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 */
308 struct device_type usb_device_type = {
309 .name = "usb_device",
310 .release = usb_release_dev,
311 .uevent = usb_dev_uevent,
312 .pm = &usb_device_pm_ops,
316 /* Returns 1 if @usb_bus is WUSB, 0 otherwise */
317 static unsigned usb_bus_is_wusb(struct usb_bus *bus)
319 struct usb_hcd *hcd = container_of(bus, struct usb_hcd, self);
320 return hcd->wireless;
325 * usb_alloc_dev - usb device constructor (usbcore-internal)
326 * @parent: hub to which device is connected; null to allocate a root hub
327 * @bus: bus used to access the device
328 * @port1: one-based index of port; ignored for root hubs
329 * Context: !in_interrupt()
331 * Only hub drivers (including virtual root hub drivers for host
332 * controllers) should ever call this.
334 * This call may not be used in a non-sleeping context.
336 struct usb_device *usb_alloc_dev(struct usb_device *parent,
337 struct usb_bus *bus, unsigned port1)
339 struct usb_device *dev;
340 struct usb_hcd *usb_hcd = container_of(bus, struct usb_hcd, self);
341 unsigned root_hub = 0;
343 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
347 if (!usb_get_hcd(bus_to_hcd(bus))) {
352 device_initialize(&dev->dev);
353 dev->dev.bus = &usb_bus_type;
354 dev->dev.type = &usb_device_type;
355 dev->dev.groups = usb_device_groups;
356 dev->dev.dma_mask = bus->controller->dma_mask;
357 set_dev_node(&dev->dev, dev_to_node(bus->controller));
358 dev->state = USB_STATE_ATTACHED;
359 atomic_set(&dev->urbnum, 0);
361 INIT_LIST_HEAD(&dev->ep0.urb_list);
362 dev->ep0.desc.bLength = USB_DT_ENDPOINT_SIZE;
363 dev->ep0.desc.bDescriptorType = USB_DT_ENDPOINT;
364 /* ep0 maxpacket comes later, from device descriptor */
365 usb_enable_endpoint(dev, &dev->ep0, true);
368 /* Save readable and stable topology id, distinguishing devices
369 * by location for diagnostics, tools, driver model, etc. The
370 * string is a path along hub ports, from the root. Each device's
371 * dev->devpath will be stable until USB is re-cabled, and hubs
372 * are often labeled with these port numbers. The name isn't
373 * as stable: bus->busnum changes easily from modprobe order,
374 * cardbus or pci hotplugging, and so on.
376 if (unlikely(!parent)) {
377 dev->devpath[0] = '0';
379 dev->dev.parent = bus->controller;
380 dev_set_name(&dev->dev, "usb%d", bus->busnum);
383 /* match any labeling on the hubs; it's one-based */
384 if (parent->devpath[0] == '0')
385 snprintf(dev->devpath, sizeof dev->devpath,
388 snprintf(dev->devpath, sizeof dev->devpath,
389 "%s.%d", parent->devpath, port1);
391 dev->dev.parent = &parent->dev;
392 dev_set_name(&dev->dev, "%d-%s", bus->busnum, dev->devpath);
394 /* hub driver sets up TT records */
397 dev->portnum = port1;
399 dev->parent = parent;
400 INIT_LIST_HEAD(&dev->filelist);
403 mutex_init(&dev->pm_mutex);
404 INIT_DELAYED_WORK(&dev->autosuspend, usb_autosuspend_work);
405 INIT_WORK(&dev->autoresume, usb_autoresume_work);
406 dev->autosuspend_delay = usb_autosuspend_delay * HZ;
407 dev->connect_time = jiffies;
408 dev->active_duration = -jiffies;
410 if (root_hub) /* Root hub always ok [and always wired] */
413 dev->authorized = usb_hcd->authorized_default;
414 dev->wusb = usb_bus_is_wusb(bus)? 1 : 0;
420 * usb_get_dev - increments the reference count of the usb device structure
421 * @dev: the device being referenced
423 * Each live reference to a device should be refcounted.
