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1/*
2 * drivers/usb/core/usb.c
3 *
4 * (C) Copyright Linus Torvalds 1999
5 * (C) Copyright Johannes Erdfelt 1999-2001
6 * (C) Copyright Andreas Gal 1999
7 * (C) Copyright Gregory P. Smith 1999
8 * (C) Copyright Deti Fliegl 1999 (new USB architecture)
9 * (C) Copyright Randy Dunlap 2000
10 * (C) Copyright David Brownell 2000-2004
11 * (C) Copyright Yggdrasil Computing, Inc. 2000
12 * (usb_device_id matching changes by Adam J. Richter)
13 * (C) Copyright Greg Kroah-Hartman 2002-2003
14 *
15 * Released under the GPLv2 only.
16 * SPDX-License-Identifier: GPL-2.0
17 *
18 * NOTE! This is not actually a driver at all, rather this is
19 * just a collection of helper routines that implement the
20 * generic USB things that the real drivers can use..
21 *
22 * Think of this as a "USB library" rather than anything else.
23 * It should be considered a slave, with no callbacks. Callbacks
24 * are evil.
25 */
26
27#include <linux/module.h>
28#include <linux/moduleparam.h>
29#include <linux/string.h>
30#include <linux/bitops.h>
31#include <linux/slab.h>
32#include <linux/interrupt.h> /* for in_interrupt() */
33#include <linux/kmod.h>
34#include <linux/init.h>
35#include <linux/spinlock.h>
36#include <linux/errno.h>
37#include <linux/usb.h>
38#include <linux/usb/hcd.h>
39#include <linux/mutex.h>
40#include <linux/workqueue.h>
41#include <linux/debugfs.h>
42#include <linux/usb/of.h>
43
44#include <asm/io.h>
45#include <linux/scatterlist.h>
46#include <linux/mm.h>
47#include <linux/dma-mapping.h>
48
49#include "usb.h"
50
51
52const char *usbcore_name = "usbcore";
53
54static bool nousb; /* Disable USB when built into kernel image */
55
56module_param(nousb, bool, 0444);
57
58/*
59 * for external read access to <nousb>
60 */
61int usb_disabled(void)
62{
63 return nousb;
64}
65EXPORT_SYMBOL_GPL(usb_disabled);
66
67#ifdef CONFIG_PM
68static int usb_autosuspend_delay = 2; /* Default delay value,
69 * in seconds */
70module_param_named(autosuspend, usb_autosuspend_delay, int, 0644);
71MODULE_PARM_DESC(autosuspend, "default autosuspend delay");
72
73#else
74#define usb_autosuspend_delay 0
75#endif
76
77
78/**
79 * usb_find_alt_setting() - Given a configuration, find the alternate setting
80 * for the given interface.
81 * @config: the configuration to search (not necessarily the current config).
82 * @iface_num: interface number to search in
83 * @alt_num: alternate interface setting number to search for.
84 *
85 * Search the configuration's interface cache for the given alt setting.
86 *
87 * Return: The alternate setting, if found. %NULL otherwise.
88 */
89struct usb_host_interface *usb_find_alt_setting(
90 struct usb_host_config *config,
91 unsigned int iface_num,
92 unsigned int alt_num)
93{
94 struct usb_interface_cache *intf_cache = NULL;
95 int i;
96
97 for (i = 0; i < config->desc.bNumInterfaces; i++) {
98 if (config->intf_cache[i]->altsetting[0].desc.bInterfaceNumber
99 == iface_num) {
100 intf_cache = config->intf_cache[i];
101 break;
102 }
103 }
104 if (!intf_cache)
105 return NULL;
106 for (i = 0; i < intf_cache->num_altsetting; i++)
107 if (intf_cache->altsetting[i].desc.bAlternateSetting == alt_num)
108 return &intf_cache->altsetting[i];
109
110 printk(KERN_DEBUG "Did not find alt setting %u for intf %u, "
111 "config %u\n", alt_num, iface_num,
112 config->desc.bConfigurationValue);
113 return NULL;
114}
115EXPORT_SYMBOL_GPL(usb_find_alt_setting);
116
117/**
118 * usb_ifnum_to_if - get the interface object with a given interface number
119 * @dev: the device whose current configuration is considered
120 * @ifnum: the desired interface
121 *
122 * This walks the device descriptor for the currently active configuration
123 * to find the interface object with the particular interface number.
124 *
125 * Note that configuration descriptors are not required to assign interface
126 * numbers sequentially, so that it would be incorrect to assume that
127 * the first interface in that descriptor corresponds to interface zero.
128 * This routine helps device drivers avoid such mistakes.
129 * However, you should make sure that you do the right thing with any
130 * alternate settings available for this interfaces.
131 *
132 * Don't call this function unless you are bound to one of the interfaces
133 * on this device or you have locked the device!
134 *
135 * Return: A pointer to the interface that has @ifnum as interface number,
136 * if found. %NULL otherwise.
137 */
138struct usb_interface *usb_ifnum_to_if(const struct usb_device *dev,
139 unsigned ifnum)
140{
141 struct usb_host_config *config = dev->actconfig;
142 int i;
143
144 if (!config)
145 return NULL;
146 for (i = 0; i < config->desc.bNumInterfaces; i++)
147 if (config->interface[i]->altsetting[0]
148 .desc.bInterfaceNumber == ifnum)
149 return config->interface[i];
150
151 return NULL;
152}
153EXPORT_SYMBOL_GPL(usb_ifnum_to_if);
154
155/**
156 * usb_altnum_to_altsetting - get the altsetting structure with a given alternate setting number.
157 * @intf: the interface containing the altsetting in question
158 * @altnum: the desired alternate setting number
159 *
160 * This searches the altsetting array of the specified interface for
161 * an entry with the correct bAlternateSetting value.
162 *
163 * Note that altsettings need not be stored sequentially by number, so
164 * it would be incorrect to assume that the first altsetting entry in
165 * the array corresponds to altsetting zero. This routine helps device
166 * drivers avoid such mistakes.
167 *
168 * Don't call this function unless you are bound to the intf interface
169 * or you have locked the device!
170 *
171 * Return: A pointer to the entry of the altsetting array of @intf that
172 * has @altnum as the alternate setting number. %NULL if not found.
173 */
174struct usb_host_interface *usb_altnum_to_altsetting(
175 const struct usb_interface *intf,
176 unsigned int altnum)
177{
178 int i;
179
180 for (i = 0; i < intf->num_altsetting; i++) {
181 if (intf->altsetting[i].desc.bAlternateSetting == altnum)
182 return &intf->altsetting[i];
183 }
184 return NULL;
185}
186EXPORT_SYMBOL_GPL(usb_altnum_to_altsetting);
187
188struct find_interface_arg {
189 int minor;
190 struct device_driver *drv;
191};
192
193static int __find_interface(struct device *dev, void *data)
194{
195 struct find_interface_arg *arg = data;
196 struct usb_interface *intf;
197
198 if (!is_usb_interface(dev))
199 return 0;
200
201 if (dev->driver != arg->drv)
202 return 0;
203 intf = to_usb_interface(dev);
204 return intf->minor == arg->minor;
205}
206
207/**
208 * usb_find_interface - find usb_interface pointer for driver and device
209 * @drv: the driver whose current configuration is considered
210 * @minor: the minor number of the desired device
211 *
212 * This walks the bus device list and returns a pointer to the interface
213 * with the matching minor and driver. Note, this only works for devices
214 * that share the USB major number.
215 *
216 * Return: A pointer to the interface with the matching major and @minor.
217 */
218struct usb_interface *usb_find_interface(struct usb_driver *drv, int minor)
219{
220 struct find_interface_arg argb;
221 struct device *dev;
222
223 argb.minor = minor;
224 argb.drv = &drv->drvwrap.driver;
225
226 dev = bus_find_device(&usb_bus_type, NULL, &argb, __find_interface);
227
228 /* Drop reference count from bus_find_device */
229 put_device(dev);
230
231 return dev ? to_usb_interface(dev) : NULL;
232}
233EXPORT_SYMBOL_GPL(usb_find_interface);
234
235struct each_dev_arg {
236 void *data;
237 int (*fn)(struct usb_device *, void *);
238};
239
240static int __each_dev(struct device *dev, void *data)
241{
242 struct each_dev_arg *arg = (struct each_dev_arg *)data;
243
244 /* There are struct usb_interface on the same bus, filter them out */
245 if (!is_usb_device(dev))
246 return 0;
247
248 return arg->fn(to_usb_device(dev), arg->data);
249}
250
251/**
252 * usb_for_each_dev - iterate over all USB devices in the system
253 * @data: data pointer that will be handed to the callback function
254 * @fn: callback function to be called for each USB device
255 *
256 * Iterate over all USB devices and call @fn for each, passing it @data. If it
257 * returns anything other than 0, we break the iteration prematurely and return
258 * that value.
259 */
260int usb_for_each_dev(void *data, int (*fn)(struct usb_device *, void *))
261{
262 struct each_dev_arg arg = {data, fn};
263
264 return bus_for_each_dev(&usb_bus_type, NULL, &arg, __each_dev);
265}
266EXPORT_SYMBOL_GPL(usb_for_each_dev);
267
268/**
269 * usb_release_dev - free a usb device structure when all users of it are finished.
270 * @dev: device that's been disconnected
271 *
272 * Will be called only by the device core when all users of this usb device are
273 * done.
274 */
275static void usb_release_dev(struct device *dev)
276{
277 struct usb_device *udev;
278 struct usb_hcd *hcd;
279
280 udev = to_usb_device(dev);
281 hcd = bus_to_hcd(udev->bus);
282
283 usb_destroy_configuration(udev);
284 usb_release_bos_descriptor(udev);
285 usb_put_hcd(hcd);
286 kfree(udev->product);
287 kfree(udev->manufacturer);
288 kfree(udev->serial);
289 kfree(udev);
290}
291
292static int usb_dev_uevent(struct device *dev, struct kobj_uevent_env *env)
293{
294 struct usb_device *usb_dev;
295
296 usb_dev = to_usb_device(dev);
297
298 if (add_uevent_var(env, "BUSNUM=%03d", usb_dev->bus->busnum))
299 return -ENOMEM;
300
301 if (add_uevent_var(env, "DEVNUM=%03d", usb_dev->devnum))
302 return -ENOMEM;
303
304 return 0;
305}
306
307#ifdef CONFIG_PM
308
309/* USB device Power-Management thunks.
