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/usb/hcd.h>
36 #include <linux/mutex.h>
37 #include <linux/workqueue.h>
38 #include <linux/debugfs.h>
41 #include <linux/scatterlist.h>
43 #include <linux/dma-mapping.h>
48 const char *usbcore_name = "usbcore";
50 static bool nousb; /* Disable USB when built into kernel image */
52 module_param(nousb, bool, 0444);
55 * for external read access to <nousb>
57 int usb_disabled(void)
61 EXPORT_SYMBOL_GPL(usb_disabled);
64 static int usb_autosuspend_delay = 2; /* Default delay value,
66 module_param_named(autosuspend, usb_autosuspend_delay, int, 0644);
67 MODULE_PARM_DESC(autosuspend, "default autosuspend delay");
70 #define usb_autosuspend_delay 0
75 * usb_find_alt_setting() - Given a configuration, find the alternate setting
76 * for the given interface.
77 * @config: the configuration to search (not necessarily the current config).
78 * @iface_num: interface number to search in
79 * @alt_num: alternate interface setting number to search for.
81 * Search the configuration's interface cache for the given alt setting.
83 * Return: The alternate setting, if found. %NULL otherwise.
85 struct usb_host_interface *usb_find_alt_setting(
86 struct usb_host_config *config,
87 unsigned int iface_num,
90 struct usb_interface_cache *intf_cache = NULL;
93 for (i = 0; i < config->desc.bNumInterfaces; i++) {
94 if (config->intf_cache[i]->altsetting[0].desc.bInterfaceNumber
96 intf_cache = config->intf_cache[i];
102 for (i = 0; i < intf_cache->num_altsetting; i++)
103 if (intf_cache->altsetting[i].desc.bAlternateSetting == alt_num)
104 return &intf_cache->altsetting[i];
106 printk(KERN_DEBUG "Did not find alt setting %u for intf %u, "
107 "config %u\n", alt_num, iface_num,
108 config->desc.bConfigurationValue);
111 EXPORT_SYMBOL_GPL(usb_find_alt_setting);
114 * usb_ifnum_to_if - get the interface object with a given interface number
115 * @dev: the device whose current configuration is considered
116 * @ifnum: the desired interface
118 * This walks the device descriptor for the currently active configuration
119 * to find the interface object with the particular interface number.
121 * Note that configuration descriptors are not required to assign interface
122 * numbers sequentially, so that it would be incorrect to assume that
123 * the first interface in that descriptor corresponds to interface zero.
124 * This routine helps device drivers avoid such mistakes.
125 * However, you should make sure that you do the right thing with any
126 * alternate settings available for this interfaces.
128 * Don't call this function unless you are bound to one of the interfaces
129 * on this device or you have locked the device!
131 * Return: A pointer to the interface that has @ifnum as interface number,
132 * if found. %NULL otherwise.
134 struct usb_interface *usb_ifnum_to_if(const struct usb_device *dev,
137 struct usb_host_config *config = dev->actconfig;
142 for (i = 0; i < config->desc.bNumInterfaces; i++)
143 if (config->interface[i]->altsetting[0]
144 .desc.bInterfaceNumber == ifnum)
145 return config->interface[i];
149 EXPORT_SYMBOL_GPL(usb_ifnum_to_if);
152 * usb_altnum_to_altsetting - get the altsetting structure with a given alternate setting number.
153 * @intf: the interface containing the altsetting in question
154 * @altnum: the desired alternate setting number
156 * This searches the altsetting array of the specified interface for
157 * an entry with the correct bAlternateSetting value.
159 * Note that altsettings need not be stored sequentially by number, so
160 * it would be incorrect to assume that the first altsetting entry in
161 * the array corresponds to altsetting zero. This routine helps device
162 * drivers avoid such mistakes.
164 * Don't call this function unless you are bound to the intf interface
165 * or you have locked the device!
167 * Return: A pointer to the entry of the altsetting array of @intf that
168 * has @altnum as the alternate setting number. %NULL if not found.
