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/string.h>
26 #include <linux/bitops.h>
27 #include <linux/slab.h>
28 #include <linux/interrupt.h> /* for in_interrupt() */
29 #include <linux/kmod.h>
30 #include <linux/init.h>
31 #include <linux/spinlock.h>
32 #include <linux/errno.h>
33 #include <linux/smp_lock.h>
34 #include <linux/usb.h>
35 #include <linux/mutex.h>
38 #include <asm/scatterlist.h>
40 #include <linux/dma-mapping.h>
46 const char *usbcore_name
= "usbcore";
48 static int nousb
; /* Disable USB when built into kernel image */
52 * usb_ifnum_to_if - get the interface object with a given interface number
53 * @dev: the device whose current configuration is considered
54 * @ifnum: the desired interface
56 * This walks the device descriptor for the currently active configuration
57 * and returns a pointer to the interface with that particular interface
60 * Note that configuration descriptors are not required to assign interface
61 * numbers sequentially, so that it would be incorrect to assume that
62 * the first interface in that descriptor corresponds to interface zero.
63 * This routine helps device drivers avoid such mistakes.
64 * However, you should make sure that you do the right thing with any
65 * alternate settings available for this interfaces.
67 * Don't call this function unless you are bound to one of the interfaces
68 * on this device or you have locked the device!
70 struct usb_interface
*usb_ifnum_to_if(struct usb_device
*dev
, unsigned ifnum
)
72 struct usb_host_config
*config
= dev
->actconfig
;
77 for (i
= 0; i
< config
->desc
.bNumInterfaces
; i
++)
78 if (config
->interface
[i
]->altsetting
[0]
79 .desc
.bInterfaceNumber
== ifnum
)
80 return config
->interface
[i
];
86 * usb_altnum_to_altsetting - get the altsetting structure with a given
87 * alternate setting number.
88 * @intf: the interface containing the altsetting in question
89 * @altnum: the desired alternate setting number
91 * This searches the altsetting array of the specified interface for
92 * an entry with the correct bAlternateSetting value and returns a pointer
93 * to that entry, or null.
95 * Note that altsettings need not be stored sequentially by number, so
96 * it would be incorrect to assume that the first altsetting entry in
97 * the array corresponds to altsetting zero. This routine helps device
98 * drivers avoid such mistakes.
100 * Don't call this function unless you are bound to the intf interface
101 * or you have locked the device!
103 struct usb_host_interface
*usb_altnum_to_altsetting(struct usb_interface
*intf
,
108 for (i
= 0; i
< intf
->num_altsetting
; i
++) {
109 if (intf
->altsetting
[i
].desc
.bAlternateSetting
== altnum
)
110 return &intf
->altsetting
[i
];
115 struct find_interface_arg
{
117 struct usb_interface
*interface
;
120 static int __find_interface(struct device
* dev
, void * data
)
122 struct find_interface_arg
*arg
= data
;
123 struct usb_interface
*intf
;
125 /* can't look at usb devices, only interfaces */
126 if (is_usb_device(dev
))
129 intf
= to_usb_interface(dev
);
130 if (intf
->minor
!= -1 && intf
->minor
== arg
->minor
) {
131 arg
->interface
= intf
;
138 * usb_find_interface - find usb_interface pointer for driver and device
139 * @drv: the driver whose current configuration is considered
140 * @minor: the minor number of the desired device
142 * This walks the driver device list and returns a pointer to the interface
143 * with the matching minor. Note, this only works for devices that share the
146 struct usb_interface
*usb_find_interface(struct usb_driver
*drv
, int minor
)
148 struct find_interface_arg argb
;
151 argb
.interface
= NULL
;
152 driver_for_each_device(&drv
->drvwrap
.driver
, NULL
, &argb
,
154 return argb
.interface
;
158 * usb_release_dev - free a usb device structure when all users of it are finished.
