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 usb_destroy_configuration(udev
);
188 usb_put_hcd(bus_to_hcd(udev
->bus
));
189 kfree(udev
->product
);
190 kfree(udev
->manufacturer
);
195 struct device_type usb_device_type
= {
196 .name
= "usb_device",
197 .release
= usb_release_dev
,
202 static int ksuspend_usb_init(void)
204 /* This workqueue is supposed to be both freezable and
205 * singlethreaded. Its job doesn't justify running on more
208 ksuspend_usb_wq
= create_freezeable_workqueue("ksuspend_usbd");
209 if (!ksuspend_usb_wq
)
214 static void ksuspend_usb_cleanup(void)
216 destroy_workqueue(ksuspend_usb_wq
);
221 #define ksuspend_usb_init() 0
222 #define ksuspend_usb_cleanup() do {} while (0)
224 #endif /* CONFIG_PM */
227 * usb_alloc_dev - usb device constructor (usbcore-internal)
228 * @parent: hub to which device is connected; null to allocate a root hub
229 * @bus: bus used to access the device
230 * @port1: one-based index of port; ignored for root hubs
231 * Context: !in_interrupt()
233 * Only hub drivers (including virtual root hub drivers for host
234 * controllers) should ever call this.
236 * This call may not be used in a non-sleeping context.
239 usb_alloc_dev(struct usb_device
*parent
, struct usb_bus
*bus
, unsigned port1
)
241 struct usb_device
*dev
;
243 dev
= kzalloc(sizeof(*dev
), GFP_KERNEL
);
247 if (!usb_get_hcd(bus_to_hcd(bus
))) {
252 device_initialize(&dev
->dev
);
253 dev
->dev
.bus
= &usb_bus_type
;
254 dev
->dev
.type
= &usb_device_type
;
255 dev
->dev
.dma_mask
= bus
->controller
->dma_mask
;
256 set_dev_node(&dev
->dev
, dev_to_node(bus
->controller
));
257 dev
->state
= USB_STATE_ATTACHED
;
259 INIT_LIST_HEAD(&dev
->ep0
.urb_list
);
260 dev
->ep0
.desc
.bLength
= USB_DT_ENDPOINT_SIZE
;
261 dev
->ep0
.desc
.bDescriptorType
= USB_DT_ENDPOINT
;
262 /* ep0 maxpacket comes later, from device descriptor */
263 dev
->ep_in
[0] = dev
->ep_out
[0] = &dev
->ep0
;
265 /* Save readable and stable topology id, distinguishing devices
266 * by location for diagnostics, tools, driver model, etc. The
267 * string is a path along hub ports, from the root. Each device's
268 * dev->devpath will be stable until USB is re-cabled, and hubs
269 * are often labeled with these port numbers. The bus_id isn't
270 * as stable: bus->busnum changes easily from modprobe order,
271 * cardbus or pci hotplugging, and so on.
273 if (unlikely(!parent
)) {
274 dev
->devpath
[0] = '0';
276 dev
->dev
.parent
= bus
->controller
;
277 sprintf(&dev
->dev
.bus_id
[0], "usb%d", bus
->busnum
);
279 /* match any labeling on the hubs; it's one-based */
280 if (parent
->devpath
[0] == '0')
281 snprintf(dev
->devpath
, sizeof dev
->devpath
,
284 snprintf(dev
->devpath
, sizeof dev
->devpath
,
285 "%s.%d", parent
->devpath
, port1
);
287 dev
->dev
.parent
= &parent
->dev
;
288 sprintf(&dev
->dev
.bus_id
[0], "%d-%s",
289 bus
->busnum
, dev
->devpath
);
291 /* hub driver sets up TT records */
294 dev
->portnum
= port1
;
296 dev
->parent
= parent
;
297 INIT_LIST_HEAD(&dev
->filelist
);
300 mutex_init(&dev
->pm_mutex
);
301 INIT_DELAYED_WORK(&dev
->autosuspend
, usb_autosuspend_work
);
302 dev
->autosuspend_delay
= usb_autosuspend_delay
* HZ
;
308 * usb_get_dev - increments the reference count of the usb device structure
309 * @dev: the device being referenced
311 * Each live reference to a device should be refcounted.
