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/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>
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 struct workqueue_struct
*ksuspend_usb_wq
; /* For autosuspend */
55 * usb_ifnum_to_if - get the interface object with a given interface number
56 * @dev: the device whose current configuration is considered
57 * @ifnum: the desired interface
59 * This walks the device descriptor for the currently active configuration
60 * and returns a pointer to the interface with that particular interface
63 * Note that configuration descriptors are not required to assign interface
64 * numbers sequentially, so that it would be incorrect to assume that
65 * the first interface in that descriptor corresponds to interface zero.
66 * This routine helps device drivers avoid such mistakes.
67 * However, you should make sure that you do the right thing with any
68 * alternate settings available for this interfaces.
70 * Don't call this function unless you are bound to one of the interfaces
71 * on this device or you have locked the device!
73 struct usb_interface
*usb_ifnum_to_if(const struct usb_device
*dev
,
76 struct usb_host_config
*config
= dev
->actconfig
;
81 for (i
= 0; i
< config
->desc
.bNumInterfaces
; i
++)
82 if (config
->interface
[i
]->altsetting
[0]
83 .desc
.bInterfaceNumber
== ifnum
)
84 return config
->interface
[i
];
90 * usb_altnum_to_altsetting - get the altsetting structure with a given
91 * alternate setting number.
92 * @intf: the interface containing the altsetting in question
93 * @altnum: the desired alternate setting number
95 * This searches the altsetting array of the specified interface for
96 * an entry with the correct bAlternateSetting value and returns a pointer
97 * to that entry, or null.
99 * Note that altsettings need not be stored sequentially by number, so
100 * it would be incorrect to assume that the first altsetting entry in
101 * the array corresponds to altsetting zero. This routine helps device
102 * drivers avoid such mistakes.
104 * Don't call this function unless you are bound to the intf interface
105 * or you have locked the device!
107 struct usb_host_interface
*usb_altnum_to_altsetting(const struct usb_interface
*intf
,
112 for (i
= 0; i
< intf
->num_altsetting
; i
++) {
113 if (intf
->altsetting
[i
].desc
.bAlternateSetting
== altnum
)
114 return &intf
->altsetting
[i
];
119 struct find_interface_arg
{
121 struct usb_interface
*interface
;
124 static int __find_interface(struct device
* dev
, void * data
)
126 struct find_interface_arg
*arg
= data
;
127 struct usb_interface
*intf
;
129 /* can't look at usb devices, only interfaces */
130 if (is_usb_device(dev
))
133 intf
= to_usb_interface(dev
);
134 if (intf
->minor
!= -1 && intf
->minor
== arg
->minor
) {
135 arg
->interface
= intf
;
142 * usb_find_interface - find usb_interface pointer for driver and device
143 * @drv: the driver whose current configuration is considered
144 * @minor: the minor number of the desired device
146 * This walks the driver device list and returns a pointer to the interface
147 * with the matching minor. Note, this only works for devices that share the
150 struct usb_interface
*usb_find_interface(struct usb_driver
*drv
, int minor
)
152 struct find_interface_arg argb
;
156 argb
.interface
= NULL
;
157 /* eat the error, it will be in argb.interface */
158 retval
= driver_for_each_device(&drv
->drvwrap
.driver
, NULL
, &argb
,
160 return argb
.interface
;
164 * usb_release_dev - free a usb device structure when all users of it are finished.