310 * There's no need to distinguish here between quiescing a USB device
311 * and powering it down; the generic_suspend() routine takes care of
312 * it by skipping the usb_port_suspend() call for a quiesce. And for
313 * USB interfaces there's no difference at all.
314 */
315
316static int usb_dev_prepare(struct device *dev)
317{
318 return 0; /* Implement eventually? */
319}
320
321static void usb_dev_complete(struct device *dev)
322{
323 /* Currently used only for rebinding interfaces */
324 usb_resume_complete(dev);
325}
326
327static int usb_dev_suspend(struct device *dev)
328{
329 return usb_suspend(dev, PMSG_SUSPEND);
330}
331
332static int usb_dev_resume(struct device *dev)
333{
334 return usb_resume(dev, PMSG_RESUME);
335}
336
337static int usb_dev_freeze(struct device *dev)
338{
339 return usb_suspend(dev, PMSG_FREEZE);
340}
341
342static int usb_dev_thaw(struct device *dev)
343{
344 return usb_resume(dev, PMSG_THAW);
345}
346
347static int usb_dev_poweroff(struct device *dev)
348{
349 return usb_suspend(dev, PMSG_HIBERNATE);
350}
351
352static int usb_dev_restore(struct device *dev)
353{
354 return usb_resume(dev, PMSG_RESTORE);
355}
356
357static const struct dev_pm_ops usb_device_pm_ops = {
358 .prepare = usb_dev_prepare,
359 .complete = usb_dev_complete,
360 .suspend = usb_dev_suspend,
361 .resume = usb_dev_resume,
362 .freeze = usb_dev_freeze,
363 .thaw = usb_dev_thaw,
364 .poweroff = usb_dev_poweroff,
365 .restore = usb_dev_restore,
366 .runtime_suspend = usb_runtime_suspend,
367 .runtime_resume = usb_runtime_resume,
368 .runtime_idle = usb_runtime_idle,
369};
370
371#endif /* CONFIG_PM */
372
373
374static char *usb_devnode(struct device *dev,
375 umode_t *mode, kuid_t *uid, kgid_t *gid)
376{
377 struct usb_device *usb_dev;
378
379 usb_dev = to_usb_device(dev);
380 return kasprintf(GFP_KERNEL, "bus/usb/%03d/%03d",
381 usb_dev->bus->busnum, usb_dev->devnum);
382}
383
384struct device_type usb_device_type = {
385 .name = "usb_device",
386 .release = usb_release_dev,
387 .uevent = usb_dev_uevent,
388 .devnode = usb_devnode,
389#ifdef CONFIG_PM
390 .pm = &usb_device_pm_ops,
391#endif
392};
393
394
395/* Returns 1 if @usb_bus is WUSB, 0 otherwise */
396static unsigned usb_bus_is_wusb(struct usb_bus *bus)
397{
398 struct usb_hcd *hcd = bus_to_hcd(bus);
399 return hcd->wireless;
400}
401
402
403/**
404 * usb_alloc_dev - usb device constructor (usbcore-internal)
405 * @parent: hub to which device is connected; null to allocate a root hub
406 * @bus: bus used to access the device
407 * @port1: one-based index of port; ignored for root hubs
408 * Context: !in_interrupt()
409 *
410 * Only hub drivers (including virtual root hub drivers for host
411 * controllers) should ever call this.
412 *
413 * This call may not be used in a non-sleeping context.
414 *
415 * Return: On success, a pointer to the allocated usb device. %NULL on
416 * failure.
417 */
418struct usb_device *usb_alloc_dev(struct usb_device *parent,
419 struct usb_bus *bus, unsigned port1)
420{
421 struct usb_device *dev;
422 struct usb_hcd *usb_hcd = bus_to_hcd(bus);
423 unsigned root_hub = 0;
424 unsigned raw_port = port1;
425
426 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
427 if (!dev)
428 return NULL;
429
430 if (!usb_get_hcd(usb_hcd)) {
431 kfree(dev);
432 return NULL;
433 }
434 /* Root hubs aren't true devices, so don't allocate HCD resources */
435 if (usb_hcd->driver->alloc_dev && parent &&
436 !usb_hcd->driver->alloc_dev(usb_hcd, dev)) {
437 usb_put_hcd(bus_to_hcd(bus));
438 kfree(dev);
439 return NULL;
440 }
441
442 device_initialize(&dev->dev);
443 dev->dev.bus = &usb_bus_type;
444 dev->dev.type = &usb_device_type;
445 dev->dev.groups = usb_device_groups;
446 /*
447 * Fake a dma_mask/offset for the USB device:
448 * We cannot really use the dma-mapping API (dma_alloc_* and
449 * dma_map_*) for USB devices but instead need to use
450 * usb_alloc_coherent and pass data in 'urb's, but some subsystems
451 * manually look into the mask/offset pair to determine whether
452 * they need bounce buffers.
453 * Note: calling dma_set_mask() on a USB device would set the
454 * mask for the entire HCD, so don't do that.
455 */
456 dev->dev.dma_mask = bus->controller->dma_mask;
457 dev->dev.dma_pfn_offset = bus->controller->dma_pfn_offset;
458 set_dev_node(&dev->dev, dev_to_node(bus->controller));
459 dev->state = USB_STATE_ATTACHED;
460 dev->lpm_disable_count = 1;
461 atomic_set(&dev->urbnum, 0);
462
463 INIT_LIST_HEAD(&dev->ep0.urb_list);
464 dev->ep0.desc.bLength = USB_DT_ENDPOINT_SIZE;
465 dev->ep0.desc.bDescriptorType = USB_DT_ENDPOINT;
466 /* ep0 maxpacket comes later, from device descriptor */
467 usb_enable_endpoint(dev, &dev->ep0, false);
468 dev->can_submit = 1;
469
470 /* Save readable and stable topology id, distinguishing devices
471 * by location for diagnostics, tools, driver model, etc. The
472 * string is a path along hub ports, from the root. Each device's
473 * dev->devpath will be stable until USB is re-cabled, and hubs
474 * are often labeled with these port numbers. The name isn't
475 * as stable: bus->busnum changes easily from modprobe order,
476 * cardbus or pci hotplugging, and so on.
477 */
478 if (unlikely(!parent)) {
479 dev->devpath[0] = '0';
480 dev->route = 0;
481
482 dev->dev.parent = bus->controller;
483 dev_set_name(&dev->dev, "usb%d", bus->busnum);
484 root_hub = 1;
485 } else {
486 /* match any labeling on the hubs; it's one-based */
487 if (parent->devpath[0] == '0') {
488 snprintf(dev->devpath, sizeof dev->devpath,
489 "%d", port1);
490 /* Root ports are not counted in route string */
491 dev->route = 0;
492 } else {
493 snprintf(dev->devpath, sizeof dev->devpath,
494 "%s.%d", parent->devpath, port1);
495 /* Route string assumes hubs have less than 16 ports */
496 if (port1 < 15)
497 dev->route = parent->route +
498 (port1 << ((parent->level - 1)*4));
499 else
500 dev->route = parent->route +
501 (15 << ((parent->level - 1)*4));
502 }
503
504 dev->dev.parent = &parent->dev;
505 dev_set_name(&dev->dev, "%d-%s", bus->busnum, dev->devpath);
506
507 if (!parent->parent) {
508 /* device under root hub's port */
509 raw_port = usb_hcd_find_raw_port_number(usb_hcd,
510 port1);
511 }
512 dev->dev.of_node = usb_of_get_child_node(parent->dev.of_node,
513 raw_port);
514
515 /* hub driver sets up TT records */
516 }
517
518 dev->portnum = port1;
519 dev->bus = bus;
520 dev->parent = parent;
521 INIT_LIST_HEAD(&dev->filelist);
522
523#ifdef CONFIG_PM
524 pm_runtime_set_autosuspend_delay(&dev->dev,
525 usb_autosuspend_delay * 1000);
526 dev->connect_time = jiffies;
527 dev->active_duration = -jiffies;
528#endif
529 if (root_hub) /* Root hub always ok [and always wired] */
530 dev->authorized = 1;
531 else {
532 dev->authorized = !!HCD_DEV_AUTHORIZED(usb_hcd);
533 dev->wusb = usb_bus_is_wusb(bus) ? 1 : 0;
534 }
535 return dev;
536}
537EXPORT_SYMBOL_GPL(usb_alloc_dev);
538
539/**
540 * usb_get_dev - increments the reference count of the usb device structure
541 * @dev: the device being referenced
542 *
543 * Each live reference to a device should be refcounted.
544 *
545 * Drivers for USB interfaces should normally record such references in
546 * their probe() methods, when they bind to an interface, and release
547 * them by calling usb_put_dev(), in their disconnect() methods.
548 *
549 * Return: A pointer to the device with the incremented reference counter.
550 */
551struct usb_device *usb_get_dev(struct usb_device *dev)
552{
553 if (dev)
554 get_device(&dev->dev);
555 return dev;
556}
557EXPORT_SYMBOL_GPL(usb_get_dev);
558
559/**
560 * usb_put_dev - release a use of the usb device structure
561 * @dev: device that's been disconnected
562 *
563 * Must be called when a user of a device is finished with it. When the last
564 * user of the device calls this function, the memory of the device is freed.
