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/smp_lock.h>
35 #include <linux/usb.h>
36 #include <linux/mutex.h>
37 #include <linux/workqueue.h>
40 #include <asm/scatterlist.h>
42 #include <linux/dma-mapping.h>
48 const char *usbcore_name
= "usbcore";
50 static int nousb
; /* Disable USB when built into kernel image */
52 /* Workqueue for autosuspend and for remote wakeup of root hubs */
53 struct workqueue_struct
*ksuspend_usb_wq
;
55 #ifdef CONFIG_USB_SUSPEND
56 static int usb_autosuspend_delay
= 2; /* Default delay value,
58 module_param_named(autosuspend
, usb_autosuspend_delay
, int, 0644);
59 MODULE_PARM_DESC(autosuspend
, "default autosuspend delay");
62 #define usb_autosuspend_delay 0
67 * usb_ifnum_to_if - get the interface object with a given interface number
68 * @dev: the device whose current configuration is considered
69 * @ifnum: the desired interface
71 * This walks the device descriptor for the currently active configuration
72 * and returns a pointer to the interface with that particular interface
75 * Note that configuration descriptors are not required to assign interface
76 * numbers sequentially, so that it would be incorrect to assume that
77 * the first interface in that descriptor corresponds to interface zero.
78 * This routine helps device drivers avoid such mistakes.
79 * However, you should make sure that you do the right thing with any
80 * alternate settings available for this interfaces.
82 * Don't call this function unless you are bound to one of the interfaces
83 * on this device or you have locked the device!
85 struct usb_interface
*usb_ifnum_to_if(const struct usb_device
*dev
,
88 struct usb_host_config
*config
= dev
->actconfig
;
93 for (i
= 0; i
< config
->desc
.bNumInterfaces
; i
++)
94 if (config
->interface
[i
]->altsetting
[0]
95 .desc
.bInterfaceNumber
== ifnum
)
96 return config
->interface
[i
];
102 * usb_altnum_to_altsetting - get the altsetting structure with a given
103 * alternate setting number.
104 * @intf: the interface containing the altsetting in question
105 * @altnum: the desired alternate setting number
107 * This searches the altsetting array of the specified interface for
108 * an entry with the correct bAlternateSetting value and returns a pointer
109 * to that entry, or null.
111 * Note that altsettings need not be stored sequentially by number, so
112 * it would be incorrect to assume that the first altsetting entry in
113 * the array corresponds to altsetting zero. This routine helps device
114 * drivers avoid such mistakes.
116 * Don't call this function unless you are bound to the intf interface
117 * or you have locked the device!
119 struct usb_host_interface
*usb_altnum_to_altsetting(const struct usb_interface
*intf
,
124 for (i
= 0; i
< intf
->num_altsetting
; i
++) {
125 if (intf
->altsetting
[i
].desc
.bAlternateSetting
== altnum
)
126 return &intf
->altsetting
[i
];
131 struct find_interface_arg
{
133 struct usb_interface
*interface
;
136 static int __find_interface(struct device
* dev
, void * data
)
138 struct find_interface_arg
*arg
= data
;
139 struct usb_interface
*intf
;
141 /* can't look at usb devices, only interfaces */
142 if (is_usb_device(dev
))
145 intf
= to_usb_interface(dev
);
146 if (intf
->minor
!= -1 && intf
->minor
== arg
->minor
) {
147 arg
->interface
= intf
;
154 * usb_find_interface - find usb_interface pointer for driver and device
155 * @drv: the driver whose current configuration is considered
156 * @minor: the minor number of the desired device
158 * This walks the driver device list and returns a pointer to the interface
159 * with the matching minor. Note, this only works for devices that share the
162 struct usb_interface
*usb_find_interface(struct usb_driver
*drv
, int minor
)
164 struct find_interface_arg argb
;
168 argb
.interface
= NULL
;
169 /* eat the error, it will be in argb.interface */
170 retval
= driver_for_each_device(&drv
->drvwrap
.driver
, NULL
, &argb
,
172 return argb
.interface
;
176 * usb_release_dev - free a usb device structure when all users of it are finished.
