a device and its parent, always lock the
621 * the parent first.
622 */
623
624/**
625 * usb_lock_device_for_reset - cautiously acquire the lock for a usb device structure
626 * @udev: device that's being locked
627 * @iface: interface bound to the driver making the request (optional)
628 *
629 * Attempts to acquire the device lock, but fails if the device is
630 * NOTATTACHED or SUSPENDED, or if iface is specified and the interface
631 * is neither BINDING nor BOUND. Rather than sleeping to wait for the
632 * lock, the routine polls repeatedly. This is to prevent deadlock with
633 * disconnect; in some drivers (such as usb-storage) the disconnect()
634 * or suspend() method will block waiting for a device reset to complete.
635 *
636 * Return: A negative error code for failure, otherwise 0.
637 */
638int usb_lock_device_for_reset(struct usb_device *udev,
639 const struct usb_interface *iface)
640{
641 unsigned long jiffies_expire = jiffies + HZ;
642
643 if (udev->state == USB_STATE_NOTATTACHED)
644 return -ENODEV;
645 if (udev->state == USB_STATE_SUSPENDED)
646 return -EHOSTUNREACH;
647 if (iface && (iface->condition == USB_INTERFACE_UNBINDING ||
648 iface->condition == USB_INTERFACE_UNBOUND))
649 return -EINTR;
650
651 while (!usb_trylock_device(udev)) {
652
653 /* If we can't acquire the lock after waiting one second,
654 * we're probably deadlocked */
655 if (time_after(jiffies, jiffies_expire))
656 return -EBUSY;
657
658 msleep(15);
659 if (udev->state == USB_STATE_NOTATTACHED)
660 return -ENODEV;
661 if (udev->state == USB_STATE_SUSPENDED)
662 return -EHOSTUNREACH;
663 if (iface && (iface->condition == USB_INTERFACE_UNBINDING ||
664 iface->condition == USB_INTERFACE_UNBOUND))
665 return -EINTR;
666 }
667 return 0;
668}
669EXPORT_SYMBOL_GPL(usb_lock_device_for_reset);
670
671/**
672 * usb_get_current_frame_number - return current bus frame number
673 * @dev: the device whose bus is being queried
674 *
675 * Return: The current frame number for the USB host controller used
676 * with the given USB device. This can be used when scheduling
677 * isochronous requests.
678 *
679 * Note: Different kinds of host controller have different "scheduling
680 * horizons". While one type might support scheduling only 32 frames
681 * into the future, others could support scheduling up to 1024 frames
682 * into the future.
683 *
684 */
685int usb_get_current_frame_number(struct usb_device *dev)
686{
687 return usb_hcd_get_frame_number(dev);
688}
689EXPORT_SYMBOL_GPL(usb_get_current_frame_number);
690
691/*-------------------------------------------------------------------*/
692/*
693 * __usb_get_extra_descriptor() finds a descriptor of specific type in the
694 * extra field of the interface and endpoint descriptor structs.
695 */
696
697int __usb_get_extra_descriptor(char *buffer, unsigned size,
698 unsigned char type, void **ptr)
699{
700 struct usb_descriptor_header *header;
701
702 while (size >= sizeof(struct usb_descriptor_header)) {
703 header = (struct usb_descriptor_header *)buffer;
704
705 if (header->bLength < 2) {
706 printk(KERN_ERR
707 "%s: bogus descriptor, type %d length %d\n",
708 usbcore_name,
709 header->bDescriptorType,
710 header->bLength);
711 return -1;
712 }
713
714 if (header->bDescriptorType == type) {
715 *ptr = header;
716 return 0;
717 }
718
719 buffer += header->bLength;
720 size -= header->bLength;
721 }
722 return -1;
723}
724EXPORT_SYMBOL_GPL(__usb_get_extra_descriptor);
725
726/**
727 * usb_alloc_coherent - allocate dma-consistent buffer for URB_NO_xxx_DMA_MAP
728 * @dev: device the buffer will be used with
729 * @size: requested buffer size
730 * @mem_flags: affect whether allocation may block
731 * @dma: used to return DMA address of buffer
732 *
733 * Return: Either null (indicating no buffer could be allocated), or the
734 * cpu-space pointer to a buffer that may be used to perform DMA to the
735 * specified device. Such cpu-space buffers are returned along with the DMA
736 * address (through the pointer provided).
737 *
738 * Note:
739 * These buffers are used with URB_NO_xxx_DMA_MAP set in urb->transfer_flags
740 * to avoid behaviors like using "DMA bounce buffers", or thrashing IOMMU
741 * hardware during URB completion/resubmit. The implementation varies between
742 * platforms, depending on details of how DMA will work to this device.
743 * Using these buffers also eliminates cacheline sharing problems on
744 * architectures where CPU caches are not DMA-coherent. On systems without
745 * bus-snooping caches, these buffers are uncached.