565 */
566void usb_put_dev(struct usb_device *dev)
567{
568 if (dev)
569 put_device(&dev->dev);
570}
571EXPORT_SYMBOL_GPL(usb_put_dev);
572
573/**
574 * usb_get_intf - increments the reference count of the usb interface structure
575 * @intf: the interface being referenced
576 *
577 * Each live reference to a interface must be refcounted.
578 *
579 * Drivers for USB interfaces should normally record such references in
580 * their probe() methods, when they bind to an interface, and release
581 * them by calling usb_put_intf(), in their disconnect() methods.
582 *
583 * Return: A pointer to the interface with the incremented reference counter.
584 */
585struct usb_interface *usb_get_intf(struct usb_interface *intf)
586{
587 if (intf)
588 get_device(&intf->dev);
589 return intf;
590}
591EXPORT_SYMBOL_GPL(usb_get_intf);
592
593/**
594 * usb_put_intf - release a use of the usb interface structure
595 * @intf: interface that's been decremented
596 *
597 * Must be called when a user of an interface is finished with it. When the
598 * last user of the interface calls this function, the memory of the interface
599 * is freed.
600 */
601void usb_put_intf(struct usb_interface *intf)
602{
603 if (intf)
604 put_device(&intf->dev);
605}
606EXPORT_SYMBOL_GPL(usb_put_intf);
607
608/* USB device locking
609 *
610 * USB devices and interfaces are locked using the semaphore in their
611 * embedded struct device. The hub driver guarantees that whenever a
612 * device is connected or disconnected, drivers are called with the
613 * USB device locked as well as their particular interface.
614 *
615 * Complications arise when several devices are to be locked at the same
616 * time. Only hub-aware drivers that are part of usbcore ever have to
617 * do this; nobody else needs to worry about it. The rule for locking
618 * is simple:
619 *
620 * When locking both a device and its parent, always lock the
621 * the parent first.
622 */
623
624/**
625 * usb_lock_device_for_reset - cautiously acquire the lock for a usb device structure
626 * @udev: device that's being locked
627 * @iface: interface bound to the driver making the request (optional)
628 *
629 * Attempts to acquire the device lock, but fails if the device is
630 * NOTATTACHED or SUSPENDED, or if iface is specified and the interface
631 * is neither BINDING nor BOUND. Rather than sleeping to wait for the
632 * lock, the routine polls repeatedly. This is to prevent deadlock with
633 * disconnect; in some drivers (such as usb-storage) the disconnect()
634 * or suspend() method will block waiting for a device reset to complete.
635 *
636 * Return: A negative error code for failure, otherwise 0.
637 */
638int usb_lock_device_for_reset(struct usb_device *udev,
639 const struct usb_interface *iface)
640{
641 unsigned long jiffies_expire = jiffies + HZ;
642
643 if (udev->state == USB_STATE_NOTATTACHED)
644 return -ENODEV;
645 if (udev->state == USB_STATE_SUSPENDED)
646 return -EHOSTUNREACH;
647 if (iface && (iface->condition == USB_INTERFACE_UNBINDING ||
648 iface->condition == USB_INTERFACE_UNBOUND))
649 return -EINTR;
650
651 while (!usb_trylock_device(udev)) {
652
653 /* If we can't acquire the lock after waiting one second,
654 * we're probably deadlocked */
655 if (time_after(jiffies, jiffies_expire))
656 return -EBUSY;
657
658 msleep(15);
659 if (udev->state == USB_STATE_NOTATTACHED)
660 return -ENODEV;
661 if (udev->state == USB_STATE_SUSPENDED)
662 return -EHOSTUNREACH;
663 if (iface && (iface->condition == USB_INTERFACE_UNBINDING ||
664 iface->condition == USB_INTERFACE_UNBOUND))
665 return -EINTR;
666 }
667 return 0;
668}
669EXPORT_SYMBOL_GPL(usb_lock_device_for_reset);
670
671/**
672 * usb_get_current_frame_number - return current bus frame number
673 * @dev: the device whose bus is being queried
674 *
675 * Return: The current frame number for the USB host controller used
676 * with the given USB device. This can be used when scheduling
677 * isochronous requests.
678 *
679 * Note: Different kinds of host controller have different "scheduling
680 * horizons". While one type might support scheduling only 32 frames
681 * into the future, others could support scheduling up to 1024 frames
682 * into the future.
683 *
684 */
685int usb_get_current_frame_number(struct usb_device *dev)
686{
687 return usb_hcd_get_frame_number(dev);
688}
689EXPORT_SYMBOL_GPL(usb_get_current_frame_number);
690
691/*-------------------------------------------------------------------*/
692/*
693 * __usb_get_extra_descriptor() finds a descriptor of specific type in the
694 * extra field of the interface and endpoint descriptor structs.
695 */
696
697int __usb_get_extra_descriptor(char *buffer, unsigned size,
698 unsigned char type, void **ptr)
699{
700 struct usb_descriptor_header *header;
701
702 while (size >= sizeof(struct usb_descriptor_header)) {
703 header = (struct usb_descriptor_header *)buffer;
704
705 if (header->bLength < 2) {
706 printk(KERN_ERR
707 "%s: bogus descriptor, type %d length %d\n",
708 usbcore_name,
709 header->bDescriptorType,
710 header->bLength);
711 return -1;
712 }
713
714 if (header->bDescriptorType == type) {
715 *ptr = header;
716 return 0;
717 }
718
719 buffer += header->bLength;
720 size -= header->bLength;
721 }
722 return -1;
723}
724EXPORT_SYMBOL_GPL(__usb_get_extra_descriptor);
725
726/**
727 * usb_alloc_coherent - allocate dma-consistent buffer for URB_NO_xxx_DMA_MAP
728 * @dev: device the buffer will be used with
729 * @size: requested buffer size
730 * @mem_flags: affect whether allocation may block
731 * @dma: used to return DMA address of buffer
732 *
733 * Return: Either null (indicating no buffer could be allocated), or the
734 * cpu-space pointer to a buffer that may be used to perform DMA to the
735 * specified device. Such cpu-space buffers are returned along with the DMA
736 * address (through the pointer provided).
737 *
738 * Note:
739 * These buffers are used with URB_NO_xxx_DMA_MAP set in urb->transfer_flags
740 * to avoid behaviors like using "DMA bounce buffers", or thrashing IOMMU
741 * hardware during URB completion/resubmit. The implementation varies between
742 * platforms, depending on details of how DMA will work to this device.
743 * Using these buffers also eliminates cacheline sharing problems on
744 * architectures where CPU caches are not DMA-coherent. On systems without
745 * bus-snooping caches, these buffers are uncached.
746 *
747 * When the buffer is no longer used, free it with usb_free_coherent().
748 */
749void *usb_alloc_coherent(struct usb_device *dev, size_t size, gfp_t mem_flags,
750 dma_addr_t *dma)
751{
752 if (!dev || !dev->bus)
753 return NULL;
754 return hcd_buffer_alloc(dev->bus, size, mem_flags, dma);
755}
756EXPORT_SYMBOL_GPL(usb_alloc_coherent);
757
758/**
759 * usb_free_coherent - free memory allocated with usb_alloc_coherent()
760 * @dev: device the buffer was used with
761 * @size: requested buffer size
762 * @addr: CPU address of buffer
763 * @dma: DMA address of buffer
764 *
765 * This reclaims an I/O buffer, letting it be reused. The memory must have
766 * been allocated using usb_alloc_coherent(), and the parameters must match
767 * those provided in that allocation request.
768 */
769void usb_free_coherent(struct usb_device *dev, size_t size, void *addr,
770 dma_addr_t dma)
771{
772 if (!dev || !dev->bus)
773 return;
774 if (!addr)
775 return;
776 hcd_buffer_free(dev->bus, size, addr, dma);
777}
778EXPORT_SYMBOL_GPL(usb_free_coherent);
779
780/**
781 * usb_buffer_map - create DMA mapping(s) for an urb
782 * @urb: urb whose transfer_buffer/setup_packet will be mapped
783 *
784 * URB_NO_TRANSFER_DMA_MAP is added to urb->transfer_flags if the operation
785 * succeeds. If the device is connected to this system through a non-DMA
786 * controller, this operation always succeeds.
787 *
788 * This call would normally be used for an urb which is reused, perhaps
789 * as the target of a large periodic transfer, with usb_buffer_dmasync()
790 * calls to synchronize memory and dma state.
791 *
792 * Reverse the effect of this call with usb_buffer_unmap().
793 *
794 * Return: Either %NULL (indicating no buffer could be mapped), or @urb.
795 *
796 */
797#if 0
798struct urb *usb_buffer_map(struct urb *urb)
799{
800 struct usb_bus *bus;
801 struct device *controller;
802
803 if (!urb
804 || !urb->dev
805 || !(bus = urb->dev->bus)
806 || !(controller = bus->controller))
807 return NULL;
808
809 if (controller->dma_mask) {
810 urb->transfer_dma = dma_map_single(controller,
811 urb->transfer_buffer, urb->transfer_buffer_length,
812 usb_pipein(urb->pipe)
813 ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
814 /* FIXME generic api broken like pci, can't report errors */
815 /* if (urb->transfer_dma == DMA_ADDR_INVALID) return 0; */
816 } else
817 urb->transfer_dma = ~0;
818 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
819 return urb;
820}
821EXPORT_SYMBOL_GPL(usb_buffer_map);
822#endif /* 0 */
823
824/* XXX DISABLED, no users currently. If you wish to re-enable this
825 * XXX please determine whether the sync is to transfer ownership of
826 * XXX the buffer from device to cpu or vice verse, and thusly use the
827 * XXX appropriate _for_{cpu,device}() method. -DaveM
828 */
829#if 0
830
831/**
832 * usb_buffer_dmasync - synchronize DMA and CPU view of buffer(s)
833 * @urb: urb whose transfer_buffer/setup_packet will be synchronized
834 */
835void usb_buffer_dmasync(struct urb *urb)
836{
837 struct usb_bus *bus;
838 struct device *controller;
839
840 if (!urb
841 || !(urb->transfer_flags & URB_NO_TRANSFER_DMA_MAP)
842 || !urb->dev
843 || !(bus = urb->dev->bus)
844 || !(controller = bus->controller))
845 return;
846
847 if (controller->dma_mask) {
848 dma_sync_single_for_cpu(controller,
849 urb->transfer_dma, urb->transfer_buffer_length,
850 usb_pipein(urb->pipe)
851 ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
852 if (usb_pipecontrol(urb->pipe))
853 dma_sync_single_for_cpu(controller,
854 urb->setup_dma,
855 sizeof(struct usb_ctrlrequest),
856 DMA_TO_DEVICE);
857 }
858}
859EXPORT_SYMBOL_GPL(usb_buffer_dmasync);
860#endif
861
862/**
863 * usb_buffer_unmap - free DMA mapping(s) for an urb
864 * @urb: urb whose transfer_buffer will be unmapped
865 *
866 * Reverses the effect of usb_buffer_map().