313 * Drivers for USB interfaces should normally record such references in
314 * their probe() methods, when they bind to an interface, and release
315 * them by calling usb_put_dev(), in their disconnect() methods.
317 * A pointer to the device with the incremented reference counter is returned.
319 struct usb_device
*usb_get_dev(struct usb_device
*dev
)
322 get_device(&dev
->dev
);
327 * usb_put_dev - release a use of the usb device structure
328 * @dev: device that's been disconnected
330 * Must be called when a user of a device is finished with it. When the last
331 * user of the device calls this function, the memory of the device is freed.
333 void usb_put_dev(struct usb_device
*dev
)
336 put_device(&dev
->dev
);
340 * usb_get_intf - increments the reference count of the usb interface structure
341 * @intf: the interface being referenced
343 * Each live reference to a interface must be refcounted.
345 * Drivers for USB interfaces should normally record such references in
346 * their probe() methods, when they bind to an interface, and release
347 * them by calling usb_put_intf(), in their disconnect() methods.
349 * A pointer to the interface with the incremented reference counter is
352 struct usb_interface
*usb_get_intf(struct usb_interface
*intf
)
355 get_device(&intf
->dev
);
360 * usb_put_intf - release a use of the usb interface structure
361 * @intf: interface that's been decremented
363 * Must be called when a user of an interface is finished with it. When the
364 * last user of the interface calls this function, the memory of the interface
367 void usb_put_intf(struct usb_interface
*intf
)
370 put_device(&intf
->dev
);
374 /* USB device locking
376 * USB devices and interfaces are locked using the semaphore in their
377 * embedded struct device. The hub driver guarantees that whenever a
378 * device is connected or disconnected, drivers are called with the
379 * USB device locked as well as their particular interface.
381 * Complications arise when several devices are to be locked at the same
382 * time. Only hub-aware drivers that are part of usbcore ever have to
383 * do this; nobody else needs to worry about it. The rule for locking
386 * When locking both a device and its parent, always lock the
391 * usb_lock_device_for_reset - cautiously acquire the lock for a
392 * usb device structure
393 * @udev: device that's being locked
394 * @iface: interface bound to the driver making the request (optional)
396 * Attempts to acquire the device lock, but fails if the device is
397 * NOTATTACHED or SUSPENDED, or if iface is specified and the interface
398 * is neither BINDING nor BOUND. Rather than sleeping to wait for the
399 * lock, the routine polls repeatedly. This is to prevent deadlock with
400 * disconnect; in some drivers (such as usb-storage) the disconnect()
401 * or suspend() method will block waiting for a device reset to complete.
403 * Returns a negative error code for failure, otherwise 1 or 0 to indicate
404 * that the device will or will not have to be unlocked. (0 can be
405 * returned when an interface is given and is BINDING, because in that
406 * case the driver already owns the device lock.)
