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>
37 #include <linux/debugfs.h>
40 #include <linux/scatterlist.h>
42 #include <linux/dma-mapping.h>
48 const char *usbcore_name = "usbcore";
50 static int nousb; /* Disable USB when built into kernel image */
52 #ifdef CONFIG_USB_SUSPEND
53 static int usb_autosuspend_delay = 2; /* Default delay value,
55 module_param_named(autosuspend, usb_autosuspend_delay, int, 0644);
56 MODULE_PARM_DESC(autosuspend, "default autosuspend delay");
59 #define usb_autosuspend_delay 0
64 * usb_find_alt_setting() - Given a configuration, find the alternate setting
65 * for the given interface.
66 * @config: the configuration to search (not necessarily the current config).
67 * @iface_num: interface number to search in
68 * @alt_num: alternate interface setting number to search for.
70 * Search the configuration's interface cache for the given alt setting.
72 struct usb_host_interface *usb_find_alt_setting(
73 struct usb_host_config *config,
74 unsigned int iface_num,
77 struct usb_interface_cache *intf_cache = NULL;
80 for (i = 0; i < config->desc.bNumInterfaces; i++) {
81 if (config->intf_cache[i]->altsetting[0].desc.bInterfaceNumber
83 intf_cache = config->intf_cache[i];
89 for (i = 0; i < intf_cache->num_altsetting; i++)
90 if (intf_cache->altsetting[i].desc.bAlternateSetting == alt_num)
91 return &intf_cache->altsetting[i];
93 printk(KERN_DEBUG "Did not find alt setting %u for intf %u, "
94 "config %u\n", alt_num, iface_num,
95 config->desc.bConfigurationValue);
98 EXPORT_SYMBOL_GPL(usb_find_alt_setting);
101 * usb_ifnum_to_if - get the interface object with a given interface number
102 * @dev: the device whose current configuration is considered
103 * @ifnum: the desired interface
105 * This walks the device descriptor for the currently active configuration
106 * and returns a pointer to the interface with that particular interface
109 * Note that configuration descriptors are not required to assign interface
110 * numbers sequentially, so that it would be incorrect to assume that
111 * the first interface in that descriptor corresponds to interface zero.
112 * This routine helps device drivers avoid such mistakes.
113 * However, you should make sure that you do the right thing with any
114 * alternate settings available for this interfaces.
116 * Don't call this function unless you are bound to one of the interfaces
117 * on this device or you have locked the device!
119 struct usb_interface *usb_ifnum_to_if(const struct usb_device *dev,
122 struct usb_host_config *config = dev->actconfig;
127 for (i = 0; i < config->desc.bNumInterfaces; i++)
128 if (config->interface[i]->altsetting[0]
129 .desc.bInterfaceNumber == ifnum)
130 return config->interface[i];
134 EXPORT_SYMBOL_GPL(usb_ifnum_to_if);
137 * usb_altnum_to_altsetting - get the altsetting structure with a given alternate setting number.
138 * @intf: the interface containing the altsetting in question
139 * @altnum: the desired alternate setting number
141 * This searches the altsetting array of the specified interface for
142 * an entry with the correct bAlternateSetting value and returns a pointer
143 * to that entry, or null.
145 * Note that altsettings need not be stored sequentially by number, so
146 * it would be incorrect to assume that the first altsetting entry in
147 * the array corresponds to altsetting zero. This routine helps device
148 * drivers avoid such mistakes.
150 * Don't call this function unless you are bound to the intf interface
151 * or you have locked the device!
153 struct usb_host_interface *usb_altnum_to_altsetting(
154 const struct usb_interface *intf,
159 for (i = 0; i < intf->num_altsetting; i++) {
160 if (intf->altsetting[i].desc.bAlternateSetting == altnum)
161 return &intf->altsetting[i];
165 EXPORT_SYMBOL_GPL(usb_altnum_to_altsetting);
167 struct find_interface_arg {
169 struct device_driver *drv;
172 static int __find_interface(struct device *dev, void *data)
174 struct find_interface_arg *arg = data;
175 struct usb_interface *intf;
177 if (!is_usb_interface(dev))
180 if (dev->driver != arg->drv)
182 intf = to_usb_interface(dev);
183 return intf->minor == arg->minor;
187 * usb_find_interface - find usb_interface pointer for driver and device
188 * @drv: the driver whose current configuration is considered
189 * @minor: the minor number of the desired device
191 * This walks the bus device list and returns a pointer to the interface
192 * with the matching minor and driver. Note, this only works for devices
193 * that share the USB major number.