165 * @dev: device that's been disconnected
167 * Will be called only by the device core when all users of this usb device are
170 static void usb_release_dev(struct device
*dev
)
172 struct usb_device
*udev
;
174 udev
= to_usb_device(dev
);
176 #ifdef CONFIG_USB_SUSPEND
177 cancel_delayed_work(&udev
->autosuspend
);
178 flush_workqueue(ksuspend_usb_wq
);
180 usb_destroy_configuration(udev
);
181 usb_put_hcd(bus_to_hcd(udev
->bus
));
182 kfree(udev
->product
);
183 kfree(udev
->manufacturer
);
190 static int ksuspend_usb_init(void)
192 ksuspend_usb_wq
= create_singlethread_workqueue("ksuspend_usbd");
193 if (!ksuspend_usb_wq
)
198 static void ksuspend_usb_cleanup(void)
200 destroy_workqueue(ksuspend_usb_wq
);
203 #ifdef CONFIG_USB_SUSPEND
205 /* usb_autosuspend_work - callback routine to autosuspend a USB device */
206 static void usb_autosuspend_work(void *_udev
)
208 struct usb_device
*udev
= _udev
;
212 usb_suspend_both(udev
, PMSG_SUSPEND
);
218 static void usb_autosuspend_work(void *_udev
)
221 #endif /* CONFIG_USB_SUSPEND */
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
.dma_mask
= bus
->controller
->dma_mask
;
259 dev
->dev
.release
= usb_release_dev
;
260 dev
->state
= USB_STATE_ATTACHED
;
262 /* This magic assignment distinguishes devices from interfaces */
263 dev
->dev
.platform_data
= &usb_generic_driver
;
265 INIT_LIST_HEAD(&dev
->ep0
.urb_list
);
266 dev
->ep0
.desc
.bLength
= USB_DT_ENDPOINT_SIZE
;
267 dev
->ep0
.desc
.bDescriptorType
= USB_DT_ENDPOINT
;
268 /* ep0 maxpacket comes later, from device descriptor */
269 dev
->ep_in
[0] = dev
->ep_out
[0] = &dev
->ep0
;
271 /* Save readable and stable topology id, distinguishing devices
272 * by location for diagnostics, tools, driver model, etc. The
273 * string is a path along hub ports, from the root. Each device's
274 * dev->devpath will be stable until USB is re-cabled, and hubs
275 * are often labeled with these port numbers. The bus_id isn't
276 * as stable: bus->busnum changes easily from modprobe order,
277 * cardbus or pci hotplugging, and so on.
279 if (unlikely (!parent
)) {
280 dev
->devpath
[0] = '0';
282 dev
->dev
.parent
= bus
->controller
;
283 sprintf (&dev
->dev
.bus_id
[0], "usb%d", bus
->busnum
);
285 /* match any labeling on the hubs; it's one-based */
286 if (parent
->devpath
[0] == '0')
287 snprintf (dev
->devpath
, sizeof dev
->devpath
,
290 snprintf (dev
->devpath
, sizeof dev
->devpath
,
291 "%s.%d", parent
->devpath
, port1
);
293 dev
->dev
.parent
= &parent
->dev
;
294 sprintf (&dev
->dev
.bus_id
[0], "%d-%s",
295 bus
->busnum
, dev
->devpath
);
297 /* hub driver sets up TT records */
300 dev
->portnum
= port1
;
302 dev
->parent
= parent
;
303 INIT_LIST_HEAD(&dev
->filelist
);
306 mutex_init(&dev
->pm_mutex
);
307 INIT_WORK(&dev
->autosuspend
, usb_autosuspend_work
, dev
);
313 * usb_get_dev - increments the reference count of the usb device structure
314 * @dev: the device being referenced
316 * Each live reference to a device should be refcounted.
318 * Drivers for USB interfaces should normally record such references in
319 * their probe() methods, when they bind to an interface, and release
320 * them by calling usb_put_dev(), in their disconnect() methods.
322 * A pointer to the device with the incremented reference counter is returned.
324 struct usb_device
*usb_get_dev(struct usb_device
*dev
)
327 get_device(&dev
->dev
);
332 * usb_put_dev - release a use of the usb device structure
333 * @dev: device that's been disconnected
335 * Must be called when a user of a device is finished with it. When the last
336 * user of the device calls this function, the memory of the device is freed.
338 void usb_put_dev(struct usb_device
*dev
)
341 put_device(&dev
->dev
);
345 * usb_get_intf - increments the reference count of the usb interface structure
346 * @intf: the interface being referenced
348 * Each live reference to a interface must be refcounted.
