2 * drivers/usb/core/usb.c
4 * (C) Copyright Linus Torvalds 1999
5 * (C) Copyright Johannes Erdfelt 1999-2001
6 * (C) Copyright Andreas Gal 1999
7 * (C) Copyright Gregory P. Smith 1999
8 * (C) Copyright Deti Fliegl 1999 (new USB architecture)
9 * (C) Copyright Randy Dunlap 2000
10 * (C) Copyright David Brownell 2000-2004
11 * (C) Copyright Yggdrasil Computing, Inc. 2000
12 * (usb_device_id matching changes by Adam J. Richter)
13 * (C) Copyright Greg Kroah-Hartman 2002-2003
15 * NOTE! This is not actually a driver at all, rather this is
16 * just a collection of helper routines that implement the
17 * generic USB things that the real drivers can use..
19 * Think of this as a "USB library" rather than anything else.
20 * It should be considered a slave, with no callbacks. Callbacks
24 #include <linux/module.h>
25 #include <linux/moduleparam.h>
26 #include <linux/string.h>
27 #include <linux/bitops.h>
28 #include <linux/slab.h>
29 #include <linux/interrupt.h> /* for in_interrupt() */
30 #include <linux/kmod.h>
31 #include <linux/init.h>
32 #include <linux/spinlock.h>
33 #include <linux/errno.h>
34 #include <linux/usb.h>
35 #include <linux/mutex.h>
36 #include <linux/workqueue.h>
39 #include <asm/scatterlist.h>
41 #include <linux/dma-mapping.h>
47 const char *usbcore_name
= "usbcore";
49 static int nousb
; /* Disable USB when built into kernel image */
51 /* Workqueue for autosuspend and for remote wakeup of root hubs */
52 struct workqueue_struct
*ksuspend_usb_wq
;
54 #ifdef CONFIG_USB_SUSPEND
55 static int usb_autosuspend_delay
= 2; /* Default delay value,
57 module_param_named(autosuspend
, usb_autosuspend_delay
, int, 0644);
58 MODULE_PARM_DESC(autosuspend
, "default autosuspend delay");
61 #define usb_autosuspend_delay 0
66 * usb_ifnum_to_if - get the interface object with a given interface number
67 * @dev: the device whose current configuration is considered
68 * @ifnum: the desired interface
70 * This walks the device descriptor for the currently active configuration
71 * and returns a pointer to the interface with that particular interface
74 * Note that configuration descriptors are not required to assign interface
75 * numbers sequentially, so that it would be incorrect to assume that
76 * the first interface in that descriptor corresponds to interface zero.
77 * This routine helps device drivers avoid such mistakes.
78 * However, you should make sure that you do the right thing with any
79 * alternate settings available for this interfaces.
81 * Don't call this function unless you are bound to one of the interfaces
82 * on this device or you have locked the device!
84 struct usb_interface
*usb_ifnum_to_if(const struct usb_device
*dev
,
87 struct usb_host_config
*config
= dev
->actconfig
;
92 for (i
= 0; i
< config
->desc
.bNumInterfaces
; i
++)
93 if (config
->interface
[i
]->altsetting
[0]
94 .desc
.bInterfaceNumber
== ifnum
)
95 return config
->interface
[i
];
101 * usb_altnum_to_altsetting - get the altsetting structure with a given
102 * alternate setting number.
103 * @intf: the interface containing the altsetting in question
104 * @altnum: the desired alternate setting number
106 * This searches the altsetting array of the specified interface for
107 * an entry with the correct bAlternateSetting value and returns a pointer
108 * to that entry, or null.
110 * Note that altsettings need not be stored sequentially by number, so
111 * it would be incorrect to assume that the first altsetting entry in
112 * the array corresponds to altsetting zero. This routine helps device
113 * drivers avoid such mistakes.
115 * Don't call this function unless you are bound to the intf interface
116 * or you have locked the device!