408 int usb_lock_device_for_reset(struct usb_device
*udev
,
409 const struct usb_interface
*iface
)
411 unsigned long jiffies_expire
= jiffies
+ HZ
;
413 if (udev
->state
== USB_STATE_NOTATTACHED
)
415 if (udev
->state
== USB_STATE_SUSPENDED
)
416 return -EHOSTUNREACH
;
418 switch (iface
->condition
) {
419 case USB_INTERFACE_BINDING
:
421 case USB_INTERFACE_BOUND
:
428 while (usb_trylock_device(udev
) != 0) {
430 /* If we can't acquire the lock after waiting one second,
431 * we're probably deadlocked */
432 if (time_after(jiffies
, jiffies_expire
))
436 if (udev
->state
== USB_STATE_NOTATTACHED
)
438 if (udev
->state
== USB_STATE_SUSPENDED
)
439 return -EHOSTUNREACH
;
440 if (iface
&& iface
->condition
!= USB_INTERFACE_BOUND
)
447 static struct usb_device
*match_device(struct usb_device
*dev
,
448 u16 vendor_id
, u16 product_id
)
450 struct usb_device
*ret_dev
= NULL
;
453 dev_dbg(&dev
->dev
, "check for vendor %04x, product %04x ...\n",
454 le16_to_cpu(dev
->descriptor
.idVendor
),
455 le16_to_cpu(dev
->descriptor
.idProduct
));
457 /* see if this device matches */
458 if ((vendor_id
== le16_to_cpu(dev
->descriptor
.idVendor
)) &&
459 (product_id
== le16_to_cpu(dev
->descriptor
.idProduct
))) {
460 dev_dbg(&dev
->dev
, "matched this device!\n");
461 ret_dev
= usb_get_dev(dev
);
465 /* look through all of the children of this device */
466 for (child
= 0; child
< dev
->maxchild
; ++child
) {
467 if (dev
->children
[child
]) {
468 usb_lock_device(dev
->children
[child
]);
469 ret_dev
= match_device(dev
->children
[child
],
470 vendor_id
, product_id
);
471 usb_unlock_device(dev
->children
[child
]);
481 * usb_find_device - find a specific usb device in the system
482 * @vendor_id: the vendor id of the device to find
483 * @product_id: the product id of the device to find
485 * Returns a pointer to a struct usb_device if such a specified usb
486 * device is present in the system currently. The usage count of the
487 * device will be incremented if a device is found. Make sure to call
488 * usb_put_dev() when the caller is finished with the device.
490 * If a device with the specified vendor and product id is not found,
493 struct usb_device
*usb_find_device(u16 vendor_id
, u16 product_id
)
495 struct list_head
*buslist
;
497 struct usb_device
*dev
= NULL
;
499 mutex_lock(&usb_bus_list_lock
);
500 for (buslist
= usb_bus_list
.next
;
501 buslist
!= &usb_bus_list
;
502 buslist
= buslist
->next
) {
503 bus
= container_of(buslist
, struct usb_bus
, bus_list
);
506 usb_lock_device(bus
->root_hub
);
507 dev
= match_device(bus
->root_hub
, vendor_id
, product_id
);
508 usb_unlock_device(bus
->root_hub
);
513 mutex_unlock(&usb_bus_list_lock
);
518 * usb_get_current_frame_number - return current bus frame number
519 * @dev: the device whose bus is being queried
521 * Returns the current frame number for the USB host controller
522 * used with the given USB device. This can be used when scheduling
523 * isochronous requests.
525 * Note that different kinds of host controller have different
526 * "scheduling horizons". While one type might support scheduling only
527 * 32 frames into the future, others could support scheduling up to
528 * 1024 frames into the future.
530 int usb_get_current_frame_number(struct usb_device
*dev
)
532 return usb_hcd_get_frame_number(dev
);
535 /*-------------------------------------------------------------------*/
537 * __usb_get_extra_descriptor() finds a descriptor of specific type in the
538 * extra field of the interface and endpoint descriptor structs.
541 int __usb_get_extra_descriptor(char *buffer
, unsigned size
,
542 unsigned char type
, void **ptr
)
544 struct usb_descriptor_header
*header
;
546 while (size
>= sizeof(struct usb_descriptor_header
)) {
547 header
= (struct usb_descriptor_header
*)buffer
;
549 if (header
->bLength
< 2) {
551 "%s: bogus descriptor, type %d length %d\n",
553 header
->bDescriptorType
,
558 if (header
->bDescriptorType
== type
) {
563 buffer
+= header
->bLength
;
564 size
-= header
->bLength
;
570 * usb_buffer_alloc - allocate dma-consistent buffer for URB_NO_xxx_DMA_MAP
571 * @dev: device the buffer will be used with
572 * @size: requested buffer size
573 * @mem_flags: affect whether allocation may block
574 * @dma: used to return DMA address of buffer
576 * Return value is either null (indicating no buffer could be allocated), or
577 * the cpu-space pointer to a buffer that may be used to perform DMA to the
578 * specified device. Such cpu-space buffers are returned along with the DMA
579 * address (through the pointer provided).
581 * These buffers are used with URB_NO_xxx_DMA_MAP set in urb->transfer_flags
582 * to avoid behaviors like using "DMA bounce buffers", or thrashing IOMMU
583 * hardware during URB completion/resubmit. The implementation varies between
584 * platforms, depending on details of how DMA will work to this device.