177 * @dev: device that's been disconnected
179 * Will be called only by the device core when all users of this usb device are
182 static void usb_release_dev(struct device
*dev
)
184 struct usb_device
*udev
;
186 udev
= to_usb_device(dev
);
188 #ifdef CONFIG_USB_SUSPEND
189 cancel_delayed_work(&udev
->autosuspend
);
190 flush_workqueue(ksuspend_usb_wq
);
192 usb_destroy_configuration(udev
);
193 usb_put_hcd(bus_to_hcd(udev
->bus
));
194 kfree(udev
->product
);
195 kfree(udev
->manufacturer
);
202 static int ksuspend_usb_init(void)
204 ksuspend_usb_wq
= create_singlethread_workqueue("ksuspend_usbd");
205 if (!ksuspend_usb_wq
)
210 static void ksuspend_usb_cleanup(void)
212 destroy_workqueue(ksuspend_usb_wq
);
217 #define ksuspend_usb_init() 0
218 #define ksuspend_usb_cleanup() do {} while (0)
220 #endif /* CONFIG_PM */
223 * usb_alloc_dev - usb device constructor (usbcore-internal)
224 * @parent: hub to which device is connected; null to allocate a root hub
225 * @bus: bus used to access the device
226 * @port1: one-based index of port; ignored for root hubs
227 * Context: !in_interrupt()
229 * Only hub drivers (including virtual root hub drivers for host
230 * controllers) should ever call this.
232 * This call may not be used in a non-sleeping context.
235 usb_alloc_dev(struct usb_device
*parent
, struct usb_bus
*bus
, unsigned port1
)
237 struct usb_device
*dev
;
239 dev
= kzalloc(sizeof(*dev
), GFP_KERNEL
);
243 if (!usb_get_hcd(bus_to_hcd(bus
))) {
248 device_initialize(&dev
->dev
);
249 dev
->dev
.bus
= &usb_bus_type
;
250 dev
->dev
.dma_mask
= bus
->controller
->dma_mask
;
251 dev
->dev
.release
= usb_release_dev
;
252 dev
->state
= USB_STATE_ATTACHED
;
254 /* This magic assignment distinguishes devices from interfaces */
255 dev
->dev
.platform_data
= &usb_generic_driver
;
257 INIT_LIST_HEAD(&dev
->ep0
.urb_list
);
258 dev
->ep0
.desc
.bLength
= USB_DT_ENDPOINT_SIZE
;
259 dev
->ep0
.desc
.bDescriptorType
= USB_DT_ENDPOINT
;
260 /* ep0 maxpacket comes later, from device descriptor */
261 dev
->ep_in
[0] = dev
->ep_out
[0] = &dev
->ep0
;
263 /* Save readable and stable topology id, distinguishing devices
264 * by location for diagnostics, tools, driver model, etc. The
265 * string is a path along hub ports, from the root. Each device's
266 * dev->devpath will be stable until USB is re-cabled, and hubs
267 * are often labeled with these port numbers. The bus_id isn't
268 * as stable: bus->busnum changes easily from modprobe order,
269 * cardbus or pci hotplugging, and so on.
271 if (unlikely(!parent
)) {
272 dev
->devpath
[0] = '0';
274 dev
->dev
.parent
= bus
->controller
;
275 sprintf(&dev
->dev
.bus_id
[0], "usb%d", bus
->busnum
);
277 /* match any labeling on the hubs; it's one-based */
278 if (parent
->devpath
[0] == '0')
279 snprintf(dev
->devpath
, sizeof dev
->devpath
,
282 snprintf(dev
->devpath
, sizeof dev
->devpath
,
283 "%s.%d", parent
->devpath
, port1
);
285 dev
->dev
.parent
= &parent
->dev
;
286 sprintf(&dev
->dev
.bus_id
[0], "%d-%s",
287 bus
->busnum
, dev
->devpath
);
289 /* hub driver sets up TT records */
292 dev
->portnum
= port1
;
294 dev
->parent
= parent
;
295 INIT_LIST_HEAD(&dev
->filelist
);
298 mutex_init(&dev
->pm_mutex
);
299 INIT_DELAYED_WORK(&dev
->autosuspend
, usb_autosuspend_work
);
300 dev
->autosuspend_delay
= usb_autosuspend_delay
* HZ
;
306 * usb_get_dev - increments the reference count of the usb device structure
307 * @dev: the device being referenced
309 * Each live reference to a device should be refcounted.