118 struct usb_host_interface
*usb_altnum_to_altsetting(const struct usb_interface
*intf
,
123 for (i
= 0; i
< intf
->num_altsetting
; i
++) {
124 if (intf
->altsetting
[i
].desc
.bAlternateSetting
== altnum
)
125 return &intf
->altsetting
[i
];
130 struct find_interface_arg
{
132 struct usb_interface
*interface
;
135 static int __find_interface(struct device
* dev
, void * data
)
137 struct find_interface_arg
*arg
= data
;
138 struct usb_interface
*intf
;
140 /* can't look at usb devices, only interfaces */
141 if (is_usb_device(dev
))
144 intf
= to_usb_interface(dev
);
145 if (intf
->minor
!= -1 && intf
->minor
== arg
->minor
) {
146 arg
->interface
= intf
;
153 * usb_find_interface - find usb_interface pointer for driver and device
154 * @drv: the driver whose current configuration is considered
155 * @minor: the minor number of the desired device
157 * This walks the driver device list and returns a pointer to the interface
158 * with the matching minor. Note, this only works for devices that share the
161 struct usb_interface
*usb_find_interface(struct usb_driver
*drv
, int minor
)
163 struct find_interface_arg argb
;
167 argb
.interface
= NULL
;
168 /* eat the error, it will be in argb.interface */
169 retval
= driver_for_each_device(&drv
->drvwrap
.driver
, NULL
, &argb
,
171 return argb
.interface
;
175 * usb_release_dev - free a usb device structure when all users of it are finished.
176 * @dev: device that's been disconnected
178 * Will be called only by the device core when all users of this usb device are
181 static void usb_release_dev(struct device
*dev
)
183 struct usb_device
*udev
;
185 udev
= to_usb_device(dev
);
187 #ifdef CONFIG_USB_SUSPEND
188 cancel_delayed_work(&udev
->autosuspend
);
189 flush_workqueue(ksuspend_usb_wq
);
191 usb_destroy_configuration(udev
);
192 usb_put_hcd(bus_to_hcd(udev
->bus
));
193 kfree(udev
->product
);
194 kfree(udev
->manufacturer
);
199 struct device_type usb_device_type
= {
200 .name
= "usb_device",
201 .release
= usb_release_dev
,
206 static int ksuspend_usb_init(void)
208 ksuspend_usb_wq
= create_singlethread_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 dev
->state
= USB_STATE_ATTACHED
;
258 INIT_LIST_HEAD(&dev
->ep0
.urb_list
);
259 dev
->ep0
.desc
.bLength
= USB_DT_ENDPOINT_SIZE
;
260 dev
->ep0
.desc
.bDescriptorType
= USB_DT_ENDPOINT
;
261 /* ep0 maxpacket comes later, from device descriptor */
262 dev
->ep_in
[0] = dev
->ep_out
[0] = &dev
->ep0
;
264 /* Save readable and stable topology id, distinguishing devices
265 * by location for diagnostics, tools, driver model, etc. The
266 * string is a path along hub ports, from the root. Each device's
267 * dev->devpath will be stable until USB is re-cabled, and hubs
268 * are often labeled with these port numbers. The bus_id isn't
269 * as stable: bus->busnum changes easily from modprobe order,
270 * cardbus or pci hotplugging, and so on.
272 if (unlikely(!parent
)) {
273 dev
->devpath
[0] = '0';
275 dev
->dev
.parent
= bus
->controller
;
276 sprintf(&dev
->dev
.bus_id
[0], "usb%d", bus
->busnum
);
278 /* match any labeling on the hubs; it's one-based */
279 if (parent
->devpath
[0] == '0')
280 snprintf(dev
->devpath
, sizeof dev
->devpath
,
283 snprintf(dev
->devpath
, sizeof dev
->devpath
,
284 "%s.%d", parent
->devpath
, port1
);
286 dev
->dev
.parent
= &parent
->dev
;
287 sprintf(&dev
->dev
.bus_id
[0], "%d-%s",
288 bus
->busnum
, dev
->devpath
);
290 /* hub driver sets up TT records */
293 dev
->portnum
= port1
;
295 dev
->parent
= parent
;
296 INIT_LIST_HEAD(&dev
->filelist
);
299 mutex_init(&dev
->pm_mutex
);
300 INIT_DELAYED_WORK(&dev
->autosuspend
, usb_autosuspend_work
);
301 dev
->autosuspend_delay
= usb_autosuspend_delay
* HZ
;
307 * usb_get_dev - increments the reference count of the usb device structure
308 * @dev: the device being referenced
310 * Each live reference to a device should be refcounted.
