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/of.h>
29#include <linux/string.h>
30#include <linux/bitops.h>
31#include <linux/slab.h>
32#include <linux/kmod.h>
33#include <linux/init.h>
34#include <linux/spinlock.h>
35#include <linux/errno.h>
36#include <linux/usb.h>
37#include <linux/usb/hcd.h>
38#include <linux/mutex.h>
39#include <linux/workqueue.h>
40#include <linux/debugfs.h>
41#include <linux/usb/of.h>
42
43#include <asm/io.h>
44#include <linux/scatterlist.h>
45#include <linux/mm.h>
46#include <linux/dma-mapping.h>
47
48#include "hub.h"
49
50const char *usbcore_name = "usbcore";
51
52static bool nousb; /* Disable USB when built into kernel image */
53
54module_param(nousb, bool, 0444);
55
56/*
57 * for external read access to <nousb>
58 */
59int usb_disabled(void)
60{
61 return nousb;
62}
63EXPORT_SYMBOL_GPL(usb_disabled);
64
65#ifdef CONFIG_PM
66/* Default delay value, in seconds */
67static int usb_autosuspend_delay = CONFIG_USB_AUTOSUSPEND_DELAY;
68module_param_named(autosuspend, usb_autosuspend_delay, int, 0644);
69MODULE_PARM_DESC(autosuspend, "default autosuspend delay");
70
71#else
72#define usb_autosuspend_delay 0
73#endif
74
75static bool match_endpoint(struct usb_endpoint_descriptor *epd,
76 struct usb_endpoint_descriptor **bulk_in,
77 struct usb_endpoint_descriptor **bulk_out,
78 struct usb_endpoint_descriptor **int_in,
79 struct usb_endpoint_descriptor **int_out)
80{
81 switch (usb_endpoint_type(epd)) {
82 case USB_ENDPOINT_XFER_BULK:
83 if (usb_endpoint_dir_in(epd)) {
84 if (bulk_in && !*bulk_in) {
85 *bulk_in = epd;
86 break;
87 }
88 } else {
89 if (bulk_out && !*bulk_out) {
90 *bulk_out = epd;
91 break;
92 }
93 }
94
95 return false;
96 case USB_ENDPOINT_XFER_INT:
97 if (usb_endpoint_dir_in(epd)) {
98 if (int_in && !*int_in) {
99 *int_in = epd;
100 break;
101 }
102 } else {
103 if (int_out && !*int_out) {
104 *int_out = epd;
105 break;
106 }
107 }
108
109 return false;
110 default:
111 return false;
112 }
113
114 return (!bulk_in || *bulk_in) && (!bulk_out || *bulk_out) &&
115 (!int_in || *int_in) && (!int_out || *int_out);
116}
117
118/**
119 * usb_find_common_endpoints() -- look up common endpoint descriptors
120 * @alt: alternate setting to search
121 * @bulk_in: pointer to descriptor pointer, or NULL
122 * @bulk_out: pointer to descriptor pointer, or NULL
123 * @int_in: pointer to descriptor pointer, or NULL
124 * @int_out: pointer to descriptor pointer, or NULL
125 *
126 * Search the alternate setting's endpoint descriptors for the first bulk-in,
127 * bulk-out, interrupt-in and interrupt-out endpoints and return them in the
128 * provided pointers (unless they are NULL).
129 *
130 * If a requested endpoint is not found, the corresponding pointer is set to
131 * NULL.
132 *
133 * Return: Zero if all requested descriptors were found, or -ENXIO otherwise.
134 */
135int usb_find_common_endpoints(struct usb_host_interface *alt,
136 struct usb_endpoint_descriptor **bulk_in,
137 struct usb_endpoint_descriptor **bulk_out,
138 struct usb_endpoint_descriptor **int_in,
139 struct usb_endpoint_descriptor **int_out)
140{
141 struct usb_endpoint_descriptor *epd;
142 int i;
143
144 if (bulk_in)
145 *bulk_in = NULL;
146 if (bulk_out)
147 *bulk_out = NULL;
148 if (int_in)
149 *int_in = NULL;
150 if (int_out)
151 *int_out = NULL;
152
153 for (i = 0; i < alt->desc.bNumEndpoints; ++i) {
154 epd = &alt->endpoint[i].desc;
155
156 if (match_endpoint(epd, bulk_in, bulk_out, int_in, int_out))
157 return 0;
158 }
159
160 return -ENXIO;
161}
162EXPORT_SYMBOL_GPL(usb_find_common_endpoints);
163
164/**
165 * usb_find_common_endpoints_reverse() -- look up common endpoint descriptors
166 * @alt: alternate setting to search
167 * @bulk_in: pointer to descriptor pointer, or NULL
168 * @bulk_out: pointer to descriptor pointer, or NULL
169 * @int_in: pointer to descriptor pointer, or NULL
170 * @int_out: pointer to descriptor pointer, or NULL
171 *
172 * Search the alternate setting's endpoint descriptors for the last bulk-in,
173 * bulk-out, interrupt-in and interrupt-out endpoints and return them in the
174 * provided pointers (unless they are NULL).