311 * Drivers for USB interfaces should normally record such references in
312 * their probe() methods, when they bind to an interface, and release
313 * them by calling usb_put_dev(), in their disconnect() methods.
315 * A pointer to the device with the incremented reference counter is returned.
317 struct usb_device
*usb_get_dev(struct usb_device
*dev
)
320 get_device(&dev
->dev
);
325 * usb_put_dev - release a use of the usb device structure
326 * @dev: device that's been disconnected
328 * Must be called when a user of a device is finished with it. When the last
329 * user of the device calls this function, the memory of the device is freed.
331 void usb_put_dev(struct usb_device
*dev
)
334 put_device(&dev
->dev
);
338 * usb_get_intf - increments the reference count of the usb interface structure
339 * @intf: the interface being referenced
341 * Each live reference to a interface must be refcounted.
343 * Drivers for USB interfaces should normally record such references in
344 * their probe() methods, when they bind to an interface, and release
345 * them by calling usb_put_intf(), in their disconnect() methods.
347 * A pointer to the interface with the incremented reference counter is
350 struct usb_interface
*usb_get_intf(struct usb_interface
*intf
)
353 get_device(&intf
->dev
);
358 * usb_put_intf - release a use of the usb interface structure
359 * @intf: interface that's been decremented
361 * Must be called when a user of an interface is finished with it. When the
362 * last user of the interface calls this function, the memory of the interface
365 void usb_put_intf(struct usb_interface
*intf
)
368 put_device(&intf
->dev
);
372 /* USB device locking
374 * USB devices and interfaces are locked using the semaphore in their
375 * embedded struct device. The hub driver guarantees that whenever a
376 * device is connected or disconnected, drivers are called with the
377 * USB device locked as well as their particular interface.
379 * Complications arise when several devices are to be locked at the same
380 * time. Only hub-aware drivers that are part of usbcore ever have to
381 * do this; nobody else needs to worry about it. The rule for locking
384 * When locking both a device and its parent, always lock the
389 * usb_lock_device_for_reset - cautiously acquire the lock for a
390 * usb device structure
391 * @udev: device that's being locked
392 * @iface: interface bound to the driver making the request (optional)
394 * Attempts to acquire the device lock, but fails if the device is
395 * NOTATTACHED or SUSPENDED, or if iface is specified and the interface
396 * is neither BINDING nor BOUND. Rather than sleeping to wait for the
397 * lock, the routine polls repeatedly. This is to prevent deadlock with
398 * disconnect; in some drivers (such as usb-storage) the disconnect()
399 * or suspend() method will block waiting for a device reset to complete.
401 * Returns a negative error code for failure, otherwise 1 or 0 to indicate
402 * that the device will or will not have to be unlocked. (0 can be
403 * returned when an interface is given and is BINDING, because in that
404 * case the driver already owns the device lock.)