867 */
868#if 0
869void usb_buffer_unmap(struct urb *urb)
870{
871 struct usb_bus *bus;
872 struct device *controller;
873
874 if (!urb
875 || !(urb->transfer_flags & URB_NO_TRANSFER_DMA_MAP)
876 || !urb->dev
877 || !(bus = urb->dev->bus)
878 || !(controller = bus->controller))
879 return;
880
881 if (controller->dma_mask) {
882 dma_unmap_single(controller,
883 urb->transfer_dma, urb->transfer_buffer_length,
884 usb_pipein(urb->pipe)
885 ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
886 }
887 urb->transfer_flags &= ~URB_NO_TRANSFER_DMA_MAP;
888}
889EXPORT_SYMBOL_GPL(usb_buffer_unmap);
890#endif /* 0 */
891
892#if 0
893/**
894 * usb_buffer_map_sg - create scatterlist DMA mapping(s) for an endpoint
895 * @dev: device to which the scatterlist will be mapped
896 * @is_in: mapping transfer direction
897 * @sg: the scatterlist to map
898 * @nents: the number of entries in the scatterlist
899 *
900 * Return: Either < 0 (indicating no buffers could be mapped), or the
901 * number of DMA mapping array entries in the scatterlist.
902 *
903 * Note:
904 * The caller is responsible for placing the resulting DMA addresses from
905 * the scatterlist into URB transfer buffer pointers, and for setting the
906 * URB_NO_TRANSFER_DMA_MAP transfer flag in each of those URBs.
907 *
908 * Top I/O rates come from queuing URBs, instead of waiting for each one
909 * to complete before starting the next I/O. This is particularly easy
910 * to do with scatterlists. Just allocate and submit one URB for each DMA
911 * mapping entry returned, stopping on the first error or when all succeed.
912 * Better yet, use the usb_sg_*() calls, which do that (and more) for you.
913 *
914 * This call would normally be used when translating scatterlist requests,
915 * rather than usb_buffer_map(), since on some hardware (with IOMMUs) it
916 * may be able to coalesce mappings for improved I/O efficiency.
917 *
918 * Reverse the effect of this call with usb_buffer_unmap_sg().
919 */
920int usb_buffer_map_sg(const struct usb_device *dev, int is_in,
921 struct scatterlist *sg, int nents)
922{
923 struct usb_bus *bus;
924 struct device *controller;
925
926 if (!dev
927 || !(bus = dev->bus)
928 || !(controller = bus->controller)
929 || !controller->dma_mask)
930 return -EINVAL;
931
932 /* FIXME generic api broken like pci, can't report errors */
933 return dma_map_sg(controller, sg, nents,
934 is_in ? DMA_FROM_DEVICE : DMA_TO_DEVICE) ? : -ENOMEM;
935}
936EXPORT_SYMBOL_GPL(usb_buffer_map_sg);
937#endif
938
939/* XXX DISABLED, no users currently. If you wish to re-enable this
940 * XXX please determine whether the sync is to transfer ownership of
941 * XXX the buffer from device to cpu or vice verse, and thusly use the
942 * XXX appropriate _for_{cpu,device}() method. -DaveM
943 */
944#if 0
945
946/**
947 * usb_buffer_dmasync_sg - synchronize DMA and CPU view of scatterlist buffer(s)
948 * @dev: device to which the scatterlist will be mapped
949 * @is_in: mapping transfer direction
950 * @sg: the scatterlist to synchronize
951 * @n_hw_ents: the positive return value from usb_buffer_map_sg
952 *
953 * Use this when you are re-using a scatterlist's data buffers for
954 * another USB request.
955 */
956void usb_buffer_dmasync_sg(const struct usb_device *dev, int is_in,
957 struct scatterlist *sg, int n_hw_ents)
958{
959 struct usb_bus *bus;
960 struct device *controller;
961
962 if (!dev
963 || !(bus = dev->bus)
964 || !(controller = bus->controller)
965 || !controller->dma_mask)
966 return;
967
968 dma_sync_sg_for_cpu(controller, sg, n_hw_ents,
969 is_in ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
970}
971EXPORT_SYMBOL_GPL(usb_buffer_dmasync_sg);
972#endif
973
974#if 0
975/**
976 * usb_buffer_unmap_sg - free DMA mapping(s) for a scatterlist
977 * @dev: device to which the scatterlist will be mapped
978 * @is_in: mapping transfer direction
979 * @sg: the scatterlist to unmap
980 * @n_hw_ents: the positive return value from usb_buffer_map_sg
981 *
982 * Reverses the effect of usb_buffer_map_sg().
983 */
984void usb_buffer_unmap_sg(const struct usb_device *dev, int is_in,
985 struct scatterlist *sg, int n_hw_ents)
986{
987 struct usb_bus *bus;
988 struct device *controller;
989
990 if (!dev
991 || !(bus = dev->bus)
992 || !(controller = bus->controller)
993 || !controller->dma_mask)
994 return;
995
996 dma_unmap_sg(controller, sg, n_hw_ents,
997 is_in ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
998}
999EXPORT_SYMBOL_GPL(usb_buffer_unmap_sg);
1000#endif
1001
1002/*
1003 * Notifications of device and interface registration
1004 */
1005static int usb_bus_notify(struct notifier_block *nb, unsigned long action,
1006 void *data)
1007{
1008 struct device *dev = data;
1009
1010 switch (action) {
1011 case BUS_NOTIFY_ADD_DEVICE:
1012 if (dev->type == &usb_device_type)
1013 (void) usb_create_sysfs_dev_files(to_usb_device(dev));
1014 else if (dev->type == &usb_if_device_type)
1015 usb_create_sysfs_intf_files(to_usb_interface(dev));
1016 break;
1017
1018 case BUS_NOTIFY_DEL_DEVICE:
1019 if (dev->type == &usb_device_type)
1020 usb_remove_sysfs_dev_files(to_usb_device(dev));
1021 else if (dev->type == &usb_if_device_type)
1022 usb_remove_sysfs_intf_files(to_usb_interface(dev));
1023 break;
1024 }
1025 return 0;
1026}
1027
1028static struct notifier_block usb_bus_nb = {
1029 .notifier_call = usb_bus_notify,
1030};
1031
1032struct dentry *usb_debug_root;
1033EXPORT_SYMBOL_GPL(usb_debug_root);
1034
1035static struct dentry *usb_debug_devices;
1036
1037static int usb_debugfs_init(void)
1038{
1039 usb_debug_root = debugfs_create_dir("usb", NULL);
1040 if (!usb_debug_root)
1041 return -ENOENT;
1042
1043 usb_debug_devices = debugfs_create_file("devices", 0444,
1044 usb_debug_root, NULL,
1045 &usbfs_devices_fops);
1046 if (!usb_debug_devices) {
1047 debugfs_remove(usb_debug_root);
1048 usb_debug_root = NULL;
1049 return -ENOENT;
1050 }
1051
1052 return 0;
1053}
1054
1055static void usb_debugfs_cleanup(void)
1056{
1057 debugfs_remove(usb_debug_devices);
1058 debugfs_remove(usb_debug_root);
1059}
1060
1061/*
1062 * Init
1063 */
1064static int __init usb_init(void)
1065{
1066 int retval;
1067 if (usb_disabled()) {
1068 pr_info("%s: USB support disabled\n", usbcore_name);
1069 return 0;
1070 }
1071 usb_init_pool_max();
1072
1073 retval = usb_debugfs_init();
1074 if (retval)
1075 goto out;
1076
1077 usb_acpi_register();
1078 retval = bus_register(&usb_bus_type);
1079 if (retval)
1080 goto bus_register_failed;
1081 retval = bus_register_notifier(&usb_bus_type, &usb_bus_nb);
1082 if (retval)
1083 goto bus_notifier_failed;
1084 retval = usb_major_init();
1085 if (retval)
1086 goto major_init_failed;
1087 retval = usb_register(&usbfs_driver);
1088 if (retval)
1089 goto driver_register_failed;
1090 retval = usb_devio_init();
1091 if (retval)
1092 goto usb_devio_init_failed;
1093 retval = usb_hub_init();
1094 if (retval)
1095 goto hub_init_failed;
1096 retval = usb_register_device_driver(&usb_generic_driver, THIS_MODULE);
1097 if (!retval)
1098 goto out;
1099
1100 usb_hub_cleanup();
1101hub_init_failed:
1102 usb_devio_cleanup();
1103usb_devio_init_failed:
1104 usb_deregister(&usbfs_driver);
1105driver_register_failed:
1106 usb_major_cleanup();
1107major_init_failed:
1108 bus_unregister_notifier(&usb_bus_type, &usb_bus_nb);
1109bus_notifier_failed:
1110 bus_unregister(&usb_bus_type);
1111bus_register_failed:
1112 usb_acpi_unregister();
1113 usb_debugfs_cleanup();
1114out:
1115 return retval;
1116}
1117
1118/*
1119 * Cleanup
1120 */
1121static void __exit usb_exit(void)
1122{
1123 /* This will matter if shutdown/reboot does exitcalls. */
1124 if (usb_disabled())
1125 return;
1126
1127 usb_deregister_device_driver(&usb_generic_driver);
1128 usb_major_cleanup();
1129 usb_deregister(&usbfs_driver);
1130 usb_devio_cleanup();
1131 usb_hub_cleanup();
1132 bus_unregister_notifier(&usb_bus_type, &usb_bus_nb);
1133 bus_unregister(&usb_bus_type);
1134 usb_acpi_unregister();
1135 usb_debugfs_cleanup();
1136 idr_destroy(&usb_bus_idr);
1137}
1138
1139subsys_initcall(usb_init);
1140module_exit(usb_exit);
1141MODULE_LICENSE("GPL");
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * drivers/usb/core/usb.c
4 *
5 * (C) Copyright Linus Torvalds 1999
6 * (C) Copyright Johannes Erdfelt 1999-2001
7 * (C) Copyright Andreas Gal 1999
8 * (C) Copyright Gregory P. Smith 1999
9 * (C) Copyright Deti Fliegl 1999 (new USB architecture)
10 * (C) Copyright Randy Dunlap 2000
11 * (C) Copyright David Brownell 2000-2004
12 * (C) Copyright Yggdrasil Computing, Inc. 2000
13 * (usb_device_id matching changes by Adam J. Richter)
14 * (C) Copyright Greg Kroah-Hartman 2002-2003
15 *
16 * Released under the GPLv2 only.
