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