425 * Drivers for USB interfaces should normally record such references in
426 * their probe() methods, when they bind to an interface, and release
427 * them by calling usb_put_dev(), in their disconnect() methods.
429 * A pointer to the device with the incremented reference counter is returned.
431 struct usb_device *usb_get_dev(struct usb_device *dev)
434 get_device(&dev->dev);
437 EXPORT_SYMBOL_GPL(usb_get_dev);
440 * usb_put_dev - release a use of the usb device structure
441 * @dev: device that's been disconnected
443 * Must be called when a user of a device is finished with it. When the last
444 * user of the device calls this function, the memory of the device is freed.
446 void usb_put_dev(struct usb_device *dev)
449 put_device(&dev->dev);
451 EXPORT_SYMBOL_GPL(usb_put_dev);
454 * usb_get_intf - increments the reference count of the usb interface structure
455 * @intf: the interface being referenced
457 * Each live reference to a interface must be refcounted.
459 * Drivers for USB interfaces should normally record such references in
460 * their probe() methods, when they bind to an interface, and release
461 * them by calling usb_put_intf(), in their disconnect() methods.
463 * A pointer to the interface with the incremented reference counter is
466 struct usb_interface *usb_get_intf(struct usb_interface *intf)
469 get_device(&intf->dev);
472 EXPORT_SYMBOL_GPL(usb_get_intf);
475 * usb_put_intf - release a use of the usb interface structure
476 * @intf: interface that's been decremented
478 * Must be called when a user of an interface is finished with it. When the
479 * last user of the interface calls this function, the memory of the interface
482 void usb_put_intf(struct usb_interface *intf)
485 put_device(&intf->dev);
487 EXPORT_SYMBOL_GPL(usb_put_intf);
489 /* USB device locking
491 * USB devices and interfaces are locked using the semaphore in their
492 * embedded struct device. The hub driver guarantees that whenever a
493 * device is connected or disconnected, drivers are called with the
494 * USB device locked as well as their particular interface.
496 * Complications arise when several devices are to be locked at the same
497 * time. Only hub-aware drivers that are part of usbcore ever have to
498 * do this; nobody else needs to worry about it. The rule for locking
501 * When locking both a device and its parent, always lock the
506 * usb_lock_device_for_reset - cautiously acquire the lock for a usb device structure
507 * @udev: device that's being locked
508 * @iface: interface bound to the driver making the request (optional)
510 * Attempts to acquire the device lock, but fails if the device is
511 * NOTATTACHED or SUSPENDED, or if iface is specified and the interface
512 * is neither BINDING nor BOUND. Rather than sleeping to wait for the
513 * lock, the routine polls repeatedly. This is to prevent deadlock with
514 * disconnect; in some drivers (such as usb-storage) the disconnect()
515 * or suspend() method will block waiting for a device reset to complete.
517 * Returns a negative error code for failure, otherwise 0.