17 *
18 * NOTE! This is not actually a driver at all, rather this is
19 * just a collection of helper routines that implement the
20 * generic USB things that the real drivers can use..
21 *
22 * Think of this as a "USB library" rather than anything else,
23 * with no callbacks. Callbacks are evil.
24 */
25
26#include <linux/module.h>
27#include <linux/moduleparam.h>
28#include <linux/string.h>
29#include <linux/bitops.h>
30#include <linux/slab.h>
31#include <linux/kmod.h>
32#include <linux/init.h>
33#include <linux/spinlock.h>
34#include <linux/errno.h>
35#include <linux/usb.h>
36#include <linux/usb/hcd.h>
37#include <linux/mutex.h>
38#include <linux/workqueue.h>
39#include <linux/debugfs.h>
40#include <linux/usb/of.h>
41
42#include <asm/io.h>
43#include <linux/scatterlist.h>
44#include <linux/mm.h>
45#include <linux/dma-mapping.h>
46
47#include "hub.h"
48
49const char *usbcore_name = "usbcore";
50
51static bool nousb; /* Disable USB when built into kernel image */
52
53module_param(nousb, bool, 0444);
54
55/*
56 * for external read access to <nousb>
57 */
58int usb_disabled(void)
59{
60 return nousb;
61}
62EXPORT_SYMBOL_GPL(usb_disabled);
63
64#ifdef CONFIG_PM
65/* Default delay value, in seconds */
66static int usb_autosuspend_delay = CONFIG_USB_AUTOSUSPEND_DELAY;
67module_param_named(autosuspend, usb_autosuspend_delay, int, 0644);
68MODULE_PARM_DESC(autosuspend, "default autosuspend delay");
69
70#else
71#define usb_autosuspend_delay 0
72#endif
73
74static bool match_endpoint(struct usb_endpoint_descriptor *epd,
75 struct usb_endpoint_descriptor **bulk_in,
76 struct usb_endpoint_descriptor **bulk_out,
77 struct usb_endpoint_descriptor **int_in,
78 struct usb_endpoint_descriptor **int_out)
79{
80 switch (usb_endpoint_type(epd)) {
81 case USB_ENDPOINT_XFER_BULK:
82 if (usb_endpoint_dir_in(epd)) {
83 if (bulk_in && !*bulk_in) {
84 *bulk_in = epd;
85 break;
86 }
87 } else {
88 if (bulk_out && !*bulk_out) {
89 *bulk_out = epd;
90 break;
91 }
92 }
93
94 return false;
95 case USB_ENDPOINT_XFER_INT:
96 if (usb_endpoint_dir_in(epd)) {
97 if (int_in && !*int_in) {
98 *int_in = epd;
99 break;
100 }
101 } else {
102 if (int_out && !*int_out) {
103 *int_out = epd;
104 break;
105 }
106 }
107
108 return false;
109 default:
110 return false;
111 }
112
113 return (!bulk_in || *bulk_in) && (!bulk_out || *bulk_out) &&
114 (!int_in || *int_in) && (!int_out || *int_out);
115}
116
117/**
118 * usb_find_common_endpoints() -- look up common endpoint descriptors
119 * @alt: alternate setting to search
120 * @bulk_in: pointer to descriptor pointer, or NULL
121 * @bulk_out: pointer to descriptor pointer, or NULL
122 * @int_in: pointer to descriptor pointer, or NULL
123 * @int_out: pointer to descriptor pointer, or NULL
124 *
125 * Search the alternate setting's endpoint descriptors for the first bulk-in,
126 * bulk-out, interrupt-in and interrupt-out endpoints and return them in the
127 * provided pointers (unless they are NULL).
128 *
129 * If a requested endpoint is not found, the corresponding pointer is set to
130 * NULL.
131 *
132 * Return: Zero if all requested descriptors were found, or -ENXIO otherwise.
133 */
134int usb_find_common_endpoints(struct usb_host_interface *alt,
135 struct usb_endpoint_descriptor **bulk_in,
136 struct usb_endpoint_descriptor **bulk_out,
137 struct usb_endpoint_descriptor **int_in,
138 struct usb_endpoint_descriptor **int_out)
139{
140 struct usb_endpoint_descriptor *epd;
141 int i;
142
143 if (bulk_in)
144 *bulk_in = NULL;
145 if (bulk_out)
146 *bulk_out = NULL;
147 if (int_in)
148 *int_in = NULL;
149 if (int_out)
150 *int_out = NULL;
151
152 for (i = 0; i < alt->desc.bNumEndpoints; ++i) {
153 epd = &alt->endpoint[i].desc;
154
155 if (match_endpoint(epd, bulk_in, bulk_out, int_in, int_out))
156 return 0;
157 }
158
159 return -ENXIO;
160}
161EXPORT_SYMBOL_GPL(usb_find_common_endpoints);
162
163/**
164 * usb_find_common_endpoints_reverse() -- look up common endpoint descriptors
165 * @alt: alternate setting to search
166 * @bulk_in: pointer to descriptor pointer, or NULL
167 * @bulk_out: pointer to descriptor pointer, or NULL
168 * @int_in: pointer to descriptor pointer, or NULL
169 * @int_out: pointer to descriptor pointer, or NULL
170 *
171 * Search the alternate setting's endpoint descriptors for the last bulk-in,
172 * bulk-out, interrupt-in and interrupt-out endpoints and return them in the
173 * provided pointers (unless they are NULL).
174 *
175 * If a requested endpoint is not found, the corresponding pointer is set to
176 * NULL.
177 *
178 * Return: Zero if all requested descriptors were found, or -ENXIO otherwise.
179 */
180int usb_find_common_endpoints_reverse(struct usb_host_interface *alt,
181 struct usb_endpoint_descriptor **bulk_in,
182 struct usb_endpoint_descriptor **bulk_out,
183 struct usb_endpoint_descriptor **int_in,
184 struct usb_endpoint_descriptor **int_out)
185{
186 struct usb_endpoint_descriptor *epd;
187 int i;
188
189 if (bulk_in)
190 *bulk_in = NULL;
191 if (bulk_out)
192 *bulk_out = NULL;
193 if (int_in)
194 *int_in = NULL;
195 if (int_out)
196 *int_out = NULL;
197
198 for (i = alt->desc.bNumEndpoints - 1; i >= 0; --i) {
199 epd = &alt->endpoint[i].desc;
200
201 if (match_endpoint(epd, bulk_in, bulk_out, int_in, int_out))
202 return 0;
203 }
204
205 return -ENXIO;
206}
207EXPORT_SYMBOL_GPL(usb_find_common_endpoints_reverse);
208
209/**
210 * usb_find_alt_setting() - Given a configuration, find the alternate setting
211 * for the given interface.
212 * @config: the configuration to search (not necessarily the current config).
213 * @iface_num: interface number to search in
214 * @alt_num: alternate interface setting number to search for.
215 *
216 * Search the configuration's interface cache for the given alt setting.
217 *
218 * Return: The alternate setting, if found. %NULL otherwise.
219 */
220struct usb_host_interface *usb_find_alt_setting(
221 struct usb_host_config *config,
222 unsigned int iface_num,
223 unsigned int alt_num)
224{
225 struct usb_interface_cache *intf_cache = NULL;
226 int i;
227
228 if (!config)
229 return NULL;
230 for (i = 0; i < config->desc.bNumInterfaces; i++) {
231 if (config->intf_cache[i]->altsetting[0].desc.bInterfaceNumber
232 == iface_num) {
233 intf_cache = config->intf_cache[i];
234 break;
235 }
236 }
237 if (!intf_cache)
238 return NULL;
239 for (i = 0; i < intf_cache->num_altsetting; i++)
240 if (intf_cache->altsetting[i].desc.bAlternateSetting == alt_num)
241 return &intf_cache->altsetting[i];
242
243 printk(KERN_DEBUG "Did not find alt setting %u for intf %u, "
244 "config %u\n", alt_num, iface_num,
245 config->desc.bConfigurationValue);
246 return NULL;
247}
248EXPORT_SYMBOL_GPL(usb_find_alt_setting);
249
250/**
251 * usb_ifnum_to_if - get the interface object with a given interface number
252 * @dev: the device whose current configuration is considered
253 * @ifnum: the desired interface
254 *
255 * This walks the device descriptor for the currently active configuration
256 * to find the interface object with the particular interface number.
257 *
258 * Note that configuration descriptors are not required to assign interface
259 * numbers sequentially, so that it would be incorrect to assume that
260 * the first interface in that descriptor corresponds to interface zero.