406 int usb_lock_device_for_reset(struct usb_device
*udev
,
407 const struct usb_interface
*iface
)
409 unsigned long jiffies_expire
= jiffies
+ HZ
;
411 if (udev
->state
== USB_STATE_NOTATTACHED
)
413 if (udev
->state
== USB_STATE_SUSPENDED
)
414 return -EHOSTUNREACH
;
416 switch (iface
->condition
) {
417 case USB_INTERFACE_BINDING
:
419 case USB_INTERFACE_BOUND
:
426 while (usb_trylock_device(udev
) != 0) {
428 /* If we can't acquire the lock after waiting one second,
429 * we're probably deadlocked */
430 if (time_after(jiffies
, jiffies_expire
))
434 if (udev
->state
== USB_STATE_NOTATTACHED
)
436 if (udev
->state
== USB_STATE_SUSPENDED
)
437 return -EHOSTUNREACH
;
438 if (iface
&& iface
->condition
!= USB_INTERFACE_BOUND
)
445 static struct usb_device
*match_device(struct usb_device
*dev
,
446 u16 vendor_id
, u16 product_id
)
448 struct usb_device
*ret_dev
= NULL
;
451 dev_dbg(&dev
->dev
, "check for vendor %04x, product %04x ...\n",
452 le16_to_cpu(dev
->descriptor
.idVendor
),
453 le16_to_cpu(dev
->descriptor
.idProduct
));
455 /* see if this device matches */
456 if ((vendor_id
== le16_to_cpu(dev
->descriptor
.idVendor
)) &&
457 (product_id
== le16_to_cpu(dev
->descriptor
.idProduct
))) {
458 dev_dbg(&dev
->dev
, "matched this device!\n");
459 ret_dev
= usb_get_dev(dev
);
463 /* look through all of the children of this device */
464 for (child
= 0; child
< dev
->maxchild
; ++child
) {
465 if (dev
->children
[child
]) {
466 usb_lock_device(dev
->children
[child
]);
467 ret_dev
= match_device(dev
->children
[child
],
468 vendor_id
, product_id
);
469 usb_unlock_device(dev
->children
[child
]);
479 * usb_find_device - find a specific usb device in the system
480 * @vendor_id: the vendor id of the device to find
481 * @product_id: the product id of the device to find
483 * Returns a pointer to a struct usb_device if such a specified usb
484 * device is present in the system currently. The usage count of the
485 * device will be incremented if a device is found. Make sure to call
486 * usb_put_dev() when the caller is finished with the device.
488 * If a device with the specified vendor and product id is not found,
491 struct usb_device
*usb_find_device(u16 vendor_id
, u16 product_id
)
493 struct list_head
*buslist
;
495 struct usb_device
*dev
= NULL
;
497 mutex_lock(&usb_bus_list_lock
);
498 for (buslist
= usb_bus_list
.next
;
499 buslist
!= &usb_bus_list
;
500 buslist
= buslist
->next
) {
501 bus
= container_of(buslist
, struct usb_bus
, bus_list
);
504 usb_lock_device(bus
->root_hub
);
505 dev
= match_device(bus
->root_hub
, vendor_id
, product_id
);
506 usb_unlock_device(bus
->root_hub
);
511 mutex_unlock(&usb_bus_list_lock
);
516 * usb_get_current_frame_number - return current bus frame number
517 * @dev: the device whose bus is being queried
519 * Returns the current frame number for the USB host controller
520 * used with the given USB device. This can be used when scheduling
521 * isochronous requests.
523 * Note that different kinds of host controller have different
524 * "scheduling horizons". While one type might support scheduling only
525 * 32 frames into the future, others could support scheduling up to
526 * 1024 frames into the future.
528 int usb_get_current_frame_number(struct usb_device
*dev
)
530 return usb_hcd_get_frame_number(dev
);
533 /*-------------------------------------------------------------------*/
535 * __usb_get_extra_descriptor() finds a descriptor of specific type in the
536 * extra field of the interface and endpoint descriptor structs.
539 int __usb_get_extra_descriptor(char *buffer
, unsigned size
,
540 unsigned char type
, void **ptr
)
542 struct usb_descriptor_header
*header
;
544 while (size
>= sizeof(struct usb_descriptor_header
)) {
545 header
= (struct usb_descriptor_header
*)buffer
;
547 if (header
->bLength
< 2) {
549 "%s: bogus descriptor, type %d length %d\n",
551 header
->bDescriptorType
,
556 if (header
->bDescriptorType
== type
) {
561 buffer
+= header
->bLength
;
562 size
-= header
->bLength
;
568 * usb_buffer_alloc - allocate dma-consistent buffer for URB_NO_xxx_DMA_MAP
569 * @dev: device the buffer will be used with
570 * @size: requested buffer size
571 * @mem_flags: affect whether allocation may block
572 * @dma: used to return DMA address of buffer
574 * Return value is either null (indicating no buffer could be allocated), or
575 * the cpu-space pointer to a buffer that may be used to perform DMA to the
576 * specified device. Such cpu-space buffers are returned along with the DMA
577 * address (through the pointer provided).