170 struct usb_host_interface *usb_altnum_to_altsetting(
171 const struct usb_interface *intf,
176 for (i = 0; i < intf->num_altsetting; i++) {
177 if (intf->altsetting[i].desc.bAlternateSetting == altnum)
178 return &intf->altsetting[i];
182 EXPORT_SYMBOL_GPL(usb_altnum_to_altsetting);
184 struct find_interface_arg {
186 struct device_driver *drv;
189 static int __find_interface(struct device *dev, void *data)
191 struct find_interface_arg *arg = data;
192 struct usb_interface *intf;
194 if (!is_usb_interface(dev))
197 if (dev->driver != arg->drv)
199 intf = to_usb_interface(dev);
200 return intf->minor == arg->minor;
204 * usb_find_interface - find usb_interface pointer for driver and device
205 * @drv: the driver whose current configuration is considered
206 * @minor: the minor number of the desired device
208 * This walks the bus device list and returns a pointer to the interface
209 * with the matching minor and driver. Note, this only works for devices
210 * that share the USB major number.
212 * Return: A pointer to the interface with the matching major and @minor.
214 struct usb_interface *usb_find_interface(struct usb_driver *drv, int minor)
216 struct find_interface_arg argb;
220 argb.drv = &drv->drvwrap.driver;
222 dev = bus_find_device(&usb_bus_type, NULL, &argb, __find_interface);
224 /* Drop reference count from bus_find_device */
227 return dev ? to_usb_interface(dev) : NULL;
229 EXPORT_SYMBOL_GPL(usb_find_interface);
231 struct each_dev_arg {
233 int (*fn)(struct usb_device *, void *);
236 static int __each_dev(struct device *dev, void *data)
238 struct each_dev_arg *arg = (struct each_dev_arg *)data;
240 /* There are struct usb_interface on the same bus, filter them out */
241 if (!is_usb_device(dev))
244 return arg->fn(container_of(dev, struct usb_device, dev), arg->data);
248 * usb_for_each_dev - iterate over all USB devices in the system
249 * @data: data pointer that will be handed to the callback function
250 * @fn: callback function to be called for each USB device
252 * Iterate over all USB devices and call @fn for each, passing it @data. If it
253 * returns anything other than 0, we break the iteration prematurely and return
256 int usb_for_each_dev(void *data, int (*fn)(struct usb_device *, void *))
258 struct each_dev_arg arg = {data, fn};
260 return bus_for_each_dev(&usb_bus_type, NULL, &arg, __each_dev);
262 EXPORT_SYMBOL_GPL(usb_for_each_dev);
265 * usb_release_dev - free a usb device structure when all users of it are finished.
266 * @dev: device that's been disconnected
268 * Will be called only by the device core when all users of this usb device are
271 static void usb_release_dev(struct device *dev)
273 struct usb_device *udev;
276 udev = to_usb_device(dev);
277 hcd = bus_to_hcd(udev->bus);
279 usb_destroy_configuration(udev);
280 usb_release_bos_descriptor(udev);
282 kfree(udev->product);
283 kfree(udev->manufacturer);
288 static int usb_dev_uevent(struct device *dev, struct kobj_uevent_env *env)
290 struct usb_device *usb_dev;
292 usb_dev = to_usb_device(dev);
294 if (add_uevent_var(env, "BUSNUM=%03d", usb_dev->bus->busnum))
297 if (add_uevent_var(env, "DEVNUM=%03d", usb_dev->devnum))
305 /* USB device Power-Management thunks.
306 * There's no need to distinguish here between quiescing a USB device
307 * and powering it down; the generic_suspend() routine takes care of
308 * it by skipping the usb_port_suspend() call for a quiesce. And for
309 * USB interfaces there's no difference at all.
