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>
39 #include <linux/usb/of.h>
42 #include <linux/scatterlist.h>
44 #include <linux/dma-mapping.h>
49 const char *usbcore_name = "usbcore";
51 static bool nousb; /* Disable USB when built into kernel image */
53 module_param(nousb, bool, 0444);
56 * for external read access to <nousb>
58 int usb_disabled(void)
62 EXPORT_SYMBOL_GPL(usb_disabled);
65 static int usb_autosuspend_delay = 2; /* Default delay value,
67 module_param_named(autosuspend, usb_autosuspend_delay, int, 0644);
68 MODULE_PARM_DESC(autosuspend, "default autosuspend delay");
71 #define usb_autosuspend_delay 0
76 * usb_find_alt_setting() - Given a configuration, find the alternate setting
77 * for the given interface.
78 * @config: the configuration to search (not necessarily the current config).
79 * @iface_num: interface number to search in
80 * @alt_num: alternate interface setting number to search for.
82 * Search the configuration's interface cache for the given alt setting.
84 * Return: The alternate setting, if found. %NULL otherwise.
86 struct usb_host_interface *usb_find_alt_setting(
87 struct usb_host_config *config,
88 unsigned int iface_num,
91 struct usb_interface_cache *intf_cache = NULL;
94 for (i = 0; i < config->desc.bNumInterfaces; i++) {
95 if (config->intf_cache[i]->altsetting[0].desc.bInterfaceNumber
97 intf_cache = config->intf_cache[i];
103 for (i = 0; i < intf_cache->num_altsetting; i++)
104 if (intf_cache->altsetting[i].desc.bAlternateSetting == alt_num)
105 return &intf_cache->altsetting[i];
107 printk(KERN_DEBUG "Did not find alt setting %u for intf %u, "
108 "config %u\n", alt_num, iface_num,
109 config->desc.bConfigurationValue);
112 EXPORT_SYMBOL_GPL(usb_find_alt_setting);
115 * usb_ifnum_to_if - get the interface object with a given interface number
116 * @dev: the device whose current configuration is considered
117 * @ifnum: the desired interface
119 * This walks the device descriptor for the currently active configuration
120 * to find the interface object with the particular interface number.
122 * Note that configuration descriptors are not required to assign interface
123 * numbers sequentially, so that it would be incorrect to assume that
124 * the first interface in that descriptor corresponds to interface zero.
125 * This routine helps device drivers avoid such mistakes.
126 * However, you should make sure that you do the right thing with any
127 * alternate settings available for this interfaces.
129 * Don't call this function unless you are bound to one of the interfaces
130 * on this device or you have locked the device!
132 * Return: A pointer to the interface that has @ifnum as interface number,
133 * if found. %NULL otherwise.
135 struct usb_interface *usb_ifnum_to_if(const struct usb_device *dev,
138 struct usb_host_config *config = dev->actconfig;
143 for (i = 0; i < config->desc.bNumInterfaces; i++)
144 if (config->interface[i]->altsetting[0]
145 .desc.bInterfaceNumber == ifnum)
146 return config->interface[i];
150 EXPORT_SYMBOL_GPL(usb_ifnum_to_if);
153 * usb_altnum_to_altsetting - get the altsetting structure with a given alternate setting number.
154 * @intf: the interface containing the altsetting in question
155 * @altnum: the desired alternate setting number
157 * This searches the altsetting array of the specified interface for
158 * an entry with the correct bAlternateSetting value.
160 * Note that altsettings need not be stored sequentially by number, so
161 * it would be incorrect to assume that the first altsetting entry in
162 * the array corresponds to altsetting zero. This routine helps device
163 * drivers avoid such mistakes.
165 * Don't call this function unless you are bound to the intf interface
166 * or you have locked the device!
168 * Return: A pointer to the entry of the altsetting array of @intf that
169 * has @altnum as the alternate setting number. %NULL if not found.