579 * These buffers are used with URB_NO_xxx_DMA_MAP set in urb->transfer_flags
580 * to avoid behaviors like using "DMA bounce buffers", or tying down I/O
581 * mapping hardware for long idle periods. The implementation varies between
582 * platforms, depending on details of how DMA will work to this device.
583 * Using these buffers also helps prevent cacheline sharing problems on
584 * architectures where CPU caches are not DMA-coherent.
586 * When the buffer is no longer used, free it with usb_buffer_free().
588 void *usb_buffer_alloc(
589 struct usb_device
*dev
,
595 if (!dev
|| !dev
->bus
)
597 return hcd_buffer_alloc(dev
->bus
, size
, mem_flags
, dma
);
601 * usb_buffer_free - free memory allocated with usb_buffer_alloc()
602 * @dev: device the buffer was used with
603 * @size: requested buffer size
604 * @addr: CPU address of buffer
605 * @dma: DMA address of buffer
607 * This reclaims an I/O buffer, letting it be reused. The memory must have
608 * been allocated using usb_buffer_alloc(), and the parameters must match
609 * those provided in that allocation request.
611 void usb_buffer_free(
612 struct usb_device
*dev
,
618 if (!dev
|| !dev
->bus
)
622 hcd_buffer_free(dev
->bus
, size
, addr
, dma
);
626 * usb_buffer_map - create DMA mapping(s) for an urb
627 * @urb: urb whose transfer_buffer/setup_packet will be mapped
629 * Return value is either null (indicating no buffer could be mapped), or
630 * the parameter. URB_NO_TRANSFER_DMA_MAP and URB_NO_SETUP_DMA_MAP are
631 * added to urb->transfer_flags if the operation succeeds. If the device
632 * is connected to this system through a non-DMA controller, this operation
635 * This call would normally be used for an urb which is reused, perhaps
636 * as the target of a large periodic transfer, with usb_buffer_dmasync()
637 * calls to synchronize memory and dma state.
639 * Reverse the effect of this call with usb_buffer_unmap().
642 struct urb
*usb_buffer_map(struct urb
*urb
)
645 struct device
*controller
;
649 || !(bus
= urb
->dev
->bus
)
650 || !(controller
= bus
->controller
))
653 if (controller
->dma_mask
) {
654 urb
->transfer_dma
= dma_map_single(controller
,
655 urb
->transfer_buffer
, urb
->transfer_buffer_length
,
656 usb_pipein(urb
->pipe
)
657 ? DMA_FROM_DEVICE
: DMA_TO_DEVICE
);
658 if (usb_pipecontrol(urb
->pipe
))
659 urb
->setup_dma
= dma_map_single(controller
,
661 sizeof(struct usb_ctrlrequest
),
663 // FIXME generic api broken like pci, can't report errors
664 // if (urb->transfer_dma == DMA_ADDR_INVALID) return 0;
666 urb
->transfer_dma
= ~0;
667 urb
->transfer_flags
|= (URB_NO_TRANSFER_DMA_MAP
668 | URB_NO_SETUP_DMA_MAP
);
673 /* XXX DISABLED, no users currently. If you wish to re-enable this
674 * XXX please determine whether the sync is to transfer ownership of
675 * XXX the buffer from device to cpu or vice verse, and thusly use the
676 * XXX appropriate _for_{cpu,device}() method. -DaveM
681 * usb_buffer_dmasync - synchronize DMA and CPU view of buffer(s)
682 * @urb: urb whose transfer_buffer/setup_packet will be synchronized
684 void usb_buffer_dmasync(struct urb
*urb
)
687 struct device
*controller
;
690 || !(urb
->transfer_flags
& URB_NO_TRANSFER_DMA_MAP
)
692 || !(bus
= urb
->dev
->bus
)
693 || !(controller
= bus
->controller
))
696 if (controller
->dma_mask
) {
697 dma_sync_single(controller
,
698 urb
->transfer_dma
, urb
->transfer_buffer_length
,
699 usb_pipein(urb
->pipe
)
700 ? DMA_FROM_DEVICE
: DMA_TO_DEVICE
);
701 if (usb_pipecontrol(urb
->pipe
))
702 dma_sync_single(controller
,
704 sizeof(struct usb_ctrlrequest
),
711 * usb_buffer_unmap - free DMA mapping(s) for an urb
712 * @urb: urb whose transfer_buffer will be unmapped
714 * Reverses the effect of usb_buffer_map().
