2 * drivers/usb/core/usb.c
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
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..
19 * Think of this as a "USB library" rather than anything else.
20 * It should be considered a slave, with no callbacks. Callbacks
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/mutex.h>
36 #include <linux/workqueue.h>
39 #include <asm/scatterlist.h>
41 #include <linux/dma-mapping.h>
47 const char *usbcore_name = "usbcore";
49 static int nousb; /* Disable USB when built into kernel image */
51 /* Workqueue for autosuspend and for remote wakeup of root hubs */
52 struct workqueue_struct *ksuspend_usb_wq;
54 #ifdef CONFIG_USB_SUSPEND
55 static int usb_autosuspend_delay = 2; /* Default delay value,
57 module_param_named(autosuspend, usb_autosuspend_delay, int, 0644);
58 MODULE_PARM_DESC(autosuspend, "default autosuspend delay");
61 #define usb_autosuspend_delay 0
66 * usb_ifnum_to_if - get the interface object with a given interface number
67 * @dev: the device whose current configuration is considered
68 * @ifnum: the desired interface
70 * This walks the device descriptor for the currently active configuration
71 * and returns a pointer to the interface with that particular interface
74 * Note that configuration descriptors are not required to assign interface
75 * numbers sequentially, so that it would be incorrect to assume that
76 * the first interface in that descriptor corresponds to interface zero.
77 * This routine helps device drivers avoid such mistakes.
78 * However, you should make sure that you do the right thing with any
79 * alternate settings available for this interfaces.
81 * Don't call this function unless you are bound to one of the interfaces
82 * on this device or you have locked the device!
84 struct usb_interface *usb_ifnum_to_if(const struct usb_device *dev,
87 struct usb_host_config *config = dev->actconfig;
92 for (i = 0; i < config->desc.bNumInterfaces; i++)
93 if (config->interface[i]->altsetting[0]
94 .desc.bInterfaceNumber == ifnum)
95 return config->interface[i];
101 * usb_altnum_to_altsetting - get the altsetting structure with a given
102 * alternate setting number.
103 * @intf: the interface containing the altsetting in question
104 * @altnum: the desired alternate setting number
106 * This searches the altsetting array of the specified interface for
107 * an entry with the correct bAlternateSetting value and returns a pointer
108 * to that entry, or null.
110 * Note that altsettings need not be stored sequentially by number, so
111 * it would be incorrect to assume that the first altsetting entry in
112 * the array corresponds to altsetting zero. This routine helps device
113 * drivers avoid such mistakes.
115 * Don't call this function unless you are bound to the intf interface
116 * or you have locked the device!
118 struct usb_host_interface *usb_altnum_to_altsetting(const struct usb_interface *intf,
123 for (i = 0; i < intf->num_altsetting; i++) {
124 if (intf->altsetting[i].desc.bAlternateSetting == altnum)
125 return &intf->altsetting[i];
130 struct find_interface_arg {
132 struct usb_interface *interface;
135 static int __find_interface(struct device * dev, void * data)
137 struct find_interface_arg *arg = data;
138 struct usb_interface *intf;
140 /* can't look at usb devices, only interfaces */
141 if (is_usb_device(dev))
144 intf = to_usb_interface(dev);
145 if (intf->minor != -1 && intf->minor == arg->minor) {
146 arg->interface = intf;
153 * usb_find_interface - find usb_interface pointer for driver and device
154 * @drv: the driver whose current configuration is considered
155 * @minor: the minor number of the desired device
157 * This walks the driver device list and returns a pointer to the interface
158 * with the matching minor. Note, this only works for devices that share the
161 struct usb_interface *usb_find_interface(struct usb_driver *drv, int minor)
163 struct find_interface_arg argb;
167 argb.interface = NULL;
168 /* eat the error, it will be in argb.interface */
169 retval = driver_for_each_device(&drv->drvwrap.driver, NULL, &argb,
171 return argb.interface;
175 * usb_release_dev - free a usb device structure when all users of it are finished.