350 * Drivers for USB interfaces should normally record such references in
351 * their probe() methods, when they bind to an interface, and release
352 * them by calling usb_put_intf(), in their disconnect() methods.
354 * A pointer to the interface with the incremented reference counter is
357 struct usb_interface
*usb_get_intf(struct usb_interface
*intf
)
360 get_device(&intf
->dev
);
365 * usb_put_intf - release a use of the usb interface structure
366 * @intf: interface that's been decremented
368 * Must be called when a user of an interface is finished with it. When the
369 * last user of the interface calls this function, the memory of the interface
372 void usb_put_intf(struct usb_interface
*intf
)
375 put_device(&intf
->dev
);
379 /* USB device locking
381 * USB devices and interfaces are locked using the semaphore in their
382 * embedded struct device. The hub driver guarantees that whenever a
383 * device is connected or disconnected, drivers are called with the
384 * USB device locked as well as their particular interface.
386 * Complications arise when several devices are to be locked at the same
387 * time. Only hub-aware drivers that are part of usbcore ever have to
388 * do this; nobody else needs to worry about it. The rule for locking
391 * When locking both a device and its parent, always lock the
396 * usb_lock_device_for_reset - cautiously acquire the lock for a
397 * usb device structure
398 * @udev: device that's being locked
399 * @iface: interface bound to the driver making the request (optional)
401 * Attempts to acquire the device lock, but fails if the device is
402 * NOTATTACHED or SUSPENDED, or if iface is specified and the interface
403 * is neither BINDING nor BOUND. Rather than sleeping to wait for the
404 * lock, the routine polls repeatedly. This is to prevent deadlock with
405 * disconnect; in some drivers (such as usb-storage) the disconnect()
406 * or suspend() method will block waiting for a device reset to complete.
408 * Returns a negative error code for failure, otherwise 1 or 0 to indicate
409 * that the device will or will not have to be unlocked. (0 can be
410 * returned when an interface is given and is BINDING, because in that
411 * case the driver already owns the device lock.)
413 int usb_lock_device_for_reset(struct usb_device
*udev
,
414 const struct usb_interface
*iface
)
416 unsigned long jiffies_expire
= jiffies
+ HZ
;
418 if (udev
->state
== USB_STATE_NOTATTACHED
)
420 if (udev
->state
== USB_STATE_SUSPENDED
)
421 return -EHOSTUNREACH
;
423 switch (iface
->condition
) {
424 case USB_INTERFACE_BINDING
:
426 case USB_INTERFACE_BOUND
:
433 while (usb_trylock_device(udev
) != 0) {
435 /* If we can't acquire the lock after waiting one second,
436 * we're probably deadlocked */
437 if (time_after(jiffies
, jiffies_expire
))
441 if (udev
->state
== USB_STATE_NOTATTACHED
)
443 if (udev
->state
== USB_STATE_SUSPENDED
)
444 return -EHOSTUNREACH
;
445 if (iface
&& iface
->condition
!= USB_INTERFACE_BOUND
)
452 static struct usb_device
*match_device(struct usb_device
*dev
,
453 u16 vendor_id
, u16 product_id
)
455 struct usb_device
*ret_dev
= NULL
;
458 dev_dbg(&dev
->dev
, "check for vendor %04x, product %04x ...\n",
459 le16_to_cpu(dev
->descriptor
.idVendor
),
460 le16_to_cpu(dev
->descriptor
.idProduct
));
462 /* see if this device matches */
463 if ((vendor_id
== le16_to_cpu(dev
->descriptor
.idVendor
)) &&
464 (product_id
== le16_to_cpu(dev
->descriptor
.idProduct
))) {
465 dev_dbg (&dev
->dev
, "matched this device!\n");
466 ret_dev
= usb_get_dev(dev
);
470 /* look through all of the children of this device */
471 for (child
= 0; child
< dev
->maxchild
; ++child
) {
472 if (dev
->children
[child
]) {
473 usb_lock_device(dev
->children
[child
]);
474 ret_dev
= match_device(dev
->children
[child
],
475 vendor_id
, product_id
);
476 usb_unlock_device(dev
->children
[child
]);
486 * usb_find_device - find a specific usb device in the system
487 * @vendor_id: the vendor id of the device to find
488 * @product_id: the product id of the device to find
490 * Returns a pointer to a struct usb_device if such a specified usb
491 * device is present in the system currently. The usage count of the
492 * device will be incremented if a device is found. Make sure to call
493 * usb_put_dev() when the caller is finished with the device.