585 * Using these buffers also eliminates cacheline sharing problems on
586 * architectures where CPU caches are not DMA-coherent. On systems without
587 * bus-snooping caches, these buffers are uncached.
589 * When the buffer is no longer used, free it with usb_buffer_free().
591 void *usb_buffer_alloc(
592 struct usb_device
*dev
,
598 if (!dev
|| !dev
->bus
)
600 return hcd_buffer_alloc(dev
->bus
, size
, mem_flags
, dma
);
604 * usb_buffer_free - free memory allocated with usb_buffer_alloc()
605 * @dev: device the buffer was used with
606 * @size: requested buffer size
607 * @addr: CPU address of buffer
608 * @dma: DMA address of buffer
610 * This reclaims an I/O buffer, letting it be reused. The memory must have
611 * been allocated using usb_buffer_alloc(), and the parameters must match
612 * those provided in that allocation request.
614 void usb_buffer_free(
615 struct usb_device
*dev
,
621 if (!dev
|| !dev
->bus
)
625 hcd_buffer_free(dev
->bus
, size
, addr
, dma
);
629 * usb_buffer_map - create DMA mapping(s) for an urb
630 * @urb: urb whose transfer_buffer/setup_packet will be mapped
632 * Return value is either null (indicating no buffer could be mapped), or
633 * the parameter. URB_NO_TRANSFER_DMA_MAP and URB_NO_SETUP_DMA_MAP are
634 * added to urb->transfer_flags if the operation succeeds. If the device
635 * is connected to this system through a non-DMA controller, this operation
638 * This call would normally be used for an urb which is reused, perhaps
639 * as the target of a large periodic transfer, with usb_buffer_dmasync()
640 * calls to synchronize memory and dma state.
642 * Reverse the effect of this call with usb_buffer_unmap().
645 struct urb
*usb_buffer_map(struct urb
*urb
)
648 struct device
*controller
;
652 || !(bus
= urb
->dev
->bus
)
653 || !(controller
= bus
->controller
))
656 if (controller
->dma_mask
) {
657 urb
->transfer_dma
= dma_map_single(controller
,
658 urb
->transfer_buffer
, urb
->transfer_buffer_length
,
659 usb_pipein(urb
->pipe
)
660 ? DMA_FROM_DEVICE
: DMA_TO_DEVICE
);
661 if (usb_pipecontrol(urb
->pipe
))
662 urb
->setup_dma
= dma_map_single(controller
,
664 sizeof(struct usb_ctrlrequest
),
666 // FIXME generic api broken like pci, can't report errors
667 // if (urb->transfer_dma == DMA_ADDR_INVALID) return 0;
669 urb
->transfer_dma
= ~0;
670 urb
->transfer_flags
|= (URB_NO_TRANSFER_DMA_MAP
671 | URB_NO_SETUP_DMA_MAP
);
676 /* XXX DISABLED, no users currently. If you wish to re-enable this
677 * XXX please determine whether the sync is to transfer ownership of
678 * XXX the buffer from device to cpu or vice verse, and thusly use the
679 * XXX appropriate _for_{cpu,device}() method. -DaveM
684 * usb_buffer_dmasync - synchronize DMA and CPU view of buffer(s)
685 * @urb: urb whose transfer_buffer/setup_packet will be synchronized
687 void usb_buffer_dmasync(struct urb
*urb
)
690 struct device
*controller
;
693 || !(urb
->transfer_flags
& URB_NO_TRANSFER_DMA_MAP
)
695 || !(bus
= urb
->dev
->bus
)
696 || !(controller
= bus
->controller
))
699 if (controller
->dma_mask
) {
700 dma_sync_single(controller
,
701 urb
->transfer_dma
, urb
->transfer_buffer_length
,
702 usb_pipein(urb
->pipe
)
703 ? DMA_FROM_DEVICE
: DMA_TO_DEVICE
);
704 if (usb_pipecontrol(urb
->pipe
))
705 dma_sync_single(controller
,
707 sizeof(struct usb_ctrlrequest
),
714 * usb_buffer_unmap - free DMA mapping(s) for an urb
715 * @urb: urb whose transfer_buffer will be unmapped
717 * Reverses the effect of usb_buffer_map().
