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 <linux/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 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(
119 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
];
130 EXPORT_SYMBOL_GPL(usb_altnum_to_altsetting
);
132 struct find_interface_arg
{
134 struct usb_interface
*interface
;
137 static int __find_interface(struct device
*dev
, void *data
)
139 struct find_interface_arg
*arg
= data
;
140 struct usb_interface
*intf
;
142 /* can't look at usb devices, only interfaces */
143 if (is_usb_device(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 #ifdef CONFIG_HOTPLUG
199 static int usb_dev_uevent(struct device
*dev
, struct kobj_uevent_env
*env
)
201 struct usb_device
*usb_dev
;
203 usb_dev
= to_usb_device(dev
);
205 if (add_uevent_var(env
, "BUSNUM=%03d", usb_dev
->bus
->busnum
))
208 if (add_uevent_var(env
, "DEVNUM=%03d", usb_dev
->devnum
))
216 static int usb_dev_uevent(struct device
*dev
, struct kobj_uevent_env
*env
)
220 #endif /* CONFIG_HOTPLUG */
224 static int ksuspend_usb_init(void)
226 /* This workqueue is supposed to be both freezable and
227 * singlethreaded. Its job doesn't justify running on more
230 ksuspend_usb_wq
= create_freezeable_workqueue("ksuspend_usbd");
231 if (!ksuspend_usb_wq
)
236 static void ksuspend_usb_cleanup(void)
238 destroy_workqueue(ksuspend_usb_wq
);
241 /* USB device Power-Management thunks.
242 * There's no need to distinguish here between quiescing a USB device
243 * and powering it down; the generic_suspend() routine takes care of
244 * it by skipping the usb_port_suspend() call for a quiesce. And for
245 * USB interfaces there's no difference at all.
248 static int usb_dev_prepare(struct device
*dev
)
250 return 0; /* Implement eventually? */
253 static void usb_dev_complete(struct device
*dev
)
255 /* Currently used only for rebinding interfaces */
256 usb_resume(dev
, PMSG_RESUME
); /* Message event is meaningless */
259 static int usb_dev_suspend(struct device
*dev
)
261 return usb_suspend(dev
, PMSG_SUSPEND
);
264 static int usb_dev_resume(struct device
*dev
)
266 return usb_resume(dev
, PMSG_RESUME
);
269 static int usb_dev_freeze(struct device
*dev
)
271 return usb_suspend(dev
, PMSG_FREEZE
);
274 static int usb_dev_thaw(struct device
*dev
)
276 return usb_resume(dev
, PMSG_THAW
);
279 static int usb_dev_poweroff(struct device
*dev
)
281 return usb_suspend(dev
, PMSG_HIBERNATE
);
284 static int usb_dev_restore(struct device
*dev
)
286 return usb_resume(dev
, PMSG_RESTORE
);
289 static struct dev_pm_ops usb_device_pm_ops
= {
290 .prepare
= usb_dev_prepare
,
291 .complete
= usb_dev_complete
,
292 .suspend
= usb_dev_suspend
,
293 .resume
= usb_dev_resume
,
294 .freeze
= usb_dev_freeze
,
295 .thaw
= usb_dev_thaw
,
296 .poweroff
= usb_dev_poweroff
,
297 .restore
= usb_dev_restore
,
302 #define ksuspend_usb_init() 0
303 #define ksuspend_usb_cleanup() do {} while (0)
304 #define usb_device_pm_ops (*(struct dev_pm_ops *)0)
306 #endif /* CONFIG_PM */
309 static char *usb_nodename(struct device
*dev
)
311 struct usb_device
*usb_dev
;
313 usb_dev
= to_usb_device(dev
);
314 return kasprintf(GFP_KERNEL
, "bus/usb/%03d/%03d",
315 usb_dev
->bus
->busnum
, usb_dev
->devnum
);
318 struct device_type usb_device_type
= {
319 .name
= "usb_device",
320 .release
= usb_release_dev
,
321 .uevent
= usb_dev_uevent
,
322 .nodename
= usb_nodename
,
323 .pm
= &usb_device_pm_ops
,
327 /* Returns 1 if @usb_bus is WUSB, 0 otherwise */
328 static unsigned usb_bus_is_wusb(struct usb_bus
*bus
)
330 struct usb_hcd
*hcd
= container_of(bus
, struct usb_hcd
, self
);
331 return hcd
->wireless
;
336 * usb_alloc_dev - usb device constructor (usbcore-internal)
337 * @parent: hub to which device is connected; null to allocate a root hub
338 * @bus: bus used to access the device
339 * @port1: one-based index of port; ignored for root hubs
340 * Context: !in_interrupt()
342 * Only hub drivers (including virtual root hub drivers for host
343 * controllers) should ever call this.
