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
];
99 EXPORT_SYMBOL_GPL(usb_ifnum_to_if
);
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(
120 const struct usb_interface
*intf
,
125 for (i
= 0; i
< intf
->num_altsetting
; i
++) {
126 if (intf
->altsetting
[i
].desc
.bAlternateSetting
== altnum
)
127 return &intf
->altsetting
[i
];
131 EXPORT_SYMBOL_GPL(usb_altnum_to_altsetting
);
133 struct find_interface_arg
{
135 struct usb_interface
*interface
;
138 static int __find_interface(struct device
*dev
, void *data
)
140 struct find_interface_arg
*arg
= data
;
141 struct usb_interface
*intf
;
143 if (!is_usb_interface(dev
))
146 intf
= to_usb_interface(dev
);
147 if (intf
->minor
!= -1 && intf
->minor
== arg
->minor
) {
148 arg
->interface
= intf
;
155 * usb_find_interface - find usb_interface pointer for driver and device
156 * @drv: the driver whose current configuration is considered
157 * @minor: the minor number of the desired device
159 * This walks the driver device list and returns a pointer to the interface
160 * with the matching minor. Note, this only works for devices that share the
163 struct usb_interface
*usb_find_interface(struct usb_driver
*drv
, int minor
)
165 struct find_interface_arg argb
;
169 argb
.interface
= NULL
;
170 /* eat the error, it will be in argb.interface */
171 retval
= driver_for_each_device(&drv
->drvwrap
.driver
, NULL
, &argb
,
173 return argb
.interface
;
175 EXPORT_SYMBOL_GPL(usb_find_interface
);
178 * usb_release_dev - free a usb device structure when all users of it are finished.
179 * @dev: device that's been disconnected
181 * Will be called only by the device core when all users of this usb device are
184 static void usb_release_dev(struct device
*dev
)
186 struct usb_device
*udev
;
188 udev
= to_usb_device(dev
);
190 usb_destroy_configuration(udev
);
191 usb_put_hcd(bus_to_hcd(udev
->bus
));
192 kfree(udev
->product
);
193 kfree(udev
->manufacturer
);
198 struct device_type usb_device_type
= {
199 .name
= "usb_device",
200 .release
= usb_release_dev
,
205 static int ksuspend_usb_init(void)
207 /* This workqueue is supposed to be both freezable and
208 * singlethreaded. Its job doesn't justify running on more
211 ksuspend_usb_wq
= create_singlethread_workqueue("ksuspend_usbd");
212 if (!ksuspend_usb_wq
)
217 static void ksuspend_usb_cleanup(void)
219 destroy_workqueue(ksuspend_usb_wq
);
224 #define ksuspend_usb_init() 0
225 #define ksuspend_usb_cleanup() do {} while (0)
227 #endif /* CONFIG_PM */
230 * usb_alloc_dev - usb device constructor (usbcore-internal)
231 * @parent: hub to which device is connected; null to allocate a root hub
232 * @bus: bus used to access the device
233 * @port1: one-based index of port; ignored for root hubs
234 * Context: !in_interrupt()
236 * Only hub drivers (including virtual root hub drivers for host
237 * controllers) should ever call this.
239 * This call may not be used in a non-sleeping context.
241 struct usb_device
*usb_alloc_dev(struct usb_device
*parent
,
242 struct usb_bus
*bus
, unsigned port1
)
244 struct usb_device
*dev
;
246 dev
= kzalloc(sizeof(*dev
), GFP_KERNEL
);
250 if (!usb_get_hcd(bus_to_hcd(bus
))) {
255 device_initialize(&dev
->dev
);
256 dev
->dev
.bus
= &usb_bus_type
;
257 dev
->dev
.type
= &usb_device_type
;
258 dev
->dev
.groups
= usb_device_groups
;
259 dev
->dev
.dma_mask
= bus
->controller
->dma_mask
;
260 set_dev_node(&dev
->dev
, dev_to_node(bus
->controller
));
261 dev
->state
= USB_STATE_ATTACHED
;
262 atomic_set(&dev
->urbnum
, 0);
264 INIT_LIST_HEAD(&dev
->ep0
.urb_list
);
265 dev
->ep0
.desc
.bLength
= USB_DT_ENDPOINT_SIZE
;
266 dev
->ep0
.desc
.bDescriptorType
= USB_DT_ENDPOINT
;
267 /* ep0 maxpacket comes later, from device descriptor */
268 usb_enable_endpoint(dev
, &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_DELAYED_WORK(&dev
->autosuspend
, usb_autosuspend_work
);
308 dev
->autosuspend_delay
= usb_autosuspend_delay
* HZ
;
309 dev
->connect_time
= jiffies
;
310 dev
->active_duration
= -jiffies
;
316 * usb_get_dev - increments the reference count of the usb device structure
317 * @dev: the device being referenced
319 * Each live reference to a device should be refcounted.
