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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 * 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");