176 * @dev: device that's been disconnected
178 * Will be called only by the device core when all users of this usb device are
181 static void usb_release_dev(struct device *dev)
183 struct usb_device *udev;
185 udev = to_usb_device(dev);
187 #ifdef CONFIG_USB_SUSPEND
188 cancel_delayed_work(&udev->autosuspend);
189 flush_workqueue(ksuspend_usb_wq);
191 usb_destroy_configuration(udev);
192 usb_put_hcd(bus_to_hcd(udev->bus));
193 kfree(udev->product);
194 kfree(udev->manufacturer);
199 struct device_type usb_device_type = {
200 .name = "usb_device",
201 .release = usb_release_dev,
206 static int ksuspend_usb_init(void)
208 /* This workqueue is supposed to be both freezable and
209 * singlethreaded. Its job doesn't justify running on more
212 ksuspend_usb_wq = create_freezeable_workqueue("ksuspend_usbd");
213 if (!ksuspend_usb_wq)
218 static void ksuspend_usb_cleanup(void)
220 destroy_workqueue(ksuspend_usb_wq);
225 #define ksuspend_usb_init() 0
226 #define ksuspend_usb_cleanup() do {} while (0)
228 #endif /* CONFIG_PM */
231 * usb_alloc_dev - usb device constructor (usbcore-internal)
232 * @parent: hub to which device is connected; null to allocate a root hub
233 * @bus: bus used to access the device
234 * @port1: one-based index of port; ignored for root hubs
235 * Context: !in_interrupt()
237 * Only hub drivers (including virtual root hub drivers for host
238 * controllers) should ever call this.
240 * This call may not be used in a non-sleeping context.
243 usb_alloc_dev(struct usb_device *parent, struct usb_bus *bus, unsigned port1)
245 struct usb_device *dev;
247 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
251 if (!usb_get_hcd(bus_to_hcd(bus))) {
256 device_initialize(&dev->dev);
257 dev->dev.bus = &usb_bus_type;
258 dev->dev.type = &usb_device_type;
259 dev->dev.dma_mask = bus->controller->dma_mask;
260 dev->state = USB_STATE_ATTACHED;
262 INIT_LIST_HEAD(&dev->ep0.urb_list);
263 dev->ep0.desc.bLength = USB_DT_ENDPOINT_SIZE;
264 dev->ep0.desc.bDescriptorType = USB_DT_ENDPOINT;
265 /* ep0 maxpacket comes later, from device descriptor */
266 dev->ep_in[0] = dev->ep_out[0] = &dev->ep0;
268 /* Save readable and stable topology id, distinguishing devices
269 * by location for diagnostics, tools, driver model, etc. The
270 * string is a path along hub ports, from the root. Each device's
271 * dev->devpath will be stable until USB is re-cabled, and hubs
272 * are often labeled with these port numbers. The bus_id isn't
273 * as stable: bus->busnum changes easily from modprobe order,
274 * cardbus or pci hotplugging, and so on.
276 if (unlikely(!parent)) {
277 dev->devpath[0] = '0';
279 dev->dev.parent = bus->controller;
280 sprintf(&dev->dev.bus_id[0], "usb%d", bus->busnum);
282 /* match any labeling on the hubs; it's one-based */
283 if (parent->devpath[0] == '0')
284 snprintf(dev->devpath, sizeof dev->devpath,
287 snprintf(dev->devpath, sizeof dev->devpath,
288 "%s.%d", parent->devpath, port1);
290 dev->dev.parent = &parent->dev;
291 sprintf(&dev->dev.bus_id[0], "%d-%s",
292 bus->busnum, dev->devpath);
294 /* hub driver sets up TT records */
297 dev->portnum = port1;
299 dev->parent = parent;
300 INIT_LIST_HEAD(&dev->filelist);
303 mutex_init(&dev->pm_mutex);
304 INIT_DELAYED_WORK(&dev->autosuspend, usb_autosuspend_work);
305 dev->autosuspend_delay = usb_autosuspend_delay * HZ;
311 * usb_get_dev - increments the reference count of the usb device structure
312 * @dev: the device being referenced
314 * Each live reference to a device should be refcounted.