321 * Drivers for USB interfaces should normally record such references in
322 * their probe() methods, when they bind to an interface, and release
323 * them by calling usb_put_dev(), in their disconnect() methods.
325 * A pointer to the device with the incremented reference counter is returned.
327 struct usb_device
*usb_get_dev(struct usb_device
*dev
)
330 get_device(&dev
->dev
);
333 EXPORT_SYMBOL_GPL(usb_get_dev
);
336 * usb_put_dev - release a use of the usb device structure
337 * @dev: device that's been disconnected
339 * Must be called when a user of a device is finished with it. When the last
340 * user of the device calls this function, the memory of the device is freed.
342 void usb_put_dev(struct usb_device
*dev
)
345 put_device(&dev
->dev
);
347 EXPORT_SYMBOL_GPL(usb_put_dev
);
350 * usb_get_intf - increments the reference count of the usb interface structure
351 * @intf: the interface being referenced
353 * Each live reference to a interface must be refcounted.
355 * Drivers for USB interfaces should normally record such references in
356 * their probe() methods, when they bind to an interface, and release
357 * them by calling usb_put_intf(), in their disconnect() methods.
359 * A pointer to the interface with the incremented reference counter is
362 struct usb_interface
*usb_get_intf(struct usb_interface
*intf
)
365 get_device(&intf
->dev
);
368 EXPORT_SYMBOL_GPL(usb_get_intf
);
371 * usb_put_intf - release a use of the usb interface structure
372 * @intf: interface that's been decremented
374 * Must be called when a user of an interface is finished with it. When the
375 * last user of the interface calls this function, the memory of the interface
378 void usb_put_intf(struct usb_interface
*intf
)
381 put_device(&intf
->dev
);
383 EXPORT_SYMBOL_GPL(usb_put_intf
);
385 /* USB device locking
387 * USB devices and interfaces are locked using the semaphore in their
388 * embedded struct device. The hub driver guarantees that whenever a
389 * device is connected or disconnected, drivers are called with the
390 * USB device locked as well as their particular interface.
392 * Complications arise when several devices are to be locked at the same
393 * time. Only hub-aware drivers that are part of usbcore ever have to
394 * do this; nobody else needs to worry about it. The rule for locking
397 * When locking both a device and its parent, always lock the
402 * usb_lock_device_for_reset - cautiously acquire the lock for a
403 * usb device structure
404 * @udev: device that's being locked
405 * @iface: interface bound to the driver making the request (optional)
407 * Attempts to acquire the device lock, but fails if the device is
408 * NOTATTACHED or SUSPENDED, or if iface is specified and the interface
409 * is neither BINDING nor BOUND. Rather than sleeping to wait for the
410 * lock, the routine polls repeatedly. This is to prevent deadlock with
411 * disconnect; in some drivers (such as usb-storage) the disconnect()
412 * or suspend() method will block waiting for a device reset to complete.
414 * Returns a negative error code for failure, otherwise 0.