519 int usb_lock_device_for_reset(struct usb_device *udev,
520 const struct usb_interface *iface)
522 unsigned long jiffies_expire = jiffies + HZ;
524 if (udev->state == USB_STATE_NOTATTACHED)
526 if (udev->state == USB_STATE_SUSPENDED)
527 return -EHOSTUNREACH;
528 if (iface && (iface->condition == USB_INTERFACE_UNBINDING ||
529 iface->condition == USB_INTERFACE_UNBOUND))
532 while (usb_trylock_device(udev) != 0) {
534 /* If we can't acquire the lock after waiting one second,
535 * we're probably deadlocked */
536 if (time_after(jiffies, jiffies_expire))
540 if (udev->state == USB_STATE_NOTATTACHED)
542 if (udev->state == USB_STATE_SUSPENDED)
543 return -EHOSTUNREACH;
544 if (iface && (iface->condition == USB_INTERFACE_UNBINDING ||
545 iface->condition == USB_INTERFACE_UNBOUND))
550 EXPORT_SYMBOL_GPL(usb_lock_device_for_reset);
552 static struct usb_device *match_device(struct usb_device *dev,
553 u16 vendor_id, u16 product_id)
555 struct usb_device *ret_dev = NULL;
558 dev_dbg(&dev->dev, "check for vendor %04x, product %04x ...\n",
559 le16_to_cpu(dev->descriptor.idVendor),
560 le16_to_cpu(dev->descriptor.idProduct));
562 /* see if this device matches */
563 if ((vendor_id == le16_to_cpu(dev->descriptor.idVendor)) &&
564 (product_id == le16_to_cpu(dev->descriptor.idProduct))) {
565 dev_dbg(&dev->dev, "matched this device!\n");
566 ret_dev = usb_get_dev(dev);
570 /* look through all of the children of this device */
571 for (child = 0; child < dev->maxchild; ++child) {
572 if (dev->children[child]) {
573 usb_lock_device(dev->children[child]);
574 ret_dev = match_device(dev->children[child],
575 vendor_id, product_id);
576 usb_unlock_device(dev->children[child]);
586 * usb_find_device - find a specific usb device in the system
587 * @vendor_id: the vendor id of the device to find
588 * @product_id: the product id of the device to find
590 * Returns a pointer to a struct usb_device if such a specified usb
591 * device is present in the system currently. The usage count of the
592 * device will be incremented if a device is found. Make sure to call
593 * usb_put_dev() when the caller is finished with the device.
595 * If a device with the specified vendor and product id is not found,
598 struct usb_device *usb_find_device(u16 vendor_id, u16 product_id)
600 struct list_head *buslist;
602 struct usb_device *dev = NULL;
604 mutex_lock(&usb_bus_list_lock);
605 for (buslist = usb_bus_list.next;
606 buslist != &usb_bus_list;
607 buslist = buslist->next) {
608 bus = container_of(buslist, struct usb_bus, bus_list);
611 usb_lock_device(bus->root_hub);
612 dev = match_device(bus->root_hub, vendor_id, product_id);
613 usb_unlock_device(bus->root_hub);
618 mutex_unlock(&usb_bus_list_lock);
623 * usb_get_current_frame_number - return current bus frame number
624 * @dev: the device whose bus is being queried
626 * Returns the current frame number for the USB host controller
627 * used with the given USB device. This can be used when scheduling
628 * isochronous requests.
630 * Note that different kinds of host controller have different
631 * "scheduling horizons". While one type might support scheduling only
632 * 32 frames into the future, others could support scheduling up to
633 * 1024 frames into the future.
635 int usb_get_current_frame_number(struct usb_device *dev)
637 return usb_hcd_get_frame_number(dev);
639 EXPORT_SYMBOL_GPL(usb_get_current_frame_number);
641 /*-------------------------------------------------------------------*/
643 * __usb_get_extra_descriptor() finds a descriptor of specific type in the
644 * extra field of the interface and endpoint descriptor structs.
647 int __usb_get_extra_descriptor(char *buffer, unsigned size,
648 unsigned char type, void **ptr)
650 struct usb_descriptor_header *header;
652 while (size >= sizeof(struct usb_descriptor_header)) {
653 header = (struct usb_descriptor_header *)buffer;
655 if (header->bLength < 2) {
657 "%s: bogus descriptor, type %d length %d\n",
659 header->bDescriptorType,
664 if (header->bDescriptorType == type) {
669 buffer += header->bLength;
670 size -= header->bLength;
674 EXPORT_SYMBOL_GPL(__usb_get_extra_descriptor);
677 * usb_buffer_alloc - allocate dma-consistent buffer for URB_NO_xxx_DMA_MAP
678 * @dev: device the buffer will be used with
679 * @size: requested buffer size
680 * @mem_flags: affect whether allocation may block
681 * @dma: used to return DMA address of buffer
683 * Return value is either null (indicating no buffer could be allocated), or
684 * the cpu-space pointer to a buffer that may be used to perform DMA to the
685 * specified device. Such cpu-space buffers are returned along with the DMA
686 * address (through the pointer provided).