261 * This routine helps device drivers avoid such mistakes.
262 * However, you should make sure that you do the right thing with any
263 * alternate settings available for this interfaces.
264 *
265 * Don't call this function unless you are bound to one of the interfaces
266 * on this device or you have locked the device!
267 *
268 * Return: A pointer to the interface that has @ifnum as interface number,
269 * if found. %NULL otherwise.
270 */
271struct usb_interface *usb_ifnum_to_if(const struct usb_device *dev,
272 unsigned ifnum)
273{
274 struct usb_host_config *config = dev->actconfig;
275 int i;
276
277 if (!config)
278 return NULL;
279 for (i = 0; i < config->desc.bNumInterfaces; i++)
280 if (config->interface[i]->altsetting[0]
281 .desc.bInterfaceNumber == ifnum)
282 return config->interface[i];
283
284 return NULL;
285}
286EXPORT_SYMBOL_GPL(usb_ifnum_to_if);
287
288/**
289 * usb_altnum_to_altsetting - get the altsetting structure with a given alternate setting number.
290 * @intf: the interface containing the altsetting in question
291 * @altnum: the desired alternate setting number
292 *
293 * This searches the altsetting array of the specified interface for
294 * an entry with the correct bAlternateSetting value.
295 *
296 * Note that altsettings need not be stored sequentially by number, so
297 * it would be incorrect to assume that the first altsetting entry in
298 * the array corresponds to altsetting zero. This routine helps device
299 * drivers avoid such mistakes.
300 *
301 * Don't call this function unless you are bound to the intf interface
302 * or you have locked the device!
303 *
304 * Return: A pointer to the entry of the altsetting array of @intf that
305 * has @altnum as the alternate setting number. %NULL if not found.
306 */
307struct usb_host_interface *usb_altnum_to_altsetting(
308 const struct usb_interface *intf,
309 unsigned int altnum)
310{
311 int i;
312
313 for (i = 0; i < intf->num_altsetting; i++) {
314 if (intf->altsetting[i].desc.bAlternateSetting == altnum)
315 return &intf->altsetting[i];
316 }
317 return NULL;
318}
319EXPORT_SYMBOL_GPL(usb_altnum_to_altsetting);
320
321struct find_interface_arg {
322 int minor;
323 struct device_driver *drv;
324};
325
326static int __find_interface(struct device *dev, const void *data)
327{
328 const struct find_interface_arg *arg = data;
329 struct usb_interface *intf;
330
331 if (!is_usb_interface(dev))
332 return 0;
333
334 if (dev->driver != arg->drv)
335 return 0;
336 intf = to_usb_interface(dev);
337 return intf->minor == arg->minor;
338}
339
340/**
341 * usb_find_interface - find usb_interface pointer for driver and device
342 * @drv: the driver whose current configuration is considered
343 * @minor: the minor number of the desired device
344 *
345 * This walks the bus device list and returns a pointer to the interface
346 * with the matching minor and driver. Note, this only works for devices
347 * that share the USB major number.
348 *
349 * Return: A pointer to the interface with the matching major and @minor.
350 */
351struct usb_interface *usb_find_interface(struct usb_driver *drv, int minor)
352{
353 struct find_interface_arg argb;
354 struct device *dev;
355
356 argb.minor = minor;
357 argb.drv = &drv->drvwrap.driver;
358
359 dev = bus_find_device(&usb_bus_type, NULL, &argb, __find_interface);
360
361 /* Drop reference count from bus_find_device */
362 put_device(dev);
363
364 return dev ? to_usb_interface(dev) : NULL;
365}
366EXPORT_SYMBOL_GPL(usb_find_interface);
367
368struct each_dev_arg {
369 void *data;
370 int (*fn)(struct usb_device *, void *);
371};
372
373static int __each_dev(struct device *dev, void *data)
374{
375 struct each_dev_arg *arg = (struct each_dev_arg *)data;
376
377 /* There are struct usb_interface on the same bus, filter them out */
378 if (!is_usb_device(dev))
379 return 0;
380
381 return arg->fn(to_usb_device(dev), arg->data);
382}
383
384/**
385 * usb_for_each_dev - iterate over all USB devices in the system
386 * @data: data pointer that will be handed to the callback function
387 * @fn: callback function to be called for each USB device
388 *
389 * Iterate over all USB devices and call @fn for each, passing it @data. If it
390 * returns anything other than 0, we break the iteration prematurely and return
391 * that value.
392 */
393int usb_for_each_dev(void *data, int (*fn)(struct usb_device *, void *))
394{
395 struct each_dev_arg arg = {data, fn};
396
397 return bus_for_each_dev(&usb_bus_type, NULL, &arg, __each_dev);
398}
399EXPORT_SYMBOL_GPL(usb_for_each_dev);
400
401struct each_hub_arg {
402 void *data;
403 int (*fn)(struct device *, void *);
404};
405
406static int __each_hub(struct usb_device *hdev, void *data)
407{
408 struct each_hub_arg *arg = (struct each_hub_arg *)data;
409 struct usb_hub *hub;
410 int ret = 0;
411 int i;
412
413 hub = usb_hub_to_struct_hub(hdev);
414 if (!hub)
415 return 0;
416
417 mutex_lock(&usb_port_peer_mutex);
418
419 for (i = 0; i < hdev->maxchild; i++) {
420 ret = arg->fn(&hub->ports[i]->dev, arg->data);
421 if (ret)
422 break;
423 }
424
425 mutex_unlock(&usb_port_peer_mutex);
426
427 return ret;
428}
429
430/**
431 * usb_for_each_port - interate over all USB ports in the system
432 * @data: data pointer that will be handed to the callback function
433 * @fn: callback function to be called for each USB port
434 *
435 * Iterate over all USB ports and call @fn for each, passing it @data. If it
436 * returns anything other than 0, we break the iteration prematurely and return
437 * that value.
438 */
439int usb_for_each_port(void *data, int (*fn)(struct device *, void *))
440{
441 struct each_hub_arg arg = {data, fn};
442
443 return usb_for_each_dev(&arg, __each_hub);
444}
445EXPORT_SYMBOL_GPL(usb_for_each_port);
446
447/**
448 * usb_release_dev - free a usb device structure when all users of it are finished.
449 * @dev: device that's been disconnected
450 *
451 * Will be called only by the device core when all users of this usb device are
452 * done.
453 */
454static void usb_release_dev(struct device *dev)
455{
456 struct usb_device *udev;
457 struct usb_hcd *hcd;
458
459 udev = to_usb_device(dev);
460 hcd = bus_to_hcd(udev->bus);
461
462 usb_destroy_configuration(udev);
463 usb_release_bos_descriptor(udev);
464 of_node_put(dev->of_node);
465 usb_put_hcd(hcd);
466 kfree(udev->product);
467 kfree(udev->manufacturer);
468 kfree(udev->serial);
469 kfree(udev);
470}
471
472static int usb_dev_uevent(struct device *dev, struct kobj_uevent_env *env)
473{
474 struct usb_device *usb_dev;
475
476 usb_dev = to_usb_device(dev);
477
478 if (add_uevent_var(env, "BUSNUM=%03d", usb_dev->bus->busnum))
479 return -ENOMEM;
480
481 if (add_uevent_var(env, "DEVNUM=%03d", usb_dev->devnum))
482 return -ENOMEM;
483
484 return 0;
485}
486
487#ifdef CONFIG_PM
488
489/* USB device Power-Management thunks.
490 * There's no need to distinguish here between quiescing a USB device
491 * and powering it down; the generic_suspend() routine takes care of
492 * it by skipping the usb_port_suspend() call for a quiesce. And for
493 * USB interfaces there's no difference at all.
494 */
495
496static int usb_dev_prepare(struct device *dev)
497{
498 return 0; /* Implement eventually? */
499}
500
501static void usb_dev_complete(struct device *dev)
502{
503 /* Currently used only for rebinding interfaces */
504 usb_resume_complete(dev);
505}
506
507static int usb_dev_suspend(struct device *dev)
508{
509 return usb_suspend(dev, PMSG_SUSPEND);
510}
511
512static int usb_dev_resume(struct device *dev)
513{
514 return usb_resume(dev, PMSG_RESUME);
515}
516
517static int usb_dev_freeze(struct device *dev)
518{
519 return usb_suspend(dev, PMSG_FREEZE);
520}
521
522static int usb_dev_thaw(struct device *dev)
523{
524 return usb_resume(dev, PMSG_THAW);
525}
526
527static int usb_dev_poweroff(struct device *dev)
528{
529 return usb_suspend(dev, PMSG_HIBERNATE);
530}
531
532static int usb_dev_restore(struct device *dev)
533{
534 return usb_resume(dev, PMSG_RESTORE);
535}
536
537static const struct dev_pm_ops usb_device_pm_ops = {
538 .prepare = usb_dev_prepare,
539 .complete = usb_dev_complete,
540 .suspend = usb_dev_suspend,
541 .resume = usb_dev_resume,
542 .freeze = usb_dev_freeze,
543 .thaw = usb_dev_thaw,
544 .poweroff = usb_dev_poweroff,
545 .restore = usb_dev_restore,
546 .runtime_suspend = usb_runtime_suspend,
547 .runtime_resume = usb_runtime_resume,
548 .runtime_idle = usb_runtime_idle,
549};
550
551#endif /* CONFIG_PM */
552
553
554static char *usb_devnode(struct device *dev,
555 umode_t *mode, kuid_t *uid, kgid_t *gid)
556{
557 struct usb_device *usb_dev;
558
559 usb_dev = to_usb_device(dev);
560 return kasprintf(GFP_KERNEL, "bus/usb/%03d/%03d",
561 usb_dev->bus->busnum, usb_dev->devnum);
562}
563
564struct device_type usb_device_type = {
565 .name = "usb_device",
566 .release = usb_release_dev,
567 .uevent = usb_dev_uevent,
568 .devnode = usb_devnode,
569#ifdef CONFIG_PM
570 .pm = &usb_device_pm_ops,
571#endif
572};
573
574
575/* Returns 1 if @usb_bus is WUSB, 0 otherwise */
576static unsigned usb_bus_is_wusb(struct usb_bus *bus)
577{
578 struct usb_hcd *hcd = bus_to_hcd(bus);
579 return hcd->wireless;
580}
581
582static bool usb_dev_authorized(struct usb_device *dev, struct usb_hcd *hcd)
583{
584 struct usb_hub *hub;
585
586 if (!dev->parent)
587 return true; /* Root hub always ok [and always wired] */
588
589 switch (hcd->dev_policy) {
590 case USB_DEVICE_AUTHORIZE_NONE:
591 default:
592 return false;
593
594 case USB_DEVICE_AUTHORIZE_ALL:
595 return true;
596
597 case USB_DEVICE_AUTHORIZE_INTERNAL:
598 hub = usb_hub_to_struct_hub(dev->parent);
599 return hub->ports[dev->portnum - 1]->connect_type ==
600 USB_PORT_CONNECT_TYPE_HARD_WIRED;
601 }
602}
603
604/**
605 * usb_alloc_dev - usb device constructor (usbcore-internal)
606 * @parent: hub to which device is connected; null to allocate a root hub
607 * @bus: bus used to access the device
608 * @port1: one-based index of port; ignored for root hubs
609 *
610 * Context: task context, might sleep.