345 * This call may not be used in a non-sleeping context.
347 struct usb_device
*usb_alloc_dev(struct usb_device
*parent
,
348 struct usb_bus
*bus
, unsigned port1
)
350 struct usb_device
*dev
;
351 struct usb_hcd
*usb_hcd
= container_of(bus
, struct usb_hcd
, self
);
352 unsigned root_hub
= 0;
354 dev
= kzalloc(sizeof(*dev
), GFP_KERNEL
);
358 if (!usb_get_hcd(bus_to_hcd(bus
))) {
363 device_initialize(&dev
->dev
);
364 dev
->dev
.bus
= &usb_bus_type
;
365 dev
->dev
.type
= &usb_device_type
;
366 dev
->dev
.groups
= usb_device_groups
;
367 dev
->dev
.dma_mask
= bus
->controller
->dma_mask
;
368 set_dev_node(&dev
->dev
, dev_to_node(bus
->controller
));
369 dev
->state
= USB_STATE_ATTACHED
;
370 atomic_set(&dev
->urbnum
, 0);
372 INIT_LIST_HEAD(&dev
->ep0
.urb_list
);
373 dev
->ep0
.desc
.bLength
= USB_DT_ENDPOINT_SIZE
;
374 dev
->ep0
.desc
.bDescriptorType
= USB_DT_ENDPOINT
;
375 /* ep0 maxpacket comes later, from device descriptor */
376 usb_enable_endpoint(dev
, &dev
->ep0
, false);
379 /* Save readable and stable topology id, distinguishing devices
380 * by location for diagnostics, tools, driver model, etc. The
381 * string is a path along hub ports, from the root. Each device's
382 * dev->devpath will be stable until USB is re-cabled, and hubs
383 * are often labeled with these port numbers. The name isn't
384 * as stable: bus->busnum changes easily from modprobe order,
385 * cardbus or pci hotplugging, and so on.
387 if (unlikely(!parent
)) {
388 dev
->devpath
[0] = '0';
390 dev
->dev
.parent
= bus
->controller
;
391 dev_set_name(&dev
->dev
, "usb%d", bus
->busnum
);
394 /* match any labeling on the hubs; it's one-based */
395 if (parent
->devpath
[0] == '0')
396 snprintf(dev
->devpath
, sizeof dev
->devpath
,
399 snprintf(dev
->devpath
, sizeof dev
->devpath
,
400 "%s.%d", parent
->devpath
, port1
);
402 dev
->dev
.parent
= &parent
->dev
;
403 dev_set_name(&dev
->dev
, "%d-%s", bus
->busnum
, dev
->devpath
);
405 /* hub driver sets up TT records */
408 dev
->portnum
= port1
;
410 dev
->parent
= parent
;
411 INIT_LIST_HEAD(&dev
->filelist
);
414 mutex_init(&dev
->pm_mutex
);
415 INIT_DELAYED_WORK(&dev
->autosuspend
, usb_autosuspend_work
);
416 INIT_WORK(&dev
->autoresume
, usb_autoresume_work
);
417 dev
->autosuspend_delay
= usb_autosuspend_delay
* HZ
;
418 dev
->connect_time
= jiffies
;
419 dev
->active_duration
= -jiffies
;
421 if (root_hub
) /* Root hub always ok [and always wired] */
424 dev
->authorized
= usb_hcd
->authorized_default
;
425 dev
->wusb
= usb_bus_is_wusb(bus
)? 1 : 0;
431 * usb_get_dev - increments the reference count of the usb device structure
432 * @dev: the device being referenced
434 * Each live reference to a device should be refcounted.
436 * Drivers for USB interfaces should normally record such references in
437 * their probe() methods, when they bind to an interface, and release
438 * them by calling usb_put_dev(), in their disconnect() methods.