316 * Drivers for USB interfaces should normally record such references in
317 * their probe() methods, when they bind to an interface, and release
318 * them by calling usb_put_dev(), in their disconnect() methods.
320 * A pointer to the device with the incremented reference counter is returned.
322 struct usb_device *usb_get_dev(struct usb_device *dev)
325 get_device(&dev->dev);
330 * usb_put_dev - release a use of the usb device structure
331 * @dev: device that's been disconnected
333 * Must be called when a user of a device is finished with it. When the last
334 * user of the device calls this function, the memory of the device is freed.
336 void usb_put_dev(struct usb_device *dev)
339 put_device(&dev->dev);
343 * usb_get_intf - increments the reference count of the usb interface structure
344 * @intf: the interface being referenced
346 * Each live reference to a interface must be refcounted.
348 * Drivers for USB interfaces should normally record such references in
349 * their probe() methods, when they bind to an interface, and release
350 * them by calling usb_put_intf(), in their disconnect() methods.
352 * A pointer to the interface with the incremented reference counter is
355 struct usb_interface *usb_get_intf(struct usb_interface *intf)
358 get_device(&intf->dev);
363 * usb_put_intf - release a use of the usb interface structure
364 * @intf: interface that's been decremented
366 * Must be called when a user of an interface is finished with it. When the
367 * last user of the interface calls this function, the memory of the interface
370 void usb_put_intf(struct usb_interface *intf)
373 put_device(&intf->dev);
377 /* USB device locking
379 * USB devices and interfaces are locked using the semaphore in their
380 * embedded struct device. The hub driver guarantees that whenever a
381 * device is connected or disconnected, drivers are called with the
382 * USB device locked as well as their particular interface.
384 * Complications arise when several devices are to be locked at the same
385 * time. Only hub-aware drivers that are part of usbcore ever have to
386 * do this; nobody else needs to worry about it. The rule for locking
389 * When locking both a device and its parent, always lock the
394 * usb_lock_device_for_reset - cautiously acquire the lock for a
395 * usb device structure
396 * @udev: device that's being locked
397 * @iface: interface bound to the driver making the request (optional)
399 * Attempts to acquire the device lock, but fails if the device is
400 * NOTATTACHED or SUSPENDED, or if iface is specified and the interface
401 * is neither BINDING nor BOUND. Rather than sleeping to wait for the
402 * lock, the routine polls repeatedly. This is to prevent deadlock with
403 * disconnect; in some drivers (such as usb-storage) the disconnect()
404 * or suspend() method will block waiting for a device reset to complete.
406 * Returns a negative error code for failure, otherwise 1 or 0 to indicate
407 * that the device will or will not have to be unlocked. (0 can be
408 * returned when an interface is given and is BINDING, because in that
409 * case the driver already owns the device lock.)