195 struct usb_interface *usb_find_interface(struct usb_driver *drv, int minor)
197 struct find_interface_arg argb;
201 argb.drv = &drv->drvwrap.driver;
203 dev = bus_find_device(&usb_bus_type, NULL, &argb, __find_interface);
205 /* Drop reference count from bus_find_device */
208 return dev ? to_usb_interface(dev) : NULL;
210 EXPORT_SYMBOL_GPL(usb_find_interface);
213 * usb_release_dev - free a usb device structure when all users of it are finished.
214 * @dev: device that's been disconnected
216 * Will be called only by the device core when all users of this usb device are
219 static void usb_release_dev(struct device *dev)
221 struct usb_device *udev;
224 udev = to_usb_device(dev);
225 hcd = bus_to_hcd(udev->bus);
227 usb_destroy_configuration(udev);
229 kfree(udev->product);
230 kfree(udev->manufacturer);
235 #ifdef CONFIG_HOTPLUG
236 static int usb_dev_uevent(struct device *dev, struct kobj_uevent_env *env)
238 struct usb_device *usb_dev;
240 usb_dev = to_usb_device(dev);
242 if (add_uevent_var(env, "BUSNUM=%03d", usb_dev->bus->busnum))
245 if (add_uevent_var(env, "DEVNUM=%03d", usb_dev->devnum))
253 static int usb_dev_uevent(struct device *dev, struct kobj_uevent_env *env)
257 #endif /* CONFIG_HOTPLUG */
261 /* USB device Power-Management thunks.
262 * There's no need to distinguish here between quiescing a USB device
263 * and powering it down; the generic_suspend() routine takes care of
264 * it by skipping the usb_port_suspend() call for a quiesce. And for
265 * USB interfaces there's no difference at all.
268 static int usb_dev_prepare(struct device *dev)
270 return 0; /* Implement eventually? */
273 static void usb_dev_complete(struct device *dev)
275 /* Currently used only for rebinding interfaces */
276 usb_resume(dev, PMSG_ON); /* FIXME: change to PMSG_COMPLETE */
279 static int usb_dev_suspend(struct device *dev)
281 return usb_suspend(dev, PMSG_SUSPEND);
284 static int usb_dev_resume(struct device *dev)
286 return usb_resume(dev, PMSG_RESUME);
289 static int usb_dev_freeze(struct device *dev)
291 return usb_suspend(dev, PMSG_FREEZE);
294 static int usb_dev_thaw(struct device *dev)
296 return usb_resume(dev, PMSG_THAW);
299 static int usb_dev_poweroff(struct device *dev)
301 return usb_suspend(dev, PMSG_HIBERNATE);
304 static int usb_dev_restore(struct device *dev)
306 return usb_resume(dev, PMSG_RESTORE);
309 static const struct dev_pm_ops usb_device_pm_ops = {
310 .prepare = usb_dev_prepare,
311 .complete = usb_dev_complete,
312 .suspend = usb_dev_suspend,
313 .resume = usb_dev_resume,
314 .freeze = usb_dev_freeze,
315 .thaw = usb_dev_thaw,
316 .poweroff = usb_dev_poweroff,
317 .restore = usb_dev_restore,
322 #define usb_device_pm_ops (*(struct dev_pm_ops *) NULL)
324 #endif /* CONFIG_PM */
327 static char *usb_devnode(struct device *dev, mode_t *mode)
329 struct usb_device *usb_dev;
331 usb_dev = to_usb_device(dev);
332 return kasprintf(GFP_KERNEL, "bus/usb/%03d/%03d",
333 usb_dev->bus->busnum, usb_dev->devnum);
336 struct device_type usb_device_type = {
337 .name = "usb_device",
338 .release = usb_release_dev,
339 .uevent = usb_dev_uevent,
340 .devnode = usb_devnode,
341 .pm = &usb_device_pm_ops,
345 /* Returns 1 if @usb_bus is WUSB, 0 otherwise */
346 static unsigned usb_bus_is_wusb(struct usb_bus *bus)
348 struct usb_hcd *hcd = container_of(bus, struct usb_hcd, self);
349 return hcd->wireless;
354 * usb_alloc_dev - usb device constructor (usbcore-internal)
355 * @parent: hub to which device is connected; null to allocate a root hub
356 * @bus: bus used to access the device
357 * @port1: one-based index of port; ignored for root hubs
358 * Context: !in_interrupt()
360 * Only hub drivers (including virtual root hub drivers for host
361 * controllers) should ever call this.