495 * If a device with the specified vendor and product id is not found,
498 struct usb_device
*usb_find_device(u16 vendor_id
, u16 product_id
)
500 struct list_head
*buslist
;
502 struct usb_device
*dev
= NULL
;
504 mutex_lock(&usb_bus_list_lock
);
505 for (buslist
= usb_bus_list
.next
;
506 buslist
!= &usb_bus_list
;
507 buslist
= buslist
->next
) {
508 bus
= container_of(buslist
, struct usb_bus
, bus_list
);
511 usb_lock_device(bus
->root_hub
);
512 dev
= match_device(bus
->root_hub
, vendor_id
, product_id
);
513 usb_unlock_device(bus
->root_hub
);
518 mutex_unlock(&usb_bus_list_lock
);
523 * usb_get_current_frame_number - return current bus frame number
524 * @dev: the device whose bus is being queried
526 * Returns the current frame number for the USB host controller
527 * used with the given USB device. This can be used when scheduling
528 * isochronous requests.
530 * Note that different kinds of host controller have different
531 * "scheduling horizons". While one type might support scheduling only
532 * 32 frames into the future, others could support scheduling up to
533 * 1024 frames into the future.
535 int usb_get_current_frame_number(struct usb_device
*dev
)
537 return usb_hcd_get_frame_number (dev
);
540 /*-------------------------------------------------------------------*/
542 * __usb_get_extra_descriptor() finds a descriptor of specific type in the
543 * extra field of the interface and endpoint descriptor structs.
546 int __usb_get_extra_descriptor(char *buffer
, unsigned size
,
547 unsigned char type
, void **ptr
)
549 struct usb_descriptor_header
*header
;
551 while (size
>= sizeof(struct usb_descriptor_header
)) {
552 header
= (struct usb_descriptor_header
*)buffer
;
554 if (header
->bLength
< 2) {
556 "%s: bogus descriptor, type %d length %d\n",
558 header
->bDescriptorType
,
563 if (header
->bDescriptorType
== type
) {
568 buffer
+= header
->bLength
;
569 size
-= header
->bLength
;
575 * usb_buffer_alloc - allocate dma-consistent buffer for URB_NO_xxx_DMA_MAP
576 * @dev: device the buffer will be used with
577 * @size: requested buffer size
578 * @mem_flags: affect whether allocation may block
579 * @dma: used to return DMA address of buffer
581 * Return value is either null (indicating no buffer could be allocated), or
582 * the cpu-space pointer to a buffer that may be used to perform DMA to the
583 * specified device. Such cpu-space buffers are returned along with the DMA
584 * address (through the pointer provided).
586 * These buffers are used with URB_NO_xxx_DMA_MAP set in urb->transfer_flags
587 * to avoid behaviors like using "DMA bounce buffers", or tying down I/O
588 * mapping hardware for long idle periods. The implementation varies between
589 * platforms, depending on details of how DMA will work to this device.
590 * Using these buffers also helps prevent cacheline sharing problems on
591 * architectures where CPU caches are not DMA-coherent.
593 * When the buffer is no longer used, free it with usb_buffer_free().