411 int usb_lock_device_for_reset(struct usb_device *udev,
412 const struct usb_interface *iface)
414 unsigned long jiffies_expire = jiffies + HZ;
416 if (udev->state == USB_STATE_NOTATTACHED)
418 if (udev->state == USB_STATE_SUSPENDED)
419 return -EHOSTUNREACH;
421 switch (iface->condition) {
422 case USB_INTERFACE_BINDING:
424 case USB_INTERFACE_BOUND:
431 while (usb_trylock_device(udev) != 0) {
433 /* If we can't acquire the lock after waiting one second,
434 * we're probably deadlocked */
435 if (time_after(jiffies, jiffies_expire))
439 if (udev->state == USB_STATE_NOTATTACHED)
441 if (udev->state == USB_STATE_SUSPENDED)
442 return -EHOSTUNREACH;
443 if (iface && iface->condition != USB_INTERFACE_BOUND)
450 static struct usb_device *match_device(struct usb_device *dev,
451 u16 vendor_id, u16 product_id)
453 struct usb_device *ret_dev = NULL;
456 dev_dbg(&dev->dev, "check for vendor %04x, product %04x ...\n",
457 le16_to_cpu(dev->descriptor.idVendor),
458 le16_to_cpu(dev->descriptor.idProduct));
460 /* see if this device matches */
461 if ((vendor_id == le16_to_cpu(dev->descriptor.idVendor)) &&
462 (product_id == le16_to_cpu(dev->descriptor.idProduct))) {
463 dev_dbg(&dev->dev, "matched this device!\n");
464 ret_dev = usb_get_dev(dev);
468 /* look through all of the children of this device */
469 for (child = 0; child < dev->maxchild; ++child) {
470 if (dev->children[child]) {
471 usb_lock_device(dev->children[child]);
472 ret_dev = match_device(dev->children[child],
473 vendor_id, product_id);
474 usb_unlock_device(dev->children[child]);
484 * usb_find_device - find a specific usb device in the system
485 * @vendor_id: the vendor id of the device to find
486 * @product_id: the product id of the device to find
488 * Returns a pointer to a struct usb_device if such a specified usb
489 * device is present in the system currently. The usage count of the
490 * device will be incremented if a device is found. Make sure to call
491 * usb_put_dev() when the caller is finished with the device.
493 * If a device with the specified vendor and product id is not found,
496 struct usb_device *usb_find_device(u16 vendor_id, u16 product_id)
498 struct list_head *buslist;
500 struct usb_device *dev = NULL;
502 mutex_lock(&usb_bus_list_lock);
503 for (buslist = usb_bus_list.next;
504 buslist != &usb_bus_list;
505 buslist = buslist->next) {
506 bus = container_of(buslist, struct usb_bus, bus_list);
509 usb_lock_device(bus->root_hub);
510 dev = match_device(bus->root_hub, vendor_id, product_id);
511 usb_unlock_device(bus->root_hub);
516 mutex_unlock(&usb_bus_list_lock);
521 * usb_get_current_frame_number - return current bus frame number
522 * @dev: the device whose bus is being queried
524 * Returns the current frame number for the USB host controller
525 * used with the given USB device. This can be used when scheduling
526 * isochronous requests.
528 * Note that different kinds of host controller have different
529 * "scheduling horizons". While one type might support scheduling only
530 * 32 frames into the future, others could support scheduling up to
531 * 1024 frames into the future.
533 int usb_get_current_frame_number(struct usb_device *dev)
535 return usb_hcd_get_frame_number(dev);
538 /*-------------------------------------------------------------------*/
540 * __usb_get_extra_descriptor() finds a descriptor of specific type in the
541 * extra field of the interface and endpoint descriptor structs.
544 int __usb_get_extra_descriptor(char *buffer, unsigned size,
545 unsigned char type, void **ptr)
547 struct usb_descriptor_header *header;
549 while (size >= sizeof(struct usb_descriptor_header)) {
550 header = (struct usb_descriptor_header *)buffer;
552 if (header->bLength < 2) {
554 "%s: bogus descriptor, type %d length %d\n",
556 header->bDescriptorType,
561 if (header->bDescriptorType == type) {
566 buffer += header->bLength;
567 size -= header->bLength;
573 * usb_buffer_alloc - allocate dma-consistent buffer for URB_NO_xxx_DMA_MAP
574 * @dev: device the buffer will be used with
575 * @size: requested buffer size
576 * @mem_flags: affect whether allocation may block
577 * @dma: used to return DMA address of buffer
579 * Return value is either null (indicating no buffer could be allocated), or
580 * the cpu-space pointer to a buffer that may be used to perform DMA to the
581 * specified device. Such cpu-space buffers are returned along with the DMA
582 * address (through the pointer provided).