159 * @dev: device that's been disconnected
161 * Will be called only by the device core when all users of this usb device are
164 static void usb_release_dev(struct device
*dev
)
166 struct usb_device
*udev
;
168 udev
= to_usb_device(dev
);
170 usb_destroy_configuration(udev
);
171 usb_bus_put(udev
->bus
);
172 kfree(udev
->product
);
173 kfree(udev
->manufacturer
);
179 * usb_alloc_dev - usb device constructor (usbcore-internal)
180 * @parent: hub to which device is connected; null to allocate a root hub
181 * @bus: bus used to access the device
182 * @port1: one-based index of port; ignored for root hubs
183 * Context: !in_interrupt ()
185 * Only hub drivers (including virtual root hub drivers for host
186 * controllers) should ever call this.
188 * This call may not be used in a non-sleeping context.
191 usb_alloc_dev(struct usb_device
*parent
, struct usb_bus
*bus
, unsigned port1
)
193 struct usb_device
*dev
;
195 dev
= kzalloc(sizeof(*dev
), GFP_KERNEL
);
199 bus
= usb_bus_get(bus
);
205 device_initialize(&dev
->dev
);
206 dev
->dev
.bus
= &usb_bus_type
;
207 dev
->dev
.dma_mask
= bus
->controller
->dma_mask
;
208 dev
->dev
.release
= usb_release_dev
;
209 dev
->state
= USB_STATE_ATTACHED
;
211 /* This magic assignment distinguishes devices from interfaces */
212 dev
->dev
.platform_data
= &usb_generic_driver
;
214 INIT_LIST_HEAD(&dev
->ep0
.urb_list
);
215 dev
->ep0
.desc
.bLength
= USB_DT_ENDPOINT_SIZE
;
216 dev
->ep0
.desc
.bDescriptorType
= USB_DT_ENDPOINT
;
217 /* ep0 maxpacket comes later, from device descriptor */
218 dev
->ep_in
[0] = dev
->ep_out
[0] = &dev
->ep0
;
220 /* Save readable and stable topology id, distinguishing devices
221 * by location for diagnostics, tools, driver model, etc. The
222 * string is a path along hub ports, from the root. Each device's
223 * dev->devpath will be stable until USB is re-cabled, and hubs
224 * are often labeled with these port numbers. The bus_id isn't
225 * as stable: bus->busnum changes easily from modprobe order,
226 * cardbus or pci hotplugging, and so on.
228 if (unlikely (!parent
)) {
229 dev
->devpath
[0] = '0';
231 dev
->dev
.parent
= bus
->controller
;
232 sprintf (&dev
->dev
.bus_id
[0], "usb%d", bus
->busnum
);
234 /* match any labeling on the hubs; it's one-based */
235 if (parent
->devpath
[0] == '0')
236 snprintf (dev
->devpath
, sizeof dev
->devpath
,
239 snprintf (dev
->devpath
, sizeof dev
->devpath
,
240 "%s.%d", parent
->devpath
, port1
);
242 dev
->dev
.parent
= &parent
->dev
;
243 sprintf (&dev
->dev
.bus_id
[0], "%d-%s",
244 bus
->busnum
, dev
->devpath
);
246 /* hub driver sets up TT records */
249 dev
->portnum
= port1
;
251 dev
->parent
= parent
;
252 INIT_LIST_HEAD(&dev
->filelist
);
258 * usb_get_dev - increments the reference count of the usb device structure
259 * @dev: the device being referenced
261 * Each live reference to a device should be refcounted.
263 * Drivers for USB interfaces should normally record such references in
264 * their probe() methods, when they bind to an interface, and release
265 * them by calling usb_put_dev(), in their disconnect() methods.
267 * A pointer to the device with the incremented reference counter is returned.
269 struct usb_device
*usb_get_dev(struct usb_device
*dev
)
272 get_device(&dev
->dev
);
277 * usb_put_dev - release a use of the usb device structure
278 * @dev: device that's been disconnected
280 * Must be called when a user of a device is finished with it. When the last
281 * user of the device calls this function, the memory of the device is freed.