717 void usb_buffer_unmap(struct urb
*urb
)
720 struct device
*controller
;
723 || !(urb
->transfer_flags
& URB_NO_TRANSFER_DMA_MAP
)
725 || !(bus
= urb
->dev
->bus
)
726 || !(controller
= bus
->controller
))
729 if (controller
->dma_mask
) {
730 dma_unmap_single(controller
,
731 urb
->transfer_dma
, urb
->transfer_buffer_length
,
732 usb_pipein(urb
->pipe
)
733 ? DMA_FROM_DEVICE
: DMA_TO_DEVICE
);
734 if (usb_pipecontrol(urb
->pipe
))
735 dma_unmap_single(controller
,
737 sizeof(struct usb_ctrlrequest
),
740 urb
->transfer_flags
&= ~(URB_NO_TRANSFER_DMA_MAP
741 | URB_NO_SETUP_DMA_MAP
);
746 * usb_buffer_map_sg - create scatterlist DMA mapping(s) for an endpoint
747 * @dev: device to which the scatterlist will be mapped
748 * @pipe: endpoint defining the mapping direction
749 * @sg: the scatterlist to map
750 * @nents: the number of entries in the scatterlist
752 * Return value is either < 0 (indicating no buffers could be mapped), or
753 * the number of DMA mapping array entries in the scatterlist.
755 * The caller is responsible for placing the resulting DMA addresses from
756 * the scatterlist into URB transfer buffer pointers, and for setting the
757 * URB_NO_TRANSFER_DMA_MAP transfer flag in each of those URBs.
759 * Top I/O rates come from queuing URBs, instead of waiting for each one
760 * to complete before starting the next I/O. This is particularly easy
761 * to do with scatterlists. Just allocate and submit one URB for each DMA
762 * mapping entry returned, stopping on the first error or when all succeed.
763 * Better yet, use the usb_sg_*() calls, which do that (and more) for you.
765 * This call would normally be used when translating scatterlist requests,
766 * rather than usb_buffer_map(), since on some hardware (with IOMMUs) it
767 * may be able to coalesce mappings for improved I/O efficiency.
769 * Reverse the effect of this call with usb_buffer_unmap_sg().
771 int usb_buffer_map_sg(const struct usb_device
*dev
, unsigned pipe
,
772 struct scatterlist
*sg
, int nents
)
775 struct device
*controller
;
778 || usb_pipecontrol(pipe
)
780 || !(controller
= bus
->controller
)
781 || !controller
->dma_mask
)
784 // FIXME generic api broken like pci, can't report errors
785 return dma_map_sg(controller
, sg
, nents
,
786 usb_pipein(pipe
) ? DMA_FROM_DEVICE
: DMA_TO_DEVICE
);
789 /* XXX DISABLED, no users currently. If you wish to re-enable this
790 * XXX please determine whether the sync is to transfer ownership of
791 * XXX the buffer from device to cpu or vice verse, and thusly use the
792 * XXX appropriate _for_{cpu,device}() method. -DaveM
797 * usb_buffer_dmasync_sg - synchronize DMA and CPU view of scatterlist buffer(s)
798 * @dev: device to which the scatterlist will be mapped
799 * @pipe: endpoint defining the mapping direction
800 * @sg: the scatterlist to synchronize
801 * @n_hw_ents: the positive return value from usb_buffer_map_sg
803 * Use this when you are re-using a scatterlist's data buffers for
804 * another USB request.
806 void usb_buffer_dmasync_sg(const struct usb_device
*dev
, unsigned pipe
,
807 struct scatterlist
*sg
, int n_hw_ents
)
810 struct device
*controller
;
814 || !(controller
= bus
->controller
)
815 || !controller
->dma_mask
)
818 dma_sync_sg(controller
, sg
, n_hw_ents
,
819 usb_pipein(pipe
) ? DMA_FROM_DEVICE
: DMA_TO_DEVICE
);
824 * usb_buffer_unmap_sg - free DMA mapping(s) for a scatterlist
825 * @dev: device to which the scatterlist will be mapped
826 * @pipe: endpoint defining the mapping direction
827 * @sg: the scatterlist to unmap
828 * @n_hw_ents: the positive return value from usb_buffer_map_sg
830 * Reverses the effect of usb_buffer_map_sg().