584 * These buffers are used with URB_NO_xxx_DMA_MAP set in urb->transfer_flags
585 * to avoid behaviors like using "DMA bounce buffers", or tying down I/O
586 * mapping hardware for long idle periods. The implementation varies between
587 * platforms, depending on details of how DMA will work to this device.
588 * Using these buffers also helps prevent cacheline sharing problems on
589 * architectures where CPU caches are not DMA-coherent.
591 * When the buffer is no longer used, free it with usb_buffer_free().
593 void *usb_buffer_alloc(
594 struct usb_device *dev,
600 if (!dev || !dev->bus)
602 return hcd_buffer_alloc(dev->bus, size, mem_flags, dma);
606 * usb_buffer_free - free memory allocated with usb_buffer_alloc()
607 * @dev: device the buffer was used with
608 * @size: requested buffer size
609 * @addr: CPU address of buffer
610 * @dma: DMA address of buffer
612 * This reclaims an I/O buffer, letting it be reused. The memory must have
613 * been allocated using usb_buffer_alloc(), and the parameters must match
614 * those provided in that allocation request.
616 void usb_buffer_free(
617 struct usb_device *dev,
623 if (!dev || !dev->bus)
627 hcd_buffer_free(dev->bus, size, addr, dma);
631 * usb_buffer_map - create DMA mapping(s) for an urb
632 * @urb: urb whose transfer_buffer/setup_packet will be mapped
634 * Return value is either null (indicating no buffer could be mapped), or
635 * the parameter. URB_NO_TRANSFER_DMA_MAP and URB_NO_SETUP_DMA_MAP are
636 * added to urb->transfer_flags if the operation succeeds. If the device
637 * is connected to this system through a non-DMA controller, this operation
640 * This call would normally be used for an urb which is reused, perhaps
641 * as the target of a large periodic transfer, with usb_buffer_dmasync()
642 * calls to synchronize memory and dma state.
644 * Reverse the effect of this call with usb_buffer_unmap().
647 struct urb *usb_buffer_map(struct urb *urb)
650 struct device *controller;
654 || !(bus = urb->dev->bus)
655 || !(controller = bus->controller))
658 if (controller->dma_mask) {
659 urb->transfer_dma = dma_map_single(controller,
660 urb->transfer_buffer, urb->transfer_buffer_length,
661 usb_pipein(urb->pipe)
662 ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
663 if (usb_pipecontrol(urb->pipe))
664 urb->setup_dma = dma_map_single(controller,
666 sizeof(struct usb_ctrlrequest),
668 // FIXME generic api broken like pci, can't report errors
669 // if (urb->transfer_dma == DMA_ADDR_INVALID) return 0;
671 urb->transfer_dma = ~0;
672 urb->transfer_flags |= (URB_NO_TRANSFER_DMA_MAP
673 | URB_NO_SETUP_DMA_MAP);
678 /* XXX DISABLED, no users currently. If you wish to re-enable this
679 * XXX please determine whether the sync is to transfer ownership of
680 * XXX the buffer from device to cpu or vice verse, and thusly use the
681 * XXX appropriate _for_{cpu,device}() method. -DaveM
686 * usb_buffer_dmasync - synchronize DMA and CPU view of buffer(s)
687 * @urb: urb whose transfer_buffer/setup_packet will be synchronized
689 void usb_buffer_dmasync(struct urb *urb)
692 struct device *controller;
695 || !(urb->transfer_flags & URB_NO_TRANSFER_DMA_MAP)
697 || !(bus = urb->dev->bus)
698 || !(controller = bus->controller))
701 if (controller->dma_mask) {
702 dma_sync_single(controller,
703 urb->transfer_dma, urb->transfer_buffer_length,
704 usb_pipein(urb->pipe)
705 ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
706 if (usb_pipecontrol(urb->pipe))
707 dma_sync_single(controller,
709 sizeof(struct usb_ctrlrequest),
716 * usb_buffer_unmap - free DMA mapping(s) for an urb
717 * @urb: urb whose transfer_buffer will be unmapped
719 * Reverses the effect of usb_buffer_map().
