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