312 * Drivers for USB interfaces should normally record such references in
313 * their probe() methods, when they bind to an interface, and release
314 * them by calling usb_put_dev(), in their disconnect() methods.
316 * A pointer to the device with the incremented reference counter is returned.
318 struct usb_device
*usb_get_dev(struct usb_device
*dev
)
321 get_device(&dev
->dev
);
326 * usb_put_dev - release a use of the usb device structure
327 * @dev: device that's been disconnected
329 * Must be called when a user of a device is finished with it. When the last
330 * user of the device calls this function, the memory of the device is freed.
332 void usb_put_dev(struct usb_device
*dev
)
335 put_device(&dev
->dev
);
339 * usb_get_intf - increments the reference count of the usb interface structure
340 * @intf: the interface being referenced
342 * Each live reference to a interface must be refcounted.
344 * Drivers for USB interfaces should normally record such references in
345 * their probe() methods, when they bind to an interface, and release
346 * them by calling usb_put_intf(), in their disconnect() methods.
348 * A pointer to the interface with the incremented reference counter is
351 struct usb_interface
*usb_get_intf(struct usb_interface
*intf
)
354 get_device(&intf
->dev
);
359 * usb_put_intf - release a use of the usb interface structure
360 * @intf: interface that's been decremented
362 * Must be called when a user of an interface is finished with it. When the
363 * last user of the interface calls this function, the memory of the interface
366 void usb_put_intf(struct usb_interface
*intf
)
369 put_device(&intf
->dev
);
373 /* USB device locking
375 * USB devices and interfaces are locked using the semaphore in their
376 * embedded struct device. The hub driver guarantees that whenever a
377 * device is connected or disconnected, drivers are called with the
378 * USB device locked as well as their particular interface.
380 * Complications arise when several devices are to be locked at the same
381 * time. Only hub-aware drivers that are part of usbcore ever have to
382 * do this; nobody else needs to worry about it. The rule for locking
385 * When locking both a device and its parent, always lock the
390 * usb_lock_device_for_reset - cautiously acquire the lock for a
391 * usb device structure
392 * @udev: device that's being locked
393 * @iface: interface bound to the driver making the request (optional)
395 * Attempts to acquire the device lock, but fails if the device is
396 * NOTATTACHED or SUSPENDED, or if iface is specified and the interface
397 * is neither BINDING nor BOUND. Rather than sleeping to wait for the
398 * lock, the routine polls repeatedly. This is to prevent deadlock with
399 * disconnect; in some drivers (such as usb-storage) the disconnect()
400 * or suspend() method will block waiting for a device reset to complete.
402 * Returns a negative error code for failure, otherwise 1 or 0 to indicate
403 * that the device will or will not have to be unlocked. (0 can be
404 * returned when an interface is given and is BINDING, because in that
405 * case the driver already owns the device lock.)