440 * A pointer to the device with the incremented reference counter is returned.
442 struct usb_device
*usb_get_dev(struct usb_device
*dev
)
445 get_device(&dev
->dev
);
448 EXPORT_SYMBOL_GPL(usb_get_dev
);
451 * usb_put_dev - release a use of the usb device structure
452 * @dev: device that's been disconnected
454 * Must be called when a user of a device is finished with it. When the last
455 * user of the device calls this function, the memory of the device is freed.
457 void usb_put_dev(struct usb_device
*dev
)
460 put_device(&dev
->dev
);
462 EXPORT_SYMBOL_GPL(usb_put_dev
);
465 * usb_get_intf - increments the reference count of the usb interface structure
466 * @intf: the interface being referenced
468 * Each live reference to a interface must be refcounted.
470 * Drivers for USB interfaces should normally record such references in
471 * their probe() methods, when they bind to an interface, and release
472 * them by calling usb_put_intf(), in their disconnect() methods.
474 * A pointer to the interface with the incremented reference counter is
477 struct usb_interface
*usb_get_intf(struct usb_interface
*intf
)
480 get_device(&intf
->dev
);
483 EXPORT_SYMBOL_GPL(usb_get_intf
);
486 * usb_put_intf - release a use of the usb interface structure
487 * @intf: interface that's been decremented
489 * Must be called when a user of an interface is finished with it. When the
490 * last user of the interface calls this function, the memory of the interface
493 void usb_put_intf(struct usb_interface
*intf
)
496 put_device(&intf
->dev
);
498 EXPORT_SYMBOL_GPL(usb_put_intf
);
500 /* USB device locking
502 * USB devices and interfaces are locked using the semaphore in their
503 * embedded struct device. The hub driver guarantees that whenever a
504 * device is connected or disconnected, drivers are called with the
505 * USB device locked as well as their particular interface.
507 * Complications arise when several devices are to be locked at the same
508 * time. Only hub-aware drivers that are part of usbcore ever have to
509 * do this; nobody else needs to worry about it. The rule for locking
512 * When locking both a device and its parent, always lock the
517 * usb_lock_device_for_reset - cautiously acquire the lock for a usb device structure
518 * @udev: device that's being locked
519 * @iface: interface bound to the driver making the request (optional)
521 * Attempts to acquire the device lock, but fails if the device is
522 * NOTATTACHED or SUSPENDED, or if iface is specified and the interface
523 * is neither BINDING nor BOUND. Rather than sleeping to wait for the
524 * lock, the routine polls repeatedly. This is to prevent deadlock with
525 * disconnect; in some drivers (such as usb-storage) the disconnect()
526 * or suspend() method will block waiting for a device reset to complete.
528 * Returns a negative error code for failure, otherwise 0.
530 int usb_lock_device_for_reset(struct usb_device
*udev
,
531 const struct usb_interface
*iface
)
533 unsigned long jiffies_expire
= jiffies
+ HZ
;
535 if (udev
->state
== USB_STATE_NOTATTACHED
)
537 if (udev
->state
== USB_STATE_SUSPENDED
)
538 return -EHOSTUNREACH
;
539 if (iface
&& (iface
->condition
== USB_INTERFACE_UNBINDING
||
540 iface
->condition
== USB_INTERFACE_UNBOUND
))
543 while (usb_trylock_device(udev
) != 0) {
545 /* If we can't acquire the lock after waiting one second,
546 * we're probably deadlocked */
547 if (time_after(jiffies
, jiffies_expire
))
551 if (udev
->state
== USB_STATE_NOTATTACHED
)
553 if (udev
->state
== USB_STATE_SUSPENDED
)
554 return -EHOSTUNREACH
;
555 if (iface
&& (iface
->condition
== USB_INTERFACE_UNBINDING
||
556 iface
->condition
== USB_INTERFACE_UNBOUND
))
561 EXPORT_SYMBOL_GPL(usb_lock_device_for_reset
);
563 static struct usb_device
*match_device(struct usb_device
*dev
,
564 u16 vendor_id
, u16 product_id
)
566 struct usb_device
*ret_dev
= NULL
;
569 dev_dbg(&dev
->dev
, "check for vendor %04x, product %04x ...\n",
570 le16_to_cpu(dev
->descriptor