283 void usb_put_dev(struct usb_device
*dev
)
286 put_device(&dev
->dev
);
290 * usb_get_intf - increments the reference count of the usb interface structure
291 * @intf: the interface being referenced
293 * Each live reference to a interface must be refcounted.
295 * Drivers for USB interfaces should normally record such references in
296 * their probe() methods, when they bind to an interface, and release
297 * them by calling usb_put_intf(), in their disconnect() methods.
299 * A pointer to the interface with the incremented reference counter is
302 struct usb_interface
*usb_get_intf(struct usb_interface
*intf
)
305 get_device(&intf
->dev
);
310 * usb_put_intf - release a use of the usb interface structure
311 * @intf: interface that's been decremented
313 * Must be called when a user of an interface is finished with it. When the
314 * last user of the interface calls this function, the memory of the interface
317 void usb_put_intf(struct usb_interface
*intf
)
320 put_device(&intf
->dev
);
324 /* USB device locking
326 * USB devices and interfaces are locked using the semaphore in their
327 * embedded struct device. The hub driver guarantees that whenever a
328 * device is connected or disconnected, drivers are called with the
329 * USB device locked as well as their particular interface.
331 * Complications arise when several devices are to be locked at the same
332 * time. Only hub-aware drivers that are part of usbcore ever have to
333 * do this; nobody else needs to worry about it. The rule for locking
336 * When locking both a device and its parent, always lock the
341 * usb_lock_device_for_reset - cautiously acquire the lock for a
342 * usb device structure
343 * @udev: device that's being locked
344 * @iface: interface bound to the driver making the request (optional)
346 * Attempts to acquire the device lock, but fails if the device is
347 * NOTATTACHED or SUSPENDED, or if iface is specified and the interface
348 * is neither BINDING nor BOUND. Rather than sleeping to wait for the
349 * lock, the routine polls repeatedly. This is to prevent deadlock with
350 * disconnect; in some drivers (such as usb-storage) the disconnect()
351 * or suspend() method will block waiting for a device reset to complete.
353 * Returns a negative error code for failure, otherwise 1 or 0 to indicate
354 * that the device will or will not have to be unlocked. (0 can be
355 * returned when an interface is given and is BINDING, because in that
356 * case the driver already owns the device lock.)
358 int usb_lock_device_for_reset(struct usb_device
*udev
,
359 struct usb_interface
*iface
)
361 unsigned long jiffies_expire
= jiffies
+ HZ
;
363 if (udev
->state
== USB_STATE_NOTATTACHED
)
365 if (udev
->state
== USB_STATE_SUSPENDED
)
366 return -EHOSTUNREACH
;
368 switch (iface
->condition
) {
369 case USB_INTERFACE_BINDING
:
371 case USB_INTERFACE_BOUND
:
378 while (usb_trylock_device(udev
) != 0) {
380 /* If we can't acquire the lock after waiting one second,
381 * we're probably deadlocked */
382 if (time_after(jiffies
, jiffies_expire
))
386 if (udev
->state
== USB_STATE_NOTATTACHED
)
388 if (udev
->state
== USB_STATE_SUSPENDED
)
389 return -EHOSTUNREACH
;
390 if (iface
&& iface
->condition
!= USB_INTERFACE_BOUND
)
397 static struct usb_device
*match_device(struct usb_device
*dev
,
398 u16 vendor_id
, u16 product_id
)
400 struct usb_device
*ret_dev
= NULL
;
403 dev_dbg(&dev
->dev
, "check for vendor %04x, product %04x ...\n",
404 le16_to_cpu(dev
->descriptor
.idVendor
),
405 le16_to_cpu(dev
->descriptor
.idProduct
));
407 /* see if this device matches */
408 if ((vendor_id
== le16_to_cpu(dev
->descriptor
.idVendor
)) &&
409 (product_id
== le16_to_cpu(dev
->descriptor
.idProduct
))) {
410 dev_dbg (&dev
->dev
, "matched this device!\n");
411 ret_dev
= usb_get_dev(dev
);
415 /* look through all of the children of this device */
416 for (child
= 0; child
< dev
->maxchild
; ++child
) {
417 if (dev
->children
[child
]) {
418 usb_lock_device(dev
->children
[child
]);
419 ret_dev
= match_device(dev
->children
[child
],
420 vendor_id
, product_id
);
421 usb_unlock_device(dev
->children
[child
]);
431 * usb_find_device - find a specific usb device in the system
432 * @vendor_id: the vendor id of the device to find
433 * @product_id: the product id of the device to find
435 * Returns a pointer to a struct usb_device if such a specified usb
436 * device is present in the system currently. The usage count of the
437 * device will be incremented if a device is found. Make sure to call
438 * usb_put_dev() when the caller is finished with the device.