611 *
612 * Only hub drivers (including virtual root hub drivers for host
613 * controllers) should ever call this.
614 *
615 * This call may not be used in a non-sleeping context.
616 *
617 * Return: On success, a pointer to the allocated usb device. %NULL on
618 * failure.
619 */
620struct usb_device *usb_alloc_dev(struct usb_device *parent,
621 struct usb_bus *bus, unsigned port1)
622{
623 struct usb_device *dev;
624 struct usb_hcd *usb_hcd = bus_to_hcd(bus);
625 unsigned root_hub = 0;
626 unsigned raw_port = port1;
627
628 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
629 if (!dev)
630 return NULL;
631
632 if (!usb_get_hcd(usb_hcd)) {
633 kfree(dev);
634 return NULL;
635 }
636 /* Root hubs aren't true devices, so don't allocate HCD resources */
637 if (usb_hcd->driver->alloc_dev && parent &&
638 !usb_hcd->driver->alloc_dev(usb_hcd, dev)) {
639 usb_put_hcd(bus_to_hcd(bus));
640 kfree(dev);
641 return NULL;
642 }
643
644 device_initialize(&dev->dev);
645 dev->dev.bus = &usb_bus_type;
646 dev->dev.type = &usb_device_type;
647 dev->dev.groups = usb_device_groups;
648 set_dev_node(&dev->dev, dev_to_node(bus->sysdev));
649 dev->state = USB_STATE_ATTACHED;
650 dev->lpm_disable_count = 1;
651 atomic_set(&dev->urbnum, 0);
652
653 INIT_LIST_HEAD(&dev->ep0.urb_list);
654 dev->ep0.desc.bLength = USB_DT_ENDPOINT_SIZE;
655 dev->ep0.desc.bDescriptorType = USB_DT_ENDPOINT;
656 /* ep0 maxpacket comes later, from device descriptor */
657 usb_enable_endpoint(dev, &dev->ep0, false);
658 dev->can_submit = 1;
659
660 /* Save readable and stable topology id, distinguishing devices
661 * by location for diagnostics, tools, driver model, etc. The
662 * string is a path along hub ports, from the root. Each device's
663 * dev->devpath will be stable until USB is re-cabled, and hubs
664 * are often labeled with these port numbers. The name isn't
665 * as stable: bus->busnum changes easily from modprobe order,
666 * cardbus or pci hotplugging, and so on.
667 */
668 if (unlikely(!parent)) {
669 dev->devpath[0] = '0';
670 dev->route = 0;
671
672 dev->dev.parent = bus->controller;
673 device_set_of_node_from_dev(&dev->dev, bus->sysdev);
674 dev_set_name(&dev->dev, "usb%d", bus->busnum);
675 root_hub = 1;
676 } else {
677 /* match any labeling on the hubs; it's one-based */
678 if (parent->devpath[0] == '0') {
679 snprintf(dev->devpath, sizeof dev->devpath,
680 "%d", port1);
681 /* Root ports are not counted in route string */
682 dev->route = 0;
683 } else {
684 snprintf(dev->devpath, sizeof dev->devpath,
685 "%s.%d", parent->devpath, port1);
686 /* Route string assumes hubs have less than 16 ports */
687 if (port1 < 15)
688 dev->route = parent->route +
689 (port1 << ((parent->level - 1)*4));
690 else
691 dev->route = parent->route +
692 (15 << ((parent->level - 1)*4));
693 }
694
695 dev->dev.parent = &parent->dev;
696 dev_set_name(&dev->dev, "%d-%s", bus->busnum, dev->devpath);
697
698 if (!parent->parent) {
699 /* device under root hub's port */
700 raw_port = usb_hcd_find_raw_port_number(usb_hcd,
701 port1);
702 }
703 dev->dev.of_node = usb_of_get_device_node(parent, raw_port);
704
705 /* hub driver sets up TT records */
706 }
707
708 dev->portnum = port1;
709 dev->bus = bus;
710 dev->parent = parent;
711 INIT_LIST_HEAD(&dev->filelist);
712
713#ifdef CONFIG_PM
714 pm_runtime_set_autosuspend_delay(&dev->dev,
715 usb_autosuspend_delay * 1000);
716 dev->connect_time = jiffies;
717 dev->active_duration = -jiffies;
718#endif
719
720 dev->authorized = usb_dev_authorized(dev, usb_hcd);
721 if (!root_hub)
722 dev->wusb = usb_bus_is_wusb(bus) ? 1 : 0;
723
724 return dev;
725}
726EXPORT_SYMBOL_GPL(usb_alloc_dev);
727
728/**
729 * usb_get_dev - increments the reference count of the usb device structure
730 * @dev: the device being referenced
731 *
732 * Each live reference to a device should be refcounted.
733 *
734 * Drivers for USB interfaces should normally record such references in
735 * their probe() methods, when they bind to an interface, and release
736 * them by calling usb_put_dev(), in their disconnect() methods.
737 *
738 * Return: A pointer to the device with the incremented reference counter.
739 */
740struct usb_device *usb_get_dev(struct usb_device *dev)
741{
742 if (dev)
743 get_device(&dev->dev);
744 return dev;
745}
746EXPORT_SYMBOL_GPL(usb_get_dev);
747
748/**
749 * usb_put_dev - release a use of the usb device structure
750 * @dev: device that's been disconnected
751 *
752 * Must be called when a user of a device is finished with it. When the last
753 * user of the device calls this function, the memory of the device is freed.
754 */
755void usb_put_dev(struct usb_device *dev)
756{
757 if (dev)
758 put_device(&dev->dev);
759}
760EXPORT_SYMBOL_GPL(usb_put_dev);
761
762/**
763 * usb_get_intf - increments the reference count of the usb interface structure
764 * @intf: the interface being referenced
765 *
766 * Each live reference to a interface must be refcounted.
767 *
768 * Drivers for USB interfaces should normally record such references in
769 * their probe() methods, when they bind to an interface, and release
770 * them by calling usb_put_intf(), in their disconnect() methods.
771 *
772 * Return: A pointer to the interface with the incremented reference counter.
773 */
774struct usb_interface *usb_get_intf(struct usb_interface *intf)
775{
776 if (intf)
777 get_device(&intf->dev);
778 return intf;
779}
780EXPORT_SYMBOL_GPL(usb_get_intf);
781
782/**
783 * usb_put_intf - release a use of the usb interface structure
784 * @intf: interface that's been decremented
785 *
786 * Must be called when a user of an interface is finished with it. When the
787 * last user of the interface calls this function, the memory of the interface
788 * is freed.
789 */
790void usb_put_intf(struct usb_interface *intf)
791{
792 if (intf)
793 put_device(&intf->dev);
794}
795EXPORT_SYMBOL_GPL(usb_put_intf);
796
797/**
798 * usb_intf_get_dma_device - acquire a reference on the usb interface's DMA endpoint
799 * @intf: the usb interface
800 *
801 * While a USB device cannot perform DMA operations by itself, many USB
802 * controllers can. A call to usb_intf_get_dma_device() returns the DMA endpoint
803 * for the given USB interface, if any. The returned device structure must be
804 * released with put_device().
805 *
806 * See also usb_get_dma_device().
807 *
808 * Returns: A reference to the usb interface's DMA endpoint; or NULL if none
809 * exists.
810 */
811struct device *usb_intf_get_dma_device(struct usb_interface *intf)
812{
813 struct usb_device *udev = interface_to_usbdev(intf);
814 struct device *dmadev;
815
816 if (!udev->bus)
817 return NULL;
818
819 dmadev = get_device(udev->bus->sysdev);
820 if (!dmadev || !dmadev->dma_mask) {
821 put_device(dmadev);
822 return NULL;
823 }
824
825 return dmadev;
826}
827EXPORT_SYMBOL_GPL(usb_intf_get_dma_device);
828
829/* USB device locking
830 *
831 * USB devices and interfaces are locked using the semaphore in their
832 * embedded struct device. The hub driver guarantees that whenever a
833 * device is connected or disconnected, drivers are called with the
834 * USB device locked as well as their particular interface.
835 *
836 * Complications arise when several devices are to be locked at the same
837 * time. Only hub-aware drivers that are part of usbcore ever have to
838 * do this; nobody else needs to worry about it. The rule for locking
839 * is simple:
840 *
841 * When locking both a device and its parent, always lock the
842 * the parent first.