.idVendor
),
571 le16_to_cpu(dev
->descriptor
.idProduct
));
573 /* see if this device matches */
574 if ((vendor_id
== le16_to_cpu(dev
->descriptor
.idVendor
)) &&
575 (product_id
== le16_to_cpu(dev
->descriptor
.idProduct
))) {
576 dev_dbg(&dev
->dev
, "matched this device!\n");
577 ret_dev
= usb_get_dev(dev
);
581 /* look through all of the children of this device */
582 for (child
= 0; child
< dev
->maxchild
; ++child
) {
583 if (dev
->children
[child
]) {
584 usb_lock_device(dev
->children
[child
]);
585 ret_dev
= match_device(dev
->children
[child
],
586 vendor_id
, product_id
);
587 usb_unlock_device(dev
->children
[child
]);
597 * usb_find_device - find a specific usb device in the system
598 * @vendor_id: the vendor id of the device to find
599 * @product_id: the product id of the device to find
601 * Returns a pointer to a struct usb_device if such a specified usb
602 * device is present in the system currently. The usage count of the
603 * device will be incremented if a device is found. Make sure to call
604 * usb_put_dev() when the caller is finished with the device.
606 * If a device with the specified vendor and product id is not found,
609 struct usb_device
*usb_find_device(u16 vendor_id
, u16 product_id
)
611 struct list_head
*buslist
;
613 struct usb_device
*dev
= NULL
;
615 mutex_lock(&usb_bus_list_lock
);
616 for (buslist
= usb_bus_list
.next
;
617 buslist
!= &usb_bus_list
;
618 buslist
= buslist
->next
) {
619 bus
= container_of(buslist
, struct usb_bus
, bus_list
);
622 usb_lock_device(bus
->root_hub
);
623 dev
= match_device(bus
->root_hub
, vendor_id
, product_id
);
624 usb_unlock_device(bus
->root_hub
);
629 mutex_unlock(&usb_bus_list_lock
);
634 * usb_get_current_frame_number - return current bus frame number
635 * @dev: the device whose bus is being queried
637 * Returns the current frame number for the USB host controller
638 * used with the given USB device. This can be used when scheduling
639 * isochronous requests.
641 * Note that different kinds of host controller have different
642 * "scheduling horizons". While one type might support scheduling only
643 * 32 frames into the future, others could support scheduling up to
644 * 1024 frames into the future.
646 int usb_get_current_frame_number(struct usb_device
*dev
)
648 return usb_hcd_get_frame_number(dev
);
650 EXPORT_SYMBOL_GPL(usb_get_current_frame_number
);
652 /*-------------------------------------------------------------------*/
654 * __usb_get_extra_descriptor() finds a descriptor of specific type in the
655 * extra field of the interface and endpoint descriptor structs.
658 int __usb_get_extra_descriptor(char *buffer
, unsigned size
,
659 unsigned char type
, void **ptr
)
661 struct usb_descriptor_header
*header
;
663 while (size
>= sizeof(struct usb_descriptor_header
)) {
664 header
= (struct usb_descriptor_header
*)buffer
;
666 if (header
->bLength
< 2) {
668 "%s: bogus descriptor, type %d length %d\n",
670 header
->bDescriptorType
,
675 if (header
->bDescriptorType
== type
) {
680 buffer
+= header
->bLength
;
681 size
-= header
->bLength
;
685 EXPORT_SYMBOL_GPL(__usb_get_extra_descriptor
);
688 * usb_buffer_alloc - allocate dma-consistent buffer for URB_NO_xxx_DMA_MAP
689 * @dev: device the buffer will be used with
690 * @size: requested buffer size
691 * @mem_flags: affect whether allocation may block
692 * @dma: used to return DMA address of buffer
694 * Return value is either null (indicating no buffer could be allocated), or
695 * the cpu-space pointer to a buffer that may be used to perform DMA to the
696 * specified device. Such cpu-space buffers are returned along with the DMA
697 * address (through the pointer provided).
699 * These buffers are used with URB_NO_xxx_DMA_MAP set in urb->transfer_flags
700 * to avoid behaviors like using "DMA bounce buffers", or thrashing IOMMU
701 * hardware during URB completion/resubmit. The implementation varies between
702 * platforms, depending on details of how DMA will work to this device.