175 *
176 * If a requested endpoint is not found, the corresponding pointer is set to
177 * NULL.
178 *
179 * Return: Zero if all requested descriptors were found, or -ENXIO otherwise.
180 */
181int usb_find_common_endpoints_reverse(struct usb_host_interface *alt,
182 struct usb_endpoint_descriptor **bulk_in,
183 struct usb_endpoint_descriptor **bulk_out,
184 struct usb_endpoint_descriptor **int_in,
185 struct usb_endpoint_descriptor **int_out)
186{
187 struct usb_endpoint_descriptor *epd;
188 int i;
189
190 if (bulk_in)
191 *bulk_in = NULL;
192 if (bulk_out)
193 *bulk_out = NULL;
194 if (int_in)
195 *int_in = NULL;
196 if (int_out)
197 *int_out = NULL;
198
199 for (i = alt->desc.bNumEndpoints - 1; i >= 0; --i) {
200 epd = &alt->endpoint[i].desc;
201
202 if (match_endpoint(epd, bulk_in, bulk_out, int_in, int_out))
203 return 0;
204 }
205
206 return -ENXIO;
207}
208EXPORT_SYMBOL_GPL(usb_find_common_endpoints_reverse);
209
210/**
211 * usb_find_endpoint() - Given an endpoint address, search for the endpoint's
212 * usb_host_endpoint structure in an interface's current altsetting.
213 * @intf: the interface whose current altsetting should be searched
214 * @ep_addr: the endpoint address (number and direction) to find
215 *
216 * Search the altsetting's list of endpoints for one with the specified address.
217 *
218 * Return: Pointer to the usb_host_endpoint if found, %NULL otherwise.
219 */
220static const struct usb_host_endpoint *usb_find_endpoint(
221 const struct usb_interface *intf, unsigned int ep_addr)
222{
223 int n;
224 const struct usb_host_endpoint *ep;
225
226 n = intf->cur_altsetting->desc.bNumEndpoints;
227 ep = intf->cur_altsetting->endpoint;
228 for (; n > 0; (--n, ++ep)) {
229 if (ep->desc.bEndpointAddress == ep_addr)
230 return ep;
231 }
232 return NULL;
233}
234
235/**
236 * usb_check_bulk_endpoints - Check whether an interface's current altsetting
237 * contains a set of bulk endpoints with the given addresses.
238 * @intf: the interface whose current altsetting should be searched
239 * @ep_addrs: 0-terminated array of the endpoint addresses (number and
240 * direction) to look for
241 *
242 * Search for endpoints with the specified addresses and check their types.
243 *
244 * Return: %true if all the endpoints are found and are bulk, %false otherwise.
245 */
246bool usb_check_bulk_endpoints(
247 const struct usb_interface *intf, const u8 *ep_addrs)
248{
249 const struct usb_host_endpoint *ep;
250
251 for (; *ep_addrs; ++ep_addrs) {
252 ep = usb_find_endpoint(intf, ep_addr: *ep_addrs);
253 if (!ep || !usb_endpoint_xfer_bulk(epd: &ep->desc))
254 return false;
255 }
256 return true;
257}
258EXPORT_SYMBOL_GPL(usb_check_bulk_endpoints);
259
260/**
261 * usb_check_int_endpoints - Check whether an interface's current altsetting
262 * contains a set of interrupt endpoints with the given addresses.
263 * @intf: the interface whose current altsetting should be searched
264 * @ep_addrs: 0-terminated array of the endpoint addresses (number and
265 * direction) to look for
266 *
267 * Search for endpoints with the specified addresses and check their types.
268 *
269 * Return: %true if all the endpoints are found and are interrupt,
270 * %false otherwise.
271 */
272bool usb_check_int_endpoints(
273 const struct usb_interface *intf, const u8 *ep_addrs)
274{
275 const struct usb_host_endpoint *ep;
276
277 for (; *ep_addrs; ++ep_addrs) {
278 ep = usb_find_endpoint(intf, ep_addr: *ep_addrs);
279 if (!ep || !usb_endpoint_xfer_int(epd: &ep->desc))
280 return false;
281 }
282 return true;
283}
284EXPORT_SYMBOL_GPL(usb_check_int_endpoints);
285
286/**
287 * usb_find_alt_setting() - Given a configuration, find the alternate setting
288 * for the given interface.
289 * @config: the configuration to search (not necessarily the current config).
290 * @iface_num: interface number to search in
291 * @alt_num: alternate interface setting number to search for.
292 *
293 * Search the configuration's interface cache for the given alt setting.
294 *
295 * Return: The alternate setting, if found. %NULL otherwise.