746 *
747 * When the buffer is no longer used, free it with usb_free_coherent().
748 */
749void *usb_alloc_coherent(struct usb_device *dev, size_t size, gfp_t mem_flags,
750 dma_addr_t *dma)
751{
752 if (!dev || !dev->bus)
753 return NULL;
754 return hcd_buffer_alloc(dev->bus, size, mem_flags, dma);
755}
756EXPORT_SYMBOL_GPL(usb_alloc_coherent);
757
758/**
759 * usb_free_coherent - free memory allocated with usb_alloc_coherent()
760 * @dev: device the buffer was used with
761 * @size: requested buffer size
762 * @addr: CPU address of buffer
763 * @dma: DMA address of buffer
764 *
765 * This reclaims an I/O buffer, letting it be reused. The memory must have
766 * been allocated using usb_alloc_coherent(), and the parameters must match
767 * those provided in that allocation request.
768 */
769void usb_free_coherent(struct usb_device *dev, size_t size, void *addr,
770 dma_addr_t dma)
771{
772 if (!dev || !dev->bus)
773 return;
774 if (!addr)
775 return;
776 hcd_buffer_free(dev->bus, size, addr, dma);
777}
778EXPORT_SYMBOL_GPL(usb_free_coherent);
779
780/**
781 * usb_buffer_map - create DMA mapping(s) for an urb
782 * @urb: urb whose transfer_buffer/setup_packet will be mapped
783 *
784 * URB_NO_TRANSFER_DMA_MAP is added to urb->transfer_flags if the operation
785 * succeeds. If the device is connected to this system through a non-DMA
786 * controller, this operation always succeeds.
787 *
788 * This call would normally be used for an urb which is reused, perhaps
789 * as the target of a large periodic transfer, with usb_buffer_dmasync()
790 * calls to synchronize memory and dma state.
791 *
792 * Reverse the effect of this call with usb_buffer_unmap().
793 *
794 * Return: Either %NULL (indicating no buffer could be mapped), or @urb.
795 *
796 */
797#if 0
798struct urb *usb_buffer_map(struct urb *urb)
799{
800 struct usb_bus *bus;
801 struct device *controller;
802
803 if (!urb
804 || !urb->dev
805 || !(bus = urb->dev->bus)
806 || !(controller = bus->controller))
807 return NULL;
808
809 if (controller->dma_mask) {
810 urb->transfer_dma = dma_map_single(controller,
811 urb->transfer_buffer, urb->transfer_buffer_length,
812 usb_pipein(urb->pipe)
813 ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
814 /* FIXME generic api broken like pci, can't report errors */
815 /* if (urb->transfer_dma == DMA_ADDR_INVALID) return 0; */
816 } else
817 urb->transfer_dma = ~0;
818 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
819 return urb;
820}
821EXPORT_SYMBOL_GPL(usb_buffer_map);
822#endif /* 0 */
823
824/* XXX DISABLED, no users currently. If you wish to re-enable this
825 * XXX please determine whether the sync is to transfer ownership of
826 * XXX the buffer from device to cpu or vice verse, and thusly use the
827 * XXX appropriate _for_{cpu,device}() method. -DaveM
828 */
829#if 0
830
831/**
832 * usb_buffer_dmasync - synchronize DMA and CPU view of buffer(s)
833 * @urb: urb whose transfer_buffer/setup_packet will be synchronized
834 */
835void usb_buffer_dmasync(struct urb *urb)
836{
837 struct usb_bus *bus;
838 struct device *controller;
839
840 if (!urb
841 || !(urb->transfer_flags & URB_NO_TRANSFER_DMA_MAP)
842 || !urb->dev
843 || !(bus = urb->dev->bus)
844 || !(controller = bus->controller))
845 return;
846
847 if (controller->dma_mask) {
848 dma_sync_single_for_cpu(controller,
849 urb->transfer_dma, urb->transfer_buffer_length,
850 usb_pipein(urb->pipe)
851 ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
852 if (usb_pipecontrol(urb->pipe))
853 dma_sync_single_for_cpu(controller,
854 urb->setup_dma,
855 sizeof(struct usb_ctrlrequest),
856 DMA_TO_DEVICE);
857 }
858}
859EXPORT_SYMBOL_GPL(usb_buffer_dmasync);
860#endif
861
862/**
863 * usb_buffer_unmap - free DMA mapping(s) for an urb
864 * @urb: urb whose transfer_buffer will be unmapped
865 *
866 * Reverses the effect of usb_buffer_map().
