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