296 */
297struct usb_host_interface *usb_find_alt_setting(
298 struct usb_host_config *config,
299 unsigned int iface_num,
300 unsigned int alt_num)
301{
302 struct usb_interface_cache *intf_cache = NULL;
303 int i;
304
305 if (!config)
306 return NULL;
307 for (i = 0; i < config->desc.bNumInterfaces; i++) {
308 if (config->intf_cache[i]->altsetting[0].desc.bInterfaceNumber
309 == iface_num) {
310 intf_cache = config->intf_cache[i];
311 break;
312 }
313 }
314 if (!intf_cache)
315 return NULL;
316 for (i = 0; i < intf_cache->num_altsetting; i++)
317 if (intf_cache->altsetting[i].desc.bAlternateSetting == alt_num)
318 return &intf_cache->altsetting[i];
319
320 printk(KERN_DEBUG "Did not find alt setting %u for intf %u, "
321 "config %u\n", alt_num, iface_num,
322 config->desc.bConfigurationValue);
323 return NULL;
324}
325EXPORT_SYMBOL_GPL(usb_find_alt_setting);
326
327/**
328 * usb_ifnum_to_if - get the interface object with a given interface number
329 * @dev: the device whose current configuration is considered
330 * @ifnum: the desired interface
331 *
332 * This walks the device descriptor for the currently active configuration
333 * to find the interface object with the particular interface number.
334 *
335 * Note that configuration descriptors are not required to assign interface
336 * numbers sequentially, so that it would be incorrect to assume that
337 * the first interface in that descriptor corresponds to interface zero.
338 * This routine helps device drivers avoid such mistakes.
339 * However, you should make sure that you do the right thing with any
340 * alternate settings available for this interfaces.
341 *
342 * Don't call this function unless you are bound to one of the interfaces
343 * on this device or you have locked the device!
344 *
345 * Return: A pointer to the interface that has @ifnum as interface number,
346 * if found. %NULL otherwise.
347 */
348struct usb_interface *usb_ifnum_to_if(const struct usb_device *dev,
349 unsigned ifnum)
350{
351 struct usb_host_config *config = dev->actconfig;
352 int i;
353
354 if (!config)
355 return NULL;
356 for (i = 0; i < config->desc.bNumInterfaces; i++)
357 if (config->interface[i]->altsetting[0]
358 .desc.bInterfaceNumber == ifnum)
359 return config->interface[i];
360
361 return NULL;
362}
363EXPORT_SYMBOL_GPL(usb_ifnum_to_if);
364
365/**
366 * usb_altnum_to_altsetting - get the altsetting structure with a given alternate setting number.
367 * @intf: the interface containing the altsetting in question
368 * @altnum: the desired alternate setting number
369 *
370 * This searches the altsetting array of the specified interface for
371 * an entry with the correct bAlternateSetting value.
372 *
373 * Note that altsettings need not be stored sequentially by number, so
374 * it would be incorrect to assume that the first altsetting entry in
375 * the array corresponds to altsetting zero. This routine helps device
376 * drivers avoid such mistakes.
377 *
378 * Don't call this function unless you are bound to the intf interface
379 * or you have locked the device!
380 *
381 * Return: A pointer to the entry of the altsetting array of @intf that
382 * has @altnum as the alternate setting number. %NULL if not found.
383 */
384struct usb_host_interface *usb_altnum_to_altsetting(
385 const struct usb_interface *intf,
386 unsigned int altnum)
387{
388 int i;
389
390 for (i = 0; i < intf->num_altsetting; i++) {
391 if (intf->altsetting[i].desc.bAlternateSetting == altnum)
392 return &intf->altsetting[i];
393 }
394 return NULL;
395}
396EXPORT_SYMBOL_GPL(usb_altnum_to_altsetting);
397
398struct find_interface_arg {
399 int minor;
400 struct device_driver *drv;
401};
402
403static int __find_interface(struct device *dev, const void *data)
404{
405 const struct find_interface_arg *arg = data;
406 struct usb_interface *intf;
407
408 if (!is_usb_interface(dev))
409 return 0;
410
411 if (dev->driver != arg->drv)
412 return 0;
413 intf = to_usb_interface(dev);
414 return intf->minor == arg->minor;
415}
416
417/**
418 * usb_find_interface - find usb_interface pointer for driver and device
419 * @drv: the driver whose current configuration is considered
420 * @minor: the minor number of the desired device
421 *
422 * This walks the bus device list and returns a pointer to the interface
423 * with the matching minor and driver. Note, this only works for devices
424 * that share the USB major number.
425 *
426 * Return: A pointer to the interface with the matching major and @minor.
427 */
428struct usb_interface *usb_find_interface(struct usb_driver *drv, int minor)
429{
430 struct find_interface_arg argb;
431 struct device *dev;
432
433 argb.minor = minor;
434 argb.drv = &drv->driver;
435
436 dev = bus_find_device(bus: &usb_bus_type, NULL, data: &argb, match: __find_interface);
437
438 /* Drop reference count from bus_find_device */
439 put_device(dev);
440
441 return dev ? to_usb_interface(dev) : NULL;
442}
443EXPORT_SYMBOL_GPL(usb_find_interface);
444
445struct each_dev_arg {
446 void *data;
447 int (*fn)(struct usb_device *, void *);
448};
449
450static int __each_dev(struct device *dev, void *data)
451{
452 struct each_dev_arg *arg = (struct each_dev_arg *)data;
453
454 /* There are struct usb_interface on the same bus, filter them out */
455 if (!is_usb_device(dev))
456 return 0;
457
458 return arg->fn(to_usb_device(dev), arg->data);
459}
460
461/**
462 * usb_for_each_dev - iterate over all USB devices in the system
463 * @data: data pointer that will be handed to the callback function
464 * @fn: callback function to be called for each USB device
465 *
466 * Iterate over all USB devices and call @fn for each, passing it @data. If it
467 * returns anything other than 0, we break the iteration prematurely and return
468 * that value.