720 void usb_buffer_unmap(struct urb
*urb
)
723 struct device
*controller
;
726 || !(urb
->transfer_flags
& URB_NO_TRANSFER_DMA_MAP
)
728 || !(bus
= urb
->dev
->bus
)
729 || !(controller
= bus
->controller
))
732 if (controller
->dma_mask
) {
733 dma_unmap_single(controller
,
734 urb
->transfer_dma
, urb
->transfer_buffer_length
,
735 usb_pipein(urb
->pipe
)
736 ? DMA_FROM_DEVICE
: DMA_TO_DEVICE
);
737 if (usb_pipecontrol(urb
->pipe
))
738 dma_unmap_single(controller
,
740 sizeof(struct usb_ctrlrequest
),
743 urb
->transfer_flags
&= ~(URB_NO_TRANSFER_DMA_MAP
744 | URB_NO_SETUP_DMA_MAP
);
749 * usb_buffer_map_sg - create scatterlist DMA mapping(s) for an endpoint
750 * @dev: device to which the scatterlist will be mapped
751 * @pipe: endpoint defining the mapping direction
752 * @sg: the scatterlist to map
753 * @nents: the number of entries in the scatterlist
755 * Return value is either < 0 (indicating no buffers could be mapped), or
756 * the number of DMA mapping array entries in the scatterlist.
758 * The caller is responsible for placing the resulting DMA addresses from
759 * the scatterlist into URB transfer buffer pointers, and for setting the
760 * URB_NO_TRANSFER_DMA_MAP transfer flag in each of those URBs.
762 * Top I/O rates come from queuing URBs, instead of waiting for each one
763 * to complete before starting the next I/O. This is particularly easy
764 * to do with scatterlists. Just allocate and submit one URB for each DMA
765 * mapping entry returned, stopping on the first error or when all succeed.
766 * Better yet, use the usb_sg_*() calls, which do that (and more) for you.
768 * This call would normally be used when translating scatterlist requests,
769 * rather than usb_buffer_map(), since on some hardware (with IOMMUs) it
770 * may be able to coalesce mappings for improved I/O efficiency.
772 * Reverse the effect of this call with usb_buffer_unmap_sg().
774 int usb_buffer_map_sg(const struct usb_device
*dev
, unsigned pipe
,
775 struct scatterlist
*sg
, int nents
)
778 struct device
*controller
;
781 || usb_pipecontrol(pipe
)
783 || !(controller
= bus
->controller
)
784 || !controller
->dma_mask
)
787 // FIXME generic api broken like pci, can't report errors
788 return dma_map_sg(controller
, sg
, nents
,
789 usb_pipein(pipe
) ? DMA_FROM_DEVICE
: DMA_TO_DEVICE
);
792 /* XXX DISABLED, no users currently. If you wish to re-enable this
793 * XXX please determine whether the sync is to transfer ownership of
794 * XXX the buffer from device to cpu or vice verse, and thusly use the
795 * XXX appropriate _for_{cpu,device}() method. -DaveM
800 * usb_buffer_dmasync_sg - synchronize DMA and CPU view of scatterlist buffer(s)
801 * @dev: device to which the scatterlist will be mapped
802 * @pipe: endpoint defining the mapping direction
803 * @sg: the scatterlist to synchronize
804 * @n_hw_ents: the positive return value from usb_buffer_map_sg
806 * Use this when you are re-using a scatterlist's data buffers for
807 * another USB request.
809 void usb_buffer_dmasync_sg(const struct usb_device
*dev
, unsigned pipe
,
810 struct scatterlist
*sg
, int n_hw_ents
)
813 struct device
*controller
;
817 || !(controller
= bus
->controller
)
818 || !controller
->dma_mask
)
821 dma_sync_sg(controller
, sg
, n_hw_ents
,
822 usb_pipein(pipe
) ? DMA_FROM_DEVICE
: DMA_TO_DEVICE
);
827 * usb_buffer_unmap_sg - free DMA mapping(s) for a scatterlist
828 * @dev: device to which the scatterlist will be mapped
829 * @pipe: endpoint defining the mapping direction
830 * @sg: the scatterlist to unmap
831 * @n_hw_ents: the positive return value from usb_buffer_map_sg
833 * Reverses the effect of usb_buffer_map_sg().