416 int usb_lock_device_for_reset(struct usb_device
*udev
,
417 const struct usb_interface
*iface
)
419 unsigned long jiffies_expire
= jiffies
+ HZ
;
421 if (udev
->state
== USB_STATE_NOTATTACHED
)
423 if (udev
->state
== USB_STATE_SUSPENDED
)
424 return -EHOSTUNREACH
;
425 if (iface
&& (iface
->condition
== USB_INTERFACE_UNBINDING
||
426 iface
->condition
== USB_INTERFACE_UNBOUND
))
429 while (usb_trylock_device(udev
) != 0) {
431 /* If we can't acquire the lock after waiting one second,
432 * we're probably deadlocked */
433 if (time_after(jiffies
, jiffies_expire
))
437 if (udev
->state
== USB_STATE_NOTATTACHED
)
439 if (udev
->state
== USB_STATE_SUSPENDED
)
440 return -EHOSTUNREACH
;
441 if (iface
&& (iface
->condition
== USB_INTERFACE_UNBINDING
||
442 iface
->condition
== USB_INTERFACE_UNBOUND
))
447 EXPORT_SYMBOL_GPL(usb_lock_device_for_reset
);
449 static struct usb_device
*match_device(struct usb_device
*dev
,
450 u16 vendor_id
, u16 product_id
)
452 struct usb_device
*ret_dev
= NULL
;
455 dev_dbg(&dev
->dev
, "check for vendor %04x, product %04x ...\n",
456 le16_to_cpu(dev
->descriptor
.idVendor
),
457 le16_to_cpu(dev
->descriptor
.idProduct
));
459 /* see if this device matches */
460 if ((vendor_id
== le16_to_cpu(dev
->descriptor
.idVendor
)) &&
461 (product_id
== le16_to_cpu(dev
->descriptor
.idProduct
))) {
462 dev_dbg(&dev
->dev
, "matched this device!\n");
463 ret_dev
= usb_get_dev(dev
);
467 /* look through all of the children of this device */
468 for (child
= 0; child
< dev
->maxchild
; ++child
) {
469 if (dev
->children
[child
]) {
470 usb_lock_device(dev
->children
[child
]);
471 ret_dev
= match_device(dev
->children
[child
],
472 vendor_id
, product_id
);
473 usb_unlock_device(dev
->children
[child
]);
483 * usb_find_device - find a specific usb device in the system
484 * @vendor_id: the vendor id of the device to find
485 * @product_id: the product id of the device to find
487 * Returns a pointer to a struct usb_device if such a specified usb
488 * device is present in the system currently. The usage count of the
489 * device will be incremented if a device is found. Make sure to call
490 * usb_put_dev() when the caller is finished with the device.
492 * If a device with the specified vendor and product id is not found,
495 struct usb_device
*usb_find_device(u16 vendor_id
, u16 product_id
)
497 struct list_head
*buslist
;
499 struct usb_device
*dev
= NULL
;
501 mutex_lock(&usb_bus_list_lock
);
502 for (buslist
= usb_bus_list
.next
;
503 buslist
!= &usb_bus_list
;
504 buslist
= buslist
->next
) {
505 bus
= container_of(buslist
, struct usb_bus
, bus_list
);
508 usb_lock_device(bus
->root_hub
);
509 dev
= match_device(bus
->root_hub
, vendor_id
, product_id
);
510 usb_unlock_device(bus
->root_hub
);
515 mutex_unlock(&usb_bus_list_lock
);
519 static struct usb_device
*match_device_name(struct usb_device
*dev
,
522 struct usb_device
*ret_dev
= NULL
;
525 dev_dbg(&dev
->dev
, "check for name %s ...\n", name
);
527 /* see if this device matches */
528 if (strcmp(dev_name(&dev
->dev
), name
) == 0 ) {
529 dev_dbg(&dev
->dev
, "matched this device!\n");
530 ret_dev
= usb_get_dev(dev
);
534 /* look through all of the children of this device */
535 for (child
= 0; child
< dev
->maxchild
; ++child
) {
536 if (dev
->children
[child
]) {
537 usb_lock_device(dev
->children
[child
]);
538 ret_dev
= match_device_name(dev
->children
[child
], name
);
539 usb_unlock_device(dev
->children
[child
]);
549 * usb_find_device_by_name - find a specific usb device in the system
550 * @name: the name of the device to find
552 * Returns a pointer to a struct usb_device if such a specified usb
553 * device is present in the system currently. The usage count of the
554 * device will be incremented if a device is found. Make sure to call
555 * usb_put_dev() when the caller is finished with the device.
557 * If a device with the specified bus id is not found, NULL is returned.
559 struct usb_device
*usb_find_device_by_name(const char *name
)
561 struct list_head
*buslist
;
563 struct usb_device
*dev
= NULL
;
565 mutex_lock(&usb_bus_list_lock
);
566 for (buslist
= usb_bus_list
.next
;
567 buslist
!= &usb_bus_list
;
568 buslist
= buslist
->next
) {
569 bus
= container_of(buslist
, struct usb_bus
, bus_list
);
572 usb_lock_device(bus
->root_hub
);
573 dev
= match_device_name(bus
->root_hub
, name
);
574 usb_unlock_device(bus
->root_hub
);
579 mutex_unlock(&usb_bus_list_lock
);
582 EXPORT_SYMBOL_GPL(usb_find_device_by_name
);
585 * usb_get_current_frame_number - return current bus frame number
586 * @dev: the device whose bus is being queried
588 * Returns the current frame number for the USB host controller
589 * used with the given USB device. This can be used when scheduling
590 * isochronous requests.