363 * This call may not be used in a non-sleeping context.
365 struct usb_device *usb_alloc_dev(struct usb_device *parent,
366 struct usb_bus *bus, unsigned port1)
368 struct usb_device *dev;
369 struct usb_hcd *usb_hcd = container_of(bus, struct usb_hcd, self);
370 unsigned root_hub = 0;
372 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
376 if (!usb_get_hcd(bus_to_hcd(bus))) {
380 /* Root hubs aren't true devices, so don't allocate HCD resources */
381 if (usb_hcd->driver->alloc_dev && parent &&
382 !usb_hcd->driver->alloc_dev(usb_hcd, dev)) {
383 usb_put_hcd(bus_to_hcd(bus));
388 device_initialize(&dev->dev);
389 dev->dev.bus = &usb_bus_type;
390 dev->dev.type = &usb_device_type;
391 dev->dev.groups = usb_device_groups;
392 dev->dev.dma_mask = bus->controller->dma_mask;
393 set_dev_node(&dev->dev, dev_to_node(bus->controller));
394 dev->state = USB_STATE_ATTACHED;
395 atomic_set(&dev->urbnum, 0);
397 INIT_LIST_HEAD(&dev->ep0.urb_list);
398 dev->ep0.desc.bLength = USB_DT_ENDPOINT_SIZE;
399 dev->ep0.desc.bDescriptorType = USB_DT_ENDPOINT;
400 /* ep0 maxpacket comes later, from device descriptor */
401 usb_enable_endpoint(dev, &dev->ep0, false);
404 /* Save readable and stable topology id, distinguishing devices
405 * by location for diagnostics, tools, driver model, etc. The
406 * string is a path along hub ports, from the root. Each device's
407 * dev->devpath will be stable until USB is re-cabled, and hubs
408 * are often labeled with these port numbers. The name isn't
409 * as stable: bus->busnum changes easily from modprobe order,
410 * cardbus or pci hotplugging, and so on.
412 if (unlikely(!parent)) {
413 dev->devpath[0] = '0';
416 dev->dev.parent = bus->controller;
417 dev_set_name(&dev->dev, "usb%d", bus->busnum);
420 /* match any labeling on the hubs; it's one-based */
421 if (parent->devpath[0] == '0') {
422 snprintf(dev->devpath, sizeof dev->devpath,
424 /* Root ports are not counted in route string */
427 snprintf(dev->devpath, sizeof dev->devpath,
428 "%s.%d", parent->devpath, port1);
429 /* Route string assumes hubs have less than 16 ports */
431 dev->route = parent->route +
432 (port1 << ((parent->level - 1)*4));
434 dev->route = parent->route +
435 (15 << ((parent->level - 1)*4));
438 dev->dev.parent = &parent->dev;
439 dev_set_name(&dev->dev, "%d-%s", bus->busnum, dev->devpath);
441 /* hub driver sets up TT records */
444 dev->portnum = port1;
446 dev->parent = parent;
447 INIT_LIST_HEAD(&dev->filelist);
450 dev->autosuspend_delay = usb_autosuspend_delay * HZ;
451 dev->connect_time = jiffies;
452 dev->active_duration = -jiffies;
454 if (root_hub) /* Root hub always ok [and always wired] */
457 dev->authorized = usb_hcd->authorized_default;
458 dev->wusb = usb_bus_is_wusb(bus)? 1 : 0;
464 * usb_get_dev - increments the reference count of the usb device structure
465 * @dev: the device being referenced
467 * Each live reference to a device should be refcounted.