835 void usb_buffer_unmap_sg(const struct usb_device
*dev
, unsigned pipe
,
836 struct scatterlist
*sg
, int n_hw_ents
)
839 struct device
*controller
;
843 || !(controller
= bus
->controller
)
844 || !controller
->dma_mask
)
847 dma_unmap_sg(controller
, sg
, n_hw_ents
,
848 usb_pipein(pipe
) ? DMA_FROM_DEVICE
: DMA_TO_DEVICE
);
851 /* format to disable USB on kernel command line is: nousb */
852 __module_param_call("", nousb
, param_set_bool
, param_get_bool
, &nousb
, 0444);
855 * for external read access to <nousb>
857 int usb_disabled(void)
865 static int __init
usb_init(void)
869 pr_info("%s: USB support disabled\n", usbcore_name
);
873 retval
= ksuspend_usb_init();
876 retval
= bus_register(&usb_bus_type
);
878 goto bus_register_failed
;
879 retval
= usb_host_init();
881 goto host_init_failed
;
882 retval
= usb_major_init();
884 goto major_init_failed
;
885 retval
= usb_register(&usbfs_driver
);
887 goto driver_register_failed
;
888 retval
= usb_devio_init();
890 goto usb_devio_init_failed
;
891 retval
= usbfs_init();
894 retval
= usb_hub_init();
896 goto hub_init_failed
;
897 retval
= usb_register_device_driver(&usb_generic_driver
, THIS_MODULE
);
906 usb_devio_init_failed
:
907 usb_deregister(&usbfs_driver
);
908 driver_register_failed
:
913 bus_unregister(&usb_bus_type
);
915 ksuspend_usb_cleanup();
923 static void __exit
usb_exit(void)
925 /* This will matter if shutdown/reboot does exitcalls. */
929 usb_deregister_device_driver(&usb_generic_driver
);
932 usb_deregister(&usbfs_driver
);
936 bus_unregister(&usb_bus_type
);
937 ksuspend_usb_cleanup();
940 subsys_initcall(usb_init
);
941 module_exit(usb_exit
);
944 * USB may be built into the kernel or be built as modules.
945 * These symbols are exported for device (or host controller)
946 * driver modules to use.
949 EXPORT_SYMBOL(usb_disabled
);
951 EXPORT_SYMBOL_GPL(usb_get_intf
);
952 EXPORT_SYMBOL_GPL(usb_put_intf
);
954 EXPORT_SYMBOL(usb_put_dev
);
955 EXPORT_SYMBOL(usb_get_dev
);
956 EXPORT_SYMBOL(usb_hub_tt_clear_buffer
);
958 EXPORT_SYMBOL(usb_lock_device_for_reset
);
960 EXPORT_SYMBOL(usb_find_interface
);
961 EXPORT_SYMBOL(usb_ifnum_to_if
);
962 EXPORT_SYMBOL(usb_altnum_to_altsetting
);
964 EXPORT_SYMBOL(__usb_get_extra_descriptor
);
966 EXPORT_SYMBOL(usb_find_device
);
967 EXPORT_SYMBOL(usb_get_current_frame_number
);
969 EXPORT_SYMBOL(usb_buffer_alloc
);
970 EXPORT_SYMBOL(usb_buffer_free
);
973 EXPORT_SYMBOL(usb_buffer_map
);
974 EXPORT_SYMBOL(usb_buffer_dmasync
);
975 EXPORT_SYMBOL(usb_buffer_unmap
);
978 EXPORT_SYMBOL(usb_buffer_map_sg
);
980 EXPORT_SYMBOL(usb_buffer_dmasync_sg
);
982 EXPORT_SYMBOL(usb_buffer_unmap_sg
);
984 MODULE_LICENSE("GPL");