703 * Using these buffers also eliminates cacheline sharing problems on
704 * architectures where CPU caches are not DMA-coherent. On systems without
705 * bus-snooping caches, these buffers are uncached.
707 * When the buffer is no longer used, free it with usb_buffer_free().
709 void *usb_buffer_alloc(struct usb_device
*dev
, size_t size
, gfp_t mem_flags
,
712 if (!dev
|| !dev
->bus
)
714 return hcd_buffer_alloc(dev
->bus
, size
, mem_flags
, dma
);
716 EXPORT_SYMBOL_GPL(usb_buffer_alloc
);
719 * usb_buffer_free - free memory allocated with usb_buffer_alloc()
720 * @dev: device the buffer was used with
721 * @size: requested buffer size
722 * @addr: CPU address of buffer
723 * @dma: DMA address of buffer
725 * This reclaims an I/O buffer, letting it be reused. The memory must have
726 * been allocated using usb_buffer_alloc(), and the parameters must match
727 * those provided in that allocation request.
729 void usb_buffer_free(struct usb_device
*dev
, size_t size
, void *addr
,
732 if (!dev
|| !dev
->bus
)
736 hcd_buffer_free(dev
->bus
, size
, addr
, dma
);
738 EXPORT_SYMBOL_GPL(usb_buffer_free
);
741 * usb_buffer_map - create DMA mapping(s) for an urb
742 * @urb: urb whose transfer_buffer/setup_packet will be mapped
744 * Return value is either null (indicating no buffer could be mapped), or
745 * the parameter. URB_NO_TRANSFER_DMA_MAP and URB_NO_SETUP_DMA_MAP are
746 * added to urb->transfer_flags if the operation succeeds. If the device
747 * is connected to this system through a non-DMA controller, this operation
750 * This call would normally be used for an urb which is reused, perhaps
751 * as the target of a large periodic transfer, with usb_buffer_dmasync()
752 * calls to synchronize memory and dma state.
754 * Reverse the effect of this call with usb_buffer_unmap().
757 struct urb
*usb_buffer_map(struct urb
*urb
)
760 struct device
*controller
;
764 || !(bus
= urb
->dev
->bus
)
765 || !(controller
= bus
->controller
))
768 if (controller
->dma_mask
) {
769 urb
->transfer_dma
= dma_map_single(controller
,
770 urb
->transfer_buffer
, urb
->transfer_buffer_length
,
771 usb_pipein(urb
->pipe
)
772 ? DMA_FROM_DEVICE
: DMA_TO_DEVICE
);
773 if (usb_pipecontrol(urb
->pipe
))
774 urb
->setup_dma
= dma_map_single(controller
,
776 sizeof(struct usb_ctrlrequest
),
778 /* FIXME generic api broken like pci, can't report errors */
779 /* if (urb->transfer_dma == DMA_ADDR_INVALID) return 0; */
781 urb
->transfer_dma
= ~0;
782 urb
->transfer_flags
|= (URB_NO_TRANSFER_DMA_MAP
783 | URB_NO_SETUP_DMA_MAP
);
786 EXPORT_SYMBOL_GPL(usb_buffer_map
);
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 - synchronize DMA and CPU view of buffer(s)
798 * @urb: urb whose transfer_buffer/setup_packet will be synchronized
800 void usb_buffer_dmasync(struct urb
*urb
)
803 struct device
*controller
;
806 || !(urb
->transfer_flags
& URB_NO_TRANSFER_DMA_MAP
)
808 || !(bus
= urb
->dev
->bus
)
809 || !(controller
= bus
->controller
))
812 if (controller
->dma_mask
) {
813 dma_sync_single(controller
,
814 urb
->transfer_dma
, urb
->transfer_buffer_length
,
815 usb_pipein(urb
->pipe
)
816 ? DMA_FROM_DEVICE
: DMA_TO_DEVICE
);
817 if (usb_pipecontrol(urb
->pipe
))
818 dma_sync_single(controller
,
820 sizeof(struct usb_ctrlrequest
),
824 EXPORT_SYMBOL_GPL(usb_buffer_dmasync
);
828 * usb_buffer_unmap - free DMA mapping(s) for an urb
829 * @urb: urb whose transfer_buffer will be unmapped
831 * Reverses the effect of usb_buffer_map().