592 * Note that different kinds of host controller have different
593 * "scheduling horizons". While one type might support scheduling only
594 * 32 frames into the future, others could support scheduling up to
595 * 1024 frames into the future.
597 int usb_get_current_frame_number(struct usb_device
*dev
)
599 return usb_hcd_get_frame_number(dev
);
601 EXPORT_SYMBOL_GPL(usb_get_current_frame_number
);
603 /*-------------------------------------------------------------------*/
605 * __usb_get_extra_descriptor() finds a descriptor of specific type in the
606 * extra field of the interface and endpoint descriptor structs.
609 int __usb_get_extra_descriptor(char *buffer
, unsigned size
,
610 unsigned char type
, void **ptr
)
612 struct usb_descriptor_header
*header
;
614 while (size
>= sizeof(struct usb_descriptor_header
)) {
615 header
= (struct usb_descriptor_header
*)buffer
;
617 if (header
->bLength
< 2) {
619 "%s: bogus descriptor, type %d length %d\n",
621 header
->bDescriptorType
,
626 if (header
->bDescriptorType
== type
) {
631 buffer
+= header
->bLength
;
632 size
-= header
->bLength
;
636 EXPORT_SYMBOL_GPL(__usb_get_extra_descriptor
);
639 * usb_buffer_alloc - allocate dma-consistent buffer for URB_NO_xxx_DMA_MAP
640 * @dev: device the buffer will be used with
641 * @size: requested buffer size
642 * @mem_flags: affect whether allocation may block
643 * @dma: used to return DMA address of buffer
645 * Return value is either null (indicating no buffer could be allocated), or
646 * the cpu-space pointer to a buffer that may be used to perform DMA to the
647 * specified device. Such cpu-space buffers are returned along with the DMA
648 * address (through the pointer provided).
650 * These buffers are used with URB_NO_xxx_DMA_MAP set in urb->transfer_flags
651 * to avoid behaviors like using "DMA bounce buffers", or thrashing IOMMU
652 * hardware during URB completion/resubmit. The implementation varies between
653 * platforms, depending on details of how DMA will work to this device.
654 * Using these buffers also eliminates cacheline sharing problems on
655 * architectures where CPU caches are not DMA-coherent. On systems without
656 * bus-snooping caches, these buffers are uncached.
658 * When the buffer is no longer used, free it with usb_buffer_free().
660 void *usb_buffer_alloc(struct usb_device
*dev
, size_t size
, gfp_t mem_flags
,
663 if (!dev
|| !dev
->bus
)
665 return hcd_buffer_alloc(dev
->bus
, size
, mem_flags
, dma
);
667 EXPORT_SYMBOL_GPL(usb_buffer_alloc
);
670 * usb_buffer_free - free memory allocated with usb_buffer_alloc()
671 * @dev: device the buffer was used with
672 * @size: requested buffer size
673 * @addr: CPU address of buffer
674 * @dma: DMA address of buffer
676 * This reclaims an I/O buffer, letting it be reused. The memory must have
677 * been allocated using usb_buffer_alloc(), and the parameters must match
678 * those provided in that allocation request.
680 void usb_buffer_free(struct usb_device
*dev
, size_t size
, void *addr
,
683 if (!dev
|| !dev
->bus
)
687 hcd_buffer_free(dev
->bus
, size
, addr
, dma
);
689 EXPORT_SYMBOL_GPL(usb_buffer_free
);
692 * usb_buffer_map - create DMA mapping(s) for an urb
693 * @urb: urb whose transfer_buffer/setup_packet will be mapped
695 * Return value is either null (indicating no buffer could be mapped), or
696 * the parameter. URB_NO_TRANSFER_DMA_MAP and URB_NO_SETUP_DMA_MAP are
697 * added to urb->transfer_flags if the operation succeeds. If the device
698 * is connected to this system through a non-DMA controller, this operation
701 * This call would normally be used for an urb which is reused, perhaps
702 * as the target of a large periodic transfer, with usb_buffer_dmasync()
703 * calls to synchronize memory and dma state.
705 * Reverse the effect of this call with usb_buffer_unmap().