469 */
470int usb_for_each_dev(void *data, int (*fn)(struct usb_device *, void *))
471{
472 struct each_dev_arg arg = {data, fn};
473
474 return bus_for_each_dev(bus: &usb_bus_type, NULL, data: &arg, fn: __each_dev);
475}
476EXPORT_SYMBOL_GPL(usb_for_each_dev);
477
478/**
479 * usb_release_dev - free a usb device structure when all users of it are finished.
480 * @dev: device that's been disconnected
481 *
482 * Will be called only by the device core when all users of this usb device are
483 * done.
484 */
485static void usb_release_dev(struct device *dev)
486{
487 struct usb_device *udev;
488 struct usb_hcd *hcd;
489
490 udev = to_usb_device(dev);
491 hcd = bus_to_hcd(bus: udev->bus);
492
493 usb_destroy_configuration(dev: udev);
494 usb_release_bos_descriptor(dev: udev);
495 of_node_put(node: dev->of_node);
496 usb_put_hcd(hcd);
497 kfree(objp: udev->product);
498 kfree(objp: udev->manufacturer);
499 kfree(objp: udev->serial);
500 kfree(objp: udev);
501}
502
503static int usb_dev_uevent(const struct device *dev, struct kobj_uevent_env *env)
504{
505 const struct usb_device *usb_dev;
506
507 usb_dev = to_usb_device(dev);
508
509 if (add_uevent_var(env, format: "BUSNUM=%03d", usb_dev->bus->busnum))
510 return -ENOMEM;
511
512 if (add_uevent_var(env, format: "DEVNUM=%03d", usb_dev->devnum))
513 return -ENOMEM;
514
515 return 0;
516}
517
518#ifdef CONFIG_PM
519
520/* USB device Power-Management thunks.
521 * There's no need to distinguish here between quiescing a USB device
522 * and powering it down; the generic_suspend() routine takes care of
523 * it by skipping the usb_port_suspend() call for a quiesce. And for
524 * USB interfaces there's no difference at all.
525 */
526
527static int usb_dev_prepare(struct device *dev)
528{
529 return 0; /* Implement eventually? */
530}
531
532static void usb_dev_complete(struct device *dev)
533{
534 /* Currently used only for rebinding interfaces */
535 usb_resume_complete(dev);
536}
537
538static int usb_dev_suspend(struct device *dev)
539{
540 return usb_suspend(dev, PMSG_SUSPEND);
541}
542
543static int usb_dev_resume(struct device *dev)
544{
545 return usb_resume(dev, PMSG_RESUME);
546}
547
548static int usb_dev_freeze(struct device *dev)
549{
550 return usb_suspend(dev, PMSG_FREEZE);
551}
552
553static int usb_dev_thaw(struct device *dev)
554{
555 return usb_resume(dev, PMSG_THAW);
556}
557
558static int usb_dev_poweroff(struct device *dev)
559{
560 return usb_suspend(dev, PMSG_HIBERNATE);
561}
562
563static int usb_dev_restore(struct device *dev)
564{
565 return usb_resume(dev, PMSG_RESTORE);
566}
567
568static const struct dev_pm_ops usb_device_pm_ops = {
569 .prepare = usb_dev_prepare,
570 .complete = usb_dev_complete,
571 .suspend = usb_dev_suspend,
572 .resume = usb_dev_resume,
573 .freeze = usb_dev_freeze,
574 .thaw = usb_dev_thaw,
575 .poweroff = usb_dev_poweroff,
576 .restore = usb_dev_restore,
577 .runtime_suspend = usb_runtime_suspend,
578 .runtime_resume = usb_runtime_resume,
579 .runtime_idle = usb_runtime_idle,
580};
581
582#endif /* CONFIG_PM */
583
584
585static char *usb_devnode(const struct device *dev,
586 umode_t *mode, kuid_t *uid, kgid_t *gid)
587{
588 const struct usb_device *usb_dev;
589
590 usb_dev = to_usb_device(dev);
591 return kasprintf(GFP_KERNEL, fmt: "bus/usb/%03d/%03d",
592 usb_dev->bus->busnum, usb_dev->devnum);
593}
594
595const struct device_type usb_device_type = {
596 .name = "usb_device",
597 .release = usb_release_dev,
598 .uevent = usb_dev_uevent,
599 .devnode = usb_devnode,
600#ifdef CONFIG_PM
601 .pm = &usb_device_pm_ops,
602#endif
603};
604
605static bool usb_dev_authorized(struct usb_device *dev, struct usb_hcd *hcd)
606{
607 struct usb_hub *hub;
608
609 if (!dev->parent)
610 return true; /* Root hub always ok [and always wired] */
611
612 switch (hcd->dev_policy) {
613 case USB_DEVICE_AUTHORIZE_NONE:
614 default:
615 return false;
616
617 case USB_DEVICE_AUTHORIZE_ALL:
618 return true;
619
620 case USB_DEVICE_AUTHORIZE_INTERNAL:
621 hub = usb_hub_to_struct_hub(hdev: dev->parent);
622 return hub->ports[dev->portnum - 1]->connect_type ==
623 USB_PORT_CONNECT_TYPE_HARD_WIRED;
624 }
625}
626
627/**
628 * usb_alloc_dev - usb device constructor (usbcore-internal)
629 * @parent: hub to which device is connected; null to allocate a root hub
630 * @bus: bus used to access the device
631 * @port1: one-based index of port; ignored for root hubs
632 *
633 * Context: task context, might sleep.