867 */
868#if 0
869void usb_buffer_unmap(struct urb *urb)
870{
871 struct usb_bus *bus;
872 struct device *controller;
873
874 if (!urb
875 || !(urb->transfer_flags & URB_NO_TRANSFER_DMA_MAP)
876 || !urb->dev
877 || !(bus = urb->dev->bus)
878 || !(controller = bus->controller))
879 return;
880
881 if (controller->dma_mask) {
882 dma_unmap_single(controller,
883 urb->transfer_dma, urb->transfer_buffer_length,
884 usb_pipein(urb->pipe)
885 ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
886 }
887 urb->transfer_flags &= ~URB_NO_TRANSFER_DMA_MAP;
888}
889EXPORT_SYMBOL_GPL(usb_buffer_unmap);
890#endif /* 0 */
891
892#if 0
893/**
894 * usb_buffer_map_sg - create scatterlist DMA mapping(s) for an endpoint
895 * @dev: device to which the scatterlist will be mapped
896 * @is_in: mapping transfer direction
897 * @sg: the scatterlist to map
898 * @nents: the number of entries in the scatterlist
899 *
900 * Return: Either < 0 (indicating no buffers could be mapped), or the
901 * number of DMA mapping array entries in the scatterlist.
902 *
903 * Note:
904 * The caller is responsible for placing the resulting DMA addresses from
905 * the scatterlist into URB transfer buffer pointers, and for setting the
906 * URB_NO_TRANSFER_DMA_MAP transfer flag in each of those URBs.
907 *
908 * Top I/O rates come from queuing URBs, instead of waiting for each one
909 * to complete before starting the next I/O. This is particularly easy
910 * to do with scatterlists. Just allocate and submit one URB for each DMA
911 * mapping entry returned, stopping on the first error or when all succeed.
912 * Better yet, use the usb_sg_*() calls, which do that (and more) for you.
913 *
914 * This call would normally be used when translating scatterlist requests,
915 * rather than usb_buffer_map(), since on some hardware (with IOMMUs) it
916 * may be able to coalesce mappings for improved I/O efficiency.
917 *
918 * Reverse the effect of this call with usb_buffer_unmap_sg().
919 */
920int usb_buffer_map_sg(const struct usb_device *dev, int is_in,
921 struct scatterlist *sg, int nents)
922{
923 struct usb_bus *bus;
924 struct device *controller;
925
926 if (!dev
927 || !(bus = dev->bus)
928 || !(controller = bus->controller)
929 || !controller->dma_mask)
930 return -EINVAL;
931
932 /* FIXME generic api broken like pci, can't report errors */
933 return dma_map_sg(controller, sg, nents,
934 is_in ? DMA_FROM_DEVICE : DMA_TO_DEVICE) ? : -ENOMEM;
935}
936EXPORT_SYMBOL_GPL(usb_buffer_map_sg);
937#endif
938
939/* XXX DISABLED, no users currently. If you wish to re-enable this
940 * XXX please determine whether the sync is to transfer ownership of
941 * XXX the buffer from device to cpu or vice verse, and thusly use the
942 * XXX appropriate _for_{cpu,device}() method. -DaveM
943 */
944#if 0
945
946/**
947 * usb_buffer_dmasync_sg - synchronize DMA and CPU view of scatterlist buffer(s)
948 * @dev: device to which the scatterlist will be mapped
949 * @is_in: mapping transfer direction
950 * @sg: the scatterlist to synchronize
951 * @n_hw_ents: the positive return value from usb_buffer_map_sg
952 *
953 * Use this when you are re-using a scatterlist's data buffers for
954 * another USB request.
955 */
956void usb_buffer_dmasync_sg(const struct usb_device *dev, int is_in,
957 struct scatterlist *sg, int n_hw_ents)
958{
959 struct usb_bus *bus;
960 struct device *controller;
961
962 if (!dev
963 || !(bus = dev->bus)
964 || !(controller = bus->controller)
965 || !controller->dma_mask)
966 return;
967
968 dma_sync_sg_for_cpu(controller, sg, n_hw_ents,
969 is_in ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
970}
971EXPORT_SYMBOL_GPL(usb_buffer_dmasync_sg);
972#endif
973
974#if 0
975/**
976 * usb_buffer_unmap_sg - free DMA mapping(s) for a scatterlist
977 * @dev: device to which the scatterlist will be mapped
978 * @is_in: mapping transfer direction
979 * @sg: the scatterlist to unmap
980 * @n_hw_ents: the positive return value from usb_buffer_map_sg
981 *
982 * Reverses the effect of usb_buffer_map_sg().