312 static int usb_dev_prepare(struct device *dev)
314 struct usb_device *udev = to_usb_device(dev);
316 /* Return 0 if the current wakeup setting is wrong, otherwise 1 */
317 if (udev->do_remote_wakeup != device_may_wakeup(dev))
323 static void usb_dev_complete(struct device *dev)
325 /* Currently used only for rebinding interfaces */
326 usb_resume_complete(dev);
329 static int usb_dev_suspend(struct device *dev)
331 return usb_suspend(dev, PMSG_SUSPEND);
334 static int usb_dev_resume(struct device *dev)
336 return usb_resume(dev, PMSG_RESUME);
339 static int usb_dev_freeze(struct device *dev)
341 return usb_suspend(dev, PMSG_FREEZE);
344 static int usb_dev_thaw(struct device *dev)
346 return usb_resume(dev, PMSG_THAW);
349 static int usb_dev_poweroff(struct device *dev)
351 return usb_suspend(dev, PMSG_HIBERNATE);
354 static int usb_dev_restore(struct device *dev)
356 return usb_resume(dev, PMSG_RESTORE);
359 static const struct dev_pm_ops usb_device_pm_ops = {
360 .prepare = usb_dev_prepare,
361 .complete = usb_dev_complete,
362 .suspend = usb_dev_suspend,
363 .resume = usb_dev_resume,
364 .freeze = usb_dev_freeze,
365 .thaw = usb_dev_thaw,
366 .poweroff = usb_dev_poweroff,
367 .restore = usb_dev_restore,
368 .runtime_suspend = usb_runtime_suspend,
369 .runtime_resume = usb_runtime_resume,
370 .runtime_idle = usb_runtime_idle,
373 #endif /* CONFIG_PM */
376 static char *usb_devnode(struct device *dev,
377 umode_t *mode, kuid_t *uid, kgid_t *gid)
379 struct usb_device *usb_dev;
381 usb_dev = to_usb_device(dev);
382 return kasprintf(GFP_KERNEL, "bus/usb/%03d/%03d",
383 usb_dev->bus->busnum, usb_dev->devnum);
386 struct device_type usb_device_type = {
387 .name = "usb_device",
388 .release = usb_release_dev,
389 .uevent = usb_dev_uevent,
390 .devnode = usb_devnode,
392 .pm = &usb_device_pm_ops,
397 /* Returns 1 if @usb_bus is WUSB, 0 otherwise */
398 static unsigned usb_bus_is_wusb(struct usb_bus *bus)
400 struct usb_hcd *hcd = container_of(bus, struct usb_hcd, self);
401 return hcd->wireless;
406 * usb_alloc_dev - usb device constructor (usbcore-internal)
407 * @parent: hub to which device is connected; null to allocate a root hub
408 * @bus: bus used to access the device
409 * @port1: one-based index of port; ignored for root hubs
410 * Context: !in_interrupt()
412 * Only hub drivers (including virtual root hub drivers for host
413 * controllers) should ever call this.
415 * This call may not be used in a non-sleeping context.
417 * Return: On success, a pointer to the allocated usb device. %NULL on
420 struct usb_device *usb_alloc_dev(struct usb_device *parent,
421 struct usb_bus *bus, unsigned port1)
423 struct usb_device *dev;
424 struct usb_hcd *usb_hcd = bus_to_hcd(bus);
425 unsigned root_hub = 0;
427 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
431 if (!usb_get_hcd(usb_hcd)) {
435 /* Root hubs aren't true devices, so don't allocate HCD resources */
436 if (usb_hcd->driver->alloc_dev && parent &&
437 !usb_hcd->driver->alloc_dev(usb_hcd, dev)) {
438 usb_put_hcd(bus_to_hcd(bus));
443 device_initialize(&dev->dev);
444 dev->dev.bus = &usb_bus_type;
445 dev->dev.type = &usb_device_type;
446 dev->dev.groups = usb_device_groups;
447 dev->dev.dma_mask = bus->controller->dma_mask;
448 set_dev_node(&dev->dev, dev_to_node(bus->controller));
449 dev->state = USB_STATE_ATTACHED;
450 dev->lpm_disable_count = 1;
451 atomic_set(&dev->urbnum, 0);
453 INIT_LIST_HEAD(&dev->ep0.urb_list);
454 dev->ep0.desc.bLength = USB_DT_ENDPOINT_SIZE;
455 dev->ep0.desc.bDescriptorType = USB_DT_ENDPOINT;
456 /* ep0 maxpacket comes later, from device descriptor */
457 usb_enable_endpoint(dev, &dev->ep0, false);
460 /* Save readable and stable topology id, distinguishing devices
461 * by location for diagnostics, tools, driver model, etc. The
462 * string is a path along hub ports, from the root. Each device's
463 * dev->devpath will be stable until USB is re-cabled, and hubs
464 * are often labeled with these port numbers. The name isn't
465 * as stable: bus->busnum changes easily from modprobe order,
466 * cardbus or pci hotplugging, and so on.