722 void usb_buffer_unmap(struct urb *urb)
725 struct device *controller;
728 || !(urb->transfer_flags & URB_NO_TRANSFER_DMA_MAP)
730 || !(bus = urb->dev->bus)
731 || !(controller = bus->controller))
734 if (controller->dma_mask) {
735 dma_unmap_single(controller,
736 urb->transfer_dma, urb->transfer_buffer_length,
737 usb_pipein(urb->pipe)
738 ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
739 if (usb_pipecontrol(urb->pipe))
740 dma_unmap_single(controller,
742 sizeof(struct usb_ctrlrequest),
745 urb->transfer_flags &= ~(URB_NO_TRANSFER_DMA_MAP
746 | URB_NO_SETUP_DMA_MAP);
751 * usb_buffer_map_sg - create scatterlist DMA mapping(s) for an endpoint
752 * @dev: device to which the scatterlist will be mapped
753 * @pipe: endpoint defining the mapping direction
754 * @sg: the scatterlist to map
755 * @nents: the number of entries in the scatterlist
757 * Return value is either < 0 (indicating no buffers could be mapped), or
758 * the number of DMA mapping array entries in the scatterlist.
760 * The caller is responsible for placing the resulting DMA addresses from
761 * the scatterlist into URB transfer buffer pointers, and for setting the
762 * URB_NO_TRANSFER_DMA_MAP transfer flag in each of those URBs.
764 * Top I/O rates come from queuing URBs, instead of waiting for each one
765 * to complete before starting the next I/O. This is particularly easy
766 * to do with scatterlists. Just allocate and submit one URB for each DMA
767 * mapping entry returned, stopping on the first error or when all succeed.
768 * Better yet, use the usb_sg_*() calls, which do that (and more) for you.
770 * This call would normally be used when translating scatterlist requests,
771 * rather than usb_buffer_map(), since on some hardware (with IOMMUs) it
772 * may be able to coalesce mappings for improved I/O efficiency.
774 * Reverse the effect of this call with usb_buffer_unmap_sg().
776 int usb_buffer_map_sg(const struct usb_device *dev, unsigned pipe,
777 struct scatterlist *sg, int nents)
780 struct device *controller;
783 || usb_pipecontrol(pipe)
785 || !(controller = bus->controller)
786 || !controller->dma_mask)
789 // FIXME generic api broken like pci, can't report errors
790 return dma_map_sg(controller, sg, nents,
791 usb_pipein(pipe) ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
794 /* XXX DISABLED, no users currently. If you wish to re-enable this
795 * XXX please determine whether the sync is to transfer ownership of
796 * XXX the buffer from device to cpu or vice verse, and thusly use the
797 * XXX appropriate _for_{cpu,device}() method. -DaveM
802 * usb_buffer_dmasync_sg - synchronize DMA and CPU view of scatterlist buffer(s)
803 * @dev: device to which the scatterlist will be mapped
804 * @pipe: endpoint defining the mapping direction
805 * @sg: the scatterlist to synchronize
806 * @n_hw_ents: the positive return value from usb_buffer_map_sg
808 * Use this when you are re-using a scatterlist's data buffers for
809 * another USB request.