440 * If a device with the specified vendor and product id is not found,
443 struct usb_device
*usb_find_device(u16 vendor_id
, u16 product_id
)
445 struct list_head
*buslist
;
447 struct usb_device
*dev
= NULL
;
449 mutex_lock(&usb_bus_list_lock
);
450 for (buslist
= usb_bus_list
.next
;
451 buslist
!= &usb_bus_list
;
452 buslist
= buslist
->next
) {
453 bus
= container_of(buslist
, struct usb_bus
, bus_list
);
456 usb_lock_device(bus
->root_hub
);
457 dev
= match_device(bus
->root_hub
, vendor_id
, product_id
);
458 usb_unlock_device(bus
->root_hub
);
463 mutex_unlock(&usb_bus_list_lock
);
468 * usb_get_current_frame_number - return current bus frame number
469 * @dev: the device whose bus is being queried
471 * Returns the current frame number for the USB host controller
472 * used with the given USB device. This can be used when scheduling
473 * isochronous requests.
475 * Note that different kinds of host controller have different
476 * "scheduling horizons". While one type might support scheduling only
477 * 32 frames into the future, others could support scheduling up to
478 * 1024 frames into the future.
480 int usb_get_current_frame_number(struct usb_device
*dev
)
482 return dev
->bus
->op
->get_frame_number (dev
);
485 /*-------------------------------------------------------------------*/
487 * __usb_get_extra_descriptor() finds a descriptor of specific type in the
488 * extra field of the interface and endpoint descriptor structs.
491 int __usb_get_extra_descriptor(char *buffer
, unsigned size
,
492 unsigned char type
, void **ptr
)
494 struct usb_descriptor_header
*header
;
496 while (size
>= sizeof(struct usb_descriptor_header
)) {
497 header
= (struct usb_descriptor_header
*)buffer
;
499 if (header
->bLength
< 2) {
501 "%s: bogus descriptor, type %d length %d\n",
503 header
->bDescriptorType
,
508 if (header
->bDescriptorType
== type
) {
513 buffer
+= header
->bLength
;
514 size
-= header
->bLength
;
520 * usb_buffer_alloc - allocate dma-consistent buffer for URB_NO_xxx_DMA_MAP
521 * @dev: device the buffer will be used with
522 * @size: requested buffer size
523 * @mem_flags: affect whether allocation may block
524 * @dma: used to return DMA address of buffer
526 * Return value is either null (indicating no buffer could be allocated), or
527 * the cpu-space pointer to a buffer that may be used to perform DMA to the
528 * specified device. Such cpu-space buffers are returned along with the DMA
529 * address (through the pointer provided).
531 * These buffers are used with URB_NO_xxx_DMA_MAP set in urb->transfer_flags
532 * to avoid behaviors like using "DMA bounce buffers", or tying down I/O
533 * mapping hardware for long idle periods. The implementation varies between
534 * platforms, depending on details of how DMA will work to this device.
535 * Using these buffers also helps prevent cacheline sharing problems on
536 * architectures where CPU caches are not DMA-coherent.
538 * When the buffer is no longer used, free it with usb_buffer_free().