469 * Drivers for USB interfaces should normally record such references in
470 * their probe() methods, when they bind to an interface, and release
471 * them by calling usb_put_dev(), in their disconnect() methods.
473 * A pointer to the device with the incremented reference counter is returned.
475 struct usb_device *usb_get_dev(struct usb_device *dev)
478 get_device(&dev->dev);
481 EXPORT_SYMBOL_GPL(usb_get_dev);
484 * usb_put_dev - release a use of the usb device structure
485 * @dev: device that's been disconnected
487 * Must be called when a user of a device is finished with it. When the last
488 * user of the device calls this function, the memory of the device is freed.
490 void usb_put_dev(struct usb_device *dev)
493 put_device(&dev->dev);
495 EXPORT_SYMBOL_GPL(usb_put_dev);
498 * usb_get_intf - increments the reference count of the usb interface structure
499 * @intf: the interface being referenced
501 * Each live reference to a interface must be refcounted.
503 * Drivers for USB interfaces should normally record such references in
504 * their probe() methods, when they bind to an interface, and release
505 * them by calling usb_put_intf(), in their disconnect() methods.
507 * A pointer to the interface with the incremented reference counter is
510 struct usb_interface *usb_get_intf(struct usb_interface *intf)
513 get_device(&intf->dev);
516 EXPORT_SYMBOL_GPL(usb_get_intf);
519 * usb_put_intf - release a use of the usb interface structure
520 * @intf: interface that's been decremented
522 * Must be called when a user of an interface is finished with it. When the
523 * last user of the interface calls this function, the memory of the interface
526 void usb_put_intf(struct usb_interface *intf)
529 put_device(&intf->dev);
531 EXPORT_SYMBOL_GPL(usb_put_intf);
533 /* USB device locking
535 * USB devices and interfaces are locked using the semaphore in their
536 * embedded struct device. The hub driver guarantees that whenever a
537 * device is connected or disconnected, drivers are called with the
538 * USB device locked as well as their particular interface.
540 * Complications arise when several devices are to be locked at the same
541 * time. Only hub-aware drivers that are part of usbcore ever have to
542 * do this; nobody else needs to worry about it. The rule for locking
545 * When locking both a device and its parent, always lock the
550 * usb_lock_device_for_reset - cautiously acquire the lock for a usb device structure
551 * @udev: device that's being locked
552 * @iface: interface bound to the driver making the request (optional)
554 * Attempts to acquire the device lock, but fails if the device is
555 * NOTATTACHED or SUSPENDED, or if iface is specified and the interface
556 * is neither BINDING nor BOUND. Rather than sleeping to wait for the
557 * lock, the routine polls repeatedly. This is to prevent deadlock with
558 * disconnect; in some drivers (such as usb-storage) the disconnect()
559 * or suspend() method will block waiting for a device reset to complete.
561 * Returns a negative error code for failure, otherwise 0.
563 int usb_lock_device_for_reset(struct usb_device *udev,
564 const struct usb_interface *iface)
566 unsigned long jiffies_expire = jiffies + HZ;
568 if (udev->state == USB_STATE_NOTATTACHED)
570 if (udev->state == USB_STATE_SUSPENDED)
571 return -EHOSTUNREACH;
572 if (iface && (iface->condition == USB_INTERFACE_UNBINDING ||
573 iface->condition == USB_INTERFACE_UNBOUND))
576 while (usb_trylock_device(udev) != 0) {
578 /* If we can't acquire the lock after waiting one second,
579 * we're probably deadlocked */
580 if (time_after(jiffies, jiffies_expire))
584 if (udev->state == USB_STATE_NOTATTACHED)
586 if (udev->state == USB_STATE_SUSPENDED)
587 return -EHOSTUNREACH;
588 if (iface && (iface->condition == USB_INTERFACE_UNBINDING ||
589 iface->condition == USB_INTERFACE_UNBOUND))
594 EXPORT_SYMBOL_GPL(usb_lock_device_for_reset);
596 static struct usb_device *match_device(struct usb_device *dev,
597 u16 vendor_id, u16 product_id)
599 struct usb_device *ret_dev = NULL;
602 dev_dbg(&dev->dev, "check for vendor %04x, product %04x ...\n",
603 le16_to_cpu(dev->descriptor.idVendor),
604 le16_to_cpu(dev->descriptor.idProduct));
606 /* see if this device matches */
607 if ((vendor_id == le16_to_cpu(dev->descriptor.idVendor)) &&
608 (product_id == le16_to_cpu(dev->descriptor.idProduct))) {
609 dev_dbg(&dev->dev, "matched this device!\n");
610 ret_dev = usb_get_dev(dev);
614 /* look through all of the children of this device */
615 for (child = 0; child < dev->maxchild; ++child) {
616 if (dev->children[child]) {
617 usb_lock_device(dev->children[child]);
618 ret_dev = match_device(dev->children[child],
619 vendor_id, product_id);
620 usb_unlock_device(dev->children[child]);
630 * usb_find_device - find a specific usb device in the system
631 * @vendor_id: the vendor id of the device to find
632 * @product_id: the product id of the device to find
634 * Returns a pointer to a struct usb_device if such a specified usb
635 * device is present in the system currently. The usage count of the
636 * device will be incremented if a device is found. Make sure to call
637 * usb_put_dev() when the caller is finished with the device.