688 * These buffers are used with URB_NO_xxx_DMA_MAP set in urb->transfer_flags
689 * to avoid behaviors like using "DMA bounce buffers", or thrashing IOMMU
690 * hardware during URB completion/resubmit. The implementation varies between
691 * platforms, depending on details of how DMA will work to this device.
692 * Using these buffers also eliminates cacheline sharing problems on
693 * architectures where CPU caches are not DMA-coherent. On systems without
694 * bus-snooping caches, these buffers are uncached.
696 * When the buffer is no longer used, free it with usb_buffer_free().
698 void *usb_buffer_alloc(struct usb_device *dev, size_t size, gfp_t mem_flags,
701 if (!dev || !dev->bus)
703 return hcd_buffer_alloc(dev->bus, size, mem_flags, dma);
705 EXPORT_SYMBOL_GPL(usb_buffer_alloc);
708 * usb_buffer_free - free memory allocated with usb_buffer_alloc()
709 * @dev: device the buffer was used with
710 * @size: requested buffer size
711 * @addr: CPU address of buffer
712 * @dma: DMA address of buffer
714 * This reclaims an I/O buffer, letting it be reused. The memory must have
715 * been allocated using usb_buffer_alloc(), and the parameters must match
716 * those provided in that allocation request.
718 void usb_buffer_free(struct usb_device *dev, size_t size, void *addr,
721 if (!dev || !dev->bus)
725 hcd_buffer_free(dev->bus, size, addr, dma);
727 EXPORT_SYMBOL_GPL(usb_buffer_free);
730 * usb_buffer_map - create DMA mapping(s) for an urb
731 * @urb: urb whose transfer_buffer/setup_packet will be mapped
733 * Return value is either null (indicating no buffer could be mapped), or
734 * the parameter. URB_NO_TRANSFER_DMA_MAP and URB_NO_SETUP_DMA_MAP are
735 * added to urb->transfer_flags if the operation succeeds. If the device
736 * is connected to this system through a non-DMA controller, this operation
739 * This call would normally be used for an urb which is reused, perhaps
740 * as the target of a large periodic transfer, with usb_buffer_dmasync()
741 * calls to synchronize memory and dma state.
743 * Reverse the effect of this call with usb_buffer_unmap().
746 struct urb *usb_buffer_map(struct urb *urb)
749 struct device *controller;
753 || !(bus = urb->dev->bus)
754 || !(controller = bus->controller))
757 if (controller->dma_mask) {
758 urb->transfer_dma = dma_map_single(controller,
759 urb->transfer_buffer, urb->transfer_buffer_length,
760 usb_pipein(urb->pipe)
761 ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
762 if (usb_pipecontrol(urb->pipe))
763 urb->setup_dma = dma_map_single(controller,
765 sizeof(struct usb_ctrlrequest),
767 /* FIXME generic api broken like pci, can't report errors */
768 /* if (urb->transfer_dma == DMA_ADDR_INVALID) return 0; */
770 urb->transfer_dma = ~0;
771 urb->transfer_flags |= (URB_NO_TRANSFER_DMA_MAP
772 | URB_NO_SETUP_DMA_MAP);
775 EXPORT_SYMBOL_GPL(usb_buffer_map);
778 /* XXX DISABLED, no users currently. If you wish to re-enable this
779 * XXX please determine whether the sync is to transfer ownership of
780 * XXX the buffer from device to cpu or vice verse, and thusly use the
781 * XXX appropriate _for_{cpu,device}() method. -DaveM
786 * usb_buffer_dmasync - synchronize DMA and CPU view of buffer(s)
787 * @urb: urb whose transfer_buffer/setup_packet will be synchronized
789 void usb_buffer_dmasync(struct urb *urb)
792 struct device *controller;
795 || !(urb->transfer_flags & URB_NO_TRANSFER_DMA_MAP)
797 || !(bus = urb->dev->bus)
798 || !(controller = bus->controller))
801 if (controller->dma_mask) {
802 dma_sync_single(controller,
803 urb->transfer_dma, urb->transfer_buffer_length,
804 usb_pipein(urb->pipe)
805 ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
806 if (usb_pipecontrol(urb->pipe))
807 dma_sync_single(controller,
809 sizeof(struct usb_ctrlrequest),
813 EXPORT_SYMBOL_GPL(usb_buffer_dmasync);
817 * usb_buffer_unmap - free DMA mapping(s) for an urb
818 * @urb: urb whose transfer_buffer will be unmapped
820 * Reverses the effect of usb_buffer_map().