468 if (unlikely(!parent)) {
469 dev->devpath[0] = '0';
472 dev->dev.parent = bus->controller;
473 dev_set_name(&dev->dev, "usb%d", bus->busnum);
476 /* match any labeling on the hubs; it's one-based */
477 if (parent->devpath[0] == '0') {
478 snprintf(dev->devpath, sizeof dev->devpath,
480 /* Root ports are not counted in route string */
483 snprintf(dev->devpath, sizeof dev->devpath,
484 "%s.%d", parent->devpath, port1);
485 /* Route string assumes hubs have less than 16 ports */
487 dev->route = parent->route +
488 (port1 << ((parent->level - 1)*4));
490 dev->route = parent->route +
491 (15 << ((parent->level - 1)*4));
494 dev->dev.parent = &parent->dev;
495 dev_set_name(&dev->dev, "%d-%s", bus->busnum, dev->devpath);
497 /* hub driver sets up TT records */
500 dev->portnum = port1;
502 dev->parent = parent;
503 INIT_LIST_HEAD(&dev->filelist);
506 pm_runtime_set_autosuspend_delay(&dev->dev,
507 usb_autosuspend_delay * 1000);
508 dev->connect_time = jiffies;
509 dev->active_duration = -jiffies;
511 if (root_hub) /* Root hub always ok [and always wired] */
514 dev->authorized = !!HCD_DEV_AUTHORIZED(usb_hcd);
515 dev->wusb = usb_bus_is_wusb(bus) ? 1 : 0;
519 EXPORT_SYMBOL_GPL(usb_alloc_dev);
522 * usb_get_dev - increments the reference count of the usb device structure
523 * @dev: the device being referenced
525 * Each live reference to a device should be refcounted.
527 * Drivers for USB interfaces should normally record such references in
528 * their probe() methods, when they bind to an interface, and release
529 * them by calling usb_put_dev(), in their disconnect() methods.
531 * Return: A pointer to the device with the incremented reference counter.
533 struct usb_device *usb_get_dev(struct usb_device *dev)
536 get_device(&dev->dev);
539 EXPORT_SYMBOL_GPL(usb_get_dev);
542 * usb_put_dev - release a use of the usb device structure
543 * @dev: device that's been disconnected
545 * Must be called when a user of a device is finished with it. When the last
546 * user of the device calls this function, the memory of the device is freed.
548 void usb_put_dev(struct usb_device *dev)
551 put_device(&dev->dev);
553 EXPORT_SYMBOL_GPL(usb_put_dev);
556 * usb_get_intf - increments the reference count of the usb interface structure
557 * @intf: the interface being referenced
559 * Each live reference to a interface must be refcounted.
561 * Drivers for USB interfaces should normally record such references in
562 * their probe() methods, when they bind to an interface, and release
563 * them by calling usb_put_intf(), in their disconnect() methods.
565 * Return: A pointer to the interface with the incremented reference counter.
567 struct usb_interface *usb_get_intf(struct usb_interface *intf)
570 get_device(&intf->dev);
573 EXPORT_SYMBOL_GPL(usb_get_intf);
576 * usb_put_intf - release a use of the usb interface structure
577 * @intf: interface that's been decremented
579 * Must be called when a user of an interface is finished with it. When the
580 * last user of the interface calls this function, the memory of the interface
583 void usb_put_intf(struct usb_interface *intf)
586 put_device(&intf->dev);
588 EXPORT_SYMBOL_GPL(usb_put_intf);
590 /* USB device locking
592 * USB devices and interfaces are locked using the semaphore in their
593 * embedded struct device. The hub driver guarantees that whenever a
594 * device is connected or disconnected, drivers are called with the
595 * USB device locked as well as their particular interface.