407 int usb_lock_device_for_reset(struct usb_device
*udev
,
408 const struct usb_interface
*iface
)
410 unsigned long jiffies_expire
= jiffies
+ HZ
;
412 if (udev
->state
== USB_STATE_NOTATTACHED
)
414 if (udev
->state
== USB_STATE_SUSPENDED
)
415 return -EHOSTUNREACH
;
417 switch (iface
->condition
) {
418 case USB_INTERFACE_BINDING
:
420 case USB_INTERFACE_BOUND
:
427 while (usb_trylock_device(udev
) != 0) {
429 /* If we can't acquire the lock after waiting one second,
430 * we're probably deadlocked */
431 if (time_after(jiffies
, jiffies_expire
))
435 if (udev
->state
== USB_STATE_NOTATTACHED
)
437 if (udev
->state
== USB_STATE_SUSPENDED
)
438 return -EHOSTUNREACH
;
439 if (iface
&& iface
->condition
!= USB_INTERFACE_BOUND
)
446 static struct usb_device
*match_device(struct usb_device
*dev
,
447 u16 vendor_id
, u16 product_id
)
449 struct usb_device
*ret_dev
= NULL
;
452 dev_dbg(&dev
->dev
, "check for vendor %04x, product %04x ...\n",
453 le16_to_cpu(dev
->descriptor
.idVendor
),
454 le16_to_cpu(dev
->descriptor
.idProduct
));
456 /* see if this device matches */
457 if ((vendor_id
== le16_to_cpu(dev
->descriptor
.idVendor
)) &&
458 (product_id
== le16_to_cpu(dev
->descriptor
.idProduct
))) {
459 dev_dbg(&dev
->dev
, "matched this device!\n");
460 ret_dev
= usb_get_dev(dev
);
464 /* look through all of the children of this device */
465 for (child
= 0; child
< dev
->maxchild
; ++child
) {
466 if (dev
->children
[child
]) {
467 usb_lock_device(dev
->children
[child
]);
468 ret_dev
= match_device(dev
->children
[child
],
469 vendor_id
, product_id
);
470 usb_unlock_device(dev
->children
[child
]);
480 * usb_find_device - find a specific usb device in the system
481 * @vendor_id: the vendor id of the device to find
482 * @product_id: the product id of the device to find
484 * Returns a pointer to a struct usb_device if such a specified usb
485 * device is present in the system currently. The usage count of the
486 * device will be incremented if a device is found. Make sure to call
487 * usb_put_dev() when the caller is finished with the device.
489 * If a device with the specified vendor and product id is not found,
492 struct usb_device
*usb_find_device(u16 vendor_id
, u16 product_id
)
494 struct list_head
*buslist
;
496 struct usb_device
*dev
= NULL
;
498 mutex_lock(&usb_bus_list_lock
);
499 for (buslist
= usb_bus_list
.next
;
500 buslist
!= &usb_bus_list
;
501 buslist
= buslist
->next
) {
502 bus
= container_of(buslist
, struct usb_bus
, bus_list
);
505 usb_lock_device(bus
->root_hub
);
506 dev
= match_device(bus
->root_hub
, vendor_id
, product_id
);
507 usb_unlock_device(bus
->root_hub
);
512 mutex_unlock(&usb_bus_list_lock
);
517 * usb_get_current_frame_number - return current bus frame number
518 * @dev: the device whose bus is being queried
520 * Returns the current frame number for the USB host controller
521 * used with the given USB device. This can be used when scheduling
522 * isochronous requests.
524 * Note that different kinds of host controller have different
525 * "scheduling horizons". While one type might support scheduling only
526 * 32 frames into the future, others could support scheduling up to
527 * 1024 frames into the future.
529 int usb_get_current_frame_number(struct usb_device
*dev
)
531 return usb_hcd_get_frame_number(dev
);
534 /*-------------------------------------------------------------------*/
536 * __usb_get_extra_descriptor() finds a descriptor of specific type in the
537 * extra field of the interface and endpoint descriptor structs.
540 int __usb_get_extra_descriptor(char *buffer
, unsigned size
,
541 unsigned char type
, void **ptr
)
543 struct usb_descriptor_header
*header
;
545 while (size
>= sizeof(struct usb_descriptor_header
)) {
546 header
= (struct usb_descriptor_header
*)buffer
;
548 if (header
->bLength
< 2) {
550 "%s: bogus descriptor, type %d length %d\n",
552 header
->bDescriptorType
,
557 if (header
->bDescriptorType
== type
) {
562 buffer
+= header
->bLength
;
563 size
-= header
->bLength
;
569 * usb_buffer_alloc - allocate dma-consistent buffer for URB_NO_xxx_DMA_MAP
570 * @dev: device the buffer will be used with
571 * @size: requested buffer size
572 * @mem_flags: affect whether allocation may block
573 * @dma: used to return DMA address of buffer
575 * Return value is either null (indicating no buffer could be allocated), or
576 * the cpu-space pointer to a buffer that may be used to perform DMA to the
577 * specified device. Such cpu-space buffers are returned along with the DMA
578 * address (through the pointer provided).