634 *
635 * Only hub drivers (including virtual root hub drivers for host
636 * controllers) should ever call this.
637 *
638 * This call may not be used in a non-sleeping context.
639 *
640 * Return: On success, a pointer to the allocated usb device. %NULL on
641 * failure.
642 */
643struct usb_device *usb_alloc_dev(struct usb_device *parent,
644 struct usb_bus *bus, unsigned port1)
645{
646 struct usb_device *dev;
647 struct usb_hcd *usb_hcd = bus_to_hcd(bus);
648 unsigned raw_port = port1;
649
650 dev = kzalloc(size: sizeof(*dev), GFP_KERNEL);
651 if (!dev)
652 return NULL;
653
654 if (!usb_get_hcd(hcd: usb_hcd)) {
655 kfree(objp: dev);
656 return NULL;
657 }
658 /* Root hubs aren't true devices, so don't allocate HCD resources */
659 if (usb_hcd->driver->alloc_dev && parent &&
660 !usb_hcd->driver->alloc_dev(usb_hcd, dev)) {
661 usb_put_hcd(hcd: bus_to_hcd(bus));
662 kfree(objp: dev);
663 return NULL;
664 }
665
666 device_initialize(dev: &dev->dev);
667 dev->dev.bus = &usb_bus_type;
668 dev->dev.type = &usb_device_type;
669 dev->dev.groups = usb_device_groups;
670 set_dev_node(dev: &dev->dev, node: dev_to_node(dev: bus->sysdev));
671 dev->state = USB_STATE_ATTACHED;
672 dev->lpm_disable_count = 1;
673 atomic_set(v: &dev->urbnum, i: 0);
674
675 INIT_LIST_HEAD(list: &dev->ep0.urb_list);
676 dev->ep0.desc.bLength = USB_DT_ENDPOINT_SIZE;
677 dev->ep0.desc.bDescriptorType = USB_DT_ENDPOINT;
678 /* ep0 maxpacket comes later, from device descriptor */
679 usb_enable_endpoint(dev, ep: &dev->ep0, reset_toggle: false);
680 dev->can_submit = 1;
681
682 /* Save readable and stable topology id, distinguishing devices
683 * by location for diagnostics, tools, driver model, etc. The
684 * string is a path along hub ports, from the root. Each device's
685 * dev->devpath will be stable until USB is re-cabled, and hubs
686 * are often labeled with these port numbers. The name isn't
687 * as stable: bus->busnum changes easily from modprobe order,
688 * cardbus or pci hotplugging, and so on.
689 */
690 if (unlikely(!parent)) {
691 dev->devpath[0] = '0';
692 dev->route = 0;
693
694 dev->dev.parent = bus->controller;
695 device_set_of_node_from_dev(dev: &dev->dev, dev2: bus->sysdev);
696 dev_set_name(dev: &dev->dev, name: "usb%d", bus->busnum);
697 } else {
698 /* match any labeling on the hubs; it's one-based */
699 if (parent->devpath[0] == '0') {
700 snprintf(buf: dev->devpath, size: sizeof dev->devpath,
701 fmt: "%d", port1);
702 /* Root ports are not counted in route string */
703 dev->route = 0;
704 } else {
705 snprintf(buf: dev->devpath, size: sizeof dev->devpath,
706 fmt: "%s.%d", parent->devpath, port1);
707 /* Route string assumes hubs have less than 16 ports */
708 if (port1 < 15)
709 dev->route = parent->route +
710 (port1 << ((parent->level - 1)*4));
711 else
712 dev->route = parent->route +
713 (15 << ((parent->level - 1)*4));
714 }
715
716 dev->dev.parent = &parent->dev;
717 dev_set_name(dev: &dev->dev, name: "%d-%s", bus->busnum, dev->devpath);
718
719 if (!parent->parent) {
720 /* device under root hub's port */
721 raw_port = usb_hcd_find_raw_port_number(hcd: usb_hcd,
722 port1);
723 }
724 dev->dev.of_node = usb_of_get_device_node(hub: parent, port1: raw_port);
725
726 /* hub driver sets up TT records */
727 }
728
729 dev->portnum = port1;
730 dev->bus = bus;
731 dev->parent = parent;
732 INIT_LIST_HEAD(list: &dev->filelist);
733
734#ifdef CONFIG_PM
735 pm_runtime_set_autosuspend_delay(dev: &dev->dev,
736 delay: usb_autosuspend_delay * 1000);
737 dev->connect_time = jiffies;
738 dev->active_duration = -jiffies;
739#endif
740
741 dev->authorized = usb_dev_authorized(dev, hcd: usb_hcd);
742 return dev;
743}
744EXPORT_SYMBOL_GPL(usb_alloc_dev);
745
746/**
747 * usb_get_dev - increments the reference count of the usb device structure
748 * @dev: the device being referenced
749 *
750 * Each live reference to a device should be refcounted.