983 */
984void usb_buffer_unmap_sg(const struct usb_device *dev, int is_in,
985 struct scatterlist *sg, int n_hw_ents)
986{
987 struct usb_bus *bus;
988 struct device *controller;
989
990 if (!dev
991 || !(bus = dev->bus)
992 || !(controller = bus->controller)
993 || !controller->dma_mask)
994 return;
995
996 dma_unmap_sg(controller, sg, n_hw_ents,
997 is_in ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
998}
999EXPORT_SYMBOL_GPL(usb_buffer_unmap_sg);
1000#endif
1001
1002/*
1003 * Notifications of device and interface registration
1004 */
1005static int usb_bus_notify(struct notifier_block *nb, unsigned long action,
1006 void *data)
1007{
1008 struct device *dev = data;
1009
1010 switch (action) {
1011 case BUS_NOTIFY_ADD_DEVICE:
1012 if (dev->type == &usb_device_type)
1013 (void) usb_create_sysfs_dev_files(to_usb_device(dev));
1014 else if (dev->type == &usb_if_device_type)
1015 usb_create_sysfs_intf_files(to_usb_interface(dev));
1016 break;
1017
1018 case BUS_NOTIFY_DEL_DEVICE:
1019 if (dev->type == &usb_device_type)
1020 usb_remove_sysfs_dev_files(to_usb_device(dev));
1021 else if (dev->type == &usb_if_device_type)
1022 usb_remove_sysfs_intf_files(to_usb_interface(dev));
1023 break;
1024 }
1025 return 0;
1026}
1027
1028static struct notifier_block usb_bus_nb = {
1029 .notifier_call = usb_bus_notify,
1030};
1031
1032struct dentry *usb_debug_root;
1033EXPORT_SYMBOL_GPL(usb_debug_root);
1034
1035static struct dentry *usb_debug_devices;
1036
1037static int usb_debugfs_init(void)
1038{
1039 usb_debug_root = debugfs_create_dir("usb", NULL);
1040 if (!usb_debug_root)
1041 return -ENOENT;
1042
1043 usb_debug_devices = debugfs_create_file("devices", 0444,
1044 usb_debug_root, NULL,
1045 &usbfs_devices_fops);
1046 if (!usb_debug_devices) {
1047 debugfs_remove(usb_debug_root);
1048 usb_debug_root = NULL;
1049 return -ENOENT;
1050 }
1051
1052 return 0;
1053}
1054
1055static void usb_debugfs_cleanup(void)
1056{
1057 debugfs_remove(usb_debug_devices);
1058 debugfs_remove(usb_debug_root);
1059}
1060
1061/*
1062 * Init
1063 */
1064static int __init usb_init(void)
1065{
1066 int retval;
1067 if (usb_disabled()) {
1068 pr_info("%s: USB support disabled\n", usbcore_name);
1069 return 0;
1070 }
1071 usb_init_pool_max();
1072
1073 retval = usb_debugfs_init();
1074 if (retval)
1075 goto out;
1076
1077 usb_acpi_register();
1078 retval = bus_register(&usb_bus_type);
1079 if (retval)
1080 goto bus_register_failed;
1081 retval = bus_register_notifier(&usb_bus_type, &usb_bus_nb);
1082 if (retval)
1083 goto bus_notifier_failed;
1084 retval = usb_major_init();
1085 if (retval)
1086 goto major_init_failed;
1087 retval = usb_register(&usbfs_driver);
1088 if (retval)
1089 goto driver_register_failed;
1090 retval = usb_devio_init();
1091 if (retval)
1092 goto usb_devio_init_failed;
1093 retval = usb_hub_init();
1094 if (retval)
1095 goto hub_init_failed;
1096 retval = usb_register_device_driver(&usb_generic_driver, THIS_MODULE);
1097 if (!retval)
1098 goto out;
1099
1100 usb_hub_cleanup();
1101hub_init_failed:
1102 usb_devio_cleanup();
1103usb_devio_init_failed:
1104 usb_deregister(&usbfs_driver);
1105driver_register_failed:
1106 usb_major_cleanup();
1107major_init_failed:
1108 bus_unregister_notifier(&usb_bus_type, &usb_bus_nb);
1109bus_notifier_failed:
1110 bus_unregister(&usb_bus_type);
1111bus_register_failed:
1112 usb_acpi_unregister();
1113 usb_debugfs_cleanup();
1114out:
1115 return retval;
1116}
1117
1118/*
1119 * Cleanup
1120 */
1121static void __exit usb_exit(void)
1122{
1123 /* This will matter if shutdown/reboot does exitcalls. */
1124 if (usb_disabled())
1125 return;
1126
1127 usb_deregister_device_driver(&usb_generic_driver);
1128 usb_major_cleanup();
1129 usb_deregister(&usbfs_driver);
1130 usb_devio_cleanup();
1131 usb_hub_cleanup();
1132 bus_unregister_notifier(&usb_bus_type, &usb_bus_nb);
1133 bus_unregister(&usb_bus_type);
1134 usb_acpi_unregister();
1135 usb_debugfs_cleanup();
1136 idr_destroy(&usb_bus_idr);
1137}
1138
1139subsys_initcall(usb_init);
1140module_exit(usb_exit);
1141MODULE_LICENSE("GPL");