580 * These buffers are used with URB_NO_xxx_DMA_MAP set in urb->transfer_flags
581 * to avoid behaviors like using "DMA bounce buffers", or tying down I/O
582 * mapping hardware for long idle periods. The implementation varies between
583 * platforms, depending on details of how DMA will work to this device.
584 * Using these buffers also helps prevent cacheline sharing problems on
585 * architectures where CPU caches are not DMA-coherent.
587 * When the buffer is no longer used, free it with usb_buffer_free().
589 void *usb_buffer_alloc(
590 struct usb_device
*dev
,
596 if (!dev
|| !dev
->bus
)
598 return hcd_buffer_alloc(dev
->bus
, size
, mem_flags
, dma
);
602 * usb_buffer_free - free memory allocated with usb_buffer_alloc()
603 * @dev: device the buffer was used with
604 * @size: requested buffer size
605 * @addr: CPU address of buffer
606 * @dma: DMA address of buffer
608 * This reclaims an I/O buffer, letting it be reused. The memory must have
609 * been allocated using usb_buffer_alloc(), and the parameters must match
610 * those provided in that allocation request.
612 void usb_buffer_free(
613 struct usb_device
*dev
,
619 if (!dev
|| !dev
->bus
)
623 hcd_buffer_free(dev
->bus
, size
, addr
, dma
);
627 * usb_buffer_map - create DMA mapping(s) for an urb
628 * @urb: urb whose transfer_buffer/setup_packet will be mapped
630 * Return value is either null (indicating no buffer could be mapped), or
631 * the parameter. URB_NO_TRANSFER_DMA_MAP and URB_NO_SETUP_DMA_MAP are
632 * added to urb->transfer_flags if the operation succeeds. If the device
633 * is connected to this system through a non-DMA controller, this operation
636 * This call would normally be used for an urb which is reused, perhaps
637 * as the target of a large periodic transfer, with usb_buffer_dmasync()
638 * calls to synchronize memory and dma state.
640 * Reverse the effect of this call with usb_buffer_unmap().
643 struct urb
*usb_buffer_map(struct urb
*urb
)
646 struct device
*controller
;
650 || !(bus
= urb
->dev
->bus
)
651 || !(controller
= bus
->controller
))
654 if (controller
->dma_mask
) {
655 urb
->transfer_dma
= dma_map_single(controller
,
656 urb
->transfer_buffer
, urb
->transfer_buffer_length
,
657 usb_pipein(urb
->pipe
)
658 ? DMA_FROM_DEVICE
: DMA_TO_DEVICE
);
659 if (usb_pipecontrol(urb
->pipe
))
660 urb
->setup_dma
= dma_map_single(controller
,
662 sizeof(struct usb_ctrlrequest
),
664 // FIXME generic api broken like pci, can't report errors
665 // if (urb->transfer_dma == DMA_ADDR_INVALID) return 0;
667 urb
->transfer_dma
= ~0;
668 urb
->transfer_flags
|= (URB_NO_TRANSFER_DMA_MAP
669 | URB_NO_SETUP_DMA_MAP
);
674 /* XXX DISABLED, no users currently. If you wish to re-enable this
675 * XXX please determine whether the sync is to transfer ownership of
676 * XXX the buffer from device to cpu or vice verse, and thusly use the
677 * XXX appropriate _for_{cpu,device}() method. -DaveM
682 * usb_buffer_dmasync - synchronize DMA and CPU view of buffer(s)
683 * @urb: urb whose transfer_buffer/setup_packet will be synchronized
685 void usb_buffer_dmasync(struct urb
*urb
)
688 struct device
*controller
;
691 || !(urb
->transfer_flags
& URB_NO_TRANSFER_DMA_MAP
)
693 || !(bus
= urb
->dev
->bus
)
694 || !(controller
= bus
->controller
))
697 if (controller
->dma_mask
) {
698 dma_sync_single(controller
,
699 urb
->transfer_dma
, urb
->transfer_buffer_length
,
700 usb_pipein(urb
->pipe
)
701 ? DMA_FROM_DEVICE
: DMA_TO_DEVICE
);
702 if (usb_pipecontrol(urb
->pipe
))
703 dma_sync_single(controller
,
705 sizeof(struct usb_ctrlrequest
),
712 * usb_buffer_unmap - free DMA mapping(s) for an urb
713 * @urb: urb whose transfer_buffer will be unmapped
715 * Reverses the effect of usb_buffer_map().