597 * Complications arise when several devices are to be locked at the same
598 * time. Only hub-aware drivers that are part of usbcore ever have to
599 * do this; nobody else needs to worry about it. The rule for locking
602 * When locking both a device and its parent, always lock the
607 * usb_lock_device_for_reset - cautiously acquire the lock for a usb device structure
608 * @udev: device that's being locked
609 * @iface: interface bound to the driver making the request (optional)
611 * Attempts to acquire the device lock, but fails if the device is
612 * NOTATTACHED or SUSPENDED, or if iface is specified and the interface
613 * is neither BINDING nor BOUND. Rather than sleeping to wait for the
614 * lock, the routine polls repeatedly. This is to prevent deadlock with
615 * disconnect; in some drivers (such as usb-storage) the disconnect()
616 * or suspend() method will block waiting for a device reset to complete.
618 * Return: A negative error code for failure, otherwise 0.
620 int usb_lock_device_for_reset(struct usb_device *udev,
621 const struct usb_interface *iface)
623 unsigned long jiffies_expire = jiffies + HZ;
625 if (udev->state == USB_STATE_NOTATTACHED)
627 if (udev->state == USB_STATE_SUSPENDED)
628 return -EHOSTUNREACH;
629 if (iface && (iface->condition == USB_INTERFACE_UNBINDING ||
630 iface->condition == USB_INTERFACE_UNBOUND))
633 while (!usb_trylock_device(udev)) {
635 /* If we can't acquire the lock after waiting one second,
636 * we're probably deadlocked */
637 if (time_after(jiffies, jiffies_expire))
641 if (udev->state == USB_STATE_NOTATTACHED)
643 if (udev->state == USB_STATE_SUSPENDED)
644 return -EHOSTUNREACH;
645 if (iface && (iface->condition == USB_INTERFACE_UNBINDING ||
646 iface->condition == USB_INTERFACE_UNBOUND))
651 EXPORT_SYMBOL_GPL(usb_lock_device_for_reset);
654 * usb_get_current_frame_number - return current bus frame number
655 * @dev: the device whose bus is being queried
657 * Return: The current frame number for the USB host controller used
658 * with the given USB device. This can be used when scheduling
659 * isochronous requests.
661 * Note: Different kinds of host controller have different "scheduling
662 * horizons". While one type might support scheduling only 32 frames
663 * into the future, others could support scheduling up to 1024 frames
667 int usb_get_current_frame_number(struct usb_device *dev)
669 return usb_hcd_get_frame_number(dev);
671 EXPORT_SYMBOL_GPL(usb_get_current_frame_number);
673 /*-------------------------------------------------------------------*/
675 * __usb_get_extra_descriptor() finds a descriptor of specific type in the
676 * extra field of the interface and endpoint descriptor structs.
679 int __usb_get_extra_descriptor(char *buffer, unsigned size,
680 unsigned char type, void **ptr)
682 struct usb_descriptor_header *header;
684 while (size >= sizeof(struct usb_descriptor_header)) {
685 header = (struct usb_descriptor_header *)buffer;
687 if (header->bLength < 2) {
689 "%s: bogus descriptor, type %d length %d\n",
691 header->bDescriptorType,
696 if (header->bDescriptorType == type) {
701 buffer += header->bLength;
702 size -= header->bLength;
706 EXPORT_SYMBOL_GPL(__usb_get_extra_descriptor);
709 * usb_alloc_coherent - allocate dma-consistent buffer for URB_NO_xxx_DMA_MAP
710 * @dev: device the buffer will be used with
711 * @size: requested buffer size
712 * @mem_flags: affect whether allocation may block
713 * @dma: used to return DMA address of buffer
715 * Return: Either null (indicating no buffer could be allocated), or the
716 * cpu-space pointer to a buffer that may be used to perform DMA to the
717 * specified device. Such cpu-space buffers are returned along with the DMA
718 * address (through the pointer provided).