832 void usb_buffer_unmap_sg(const struct usb_device
*dev
, unsigned pipe
,
833 struct scatterlist
*sg
, int n_hw_ents
)
836 struct device
*controller
;
840 || !(controller
= bus
->controller
)
841 || !controller
->dma_mask
)
844 dma_unmap_sg(controller
, sg
, n_hw_ents
,
845 usb_pipein(pipe
) ? DMA_FROM_DEVICE
: DMA_TO_DEVICE
);
848 /* format to disable USB on kernel command line is: nousb */
849 __module_param_call("", nousb
, param_set_bool
, param_get_bool
, &nousb
, 0444);
852 * for external read access to <nousb>
854 int usb_disabled(void)
862 static int __init
usb_init(void)
866 pr_info("%s: USB support disabled\n", usbcore_name
);
870 retval
= ksuspend_usb_init();
873 retval
= bus_register(&usb_bus_type
);
875 goto bus_register_failed
;
876 retval
= usb_host_init();
878 goto host_init_failed
;
879 retval
= usb_major_init();
881 goto major_init_failed
;
882 retval
= usb_register(&usbfs_driver
);
884 goto driver_register_failed
;
885 retval
= usbdev_init();
887 goto usbdevice_init_failed
;
888 retval
= usbfs_init();
891 retval
= usb_hub_init();
893 goto hub_init_failed
;
894 retval
= usb_register_device_driver(&usb_generic_driver
, THIS_MODULE
);
903 usbdevice_init_failed
:
904 usb_deregister(&usbfs_driver
);
905 driver_register_failed
:
910 bus_unregister(&usb_bus_type
);
912 ksuspend_usb_cleanup();
920 static void __exit
usb_exit(void)
922 /* This will matter if shutdown/reboot does exitcalls. */
926 usb_deregister_device_driver(&usb_generic_driver
);
929 usb_deregister(&usbfs_driver
);
933 bus_unregister(&usb_bus_type
);
934 ksuspend_usb_cleanup();
937 subsys_initcall(usb_init
);
938 module_exit(usb_exit
);
941 * USB may be built into the kernel or be built as modules.
942 * These symbols are exported for device (or host controller)
943 * driver modules to use.
946 EXPORT_SYMBOL(usb_disabled
);
948 EXPORT_SYMBOL_GPL(usb_get_intf
);
949 EXPORT_SYMBOL_GPL(usb_put_intf
);
951 EXPORT_SYMBOL(usb_put_dev
);
952 EXPORT_SYMBOL(usb_get_dev
);
953 EXPORT_SYMBOL(usb_hub_tt_clear_buffer
);
955 EXPORT_SYMBOL(usb_lock_device_for_reset
);
957 EXPORT_SYMBOL(usb_find_interface
);
958 EXPORT_SYMBOL(usb_ifnum_to_if
);
959 EXPORT_SYMBOL(usb_altnum_to_altsetting
);
961 EXPORT_SYMBOL(__usb_get_extra_descriptor
);
963 EXPORT_SYMBOL(usb_find_device
);
964 EXPORT_SYMBOL(usb_get_current_frame_number
);
966 EXPORT_SYMBOL(usb_buffer_alloc
);
967 EXPORT_SYMBOL(usb_buffer_free
);
970 EXPORT_SYMBOL(usb_buffer_map
);
971 EXPORT_SYMBOL(usb_buffer_dmasync
);
972 EXPORT_SYMBOL(usb_buffer_unmap
);
975 EXPORT_SYMBOL(usb_buffer_map_sg
);
977 EXPORT_SYMBOL(usb_buffer_dmasync_sg
);
979 EXPORT_SYMBOL(usb_buffer_unmap_sg
);
981 MODULE_LICENSE("GPL");