823 void usb_buffer_unmap(struct urb *urb)
826 struct device *controller;
829 || !(urb->transfer_flags & URB_NO_TRANSFER_DMA_MAP)
831 || !(bus = urb->dev->bus)
832 || !(controller = bus->controller))
835 if (controller->dma_mask) {
836 dma_unmap_single(controller,
837 urb->transfer_dma, urb->transfer_buffer_length,
838 usb_pipein(urb->pipe)
839 ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
840 if (usb_pipecontrol(urb->pipe))
841 dma_unmap_single(controller,
843 sizeof(struct usb_ctrlrequest),
846 urb->transfer_flags &= ~(URB_NO_TRANSFER_DMA_MAP
847 | URB_NO_SETUP_DMA_MAP);
849 EXPORT_SYMBOL_GPL(usb_buffer_unmap);
853 * usb_buffer_map_sg - create scatterlist DMA mapping(s) for an endpoint
854 * @dev: device to which the scatterlist will be mapped
855 * @is_in: mapping transfer direction
856 * @sg: the scatterlist to map
857 * @nents: the number of entries in the scatterlist
859 * Return value is either < 0 (indicating no buffers could be mapped), or
860 * the number of DMA mapping array entries in the scatterlist.
862 * The caller is responsible for placing the resulting DMA addresses from
863 * the scatterlist into URB transfer buffer pointers, and for setting the
864 * URB_NO_TRANSFER_DMA_MAP transfer flag in each of those URBs.
866 * Top I/O rates come from queuing URBs, instead of waiting for each one
867 * to complete before starting the next I/O. This is particularly easy
868 * to do with scatterlists. Just allocate and submit one URB for each DMA
869 * mapping entry returned, stopping on the first error or when all succeed.
870 * Better yet, use the usb_sg_*() calls, which do that (and more) for you.
872 * This call would normally be used when translating scatterlist requests,
873 * rather than usb_buffer_map(), since on some hardware (with IOMMUs) it
874 * may be able to coalesce mappings for improved I/O efficiency.
876 * Reverse the effect of this call with usb_buffer_unmap_sg().
878 int usb_buffer_map_sg(const struct usb_device *dev, int is_in,
879 struct scatterlist *sg, int nents)
882 struct device *controller;
886 || !(controller = bus->controller)
887 || !controller->dma_mask)
890 /* FIXME generic api broken like pci, can't report errors */
891 return dma_map_sg(controller, sg, nents,
892 is_in ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
894 EXPORT_SYMBOL_GPL(usb_buffer_map_sg);
896 /* XXX DISABLED, no users currently. If you wish to re-enable this
897 * XXX please determine whether the sync is to transfer ownership of
898 * XXX the buffer from device to cpu or vice verse, and thusly use the
899 * XXX appropriate _for_{cpu,device}() method. -DaveM
904 * usb_buffer_dmasync_sg - synchronize DMA and CPU view of scatterlist buffer(s)
905 * @dev: device to which the scatterlist will be mapped
906 * @is_in: mapping transfer direction
907 * @sg: the scatterlist to synchronize
908 * @n_hw_ents: the positive return value from usb_buffer_map_sg
910 * Use this when you are re-using a scatterlist's data buffers for
911 * another USB request.