721 * These buffers are used with URB_NO_xxx_DMA_MAP set in urb->transfer_flags
722 * to avoid behaviors like using "DMA bounce buffers", or thrashing IOMMU
723 * hardware during URB completion/resubmit. The implementation varies between
724 * platforms, depending on details of how DMA will work to this device.
725 * Using these buffers also eliminates cacheline sharing problems on
726 * architectures where CPU caches are not DMA-coherent. On systems without
727 * bus-snooping caches, these buffers are uncached.
729 * When the buffer is no longer used, free it with usb_free_coherent().
731 void *usb_alloc_coherent(struct usb_device *dev, size_t size, gfp_t mem_flags,
734 if (!dev || !dev->bus)
736 return hcd_buffer_alloc(dev->bus, size, mem_flags, dma);
738 EXPORT_SYMBOL_GPL(usb_alloc_coherent);
741 * usb_free_coherent - free memory allocated with usb_alloc_coherent()
742 * @dev: device the buffer was used with
743 * @size: requested buffer size
744 * @addr: CPU address of buffer
745 * @dma: DMA address of buffer
747 * This reclaims an I/O buffer, letting it be reused. The memory must have
748 * been allocated using usb_alloc_coherent(), and the parameters must match
749 * those provided in that allocation request.
751 void usb_free_coherent(struct usb_device *dev, size_t size, void *addr,
754 if (!dev || !dev->bus)
758 hcd_buffer_free(dev->bus, size, addr, dma);
760 EXPORT_SYMBOL_GPL(usb_free_coherent);
763 * usb_buffer_map - create DMA mapping(s) for an urb
764 * @urb: urb whose transfer_buffer/setup_packet will be mapped
766 * URB_NO_TRANSFER_DMA_MAP is added to urb->transfer_flags if the operation
767 * succeeds. If the device is connected to this system through a non-DMA
768 * controller, this operation always succeeds.
770 * This call would normally be used for an urb which is reused, perhaps
771 * as the target of a large periodic transfer, with usb_buffer_dmasync()
772 * calls to synchronize memory and dma state.
774 * Reverse the effect of this call with usb_buffer_unmap().
776 * Return: Either %NULL (indicating no buffer could be mapped), or @urb.
780 struct urb *usb_buffer_map(struct urb *urb)
783 struct device *controller;
787 || !(bus = urb->dev->bus)
788 || !(controller = bus->controller))
791 if (controller->dma_mask) {
792 urb->transfer_dma = dma_map_single(controller,
793 urb->transfer_buffer, urb->transfer_buffer_length,
794 usb_pipein(urb->pipe)
795 ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
796 /* FIXME generic api broken like pci, can't report errors */
797 /* if (urb->transfer_dma == DMA_ADDR_INVALID) return 0; */
799 urb->transfer_dma = ~0;
800 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
803 EXPORT_SYMBOL_GPL(usb_buffer_map);
806 /* XXX DISABLED, no users currently. If you wish to re-enable this
807 * XXX please determine whether the sync is to transfer ownership of
808 * XXX the buffer from device to cpu or vice verse, and thusly use the
809 * XXX appropriate _for_{cpu,device}() method. -DaveM
814 * usb_buffer_dmasync - synchronize DMA and CPU view of buffer(s)
815 * @urb: urb whose transfer_buffer/setup_packet will be synchronized
817 void usb_buffer_dmasync(struct urb *urb)
820 struct device *controller;
823 || !(urb->transfer_flags & URB_NO_TRANSFER_DMA_MAP)
825 || !(bus = urb->dev->bus)
826 || !(controller = bus->controller))
829 if (controller->dma_mask) {
830 dma_sync_single_for_cpu(controller,
831 urb->transfer_dma, urb->transfer_buffer_length,
832 usb_pipein(urb->pipe)
833 ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
834 if (usb_pipecontrol(urb->pipe))
835 dma_sync_single_for_cpu(controller,
837 sizeof(struct usb_ctrlrequest),
841 EXPORT_SYMBOL_GPL(usb_buffer_dmasync);
845 * usb_buffer_unmap - free DMA mapping(s) for an urb
846 * @urb: urb whose transfer_buffer will be unmapped
848 * Reverses the effect of usb_buffer_map().