718 void usb_buffer_unmap(struct urb
*urb
)
721 struct device
*controller
;
724 || !(urb
->transfer_flags
& URB_NO_TRANSFER_DMA_MAP
)
726 || !(bus
= urb
->dev
->bus
)
727 || !(controller
= bus
->controller
))
730 if (controller
->dma_mask
) {
731 dma_unmap_single(controller
,
732 urb
->transfer_dma
, urb
->transfer_buffer_length
,
733 usb_pipein(urb
->pipe
)
734 ? DMA_FROM_DEVICE
: DMA_TO_DEVICE
);
735 if (usb_pipecontrol(urb
->pipe
))
736 dma_unmap_single(controller
,
738 sizeof(struct usb_ctrlrequest
),
741 urb
->transfer_flags
&= ~(URB_NO_TRANSFER_DMA_MAP
742 | URB_NO_SETUP_DMA_MAP
);
747 * usb_buffer_map_sg - create scatterlist DMA mapping(s) for an endpoint
748 * @dev: device to which the scatterlist will be mapped
749 * @pipe: endpoint defining the mapping direction
750 * @sg: the scatterlist to map
751 * @nents: the number of entries in the scatterlist
753 * Return value is either < 0 (indicating no buffers could be mapped), or
754 * the number of DMA mapping array entries in the scatterlist.
756 * The caller is responsible for placing the resulting DMA addresses from
757 * the scatterlist into URB transfer buffer pointers, and for setting the
758 * URB_NO_TRANSFER_DMA_MAP transfer flag in each of those URBs.
760 * Top I/O rates come from queuing URBs, instead of waiting for each one
761 * to complete before starting the next I/O. This is particularly easy
762 * to do with scatterlists. Just allocate and submit one URB for each DMA
763 * mapping entry returned, stopping on the first error or when all succeed.
764 * Better yet, use the usb_sg_*() calls, which do that (and more) for you.
766 * This call would normally be used when translating scatterlist requests,
767 * rather than usb_buffer_map(), since on some hardware (with IOMMUs) it
768 * may be able to coalesce mappings for improved I/O efficiency.
770 * Reverse the effect of this call with usb_buffer_unmap_sg().
772 int usb_buffer_map_sg(const struct usb_device
*dev
, unsigned pipe
,
773 struct scatterlist
*sg
, int nents
)
776 struct device
*controller
;
779 || usb_pipecontrol(pipe
)
781 || !(controller
= bus
->controller
)
782 || !controller
->dma_mask
)
785 // FIXME generic api broken like pci, can't report errors
786 return dma_map_sg(controller
, sg
, nents
,
787 usb_pipein(pipe
) ? DMA_FROM_DEVICE
: DMA_TO_DEVICE
);
790 /* XXX DISABLED, no users currently. If you wish to re-enable this
791 * XXX please determine whether the sync is to transfer ownership of
792 * XXX the buffer from device to cpu or vice verse, and thusly use the
793 * XXX appropriate _for_{cpu,device}() method. -DaveM
798 * usb_buffer_dmasync_sg - synchronize DMA and CPU view of scatterlist buffer(s)
799 * @dev: device to which the scatterlist will be mapped
800 * @pipe: endpoint defining the mapping direction
801 * @sg: the scatterlist to synchronize
802 * @n_hw_ents: the positive return value from usb_buffer_map_sg
804 * Use this when you are re-using a scatterlist's data buffers for
805 * another USB request.
807 void usb_buffer_dmasync_sg(const struct usb_device
*dev
, unsigned pipe
,
808 struct scatterlist
*sg
, int n_hw_ents
)
811 struct device
*controller
;
815 || !(controller
= bus
->controller
)
816 || !controller
->dma_mask
)
819 dma_sync_sg(controller
, sg
, n_hw_ents
,
820 usb_pipein(pipe
) ? DMA_FROM_DEVICE
: DMA_TO_DEVICE
);
825 * usb_buffer_unmap_sg - free DMA mapping(s) for a scatterlist
826 * @dev: device to which the scatterlist will be mapped
827 * @pipe: endpoint defining the mapping direction
828 * @sg: the scatterlist to unmap
829 * @n_hw_ents: the positive return value from usb_buffer_map_sg
831 * Reverses the effect of usb_buffer_map_sg().