834 void usb_buffer_unmap(struct urb
*urb
)
837 struct device
*controller
;
840 || !(urb
->transfer_flags
& URB_NO_TRANSFER_DMA_MAP
)
842 || !(bus
= urb
->dev
->bus
)
843 || !(controller
= bus
->controller
))
846 if (controller
->dma_mask
) {
847 dma_unmap_single(controller
,
848 urb
->transfer_dma
, urb
->transfer_buffer_length
,
849 usb_pipein(urb
->pipe
)
850 ? DMA_FROM_DEVICE
: DMA_TO_DEVICE
);
851 if (usb_pipecontrol(urb
->pipe
))
852 dma_unmap_single(controller
,
854 sizeof(struct usb_ctrlrequest
),
857 urb
->transfer_flags
&= ~(URB_NO_TRANSFER_DMA_MAP
858 | URB_NO_SETUP_DMA_MAP
);
860 EXPORT_SYMBOL_GPL(usb_buffer_unmap
);
864 * usb_buffer_map_sg - create scatterlist DMA mapping(s) for an endpoint
865 * @dev: device to which the scatterlist will be mapped
866 * @is_in: mapping transfer direction
867 * @sg: the scatterlist to map
868 * @nents: the number of entries in the scatterlist
870 * Return value is either < 0 (indicating no buffers could be mapped), or
871 * the number of DMA mapping array entries in the scatterlist.
873 * The caller is responsible for placing the resulting DMA addresses from
874 * the scatterlist into URB transfer buffer pointers, and for setting the
875 * URB_NO_TRANSFER_DMA_MAP transfer flag in each of those URBs.
877 * Top I/O rates come from queuing URBs, instead of waiting for each one
878 * to complete before starting the next I/O. This is particularly easy
879 * to do with scatterlists. Just allocate and submit one URB for each DMA
880 * mapping entry returned, stopping on the first error or when all succeed.
881 * Better yet, use the usb_sg_*() calls, which do that (and more) for you.
883 * This call would normally be used when translating scatterlist requests,
884 * rather than usb_buffer_map(), since on some hardware (with IOMMUs) it
885 * may be able to coalesce mappings for improved I/O efficiency.
887 * Reverse the effect of this call with usb_buffer_unmap_sg().
889 int usb_buffer_map_sg(const struct usb_device
*dev
, int is_in
,
890 struct scatterlist
*sg
, int nents
)
893 struct device
*controller
;
897 || !(controller
= bus
->controller
)
898 || !controller
->dma_mask
)
901 /* FIXME generic api broken like pci, can't report errors */
902 return dma_map_sg(controller
, sg
, nents
,
903 is_in
? DMA_FROM_DEVICE
: DMA_TO_DEVICE
);
905 EXPORT_SYMBOL_GPL(usb_buffer_map_sg
);
907 /* XXX DISABLED, no users currently. If you wish to re-enable this
908 * XXX please determine whether the sync is to transfer ownership of
909 * XXX the buffer from device to cpu or vice verse, and thusly use the
910 * XXX appropriate _for_{cpu,device}() method. -DaveM
915 * usb_buffer_dmasync_sg - synchronize DMA and CPU view of scatterlist buffer(s)
916 * @dev: device to which the scatterlist will be mapped
917 * @is_in: mapping transfer direction
918 * @sg: the scatterlist to synchronize
919 * @n_hw_ents: the positive return value from usb_buffer_map_sg
921 * Use this when you are re-using a scatterlist's data buffers for
922 * another USB request.
924 void usb_buffer_dmasync_sg(const struct usb_device
*dev
, int is_in
,
925 struct scatterlist
*sg
, int n_hw_ents
)
928 struct device
*controller
;
932 || !(controller
= bus
->controller
)
933 || !controller
->dma_mask
)
936 dma_sync_sg(controller
, sg
, n_hw_ents
,
937 is_in
? DMA_FROM_DEVICE
: DMA_TO_DEVICE
);
939 EXPORT_SYMBOL_GPL(usb_buffer_dmasync_sg
);
943 * usb_buffer_unmap_sg - free DMA mapping(s) for a scatterlist
944 * @dev: device to which the scatterlist will be mapped
945 * @is_in: mapping transfer direction
946 * @sg: the scatterlist to unmap
947 * @n_hw_ents: the positive return value from usb_buffer_map_sg
949 * Reverses the effect of usb_buffer_map_sg().