595 void *usb_buffer_alloc (
596 struct usb_device
*dev
,
602 if (!dev
|| !dev
->bus
)
604 return hcd_buffer_alloc (dev
->bus
, size
, mem_flags
, dma
);
608 * usb_buffer_free - free memory allocated with usb_buffer_alloc()
609 * @dev: device the buffer was used with
610 * @size: requested buffer size
611 * @addr: CPU address of buffer
612 * @dma: DMA address of buffer
614 * This reclaims an I/O buffer, letting it be reused. The memory must have
615 * been allocated using usb_buffer_alloc(), and the parameters must match
616 * those provided in that allocation request.
618 void usb_buffer_free (
619 struct usb_device
*dev
,
625 if (!dev
|| !dev
->bus
)
629 hcd_buffer_free (dev
->bus
, size
, addr
, dma
);
633 * usb_buffer_map - create DMA mapping(s) for an urb
634 * @urb: urb whose transfer_buffer/setup_packet will be mapped
636 * Return value is either null (indicating no buffer could be mapped), or
637 * the parameter. URB_NO_TRANSFER_DMA_MAP and URB_NO_SETUP_DMA_MAP are
638 * added to urb->transfer_flags if the operation succeeds. If the device
639 * is connected to this system through a non-DMA controller, this operation
642 * This call would normally be used for an urb which is reused, perhaps
643 * as the target of a large periodic transfer, with usb_buffer_dmasync()
644 * calls to synchronize memory and dma state.
646 * Reverse the effect of this call with usb_buffer_unmap().
649 struct urb
*usb_buffer_map (struct urb
*urb
)
652 struct device
*controller
;
656 || !(bus
= urb
->dev
->bus
)
657 || !(controller
= bus
->controller
))
660 if (controller
->dma_mask
) {
661 urb
->transfer_dma
= dma_map_single (controller
,
662 urb
->transfer_buffer
, urb
->transfer_buffer_length
,
663 usb_pipein (urb
->pipe
)
664 ? DMA_FROM_DEVICE
: DMA_TO_DEVICE
);
665 if (usb_pipecontrol (urb
->pipe
))
666 urb
->setup_dma
= dma_map_single (controller
,
668 sizeof (struct usb_ctrlrequest
),
670 // FIXME generic api broken like pci, can't report errors
671 // if (urb->transfer_dma == DMA_ADDR_INVALID) return 0;
673 urb
->transfer_dma
= ~0;
674 urb
->transfer_flags
|= (URB_NO_TRANSFER_DMA_MAP
675 | URB_NO_SETUP_DMA_MAP
);
680 /* XXX DISABLED, no users currently. If you wish to re-enable this
681 * XXX please determine whether the sync is to transfer ownership of
682 * XXX the buffer from device to cpu or vice verse, and thusly use the
683 * XXX appropriate _for_{cpu,device}() method. -DaveM
688 * usb_buffer_dmasync - synchronize DMA and CPU view of buffer(s)
689 * @urb: urb whose transfer_buffer/setup_packet will be synchronized
691 void usb_buffer_dmasync (struct urb
*urb
)
694 struct device
*controller
;
697 || !(urb
->transfer_flags
& URB_NO_TRANSFER_DMA_MAP
)
699 || !(bus
= urb
->dev
->bus
)
700 || !(controller
= bus
->controller
))
703 if (controller
->dma_mask
) {
704 dma_sync_single (controller
,
705 urb
->transfer_dma
, urb
->transfer_buffer_length
,
706 usb_pipein (urb
->pipe
)
707 ? DMA_FROM_DEVICE
: DMA_TO_DEVICE
);
708 if (usb_pipecontrol (urb
->pipe
))
709 dma_sync_single (controller
,
711 sizeof (struct usb_ctrlrequest
),
718 * usb_buffer_unmap - free DMA mapping(s) for an urb
719 * @urb: urb whose transfer_buffer will be unmapped
721 * Reverses the effect of usb_buffer_map().