639 * If a device with the specified vendor and product id is not found,
642 struct usb_device *usb_find_device(u16 vendor_id, u16 product_id)
644 struct list_head *buslist;
646 struct usb_device *dev = NULL;
648 mutex_lock(&usb_bus_list_lock);
649 for (buslist = usb_bus_list.next;
650 buslist != &usb_bus_list;
651 buslist = buslist->next) {
652 bus = container_of(buslist, struct usb_bus, bus_list);
655 usb_lock_device(bus->root_hub);
656 dev = match_device(bus->root_hub, vendor_id, product_id);
657 usb_unlock_device(bus->root_hub);
662 mutex_unlock(&usb_bus_list_lock);
667 * usb_get_current_frame_number - return current bus frame number
668 * @dev: the device whose bus is being queried
670 * Returns the current frame number for the USB host controller
671 * used with the given USB device. This can be used when scheduling
672 * isochronous requests.
674 * Note that different kinds of host controller have different
675 * "scheduling horizons". While one type might support scheduling only
676 * 32 frames into the future, others could support scheduling up to
677 * 1024 frames into the future.
679 int usb_get_current_frame_number(struct usb_device *dev)
681 return usb_hcd_get_frame_number(dev);
683 EXPORT_SYMBOL_GPL(usb_get_current_frame_number);
685 /*-------------------------------------------------------------------*/
687 * __usb_get_extra_descriptor() finds a descriptor of specific type in the
688 * extra field of the interface and endpoint descriptor structs.
691 int __usb_get_extra_descriptor(char *buffer, unsigned size,
692 unsigned char type, void **ptr)
694 struct usb_descriptor_header *header;
696 while (size >= sizeof(struct usb_descriptor_header)) {
697 header = (struct usb_descriptor_header *)buffer;
699 if (header->bLength < 2) {
701 "%s: bogus descriptor, type %d length %d\n",
703 header->bDescriptorType,
708 if (header->bDescriptorType == type) {
713 buffer += header->bLength;
714 size -= header->bLength;
718 EXPORT_SYMBOL_GPL(__usb_get_extra_descriptor);
721 * usb_buffer_alloc - allocate dma-consistent buffer for URB_NO_xxx_DMA_MAP
722 * @dev: device the buffer will be used with
723 * @size: requested buffer size
724 * @mem_flags: affect whether allocation may block
725 * @dma: used to return DMA address of buffer
727 * Return value is either null (indicating no buffer could be allocated), or
728 * the cpu-space pointer to a buffer that may be used to perform DMA to the
729 * specified device. Such cpu-space buffers are returned along with the DMA
730 * address (through the pointer provided).
732 * These buffers are used with URB_NO_xxx_DMA_MAP set in urb->transfer_flags
733 * to avoid behaviors like using "DMA bounce buffers", or thrashing IOMMU
734 * hardware during URB completion/resubmit. The implementation varies between
735 * platforms, depending on details of how DMA will work to this device.
736 * Using these buffers also eliminates cacheline sharing problems on
737 * architectures where CPU caches are not DMA-coherent. On systems without
738 * bus-snooping caches, these buffers are uncached.