751 *
752 * Drivers for USB interfaces should normally record such references in
753 * their probe() methods, when they bind to an interface, and release
754 * them by calling usb_put_dev(), in their disconnect() methods.
755 * However, if a driver does not access the usb_device structure after
756 * its disconnect() method returns then refcounting is not necessary,
757 * because the USB core guarantees that a usb_device will not be
758 * deallocated until after all of its interface drivers have been unbound.
759 *
760 * Return: A pointer to the device with the incremented reference counter.
761 */
762struct usb_device *usb_get_dev(struct usb_device *dev)
763{
764 if (dev)
765 get_device(dev: &dev->dev);
766 return dev;
767}
768EXPORT_SYMBOL_GPL(usb_get_dev);
769
770/**
771 * usb_put_dev - release a use of the usb device structure
772 * @dev: device that's been disconnected
773 *
774 * Must be called when a user of a device is finished with it. When the last
775 * user of the device calls this function, the memory of the device is freed.
776 */
777void usb_put_dev(struct usb_device *dev)
778{
779 if (dev)
780 put_device(dev: &dev->dev);
781}
782EXPORT_SYMBOL_GPL(usb_put_dev);
783
784/**
785 * usb_get_intf - increments the reference count of the usb interface structure
786 * @intf: the interface being referenced
787 *
788 * Each live reference to a interface must be refcounted.
789 *
790 * Drivers for USB interfaces should normally record such references in
791 * their probe() methods, when they bind to an interface, and release
792 * them by calling usb_put_intf(), in their disconnect() methods.
793 * However, if a driver does not access the usb_interface structure after
794 * its disconnect() method returns then refcounting is not necessary,
795 * because the USB core guarantees that a usb_interface will not be
796 * deallocated until after its driver has been unbound.
797 *
798 * Return: A pointer to the interface with the incremented reference counter.
799 */
800struct usb_interface *usb_get_intf(struct usb_interface *intf)
801{
802 if (intf)
803 get_device(dev: &intf->dev);
804 return intf;
805}
806EXPORT_SYMBOL_GPL(usb_get_intf);
807
808/**
809 * usb_put_intf - release a use of the usb interface structure
810 * @intf: interface that's been decremented
811 *
812 * Must be called when a user of an interface is finished with it. When the
813 * last user of the interface calls this function, the memory of the interface
814 * is freed.
815 */
816void usb_put_intf(struct usb_interface *intf)
817{
818 if (intf)
819 put_device(dev: &intf->dev);
820}
821EXPORT_SYMBOL_GPL(usb_put_intf);
822
823/**
824 * usb_intf_get_dma_device - acquire a reference on the usb interface's DMA endpoint
825 * @intf: the usb interface
826 *
827 * While a USB device cannot perform DMA operations by itself, many USB
828 * controllers can. A call to usb_intf_get_dma_device() returns the DMA endpoint
829 * for the given USB interface, if any. The returned device structure must be
830 * released with put_device().
831 *
832 * See also usb_get_dma_device().
833 *
834 * Returns: A reference to the usb interface's DMA endpoint; or NULL if none
835 * exists.
836 */
837struct device *usb_intf_get_dma_device(struct usb_interface *intf)
838{
839 struct usb_device *udev = interface_to_usbdev(intf);
840 struct device *dmadev;
841
842 if (!udev->bus)
843 return NULL;
844
845 dmadev = get_device(dev: udev->bus->sysdev);
846 if (!dmadev || !dmadev->dma_mask) {
847 put_device(dev: dmadev);
848 return NULL;
849 }
850
851 return dmadev;
852}
853EXPORT_SYMBOL_GPL(usb_intf_get_dma_device);
854
855/* USB device locking
856 *
857 * USB devices and interfaces are locked using the semaphore in their
858 * embedded struct device. The hub driver guarantees that whenever a
859 * device is connected or disconnected, drivers are called with the
860 * USB device locked as well as their particular interface.
861 *
862 * Complications arise when several devices are to be locked at the same
863 * time. Only hub-aware drivers that are part of usbcore ever have to
864 * do this; nobody else needs to worry about it. The rule for locking
865 * is simple:
866 *
867 * When locking both a device and its parent, always lock the
868 * parent first.
869 */
870
871/**
872 * usb_lock_device_for_reset - cautiously acquire the lock for a usb device structure
873 * @udev: device that's being locked
874 * @iface: interface bound to the driver making the request (optional)
875 *
876 * Attempts to acquire the device lock, but fails if the device is
877 * NOTATTACHED or SUSPENDED, or if iface is specified and the interface
878 * is neither BINDING nor BOUND. Rather than sleeping to wait for the
879 * lock, the routine polls repeatedly. This is to prevent deadlock with
880 * disconnect; in some drivers (such as usb-storage) the disconnect()
881 * or suspend() method will block waiting for a device reset to complete.