851 void usb_buffer_unmap(struct urb *urb)
854 struct device *controller;
857 || !(urb->transfer_flags & URB_NO_TRANSFER_DMA_MAP)
859 || !(bus = urb->dev->bus)
860 || !(controller = bus->controller))
863 if (controller->dma_mask) {
864 dma_unmap_single(controller,
865 urb->transfer_dma, urb->transfer_buffer_length,
866 usb_pipein(urb->pipe)
867 ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
869 urb->transfer_flags &= ~URB_NO_TRANSFER_DMA_MAP;
871 EXPORT_SYMBOL_GPL(usb_buffer_unmap);
876 * usb_buffer_map_sg - create scatterlist DMA mapping(s) for an endpoint
877 * @dev: device to which the scatterlist will be mapped
878 * @is_in: mapping transfer direction
879 * @sg: the scatterlist to map
880 * @nents: the number of entries in the scatterlist
882 * Return: Either < 0 (indicating no buffers could be mapped), or the
883 * number of DMA mapping array entries in the scatterlist.
886 * The caller is responsible for placing the resulting DMA addresses from
887 * the scatterlist into URB transfer buffer pointers, and for setting the
888 * URB_NO_TRANSFER_DMA_MAP transfer flag in each of those URBs.
890 * Top I/O rates come from queuing URBs, instead of waiting for each one
891 * to complete before starting the next I/O. This is particularly easy
892 * to do with scatterlists. Just allocate and submit one URB for each DMA
893 * mapping entry returned, stopping on the first error or when all succeed.
894 * Better yet, use the usb_sg_*() calls, which do that (and more) for you.
896 * This call would normally be used when translating scatterlist requests,
897 * rather than usb_buffer_map(), since on some hardware (with IOMMUs) it
898 * may be able to coalesce mappings for improved I/O efficiency.
900 * Reverse the effect of this call with usb_buffer_unmap_sg().
902 int usb_buffer_map_sg(const struct usb_device *dev, int is_in,
903 struct scatterlist *sg, int nents)
906 struct device *controller;
910 || !(controller = bus->controller)
911 || !controller->dma_mask)
914 /* FIXME generic api broken like pci, can't report errors */
915 return dma_map_sg(controller, sg, nents,
916 is_in ? DMA_FROM_DEVICE : DMA_TO_DEVICE) ? : -ENOMEM;
918 EXPORT_SYMBOL_GPL(usb_buffer_map_sg);
921 /* XXX DISABLED, no users currently. If you wish to re-enable this
922 * XXX please determine whether the sync is to transfer ownership of
923 * XXX the buffer from device to cpu or vice verse, and thusly use the
924 * XXX appropriate _for_{cpu,device}() method. -DaveM
929 * usb_buffer_dmasync_sg - synchronize DMA and CPU view of scatterlist buffer(s)
930 * @dev: device to which the scatterlist will be mapped
931 * @is_in: mapping transfer direction
932 * @sg: the scatterlist to synchronize
933 * @n_hw_ents: the positive return value from usb_buffer_map_sg
935 * Use this when you are re-using a scatterlist's data buffers for
936 * another USB request.
938 void usb_buffer_dmasync_sg(const struct usb_device *dev, int is_in,
939 struct scatterlist *sg, int n_hw_ents)
942 struct device *controller;
946 || !(controller = bus->controller)
947 || !controller->dma_mask)
950 dma_sync_sg_for_cpu(controller, sg, n_hw_ents,
951 is_in ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
953 EXPORT_SYMBOL_GPL(usb_buffer_dmasync_sg);
958 * usb_buffer_unmap_sg - free DMA mapping(s) for a scatterlist
959 * @dev: device to which the scatterlist will be mapped
960 * @is_in: mapping transfer direction
961 * @sg: the scatterlist to unmap
962 * @n_hw_ents: the positive return value from usb_buffer_map_sg
964 * Reverses the effect of usb_buffer_map_sg().