740 * When the buffer is no longer used, free it with usb_buffer_free().
742 void *usb_buffer_alloc(struct usb_device *dev, size_t size, gfp_t mem_flags,
745 if (!dev || !dev->bus)
747 return hcd_buffer_alloc(dev->bus, size, mem_flags, dma);
749 EXPORT_SYMBOL_GPL(usb_buffer_alloc);
752 * usb_buffer_free - free memory allocated with usb_buffer_alloc()
753 * @dev: device the buffer was used with
754 * @size: requested buffer size
755 * @addr: CPU address of buffer
756 * @dma: DMA address of buffer
758 * This reclaims an I/O buffer, letting it be reused. The memory must have
759 * been allocated using usb_buffer_alloc(), and the parameters must match
760 * those provided in that allocation request.
762 void usb_buffer_free(struct usb_device *dev, size_t size, void *addr,
765 if (!dev || !dev->bus)
769 hcd_buffer_free(dev->bus, size, addr, dma);
771 EXPORT_SYMBOL_GPL(usb_buffer_free);
774 * usb_buffer_map - create DMA mapping(s) for an urb
775 * @urb: urb whose transfer_buffer/setup_packet will be mapped
777 * Return value is either null (indicating no buffer could be mapped), or
778 * the parameter. URB_NO_TRANSFER_DMA_MAP and URB_NO_SETUP_DMA_MAP are
779 * added to urb->transfer_flags if the operation succeeds. If the device
780 * is connected to this system through a non-DMA controller, this operation
783 * This call would normally be used for an urb which is reused, perhaps
784 * as the target of a large periodic transfer, with usb_buffer_dmasync()
785 * calls to synchronize memory and dma state.
787 * Reverse the effect of this call with usb_buffer_unmap().
790 struct urb *usb_buffer_map(struct urb *urb)
793 struct device *controller;
797 || !(bus = urb->dev->bus)
798 || !(controller = bus->controller))
801 if (controller->dma_mask) {
802 urb->transfer_dma = dma_map_single(controller,
803 urb->transfer_buffer, urb->transfer_buffer_length,
804 usb_pipein(urb->pipe)
805 ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
806 if (usb_pipecontrol(urb->pipe))
807 urb->setup_dma = dma_map_single(controller,
809 sizeof(struct usb_ctrlrequest),
811 /* FIXME generic api broken like pci, can't report errors */
812 /* if (urb->transfer_dma == DMA_ADDR_INVALID) return 0; */
814 urb->transfer_dma = ~0;
815 urb->transfer_flags |= (URB_NO_TRANSFER_DMA_MAP
816 | URB_NO_SETUP_DMA_MAP);
819 EXPORT_SYMBOL_GPL(usb_buffer_map);
822 /* XXX DISABLED, no users currently. If you wish to re-enable this
823 * XXX please determine whether the sync is to transfer ownership of
824 * XXX the buffer from device to cpu or vice verse, and thusly use the
825 * XXX appropriate _for_{cpu,device}() method. -DaveM
830 * usb_buffer_dmasync - synchronize DMA and CPU view of buffer(s)
831 * @urb: urb whose transfer_buffer/setup_packet will be synchronized
833 void usb_buffer_dmasync(struct urb *urb)
836 struct device *controller;
839 || !(urb->transfer_flags & URB_NO_TRANSFER_DMA_MAP)
841 || !(bus = urb->dev->bus)
842 || !(controller = bus->controller))
845 if (controller->dma_mask) {
846 dma_sync_single_for_cpu(controller,
847 urb->transfer_dma, urb->transfer_buffer_length,
848 usb_pipein(urb->pipe)
849 ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
850 if (usb_pipecontrol(urb->pipe))
851 dma_sync_single_for_cpu(controller,
853 sizeof(struct usb_ctrlrequest),
857 EXPORT_SYMBOL_GPL(usb_buffer_dmasync);
861 * usb_buffer_unmap - free DMA mapping(s) for an urb
862 * @urb: urb whose transfer_buffer will be unmapped
864 * Reverses the effect of usb_buffer_map().