882 *
883 * Return: A negative error code for failure, otherwise 0.
884 */
885int usb_lock_device_for_reset(struct usb_device *udev,
886 const struct usb_interface *iface)
887{
888 unsigned long jiffies_expire = jiffies + HZ;
889
890 if (udev->state == USB_STATE_NOTATTACHED)
891 return -ENODEV;
892 if (udev->state == USB_STATE_SUSPENDED)
893 return -EHOSTUNREACH;
894 if (iface && (iface->condition == USB_INTERFACE_UNBINDING ||
895 iface->condition == USB_INTERFACE_UNBOUND))
896 return -EINTR;
897
898 while (!usb_trylock_device(udev)) {
899
900 /* If we can't acquire the lock after waiting one second,
901 * we're probably deadlocked */
902 if (time_after(jiffies, jiffies_expire))
903 return -EBUSY;
904
905 msleep(msecs: 15);
906 if (udev->state == USB_STATE_NOTATTACHED)
907 return -ENODEV;
908 if (udev->state == USB_STATE_SUSPENDED)
909 return -EHOSTUNREACH;
910 if (iface && (iface->condition == USB_INTERFACE_UNBINDING ||
911 iface->condition == USB_INTERFACE_UNBOUND))
912 return -EINTR;
913 }
914 return 0;
915}
916EXPORT_SYMBOL_GPL(usb_lock_device_for_reset);
917
918/**
919 * usb_get_current_frame_number - return current bus frame number
920 * @dev: the device whose bus is being queried
921 *
922 * Return: The current frame number for the USB host controller used
923 * with the given USB device. This can be used when scheduling
924 * isochronous requests.
925 *
926 * Note: Different kinds of host controller have different "scheduling
927 * horizons". While one type might support scheduling only 32 frames
928 * into the future, others could support scheduling up to 1024 frames
929 * into the future.
930 *
931 */
932int usb_get_current_frame_number(struct usb_device *dev)
933{
934 return usb_hcd_get_frame_number(udev: dev);
935}
936EXPORT_SYMBOL_GPL(usb_get_current_frame_number);
937
938/*-------------------------------------------------------------------*/
939/*
940 * __usb_get_extra_descriptor() finds a descriptor of specific type in the
941 * extra field of the interface and endpoint descriptor structs.
942 */
943
944int __usb_get_extra_descriptor(char *buffer, unsigned size,
945 unsigned char type, void **ptr, size_t minsize)
946{
947 struct usb_descriptor_header *header;
948
949 while (size >= sizeof(struct usb_descriptor_header)) {
950 header = (struct usb_descriptor_header *)buffer;
951
952 if (header->bLength < 2 || header->bLength > size) {
953 printk(KERN_ERR
954 "%s: bogus descriptor, type %d length %d\n",
955 usbcore_name,
956 header->bDescriptorType,
957 header->bLength);
958 return -1;
959 }
960
961 if (header->bDescriptorType == type && header->bLength >= minsize) {
962 *ptr = header;
963 return 0;
964 }
965
966 buffer += header->bLength;
967 size -= header->bLength;
968 }
969 return -1;
970}
971EXPORT_SYMBOL_GPL(__usb_get_extra_descriptor);
972
973/**
974 * usb_alloc_coherent - allocate dma-consistent buffer for URB_NO_xxx_DMA_MAP
975 * @dev: device the buffer will be used with
976 * @size: requested buffer size
977 * @mem_flags: affect whether allocation may block
978 * @dma: used to return DMA address of buffer
979 *
980 * Return: Either null (indicating no buffer could be allocated), or the
981 * cpu-space pointer to a buffer that may be used to perform DMA to the
982 * specified device. Such cpu-space buffers are returned along with the DMA
983 * address (through the pointer provided).
984 *
985 * Note:
986 * These buffers are used with URB_NO_xxx_DMA_MAP set in urb->transfer_flags
987 * to avoid behaviors like using "DMA bounce buffers", or thrashing IOMMU
988 * hardware during URB completion/resubmit. The implementation varies between
989 * platforms, depending on details of how DMA will work to this device.
990 * Using these buffers also eliminates cacheline sharing problems on
991 * architectures where CPU caches are not DMA-coherent. On systems without
992 * bus-snooping caches, these buffers are uncached.
993 *
994 * When the buffer is no longer used, free it with usb_free_coherent().
995 */
996void *usb_alloc_coherent(struct usb_device *dev, size_t size, gfp_t mem_flags,
997 dma_addr_t *dma)
998{
999 if (!dev || !dev->bus)
1000 return NULL;
1001 return hcd_buffer_alloc(bus: dev->bus, size, mem_flags, dma);
1002}
1003EXPORT_SYMBOL_GPL(usb_alloc_coherent);
1004
1005/**
1006 * usb_free_coherent - free memory allocated with usb_alloc_coherent()
1007 * @dev: device the buffer was used with
1008 * @size: requested buffer size
1009 * @addr: CPU address of buffer
1010 * @dma: DMA address of buffer
1011 *
1012 * This reclaims an I/O buffer, letting it be reused. The memory must have
1013 * been allocated using usb_alloc_coherent(), and the parameters must match
1014 * those provided in that allocation request.