724 void usb_buffer_unmap (struct urb
*urb
)
727 struct device
*controller
;
730 || !(urb
->transfer_flags
& URB_NO_TRANSFER_DMA_MAP
)
732 || !(bus
= urb
->dev
->bus
)
733 || !(controller
= bus
->controller
))
736 if (controller
->dma_mask
) {
737 dma_unmap_single (controller
,
738 urb
->transfer_dma
, urb
->transfer_buffer_length
,
739 usb_pipein (urb
->pipe
)
740 ? DMA_FROM_DEVICE
: DMA_TO_DEVICE
);
741 if (usb_pipecontrol (urb
->pipe
))
742 dma_unmap_single (controller
,
744 sizeof (struct usb_ctrlrequest
),
747 urb
->transfer_flags
&= ~(URB_NO_TRANSFER_DMA_MAP
748 | URB_NO_SETUP_DMA_MAP
);
753 * usb_buffer_map_sg - create scatterlist DMA mapping(s) for an endpoint
754 * @dev: device to which the scatterlist will be mapped
755 * @pipe: endpoint defining the mapping direction
756 * @sg: the scatterlist to map
757 * @nents: the number of entries in the scatterlist
759 * Return value is either < 0 (indicating no buffers could be mapped), or
760 * the number of DMA mapping array entries in the scatterlist.
762 * The caller is responsible for placing the resulting DMA addresses from
763 * the scatterlist into URB transfer buffer pointers, and for setting the
764 * URB_NO_TRANSFER_DMA_MAP transfer flag in each of those URBs.
766 * Top I/O rates come from queuing URBs, instead of waiting for each one
767 * to complete before starting the next I/O. This is particularly easy
768 * to do with scatterlists. Just allocate and submit one URB for each DMA
769 * mapping entry returned, stopping on the first error or when all succeed.
770 * Better yet, use the usb_sg_*() calls, which do that (and more) for you.
772 * This call would normally be used when translating scatterlist requests,
773 * rather than usb_buffer_map(), since on some hardware (with IOMMUs) it
774 * may be able to coalesce mappings for improved I/O efficiency.
776 * Reverse the effect of this call with usb_buffer_unmap_sg().
778 int usb_buffer_map_sg(const struct usb_device
*dev
, unsigned pipe
,
779 struct scatterlist
*sg
, int nents
)
782 struct device
*controller
;
785 || usb_pipecontrol (pipe
)
787 || !(controller
= bus
->controller
)
788 || !controller
->dma_mask
)
791 // FIXME generic api broken like pci, can't report errors
792 return dma_map_sg (controller
, sg
, nents
,
793 usb_pipein (pipe
) ? DMA_FROM_DEVICE
: DMA_TO_DEVICE
);
796 /* XXX DISABLED, no users currently. If you wish to re-enable this
797 * XXX please determine whether the sync is to transfer ownership of
798 * XXX the buffer from device to cpu or vice verse, and thusly use the
799 * XXX appropriate _for_{cpu,device}() method. -DaveM
804 * usb_buffer_dmasync_sg - synchronize DMA and CPU view of scatterlist buffer(s)
805 * @dev: device to which the scatterlist will be mapped
806 * @pipe: endpoint defining the mapping direction
807 * @sg: the scatterlist to synchronize
808 * @n_hw_ents: the positive return value from usb_buffer_map_sg
810 * Use this when you are re-using a scatterlist's data buffers for
811 * another USB request.
813 void usb_buffer_dmasync_sg(const struct usb_device
*dev
, unsigned pipe
,
814 struct scatterlist
*sg
, int n_hw_ents
)
817 struct device
*controller
;
821 || !(controller
= bus
->controller
)
822 || !controller
->dma_mask
)
825 dma_sync_sg (controller
, sg
, n_hw_ents
,
826 usb_pipein (pipe
) ? DMA_FROM_DEVICE
: DMA_TO_DEVICE
);
831 * usb_buffer_unmap_sg - free DMA mapping(s) for a scatterlist
832 * @dev: device to which the scatterlist will be mapped
833 * @pipe: endpoint defining the mapping direction
834 * @sg: the scatterlist to unmap
835 * @n_hw_ents: the positive return value from usb_buffer_map_sg
837 * Reverses the effect of usb_buffer_map_sg().