867 void usb_buffer_unmap(struct urb *urb)
870 struct device *controller;
873 || !(urb->transfer_flags & URB_NO_TRANSFER_DMA_MAP)
875 || !(bus = urb->dev->bus)
876 || !(controller = bus->controller))
879 if (controller->dma_mask) {
880 dma_unmap_single(controller,
881 urb->transfer_dma, urb->transfer_buffer_length,
882 usb_pipein(urb->pipe)
883 ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
884 if (usb_pipecontrol(urb->pipe))
885 dma_unmap_single(controller,
887 sizeof(struct usb_ctrlrequest),
890 urb->transfer_flags &= ~(URB_NO_TRANSFER_DMA_MAP
891 | URB_NO_SETUP_DMA_MAP);
893 EXPORT_SYMBOL_GPL(usb_buffer_unmap);
897 * usb_buffer_map_sg - create scatterlist DMA mapping(s) for an endpoint
898 * @dev: device to which the scatterlist will be mapped
899 * @is_in: mapping transfer direction
900 * @sg: the scatterlist to map
901 * @nents: the number of entries in the scatterlist
903 * Return value is either < 0 (indicating no buffers could be mapped), or
904 * the number of DMA mapping array entries in the scatterlist.
906 * The caller is responsible for placing the resulting DMA addresses from
907 * the scatterlist into URB transfer buffer pointers, and for setting the
908 * URB_NO_TRANSFER_DMA_MAP transfer flag in each of those URBs.
910 * Top I/O rates come from queuing URBs, instead of waiting for each one
911 * to complete before starting the next I/O. This is particularly easy
912 * to do with scatterlists. Just allocate and submit one URB for each DMA
913 * mapping entry returned, stopping on the first error or when all succeed.
914 * Better yet, use the usb_sg_*() calls, which do that (and more) for you.
916 * This call would normally be used when translating scatterlist requests,
917 * rather than usb_buffer_map(), since on some hardware (with IOMMUs) it
918 * may be able to coalesce mappings for improved I/O efficiency.
920 * Reverse the effect of this call with usb_buffer_unmap_sg().
922 int usb_buffer_map_sg(const struct usb_device *dev, int is_in,
923 struct scatterlist *sg, int nents)
926 struct device *controller;
930 || !(controller = bus->controller)
931 || !controller->dma_mask)
934 /* FIXME generic api broken like pci, can't report errors */
935 return dma_map_sg(controller, sg, nents,
936 is_in ? DMA_FROM_DEVICE : DMA_TO_DEVICE) ? : -ENOMEM;
938 EXPORT_SYMBOL_GPL(usb_buffer_map_sg);
940 /* XXX DISABLED, no users currently. If you wish to re-enable this
941 * XXX please determine whether the sync is to transfer ownership of
942 * XXX the buffer from device to cpu or vice verse, and thusly use the
943 * XXX appropriate _for_{cpu,device}() method. -DaveM
948 * usb_buffer_dmasync_sg - synchronize DMA and CPU view of scatterlist buffer(s)
949 * @dev: device to which the scatterlist will be mapped
950 * @is_in: mapping transfer direction
951 * @sg: the scatterlist to synchronize
952 * @n_hw_ents: the positive return value from usb_buffer_map_sg
954 * Use this when you are re-using a scatterlist's data buffers for
955 * another USB request.
957 void usb_buffer_dmasync_sg(const struct usb_device *dev, int is_in,
958 struct scatterlist *sg, int n_hw_ents)
961 struct device *controller;
965 || !(controller = bus->controller)
966 || !controller->dma_mask)
969 dma_sync_sg_for_cpu(controller, sg, n_hw_ents,
970 is_in ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
972 EXPORT_SYMBOL_GPL(usb_buffer_dmasync_sg);
976 * usb_buffer_unmap_sg - free DMA mapping(s) for a scatterlist
977 * @dev: device to which the scatterlist will be mapped
978 * @is_in: mapping transfer direction
979 * @sg: the scatterlist to unmap
980 * @n_hw_ents: the positive return value from usb_buffer_map_sg
982 * Reverses the effect of usb_buffer_map_sg().