951 void usb_buffer_unmap_sg(const struct usb_device
*dev
, int is_in
,
952 struct scatterlist
*sg
, int n_hw_ents
)
955 struct device
*controller
;
959 || !(controller
= bus
->controller
)
960 || !controller
->dma_mask
)
963 dma_unmap_sg(controller
, sg
, n_hw_ents
,
964 is_in
? DMA_FROM_DEVICE
: DMA_TO_DEVICE
);
966 EXPORT_SYMBOL_GPL(usb_buffer_unmap_sg
);
968 /* To disable USB, kernel command line is 'nousb' not 'usbcore.nousb' */
970 module_param(nousb
, bool, 0444);
972 core_param(nousb
, nousb
, bool, 0444);
976 * for external read access to <nousb>
978 int usb_disabled(void)
982 EXPORT_SYMBOL_GPL(usb_disabled
);
985 * Notifications of device and interface registration
987 static int usb_bus_notify(struct notifier_block
*nb
, unsigned long action
,
990 struct device
*dev
= data
;
993 case BUS_NOTIFY_ADD_DEVICE
:
994 if (dev
->type
== &usb_device_type
)
995 (void) usb_create_sysfs_dev_files(to_usb_device(dev
));
996 else if (dev
->type
== &usb_if_device_type
)
997 (void) usb_create_sysfs_intf_files(
998 to_usb_interface(dev
));
1001 case BUS_NOTIFY_DEL_DEVICE
:
1002 if (dev
->type
== &usb_device_type
)
1003 usb_remove_sysfs_dev_files(to_usb_device(dev
));
1004 else if (dev
->type
== &usb_if_device_type
)
1005 usb_remove_sysfs_intf_files(to_usb_interface(dev
));
1011 static struct notifier_block usb_bus_nb
= {
1012 .notifier_call
= usb_bus_notify
,
1018 static int __init
usb_init(void)
1022 pr_info("%s: USB support disabled\n", usbcore_name
);
1026 retval
= ksuspend_usb_init();
1029 retval
= bus_register(&usb_bus_type
);
1031 goto bus_register_failed
;
1032 retval
= bus_register_notifier(&usb_bus_type
, &usb_bus_nb
);
1034 goto bus_notifier_failed
;
1035 retval
= usb_host_init();
1037 goto host_init_failed
;
1038 retval
= usb_major_init();
1040 goto major_init_failed
;
1041 retval
= usb_register(&usbfs_driver
);
1043 goto driver_register_failed
;
1044 retval
= usb_devio_init();
1046 goto usb_devio_init_failed
;
1047 retval
= usbfs_init();
1049 goto fs_init_failed
;
1050 retval
= usb_hub_init();
1052 goto hub_init_failed
;
1053 retval
= usb_register_device_driver(&usb_generic_driver
, THIS_MODULE
);
1061 usb_devio_cleanup();
1062 usb_devio_init_failed
:
1063 usb_deregister(&usbfs_driver
);
1064 driver_register_failed
:
1065 usb_major_cleanup();
1069 bus_unregister_notifier(&usb_bus_type
, &usb_bus_nb
);
1070 bus_notifier_failed
:
1071 bus_unregister(&usb_bus_type
);
1072 bus_register_failed
:
1073 ksuspend_usb_cleanup();
1081 static void __exit
usb_exit(void)
1083 /* This will matter if shutdown/reboot does exitcalls. */
1087 usb_deregister_device_driver(&usb_generic_driver
);
1088 usb_major_cleanup();
1090 usb_deregister(&usbfs_driver
);
1091 usb_devio_cleanup();
1094 bus_unregister_notifier(&usb_bus_type
, &usb_bus_nb
);
1095 bus_unregister(&usb_bus_type
);
1096 ksuspend_usb_cleanup();
1099 subsys_initcall(usb_init
);
1100 module_exit(usb_exit
);
1101 MODULE_LICENSE("GPL");