540 void *usb_buffer_alloc (
541 struct usb_device
*dev
,
547 if (!dev
|| !dev
->bus
|| !dev
->bus
->op
|| !dev
->bus
->op
->buffer_alloc
)
549 return dev
->bus
->op
->buffer_alloc (dev
->bus
, size
, mem_flags
, dma
);
553 * usb_buffer_free - free memory allocated with usb_buffer_alloc()
554 * @dev: device the buffer was used with
555 * @size: requested buffer size
556 * @addr: CPU address of buffer
557 * @dma: DMA address of buffer
559 * This reclaims an I/O buffer, letting it be reused. The memory must have
560 * been allocated using usb_buffer_alloc(), and the parameters must match
561 * those provided in that allocation request.
563 void usb_buffer_free (
564 struct usb_device
*dev
,
570 if (!dev
|| !dev
->bus
|| !dev
->bus
->op
|| !dev
->bus
->op
->buffer_free
)
574 dev
->bus
->op
->buffer_free (dev
->bus
, size
, addr
, dma
);
578 * usb_buffer_map - create DMA mapping(s) for an urb
579 * @urb: urb whose transfer_buffer/setup_packet will be mapped
581 * Return value is either null (indicating no buffer could be mapped), or
582 * the parameter. URB_NO_TRANSFER_DMA_MAP and URB_NO_SETUP_DMA_MAP are
583 * added to urb->transfer_flags if the operation succeeds. If the device
584 * is connected to this system through a non-DMA controller, this operation
587 * This call would normally be used for an urb which is reused, perhaps
588 * as the target of a large periodic transfer, with usb_buffer_dmasync()
589 * calls to synchronize memory and dma state.
591 * Reverse the effect of this call with usb_buffer_unmap().
594 struct urb
*usb_buffer_map (struct urb
*urb
)
597 struct device
*controller
;
601 || !(bus
= urb
->dev
->bus
)
602 || !(controller
= bus
->controller
))
605 if (controller
->dma_mask
) {
606 urb
->transfer_dma
= dma_map_single (controller
,
607 urb
->transfer_buffer
, urb
->transfer_buffer_length
,
608 usb_pipein (urb
->pipe
)
609 ? DMA_FROM_DEVICE
: DMA_TO_DEVICE
);
610 if (usb_pipecontrol (urb
->pipe
))
611 urb
->setup_dma
= dma_map_single (controller
,
613 sizeof (struct usb_ctrlrequest
),
615 // FIXME generic api broken like pci, can't report errors
616 // if (urb->transfer_dma == DMA_ADDR_INVALID) return 0;
618 urb
->transfer_dma
= ~0;
619 urb
->transfer_flags
|= (URB_NO_TRANSFER_DMA_MAP
620 | URB_NO_SETUP_DMA_MAP
);
625 /* XXX DISABLED, no users currently. If you wish to re-enable this
626 * XXX please determine whether the sync is to transfer ownership of
627 * XXX the buffer from device to cpu or vice verse, and thusly use the
628 * XXX appropriate _for_{cpu,device}() method. -DaveM
633 * usb_buffer_dmasync - synchronize DMA and CPU view of buffer(s)
634 * @urb: urb whose transfer_buffer/setup_packet will be synchronized
636 void usb_buffer_dmasync (struct urb
*urb
)
639 struct device
*controller
;
642 || !(urb
->transfer_flags
& URB_NO_TRANSFER_DMA_MAP
)
644 || !(bus
= urb
->dev
->bus
)
645 || !(controller
= bus
->controller
))
648 if (controller
->dma_mask
) {
649 dma_sync_single (controller
,
650 urb
->transfer_dma
, urb
->transfer_buffer_length
,
651 usb_pipein (urb
->pipe
)
652 ? DMA_FROM_DEVICE
: DMA_TO_DEVICE
);
653 if (usb_pipecontrol (urb
->pipe
))
654 dma_sync_single (controller
,
656 sizeof (struct usb_ctrlrequest
),
663 * usb_buffer_unmap - free DMA mapping(s) for an urb
664 * @urb: urb whose transfer_buffer will be unmapped
666 * Reverses the effect of usb_buffer_map().