984 void usb_buffer_unmap_sg(const struct usb_device *dev, int is_in,
985 struct scatterlist *sg, int n_hw_ents)
988 struct device *controller;
992 || !(controller = bus->controller)
993 || !controller->dma_mask)
996 dma_unmap_sg(controller, sg, n_hw_ents,
997 is_in ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
999 EXPORT_SYMBOL_GPL(usb_buffer_unmap_sg);
1001 /* To disable USB, kernel command line is 'nousb' not 'usbcore.nousb' */
1003 module_param(nousb, bool, 0444);
1005 core_param(nousb, nousb, bool, 0444);
1009 * for external read access to <nousb>
1011 int usb_disabled(void)
1015 EXPORT_SYMBOL_GPL(usb_disabled);
1018 * Notifications of device and interface registration
1020 static int usb_bus_notify(struct notifier_block *nb, unsigned long action,
1023 struct device *dev = data;
1026 case BUS_NOTIFY_ADD_DEVICE:
1027 if (dev->type == &usb_device_type)
1028 (void) usb_create_sysfs_dev_files(to_usb_device(dev));
1029 else if (dev->type == &usb_if_device_type)
1030 (void) usb_create_sysfs_intf_files(
1031 to_usb_interface(dev));
1034 case BUS_NOTIFY_DEL_DEVICE:
1035 if (dev->type == &usb_device_type)
1036 usb_remove_sysfs_dev_files(to_usb_device(dev));
1037 else if (dev->type == &usb_if_device_type)
1038 usb_remove_sysfs_intf_files(to_usb_interface(dev));
1044 static struct notifier_block usb_bus_nb = {
1045 .notifier_call = usb_bus_notify,
1048 struct dentry *usb_debug_root;
1049 EXPORT_SYMBOL_GPL(usb_debug_root);
1051 static struct dentry *usb_debug_devices;
1053 static int usb_debugfs_init(void)
1055 usb_debug_root = debugfs_create_dir("usb", NULL);
1056 if (!usb_debug_root)
1059 usb_debug_devices = debugfs_create_file("devices", 0444,
1060 usb_debug_root, NULL,
1061 &usbfs_devices_fops);
1062 if (!usb_debug_devices) {
1063 debugfs_remove(usb_debug_root);
1064 usb_debug_root = NULL;
1071 static void usb_debugfs_cleanup(void)
1073 debugfs_remove(usb_debug_devices);
1074 debugfs_remove(usb_debug_root);
1080 static int __init usb_init(void)
1084 pr_info("%s: USB support disabled\n", usbcore_name);
1088 retval = usb_debugfs_init();
1092 retval = bus_register(&usb_bus_type);
1094 goto bus_register_failed;
1095 retval = bus_register_notifier(&usb_bus_type, &usb_bus_nb);
1097 goto bus_notifier_failed;
1098 retval = usb_major_init();
1100 goto major_init_failed;
1101 retval = usb_register(&usbfs_driver);
1103 goto driver_register_failed;
1104 retval = usb_devio_init();
1106 goto usb_devio_init_failed;
1107 retval = usbfs_init();
1109 goto fs_init_failed;
1110 retval = usb_hub_init();
1112 goto hub_init_failed;
1113 retval = usb_register_device_driver(&usb_generic_driver, THIS_MODULE);
1121 usb_devio_cleanup();
1122 usb_devio_init_failed:
1123 usb_deregister(&usbfs_driver);
1124 driver_register_failed:
1125 usb_major_cleanup();
1127 bus_unregister_notifier(&usb_bus_type, &usb_bus_nb);
1128 bus_notifier_failed:
1129 bus_unregister(&usb_bus_type);
1130 bus_register_failed:
1131 usb_debugfs_cleanup();
1139 static void __exit usb_exit(void)
1141 /* This will matter if shutdown/reboot does exitcalls. */
1145 usb_deregister_device_driver(&usb_generic_driver);
1146 usb_major_cleanup();
1148 usb_deregister(&usbfs_driver);
1149 usb_devio_cleanup();
1151 bus_unregister_notifier(&usb_bus_type, &usb_bus_nb);
1152 bus_unregister(&usb_bus_type);
1153 usb_debugfs_cleanup();
1156 subsys_initcall(usb_init);
1157 module_exit(usb_exit);
1158 MODULE_LICENSE("GPL");