708 struct urb
*usb_buffer_map(struct urb
*urb
)
711 struct device
*controller
;
715 || !(bus
= urb
->dev
->bus
)
716 || !(controller
= bus
->controller
))
719 if (controller
->dma_mask
) {
720 urb
->transfer_dma
= dma_map_single(controller
,
721 urb
->transfer_buffer
, urb
->transfer_buffer_length
,
722 usb_pipein(urb
->pipe
)
723 ? DMA_FROM_DEVICE
: DMA_TO_DEVICE
);
724 if (usb_pipecontrol(urb
->pipe
))
725 urb
->setup_dma
= dma_map_single(controller
,
727 sizeof(struct usb_ctrlrequest
),
729 /* FIXME generic api broken like pci, can't report errors */
730 /* if (urb->transfer_dma == DMA_ADDR_INVALID) return 0; */
732 urb
->transfer_dma
= ~0;
733 urb
->transfer_flags
|= (URB_NO_TRANSFER_DMA_MAP
734 | URB_NO_SETUP_DMA_MAP
);
737 EXPORT_SYMBOL_GPL(usb_buffer_map
);
740 /* XXX DISABLED, no users currently. If you wish to re-enable this
741 * XXX please determine whether the sync is to transfer ownership of
742 * XXX the buffer from device to cpu or vice verse, and thusly use the
743 * XXX appropriate _for_{cpu,device}() method. -DaveM
748 * usb_buffer_dmasync - synchronize DMA and CPU view of buffer(s)
749 * @urb: urb whose transfer_buffer/setup_packet will be synchronized
751 void usb_buffer_dmasync(struct urb
*urb
)
754 struct device
*controller
;
757 || !(urb
->transfer_flags
& URB_NO_TRANSFER_DMA_MAP
)
759 || !(bus
= urb
->dev
->bus
)
760 || !(controller
= bus
->controller
))
763 if (controller
->dma_mask
) {
764 dma_sync_single(controller
,
765 urb
->transfer_dma
, urb
->transfer_buffer_length
,
766 usb_pipein(urb
->pipe
)
767 ? DMA_FROM_DEVICE
: DMA_TO_DEVICE
);
768 if (usb_pipecontrol(urb
->pipe
))
769 dma_sync_single(controller
,
771 sizeof(struct usb_ctrlrequest
),
775 EXPORT_SYMBOL_GPL(usb_buffer_dmasync
);
779 * usb_buffer_unmap - free DMA mapping(s) for an urb
780 * @urb: urb whose transfer_buffer will be unmapped
782 * Reverses the effect of usb_buffer_map().
785 void usb_buffer_unmap(struct urb
*urb
)
788 struct device
*controller
;
791 || !(urb
->transfer_flags
& URB_NO_TRANSFER_DMA_MAP
)
793 || !(bus
= urb
->dev
->bus
)
794 || !(controller
= bus
->controller
))
797 if (controller
->dma_mask
) {
798 dma_unmap_single(controller
,
799 urb
->transfer_dma
, urb
->transfer_buffer_length
,
800 usb_pipein(urb
->pipe
)
801 ? DMA_FROM_DEVICE
: DMA_TO_DEVICE
);
802 if (usb_pipecontrol(urb
->pipe
))
803 dma_unmap_single(controller
,
805 sizeof(struct usb_ctrlrequest
),
808 urb
->transfer_flags
&= ~(URB_NO_TRANSFER_DMA_MAP
809 | URB_NO_SETUP_DMA_MAP
);
811 EXPORT_SYMBOL_GPL(usb_buffer_unmap
);
815 * usb_buffer_map_sg - create scatterlist DMA mapping(s) for an endpoint
816 * @dev: device to which the scatterlist will be mapped
817 * @is_in: mapping transfer direction
818 * @sg: the scatterlist to map
819 * @nents: the number of entries in the scatterlist
821 * Return value is either < 0 (indicating no buffers could be mapped), or
822 * the number of DMA mapping array entries in the scatterlist.
824 * The caller is responsible for placing the resulting DMA addresses from
825 * the scatterlist into URB transfer buffer pointers, and for setting the
826 * URB_NO_TRANSFER_DMA_MAP transfer flag in each of those URBs.
828 * Top I/O rates come from queuing URBs, instead of waiting for each one
829 * to complete before starting the next I/O. This is particularly easy
830 * to do with scatterlists. Just allocate and submit one URB for each DMA
831 * mapping entry returned, stopping on the first error or when all succeed.
832 * Better yet, use the usb_sg_*() calls, which do that (and more) for you.
834 * This call would normally be used when translating scatterlist requests,
835 * rather than usb_buffer_map(), since on some hardware (with IOMMUs) it
836 * may be able to coalesce mappings for improved I/O efficiency.
838 * Reverse the effect of this call with usb_buffer_unmap_sg().