811 void usb_buffer_dmasync_sg(const struct usb_device *dev, unsigned pipe,
812 struct scatterlist *sg, int n_hw_ents)
815 struct device *controller;
819 || !(controller = bus->controller)
820 || !controller->dma_mask)
823 dma_sync_sg(controller, sg, n_hw_ents,
824 usb_pipein(pipe) ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
829 * usb_buffer_unmap_sg - free DMA mapping(s) for a scatterlist
830 * @dev: device to which the scatterlist will be mapped
831 * @pipe: endpoint defining the mapping direction
832 * @sg: the scatterlist to unmap
833 * @n_hw_ents: the positive return value from usb_buffer_map_sg
835 * Reverses the effect of usb_buffer_map_sg().
837 void usb_buffer_unmap_sg(const struct usb_device *dev, unsigned pipe,
838 struct scatterlist *sg, int n_hw_ents)
841 struct device *controller;
845 || !(controller = bus->controller)
846 || !controller->dma_mask)
849 dma_unmap_sg(controller, sg, n_hw_ents,
850 usb_pipein(pipe) ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
853 /* format to disable USB on kernel command line is: nousb */
854 __module_param_call("", nousb, param_set_bool, param_get_bool, &nousb, 0444);
857 * for external read access to <nousb>
859 int usb_disabled(void)
867 static int __init usb_init(void)
871 pr_info("%s: USB support disabled\n", usbcore_name);
875 retval = ksuspend_usb_init();
878 retval = bus_register(&usb_bus_type);
880 goto bus_register_failed;
881 retval = usb_host_init();
883 goto host_init_failed;
884 retval = usb_major_init();
886 goto major_init_failed;
887 retval = usb_register(&usbfs_driver);
889 goto driver_register_failed;
890 retval = usb_devio_init();
892 goto usb_devio_init_failed;
893 retval = usbfs_init();
896 retval = usb_hub_init();
898 goto hub_init_failed;
899 retval = usb_register_device_driver(&usb_generic_driver, THIS_MODULE);
908 usb_devio_init_failed:
909 usb_deregister(&usbfs_driver);
910 driver_register_failed:
915 bus_unregister(&usb_bus_type);
917 ksuspend_usb_cleanup();
925 static void __exit usb_exit(void)
927 /* This will matter if shutdown/reboot does exitcalls. */
931 usb_deregister_device_driver(&usb_generic_driver);
934 usb_deregister(&usbfs_driver);
938 bus_unregister(&usb_bus_type);
939 ksuspend_usb_cleanup();
942 subsys_initcall(usb_init);
943 module_exit(usb_exit);
946 * USB may be built into the kernel or be built as modules.
947 * These symbols are exported for device (or host controller)
948 * driver modules to use.
951 EXPORT_SYMBOL(usb_disabled);
953 EXPORT_SYMBOL_GPL(usb_get_intf);
954 EXPORT_SYMBOL_GPL(usb_put_intf);
956 EXPORT_SYMBOL(usb_put_dev);
957 EXPORT_SYMBOL(usb_get_dev);
958 EXPORT_SYMBOL(usb_hub_tt_clear_buffer);
960 EXPORT_SYMBOL(usb_lock_device_for_reset);
962 EXPORT_SYMBOL(usb_find_interface);
963 EXPORT_SYMBOL(usb_ifnum_to_if);
964 EXPORT_SYMBOL(usb_altnum_to_altsetting);
966 EXPORT_SYMBOL(__usb_get_extra_descriptor);
968 EXPORT_SYMBOL(usb_find_device);
969 EXPORT_SYMBOL(usb_get_current_frame_number);
971 EXPORT_SYMBOL(usb_buffer_alloc);
972 EXPORT_SYMBOL(usb_buffer_free);
975 EXPORT_SYMBOL(usb_buffer_map);
976 EXPORT_SYMBOL(usb_buffer_dmasync);
977 EXPORT_SYMBOL(usb_buffer_unmap);
980 EXPORT_SYMBOL(usb_buffer_map_sg);
982 EXPORT_SYMBOL(usb_buffer_dmasync_sg);
984 EXPORT_SYMBOL(usb_buffer_unmap_sg);
986 MODULE_LICENSE("GPL");