1015 */
1016void usb_free_coherent(struct usb_device *dev, size_t size, void *addr,
1017 dma_addr_t dma)
1018{
1019 if (!dev || !dev->bus)
1020 return;
1021 if (!addr)
1022 return;
1023 hcd_buffer_free(bus: dev->bus, size, addr, dma);
1024}
1025EXPORT_SYMBOL_GPL(usb_free_coherent);
1026
1027/*
1028 * Notifications of device and interface registration
1029 */
1030static int usb_bus_notify(struct notifier_block *nb, unsigned long action,
1031 void *data)
1032{
1033 struct device *dev = data;
1034
1035 switch (action) {
1036 case BUS_NOTIFY_ADD_DEVICE:
1037 if (dev->type == &usb_device_type)
1038 (void) usb_create_sysfs_dev_files(to_usb_device(dev));
1039 else if (dev->type == &usb_if_device_type)
1040 usb_create_sysfs_intf_files(to_usb_interface(dev));
1041 break;
1042
1043 case BUS_NOTIFY_DEL_DEVICE:
1044 if (dev->type == &usb_device_type)
1045 usb_remove_sysfs_dev_files(to_usb_device(dev));
1046 else if (dev->type == &usb_if_device_type)
1047 usb_remove_sysfs_intf_files(to_usb_interface(dev));
1048 break;
1049 }
1050 return 0;
1051}
1052
1053static struct notifier_block usb_bus_nb = {
1054 .notifier_call = usb_bus_notify,
1055};
1056
1057static void usb_debugfs_init(void)
1058{
1059 debugfs_create_file(name: "devices", mode: 0444, parent: usb_debug_root, NULL,
1060 fops: &usbfs_devices_fops);
1061}
1062
1063static void usb_debugfs_cleanup(void)
1064{
1065 debugfs_lookup_and_remove(name: "devices", parent: usb_debug_root);
1066}
1067
1068/*
1069 * Init
1070 */
1071static int __init usb_init(void)
1072{
1073 int retval;
1074 if (usb_disabled()) {
1075 pr_info("%s: USB support disabled\n", usbcore_name);
1076 return 0;
1077 }
1078 usb_init_pool_max();
1079
1080 usb_debugfs_init();
1081
1082 usb_acpi_register();
1083 retval = bus_register(bus: &usb_bus_type);
1084 if (retval)
1085 goto bus_register_failed;
1086 retval = bus_register_notifier(bus: &usb_bus_type, nb: &usb_bus_nb);
1087 if (retval)
1088 goto bus_notifier_failed;
1089 retval = usb_major_init();
1090 if (retval)
1091 goto major_init_failed;
1092 retval = class_register(class: &usbmisc_class);
1093 if (retval)
1094 goto class_register_failed;
1095 retval = usb_register(&usbfs_driver);
1096 if (retval)
1097 goto driver_register_failed;
1098 retval = usb_devio_init();
1099 if (retval)
1100 goto usb_devio_init_failed;
1101 retval = usb_hub_init();
1102 if (retval)
1103 goto hub_init_failed;
1104 retval = usb_register_device_driver(&usb_generic_driver, THIS_MODULE);
1105 if (!retval)
1106 goto out;
1107
1108 usb_hub_cleanup();
1109hub_init_failed:
1110 usb_devio_cleanup();
1111usb_devio_init_failed:
1112 usb_deregister(&usbfs_driver);
1113driver_register_failed:
1114 class_unregister(class: &usbmisc_class);
1115class_register_failed:
1116 usb_major_cleanup();
1117major_init_failed:
1118 bus_unregister_notifier(bus: &usb_bus_type, nb: &usb_bus_nb);
1119bus_notifier_failed:
1120 bus_unregister(bus: &usb_bus_type);
1121bus_register_failed:
1122 usb_acpi_unregister();
1123 usb_debugfs_cleanup();
1124out:
1125 return retval;
1126}
1127
1128/*
1129 * Cleanup
1130 */
1131static void __exit usb_exit(void)
1132{
1133 /* This will matter if shutdown/reboot does exitcalls. */
1134 if (usb_disabled())
1135 return;
1136
1137 usb_release_quirk_list();
1138 usb_deregister_device_driver(&usb_generic_driver);
1139 usb_major_cleanup();
1140 usb_deregister(&usbfs_driver);
1141 usb_devio_cleanup();
1142 usb_hub_cleanup();
1143 class_unregister(class: &usbmisc_class);
1144 bus_unregister_notifier(bus: &usb_bus_type, nb: &usb_bus_nb);
1145 bus_unregister(bus: &usb_bus_type);
1146 usb_acpi_unregister();
1147 usb_debugfs_cleanup();
1148 idr_destroy(&usb_bus_idr);
1149}
1150
1151subsys_initcall(usb_init);
1152module_exit(usb_exit);
1153MODULE_LICENSE("GPL");
1154

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