843 */
844
845/**
846 * usb_lock_device_for_reset - cautiously acquire the lock for a usb device structure
847 * @udev: device that's being locked
848 * @iface: interface bound to the driver making the request (optional)
849 *
850 * Attempts to acquire the device lock, but fails if the device is
851 * NOTATTACHED or SUSPENDED, or if iface is specified and the interface
852 * is neither BINDING nor BOUND. Rather than sleeping to wait for the
853 * lock, the routine polls repeatedly. This is to prevent deadlock with
854 * disconnect; in some drivers (such as usb-storage) the disconnect()
855 * or suspend() method will block waiting for a device reset to complete.
856 *
857 * Return: A negative error code for failure, otherwise 0.
858 */
859int usb_lock_device_for_reset(struct usb_device *udev,
860 const struct usb_interface *iface)
861{
862 unsigned long jiffies_expire = jiffies + HZ;
863
864 if (udev->state == USB_STATE_NOTATTACHED)
865 return -ENODEV;
866 if (udev->state == USB_STATE_SUSPENDED)
867 return -EHOSTUNREACH;
868 if (iface && (iface->condition == USB_INTERFACE_UNBINDING ||
869 iface->condition == USB_INTERFACE_UNBOUND))
870 return -EINTR;
871
872 while (!usb_trylock_device(udev)) {
873
874 /* If we can't acquire the lock after waiting one second,
875 * we're probably deadlocked */
876 if (time_after(jiffies, jiffies_expire))
877 return -EBUSY;
878
879 msleep(15);
880 if (udev->state == USB_STATE_NOTATTACHED)
881 return -ENODEV;
882 if (udev->state == USB_STATE_SUSPENDED)
883 return -EHOSTUNREACH;
884 if (iface && (iface->condition == USB_INTERFACE_UNBINDING ||
885 iface->condition == USB_INTERFACE_UNBOUND))
886 return -EINTR;
887 }
888 return 0;
889}
890EXPORT_SYMBOL_GPL(usb_lock_device_for_reset);
891
892/**
893 * usb_get_current_frame_number - return current bus frame number
894 * @dev: the device whose bus is being queried
895 *
896 * Return: The current frame number for the USB host controller used
897 * with the given USB device. This can be used when scheduling
898 * isochronous requests.
899 *
900 * Note: Different kinds of host controller have different "scheduling
901 * horizons". While one type might support scheduling only 32 frames
902 * into the future, others could support scheduling up to 1024 frames
903 * into the future.
904 *
905 */
906int usb_get_current_frame_number(struct usb_device *dev)
907{
908 return usb_hcd_get_frame_number(dev);
909}
910EXPORT_SYMBOL_GPL(usb_get_current_frame_number);
911
912/*-------------------------------------------------------------------*/
913/*
914 * __usb_get_extra_descriptor() finds a descriptor of specific type in the
915 * extra field of the interface and endpoint descriptor structs.
916 */
917
918int __usb_get_extra_descriptor(char *buffer, unsigned size,
919 unsigned char type, void **ptr, size_t minsize)
920{
921 struct usb_descriptor_header *header;
922
923 while (size >= sizeof(struct usb_descriptor_header)) {
924 header = (struct usb_descriptor_header *)buffer;
925
926 if (header->bLength < 2 || header->bLength > size) {
927 printk(KERN_ERR
928 "%s: bogus descriptor, type %d length %d\n",
929 usbcore_name,
930 header->bDescriptorType,
931 header->bLength);
932 return -1;
933 }
934
935 if (header->bDescriptorType == type && header->bLength >= minsize) {
936 *ptr = header;
937 return 0;
938 }
939
940 buffer += header->bLength;
941 size -= header->bLength;
942 }
943 return -1;
944}
945EXPORT_SYMBOL_GPL(__usb_get_extra_descriptor);
946
947/**
948 * usb_alloc_coherent - allocate dma-consistent buffer for URB_NO_xxx_DMA_MAP
949 * @dev: device the buffer will be used with
950 * @size: requested buffer size
951 * @mem_flags: affect whether allocation may block
952 * @dma: used to return DMA address of buffer
953 *
954 * Return: Either null (indicating no buffer could be allocated), or the
955 * cpu-space pointer to a buffer that may be used to perform DMA to the
956 * specified device. Such cpu-space buffers are returned along with the DMA
957 * address (through the pointer provided).
958 *
959 * Note:
960 * These buffers are used with URB_NO_xxx_DMA_MAP set in urb->transfer_flags
961 * to avoid behaviors like using "DMA bounce buffers", or thrashing IOMMU
962 * hardware during URB completion/resubmit. The implementation varies between
963 * platforms, depending on details of how DMA will work to this device.
964 * Using these buffers also eliminates cacheline sharing problems on
965 * architectures where CPU caches are not DMA-coherent. On systems without
966 * bus-snooping caches, these buffers are uncached.
967 *
968 * When the buffer is no longer used, free it with usb_free_coherent().
969 */
970void *usb_alloc_coherent(struct usb_device *dev, size_t size, gfp_t mem_flags,
971 dma_addr_t *dma)
972{
973 if (!dev || !dev->bus)
974 return NULL;
975 return hcd_buffer_alloc(dev->bus, size, mem_flags, dma);
976}
977EXPORT_SYMBOL_GPL(usb_alloc_coherent);
978
979/**
980 * usb_free_coherent - free memory allocated with usb_alloc_coherent()
981 * @dev: device the buffer was used with
982 * @size: requested buffer size
983 * @addr: CPU address of buffer
984 * @dma: DMA address of buffer
985 *
986 * This reclaims an I/O buffer, letting it be reused. The memory must have
987 * been allocated using usb_alloc_coherent(), and the parameters must match
988 * those provided in that allocation request.
989 */
990void usb_free_coherent(struct usb_device *dev, size_t size, void *addr,
991 dma_addr_t dma)
992{
993 if (!dev || !dev->bus)
994 return;
995 if (!addr)
996 return;
997 hcd_buffer_free(dev->bus, size, addr, dma);
998}
999EXPORT_SYMBOL_GPL(usb_free_coherent);
1000
1001/*
1002 * Notifications of device and interface registration
1003 */
1004static int usb_bus_notify(struct notifier_block *nb, unsigned long action,
1005 void *data)
1006{
1007 struct device *dev = data;
1008
1009 switch (action) {
1010 case BUS_NOTIFY_ADD_DEVICE:
1011 if (dev->type == &usb_device_type)
1012 (void) usb_create_sysfs_dev_files(to_usb_device(dev));
1013 else if (dev->type == &usb_if_device_type)
1014 usb_create_sysfs_intf_files(to_usb_interface(dev));
1015 break;
1016
1017 case BUS_NOTIFY_DEL_DEVICE:
1018 if (dev->type == &usb_device_type)
1019 usb_remove_sysfs_dev_files(to_usb_device(dev));
1020 else if (dev->type == &usb_if_device_type)
1021 usb_remove_sysfs_intf_files(to_usb_interface(dev));
1022 break;
1023 }
1024 return 0;
1025}
1026
1027static struct notifier_block usb_bus_nb = {
1028 .notifier_call = usb_bus_notify,
1029};
1030
1031static void usb_debugfs_init(void)
1032{
1033 debugfs_create_file("devices", 0444, usb_debug_root, NULL,
1034 &usbfs_devices_fops);
1035}
1036
1037static void usb_debugfs_cleanup(void)
1038{
1039 debugfs_remove(debugfs_lookup("devices", usb_debug_root));
1040}
1041
1042/*
1043 * Init
1044 */
1045static int __init usb_init(void)
1046{
1047 int retval;
1048 if (usb_disabled()) {
1049 pr_info("%s: USB support disabled\n", usbcore_name);
1050 return 0;
1051 }
1052 usb_init_pool_max();
1053
1054 usb_debugfs_init();
1055
1056 usb_acpi_register();
1057 retval = bus_register(&usb_bus_type);
1058 if (retval)
1059 goto bus_register_failed;
1060 retval = bus_register_notifier(&usb_bus_type, &usb_bus_nb);
1061 if (retval)
1062 goto bus_notifier_failed;
1063 retval = usb_major_init();
1064 if (retval)
1065 goto major_init_failed;
1066 retval = usb_register(&usbfs_driver);
1067 if (retval)
1068 goto driver_register_failed;
1069 retval = usb_devio_init();
1070 if (retval)
1071 goto usb_devio_init_failed;
1072 retval = usb_hub_init();
1073 if (retval)
1074 goto hub_init_failed;
1075 retval = usb_register_device_driver(&usb_generic_driver, THIS_MODULE);
1076 if (!retval)
1077 goto out;
1078
1079 usb_hub_cleanup();
1080hub_init_failed:
1081 usb_devio_cleanup();
1082usb_devio_init_failed:
1083 usb_deregister(&usbfs_driver);
1084driver_register_failed:
1085 usb_major_cleanup();
1086major_init_failed:
1087 bus_unregister_notifier(&usb_bus_type, &usb_bus_nb);
1088bus_notifier_failed:
1089 bus_unregister(&usb_bus_type);
1090bus_register_failed:
1091 usb_acpi_unregister();
1092 usb_debugfs_cleanup();
1093out:
1094 return retval;
1095}
1096
1097/*
1098 * Cleanup
1099 */
1100static void __exit usb_exit(void)
1101{
1102 /* This will matter if shutdown/reboot does exitcalls. */
1103 if (usb_disabled())
1104 return;
1105
1106 usb_release_quirk_list();
1107 usb_deregister_device_driver(&usb_generic_driver);
1108 usb_major_cleanup();
1109 usb_deregister(&usbfs_driver);
1110 usb_devio_cleanup();
1111 usb_hub_cleanup();
1112 bus_unregister_notifier(&usb_bus_type, &usb_bus_nb);
1113 bus_unregister(&usb_bus_type);
1114 usb_acpi_unregister();
1115 usb_debugfs_cleanup();
1116 idr_destroy(&usb_bus_idr);
1117}
1118
1119subsys_initcall(usb_init);
1120module_exit(usb_exit);
1121MODULE_LICENSE("GPL");