669 void usb_buffer_unmap (struct urb
*urb
)
672 struct device
*controller
;
675 || !(urb
->transfer_flags
& URB_NO_TRANSFER_DMA_MAP
)
677 || !(bus
= urb
->dev
->bus
)
678 || !(controller
= bus
->controller
))
681 if (controller
->dma_mask
) {
682 dma_unmap_single (controller
,
683 urb
->transfer_dma
, urb
->transfer_buffer_length
,
684 usb_pipein (urb
->pipe
)
685 ? DMA_FROM_DEVICE
: DMA_TO_DEVICE
);
686 if (usb_pipecontrol (urb
->pipe
))
687 dma_unmap_single (controller
,
689 sizeof (struct usb_ctrlrequest
),
692 urb
->transfer_flags
&= ~(URB_NO_TRANSFER_DMA_MAP
693 | URB_NO_SETUP_DMA_MAP
);
698 * usb_buffer_map_sg - create scatterlist DMA mapping(s) for an endpoint
699 * @dev: device to which the scatterlist will be mapped
700 * @pipe: endpoint defining the mapping direction
701 * @sg: the scatterlist to map
702 * @nents: the number of entries in the scatterlist
704 * Return value is either < 0 (indicating no buffers could be mapped), or
705 * the number of DMA mapping array entries in the scatterlist.
707 * The caller is responsible for placing the resulting DMA addresses from
708 * the scatterlist into URB transfer buffer pointers, and for setting the
709 * URB_NO_TRANSFER_DMA_MAP transfer flag in each of those URBs.
711 * Top I/O rates come from queuing URBs, instead of waiting for each one
712 * to complete before starting the next I/O. This is particularly easy
713 * to do with scatterlists. Just allocate and submit one URB for each DMA
714 * mapping entry returned, stopping on the first error or when all succeed.
715 * Better yet, use the usb_sg_*() calls, which do that (and more) for you.
717 * This call would normally be used when translating scatterlist requests,
718 * rather than usb_buffer_map(), since on some hardware (with IOMMUs) it
719 * may be able to coalesce mappings for improved I/O efficiency.
721 * Reverse the effect of this call with usb_buffer_unmap_sg().
723 int usb_buffer_map_sg (struct usb_device
*dev
, unsigned pipe
,
724 struct scatterlist
*sg
, int nents
)
727 struct device
*controller
;
730 || usb_pipecontrol (pipe
)
732 || !(controller
= bus
->controller
)
733 || !controller
->dma_mask
)
736 // FIXME generic api broken like pci, can't report errors
737 return dma_map_sg (controller
, sg
, nents
,
738 usb_pipein (pipe
) ? DMA_FROM_DEVICE
: DMA_TO_DEVICE
);
741 /* XXX DISABLED, no users currently. If you wish to re-enable this
742 * XXX please determine whether the sync is to transfer ownership of
743 * XXX the buffer from device to cpu or vice verse, and thusly use the
744 * XXX appropriate _for_{cpu,device}() method. -DaveM
749 * usb_buffer_dmasync_sg - synchronize DMA and CPU view of scatterlist buffer(s)
750 * @dev: device to which the scatterlist will be mapped
751 * @pipe: endpoint defining the mapping direction
752 * @sg: the scatterlist to synchronize
753 * @n_hw_ents: the positive return value from usb_buffer_map_sg
755 * Use this when you are re-using a scatterlist's data buffers for
756 * another USB request.
758 void usb_buffer_dmasync_sg (struct usb_device
*dev
, unsigned pipe
,
759 struct scatterlist
*sg
, int n_hw_ents
)
762 struct device
*controller
;
766 || !(controller
= bus
->controller
)
767 || !controller
->dma_mask
)
770 dma_sync_sg (controller
, sg
, n_hw_ents
,
771 usb_pipein (pipe
) ? DMA_FROM_DEVICE
: DMA_TO_DEVICE
);
776 * usb_buffer_unmap_sg - free DMA mapping(s) for a scatterlist
777 * @dev: device to which the scatterlist will be mapped
778 * @pipe: endpoint defining the mapping direction
779 * @sg: the scatterlist to unmap
780 * @n_hw_ents: the positive return value from usb_buffer_map_sg
782 * Reverses the effect of usb_buffer_map_sg().