833 void usb_buffer_unmap_sg(const struct usb_device
*dev
, unsigned pipe
,
834 struct scatterlist
*sg
, int n_hw_ents
)
837 struct device
*controller
;
841 || !(controller
= bus
->controller
)
842 || !controller
->dma_mask
)
845 dma_unmap_sg(controller
, sg
, n_hw_ents
,
846 usb_pipein(pipe
) ? DMA_FROM_DEVICE
: DMA_TO_DEVICE
);
849 /* format to disable USB on kernel command line is: nousb */
850 __module_param_call("", nousb
, param_set_bool
, param_get_bool
, &nousb
, 0444);
853 * for external read access to <nousb>
855 int usb_disabled(void)
863 static int __init
usb_init(void)
867 pr_info("%s: USB support disabled\n", usbcore_name
);
871 retval
= ksuspend_usb_init();
874 retval
= bus_register(&usb_bus_type
);
876 goto bus_register_failed
;
877 retval
= usb_host_init();
879 goto host_init_failed
;
880 retval
= usb_major_init();
882 goto major_init_failed
;
883 retval
= usb_register(&usbfs_driver
);
885 goto driver_register_failed
;
886 retval
= usb_devio_init();
888 goto usb_devio_init_failed
;
889 retval
= usbfs_init();
892 retval
= usb_hub_init();
894 goto hub_init_failed
;
895 retval
= usb_register_device_driver(&usb_generic_driver
, THIS_MODULE
);
904 usb_devio_init_failed
:
905 usb_deregister(&usbfs_driver
);
906 driver_register_failed
:
911 bus_unregister(&usb_bus_type
);
913 ksuspend_usb_cleanup();
921 static void __exit
usb_exit(void)
923 /* This will matter if shutdown/reboot does exitcalls. */
927 usb_deregister_device_driver(&usb_generic_driver
);
930 usb_deregister(&usbfs_driver
);
934 bus_unregister(&usb_bus_type
);
935 ksuspend_usb_cleanup();
938 subsys_initcall(usb_init
);
939 module_exit(usb_exit
);
942 * USB may be built into the kernel or be built as modules.
943 * These symbols are exported for device (or host controller)
944 * driver modules to use.
947 EXPORT_SYMBOL(usb_disabled
);
949 EXPORT_SYMBOL_GPL(usb_get_intf
);
950 EXPORT_SYMBOL_GPL(usb_put_intf
);
952 EXPORT_SYMBOL(usb_put_dev
);
953 EXPORT_SYMBOL(usb_get_dev
);
954 EXPORT_SYMBOL(usb_hub_tt_clear_buffer
);
956 EXPORT_SYMBOL(usb_lock_device_for_reset
);
958 EXPORT_SYMBOL(usb_find_interface
);
959 EXPORT_SYMBOL(usb_ifnum_to_if
);
960 EXPORT_SYMBOL(usb_altnum_to_altsetting
);
962 EXPORT_SYMBOL(__usb_get_extra_descriptor
);
964 EXPORT_SYMBOL(usb_find_device
);
965 EXPORT_SYMBOL(usb_get_current_frame_number
);
967 EXPORT_SYMBOL(usb_buffer_alloc
);
968 EXPORT_SYMBOL(usb_buffer_free
);
971 EXPORT_SYMBOL(usb_buffer_map
);
972 EXPORT_SYMBOL(usb_buffer_dmasync
);
973 EXPORT_SYMBOL(usb_buffer_unmap
);
976 EXPORT_SYMBOL(usb_buffer_map_sg
);
978 EXPORT_SYMBOL(usb_buffer_dmasync_sg
);
980 EXPORT_SYMBOL(usb_buffer_unmap_sg
);
982 MODULE_LICENSE("GPL");