913 void usb_buffer_dmasync_sg(const struct usb_device *dev, int is_in,
914 struct scatterlist *sg, int n_hw_ents)
917 struct device *controller;
921 || !(controller = bus->controller)
922 || !controller->dma_mask)
925 dma_sync_sg(controller, sg, n_hw_ents,
926 is_in ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
928 EXPORT_SYMBOL_GPL(usb_buffer_dmasync_sg);
932 * usb_buffer_unmap_sg - free DMA mapping(s) for a scatterlist
933 * @dev: device to which the scatterlist will be mapped
934 * @is_in: mapping transfer direction
935 * @sg: the scatterlist to unmap
936 * @n_hw_ents: the positive return value from usb_buffer_map_sg
938 * Reverses the effect of usb_buffer_map_sg().
940 void usb_buffer_unmap_sg(const struct usb_device *dev, int is_in,
941 struct scatterlist *sg, int n_hw_ents)
944 struct device *controller;
948 || !(controller = bus->controller)
949 || !controller->dma_mask)
952 dma_unmap_sg(controller, sg, n_hw_ents,
953 is_in ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
955 EXPORT_SYMBOL_GPL(usb_buffer_unmap_sg);
957 /* To disable USB, kernel command line is 'nousb' not 'usbcore.nousb' */
959 module_param(nousb, bool, 0444);
961 core_param(nousb, nousb, bool, 0444);
965 * for external read access to <nousb>
967 int usb_disabled(void)
971 EXPORT_SYMBOL_GPL(usb_disabled);
974 * Notifications of device and interface registration
976 static int usb_bus_notify(struct notifier_block *nb, unsigned long action,
979 struct device *dev = data;
982 case BUS_NOTIFY_ADD_DEVICE:
983 if (dev->type == &usb_device_type)
984 (void) usb_create_sysfs_dev_files(to_usb_device(dev));
985 else if (dev->type == &usb_if_device_type)
986 (void) usb_create_sysfs_intf_files(
987 to_usb_interface(dev));
990 case BUS_NOTIFY_DEL_DEVICE:
991 if (dev->type == &usb_device_type)
992 usb_remove_sysfs_dev_files(to_usb_device(dev));
993 else if (dev->type == &usb_if_device_type)
994 usb_remove_sysfs_intf_files(to_usb_interface(dev));
1000 static struct notifier_block usb_bus_nb = {
1001 .notifier_call = usb_bus_notify,
1007 static int __init usb_init(void)
1011 pr_info("%s: USB support disabled\n", usbcore_name);
1015 retval = ksuspend_usb_init();
1018 retval = bus_register(&usb_bus_type);
1020 goto bus_register_failed;
1021 retval = bus_register_notifier(&usb_bus_type, &usb_bus_nb);
1023 goto bus_notifier_failed;
1024 retval = usb_host_init();
1026 goto host_init_failed;
1027 retval = usb_major_init();
1029 goto major_init_failed;
1030 retval = usb_register(&usbfs_driver);
1032 goto driver_register_failed;
1033 retval = usb_devio_init();
1035 goto usb_devio_init_failed;
1036 retval = usbfs_init();
1038 goto fs_init_failed;
1039 retval = usb_hub_init();
1041 goto hub_init_failed;
1042 retval = usb_register_device_driver(&usb_generic_driver, THIS_MODULE);
1050 usb_devio_cleanup();
1051 usb_devio_init_failed:
1052 usb_deregister(&usbfs_driver);
1053 driver_register_failed:
1054 usb_major_cleanup();
1058 bus_unregister_notifier(&usb_bus_type, &usb_bus_nb);
1059 bus_notifier_failed:
1060 bus_unregister(&usb_bus_type);
1061 bus_register_failed:
1062 ksuspend_usb_cleanup();
1070 static void __exit usb_exit(void)
1072 /* This will matter if shutdown/reboot does exitcalls. */
1076 usb_deregister_device_driver(&usb_generic_driver);
1077 usb_major_cleanup();
1079 usb_deregister(&usbfs_driver);
1080 usb_devio_cleanup();
1083 bus_unregister_notifier(&usb_bus_type, &usb_bus_nb);
1084 bus_unregister(&usb_bus_type);
1085 ksuspend_usb_cleanup();
1088 subsys_initcall(usb_init);
1089 module_exit(usb_exit);
1090 MODULE_LICENSE("GPL");