784 void usb_buffer_unmap_sg (struct usb_device
*dev
, unsigned pipe
,
785 struct scatterlist
*sg
, int n_hw_ents
)
788 struct device
*controller
;
792 || !(controller
= bus
->controller
)
793 || !controller
->dma_mask
)
796 dma_unmap_sg (controller
, sg
, n_hw_ents
,
797 usb_pipein (pipe
) ? DMA_FROM_DEVICE
: DMA_TO_DEVICE
);
800 /* format to disable USB on kernel command line is: nousb */
801 __module_param_call("", nousb
, param_set_bool
, param_get_bool
, &nousb
, 0444);
804 * for external read access to <nousb>
806 int usb_disabled(void)
814 static int __init
usb_init(void)
818 pr_info ("%s: USB support disabled\n", usbcore_name
);
822 retval
= bus_register(&usb_bus_type
);
825 retval
= usb_host_init();
827 goto host_init_failed
;
828 retval
= usb_major_init();
830 goto major_init_failed
;
831 retval
= usb_register(&usbfs_driver
);
833 goto driver_register_failed
;
834 retval
= usbdev_init();
836 goto usbdevice_init_failed
;
837 retval
= usbfs_init();
840 retval
= usb_hub_init();
842 goto hub_init_failed
;
843 retval
= usb_register_device_driver(&usb_generic_driver
, THIS_MODULE
);
852 usbdevice_init_failed
:
853 usb_deregister(&usbfs_driver
);
854 driver_register_failed
:
859 bus_unregister(&usb_bus_type
);
867 static void __exit
usb_exit(void)
869 /* This will matter if shutdown/reboot does exitcalls. */
873 usb_deregister_device_driver(&usb_generic_driver
);
876 usb_deregister(&usbfs_driver
);
880 bus_unregister(&usb_bus_type
);
883 subsys_initcall(usb_init
);
884 module_exit(usb_exit
);
887 * USB may be built into the kernel or be built as modules.
888 * These symbols are exported for device (or host controller)
889 * driver modules to use.
892 EXPORT_SYMBOL(usb_disabled
);
894 EXPORT_SYMBOL_GPL(usb_get_intf
);
895 EXPORT_SYMBOL_GPL(usb_put_intf
);
897 EXPORT_SYMBOL(usb_put_dev
);
898 EXPORT_SYMBOL(usb_get_dev
);
899 EXPORT_SYMBOL(usb_hub_tt_clear_buffer
);
901 EXPORT_SYMBOL(usb_lock_device_for_reset
);
903 EXPORT_SYMBOL(usb_find_interface
);
904 EXPORT_SYMBOL(usb_ifnum_to_if
);
905 EXPORT_SYMBOL(usb_altnum_to_altsetting
);
907 EXPORT_SYMBOL(__usb_get_extra_descriptor
);
909 EXPORT_SYMBOL(usb_find_device
);
910 EXPORT_SYMBOL(usb_get_current_frame_number
);
912 EXPORT_SYMBOL (usb_buffer_alloc
);
913 EXPORT_SYMBOL (usb_buffer_free
);
916 EXPORT_SYMBOL (usb_buffer_map
);
917 EXPORT_SYMBOL (usb_buffer_dmasync
);
918 EXPORT_SYMBOL (usb_buffer_unmap
);
921 EXPORT_SYMBOL (usb_buffer_map_sg
);
923 EXPORT_SYMBOL (usb_buffer_dmasync_sg
);
925 EXPORT_SYMBOL (usb_buffer_unmap_sg
);
927 MODULE_LICENSE("GPL");