966 void usb_buffer_unmap_sg(const struct usb_device *dev, int is_in,
967 struct scatterlist *sg, int n_hw_ents)
970 struct device *controller;
974 || !(controller = bus->controller)
975 || !controller->dma_mask)
978 dma_unmap_sg(controller, sg, n_hw_ents,
979 is_in ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
981 EXPORT_SYMBOL_GPL(usb_buffer_unmap_sg);
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 usb_create_sysfs_intf_files(to_usb_interface(dev));
1000 case BUS_NOTIFY_DEL_DEVICE:
1001 if (dev->type == &usb_device_type)
1002 usb_remove_sysfs_dev_files(to_usb_device(dev));
1003 else if (dev->type == &usb_if_device_type)
1004 usb_remove_sysfs_intf_files(to_usb_interface(dev));
1010 static struct notifier_block usb_bus_nb = {
1011 .notifier_call = usb_bus_notify,
1014 struct dentry *usb_debug_root;
1015 EXPORT_SYMBOL_GPL(usb_debug_root);
1017 static struct dentry *usb_debug_devices;
1019 static int usb_debugfs_init(void)
1021 usb_debug_root = debugfs_create_dir("usb", NULL);
1022 if (!usb_debug_root)
1025 usb_debug_devices = debugfs_create_file("devices", 0444,
1026 usb_debug_root, NULL,
1027 &usbfs_devices_fops);
1028 if (!usb_debug_devices) {
1029 debugfs_remove(usb_debug_root);
1030 usb_debug_root = NULL;
1037 static void usb_debugfs_cleanup(void)
1039 debugfs_remove(usb_debug_devices);
1040 debugfs_remove(usb_debug_root);
1046 static int __init usb_init(void)
1049 if (usb_disabled()) {
1050 pr_info("%s: USB support disabled\n", usbcore_name);
1053 usb_init_pool_max();
1055 retval = usb_debugfs_init();
1059 usb_acpi_register();
1060 retval = bus_register(&usb_bus_type);
1062 goto bus_register_failed;
1063 retval = bus_register_notifier(&usb_bus_type, &usb_bus_nb);
1065 goto bus_notifier_failed;
1066 retval = usb_major_init();
1068 goto major_init_failed;
1069 retval = usb_register(&usbfs_driver);
1071 goto driver_register_failed;
1072 retval = usb_devio_init();
1074 goto usb_devio_init_failed;
1075 retval = usb_hub_init();
1077 goto hub_init_failed;
1078 retval = usb_register_device_driver(&usb_generic_driver, THIS_MODULE);
1084 usb_devio_cleanup();
1085 usb_devio_init_failed:
1086 usb_deregister(&usbfs_driver);
1087 driver_register_failed:
1088 usb_major_cleanup();
1090 bus_unregister_notifier(&usb_bus_type, &usb_bus_nb);
1091 bus_notifier_failed:
1092 bus_unregister(&usb_bus_type);
1093 bus_register_failed:
1094 usb_acpi_unregister();
1095 usb_debugfs_cleanup();
1103 static void __exit usb_exit(void)
1105 /* This will matter if shutdown/reboot does exitcalls. */
1109 usb_deregister_device_driver(&usb_generic_driver);
1110 usb_major_cleanup();
1111 usb_deregister(&usbfs_driver);
1112 usb_devio_cleanup();
1114 bus_unregister_notifier(&usb_bus_type, &usb_bus_nb);
1115 bus_unregister(&usb_bus_type);
1116 usb_acpi_unregister();
1117 usb_debugfs_cleanup();
1120 subsys_initcall(usb_init);
1121 module_exit(usb_exit);
1122 MODULE_LICENSE("GPL");