840 int usb_buffer_map_sg(const struct usb_device
*dev
, int is_in
,
841 struct scatterlist
*sg
, int nents
)
844 struct device
*controller
;
848 || !(controller
= bus
->controller
)
849 || !controller
->dma_mask
)
852 /* FIXME generic api broken like pci, can't report errors */
853 return dma_map_sg(controller
, sg
, nents
,
854 is_in
? DMA_FROM_DEVICE
: DMA_TO_DEVICE
);
856 EXPORT_SYMBOL_GPL(usb_buffer_map_sg
);
858 /* XXX DISABLED, no users currently. If you wish to re-enable this
859 * XXX please determine whether the sync is to transfer ownership of
860 * XXX the buffer from device to cpu or vice verse, and thusly use the
861 * XXX appropriate _for_{cpu,device}() method. -DaveM
866 * usb_buffer_dmasync_sg - synchronize DMA and CPU view of scatterlist buffer(s)
867 * @dev: device to which the scatterlist will be mapped
868 * @is_in: mapping transfer direction
869 * @sg: the scatterlist to synchronize
870 * @n_hw_ents: the positive return value from usb_buffer_map_sg
872 * Use this when you are re-using a scatterlist's data buffers for
873 * another USB request.
875 void usb_buffer_dmasync_sg(const struct usb_device
*dev
, int is_in
,
876 struct scatterlist
*sg
, int n_hw_ents
)
879 struct device
*controller
;
883 || !(controller
= bus
->controller
)
884 || !controller
->dma_mask
)
887 dma_sync_sg(controller
, sg
, n_hw_ents
,
888 is_in
? DMA_FROM_DEVICE
: DMA_TO_DEVICE
);
890 EXPORT_SYMBOL_GPL(usb_buffer_dmasync_sg
);
894 * usb_buffer_unmap_sg - free DMA mapping(s) for a scatterlist
895 * @dev: device to which the scatterlist will be mapped
896 * @is_in: mapping transfer direction
897 * @sg: the scatterlist to unmap
898 * @n_hw_ents: the positive return value from usb_buffer_map_sg
900 * Reverses the effect of usb_buffer_map_sg().
902 void usb_buffer_unmap_sg(const struct usb_device
*dev
, int is_in
,
903 struct scatterlist
*sg
, int n_hw_ents
)
906 struct device
*controller
;
910 || !(controller
= bus
->controller
)
911 || !controller
->dma_mask
)
914 dma_unmap_sg(controller
, sg
, n_hw_ents
,
915 is_in
? DMA_FROM_DEVICE
: DMA_TO_DEVICE
);
917 EXPORT_SYMBOL_GPL(usb_buffer_unmap_sg
);
919 /* format to disable USB on kernel command line is: nousb */
920 __module_param_call("", nousb
, param_set_bool
, param_get_bool
, &nousb
, 0444);
923 * for external read access to <nousb>
925 int usb_disabled(void)
929 EXPORT_SYMBOL_GPL(usb_disabled
);
934 static int __init
usb_init(void)
938 pr_info("%s: USB support disabled\n", usbcore_name
);
942 retval
= ksuspend_usb_init();
945 retval
= bus_register(&usb_bus_type
);
947 goto bus_register_failed
;
948 retval
= usb_host_init();
950 goto host_init_failed
;
951 retval
= usb_major_init();
953 goto major_init_failed
;
954 retval
= usb_register(&usbfs_driver
);
956 goto driver_register_failed
;
957 retval
= usb_devio_init();
959 goto usb_devio_init_failed
;
960 retval
= usbfs_init();
963 retval
= usb_hub_init();
965 goto hub_init_failed
;
966 retval
= usb_register_device_driver(&usb_generic_driver
, THIS_MODULE
);
975 usb_devio_init_failed
:
976 usb_deregister(&usbfs_driver
);
977 driver_register_failed
:
982 bus_unregister(&usb_bus_type
);
984 ksuspend_usb_cleanup();
992 static void __exit
usb_exit(void)
994 /* This will matter if shutdown/reboot does exitcalls. */
998 usb_deregister_device_driver(&usb_generic_driver
);
1001 usb_deregister(&usbfs_driver
);
1002 usb_devio_cleanup();
1005 bus_unregister(&usb_bus_type
);
1006 ksuspend_usb_cleanup();
1009 subsys_initcall(usb_init
);
1010 module_exit(usb_exit
);
1011 MODULE_LICENSE("GPL");