839 void usb_buffer_unmap_sg(const struct usb_device
*dev
, unsigned pipe
,
840 struct scatterlist
*sg
, int n_hw_ents
)
843 struct device
*controller
;
847 || !(controller
= bus
->controller
)
848 || !controller
->dma_mask
)
851 dma_unmap_sg (controller
, sg
, n_hw_ents
,
852 usb_pipein (pipe
) ? DMA_FROM_DEVICE
: DMA_TO_DEVICE
);
855 /* format to disable USB on kernel command line is: nousb */
856 __module_param_call("", nousb
, param_set_bool
, param_get_bool
, &nousb
, 0444);
859 * for external read access to <nousb>
861 int usb_disabled(void)
869 static int __init
usb_init(void)
873 pr_info ("%s: USB support disabled\n", usbcore_name
);
877 retval
= ksuspend_usb_init();
880 retval
= bus_register(&usb_bus_type
);
882 goto bus_register_failed
;
883 retval
= usb_host_init();
885 goto host_init_failed
;
886 retval
= usb_major_init();
888 goto major_init_failed
;
889 retval
= usb_register(&usbfs_driver
);
891 goto driver_register_failed
;
892 retval
= usbdev_init();
894 goto usbdevice_init_failed
;
895 retval
= usbfs_init();
898 retval
= usb_hub_init();
900 goto hub_init_failed
;
901 retval
= usb_register_device_driver(&usb_generic_driver
, THIS_MODULE
);
910 usbdevice_init_failed
:
911 usb_deregister(&usbfs_driver
);
912 driver_register_failed
:
917 bus_unregister(&usb_bus_type
);
919 ksuspend_usb_cleanup();
927 static void __exit
usb_exit(void)
929 /* This will matter if shutdown/reboot does exitcalls. */
933 usb_deregister_device_driver(&usb_generic_driver
);
936 usb_deregister(&usbfs_driver
);
940 bus_unregister(&usb_bus_type
);
941 ksuspend_usb_cleanup();
944 subsys_initcall(usb_init
);
945 module_exit(usb_exit
);
948 * USB may be built into the kernel or be built as modules.
949 * These symbols are exported for device (or host controller)
950 * driver modules to use.
953 EXPORT_SYMBOL(usb_disabled
);
955 EXPORT_SYMBOL_GPL(usb_get_intf
);
956 EXPORT_SYMBOL_GPL(usb_put_intf
);
958 EXPORT_SYMBOL(usb_put_dev
);
959 EXPORT_SYMBOL(usb_get_dev
);
960 EXPORT_SYMBOL(usb_hub_tt_clear_buffer
);
962 EXPORT_SYMBOL(usb_lock_device_for_reset
);
964 EXPORT_SYMBOL(usb_find_interface
);
965 EXPORT_SYMBOL(usb_ifnum_to_if
);
966 EXPORT_SYMBOL(usb_altnum_to_altsetting
);
968 EXPORT_SYMBOL(__usb_get_extra_descriptor
);
970 EXPORT_SYMBOL(usb_find_device
);
971 EXPORT_SYMBOL(usb_get_current_frame_number
);
973 EXPORT_SYMBOL (usb_buffer_alloc
);
974 EXPORT_SYMBOL (usb_buffer_free
);
977 EXPORT_SYMBOL (usb_buffer_map
);
978 EXPORT_SYMBOL (usb_buffer_dmasync
);
979 EXPORT_SYMBOL (usb_buffer_unmap
);
982 EXPORT_SYMBOL (usb_buffer_map_sg
);
984 EXPORT_SYMBOL (usb_buffer_dmasync_sg
);
986 EXPORT_SYMBOL (usb_buffer_unmap_sg
);
988 MODULE_LICENSE("GPL");