171 struct usb_host_interface *usb_altnum_to_altsetting(
172 const struct usb_interface *intf,
177 for (i = 0; i < intf->num_altsetting; i++) {
178 if (intf->altsetting[i].desc.bAlternateSetting == altnum)
179 return &intf->altsetting[i];
183 EXPORT_SYMBOL_GPL(usb_altnum_to_altsetting);
185 struct find_interface_arg {
187 struct device_driver *drv;
190 static int __find_interface(struct device *dev, void *data)
192 struct find_interface_arg *arg = data;
193 struct usb_interface *intf;
195 if (!is_usb_interface(dev))
198 if (dev->driver != arg->drv)
200 intf = to_usb_interface(dev);
201 return intf->minor == arg->minor;
205 * usb_find_interface - find usb_interface pointer for driver and device
206 * @drv: the driver whose current configuration is considered
207 * @minor: the minor number of the desired device
209 * This walks the bus device list and returns a pointer to the interface
210 * with the matching minor and driver. Note, this only works for devices
211 * that share the USB major number.
213 * Return: A pointer to the interface with the matching major and @minor.
215 struct usb_interface *usb_find_interface(struct usb_driver *drv, int minor)
217 struct find_interface_arg argb;
221 argb.drv = &drv->drvwrap.driver;
223 dev = bus_find_device(&usb_bus_type, NULL, &argb, __find_interface);
225 /* Drop reference count from bus_find_device */
228 return dev ? to_usb_interface(dev) : NULL;
230 EXPORT_SYMBOL_GPL(usb_find_interface);
232 struct each_dev_arg {
234 int (*fn)(struct usb_device *, void *);
237 static int __each_dev(struct device *dev, void *data)
239 struct each_dev_arg *arg = (struct each_dev_arg *)data;
241 /* There are struct usb_interface on the same bus, filter them out */
242 if (!is_usb_device(dev))
245 return arg->fn(to_usb_device(dev), arg->data);
249 * usb_for_each_dev - iterate over all USB devices in the system
250 * @data: data pointer that will be handed to the callback function
251 * @fn: callback function to be called for each USB device
253 * Iterate over all USB devices and call @fn for each, passing it @data. If it
254 * returns anything other than 0, we break the iteration prematurely and return
257 int usb_for_each_dev(void *data, int (*fn)(struct usb_device *, void *))
259 struct each_dev_arg arg = {data, fn};
261 return bus_for_each_dev(&usb_bus_type, NULL, &arg, __each_dev);
263 EXPORT_SYMBOL_GPL(usb_for_each_dev);
266 * usb_release_dev - free a usb device structure when all users of it are finished.
267 * @dev: device that's been disconnected
269 * Will be called only by the device core when all users of this usb device are
272 static void usb_release_dev(struct device *dev)
274 struct usb_device *udev;
277 udev = to_usb_device(dev);
278 hcd = bus_to_hcd(udev->bus);
280 usb_destroy_configuration(udev);
281 usb_release_bos_descriptor(udev);
283 kfree(udev->product);
284 kfree(udev->manufacturer);
289 static int usb_dev_uevent(struct device *dev, struct kobj_uevent_env *env)
291 struct usb_device *usb_dev;
293 usb_dev = to_usb_device(dev);
295 if (add_uevent_var(env, "BUSNUM=%03d", usb_dev->bus->busnum))
298 if (add_uevent_var(env, "DEVNUM=%03d", usb_dev->devnum))
306 /* USB device Power-Management thunks.
307 * There's no need to distinguish here between quiescing a USB device
308 * and powering it down; the generic_suspend() routine takes care of
309 * it by skipping the usb_port_suspend() call for a quiesce. And for
310 * USB interfaces there's no difference at all.
313 static int usb_dev_prepare(struct device *dev)
315 struct usb_device *udev = to_usb_device(dev);
317 /* Return 0 if the current wakeup setting is wrong, otherwise 1 */
318 if (udev->do_remote_wakeup != device_may_wakeup(dev))
324 static void usb_dev_complete(struct device *dev)
326 /* Currently used only for rebinding interfaces */
327 usb_resume_complete(dev);
330 static int usb_dev_suspend(struct device *dev)
332 return usb_suspend(dev, PMSG_SUSPEND);
335 static int usb_dev_resume(struct device *dev)
337 return usb_resume(dev, PMSG_RESUME);
340 static int usb_dev_freeze(struct device *dev)
342 return usb_suspend(dev, PMSG_FREEZE);
345 static int usb_dev_thaw(struct device *dev)
347 return usb_resume(dev, PMSG_THAW);
350 static int usb_dev_poweroff(struct device *dev)
352 return usb_suspend(dev, PMSG_HIBERNATE);
355 static int usb_dev_restore(struct device *dev)
357 return usb_resume(dev, PMSG_RESTORE);
360 static const struct dev_pm_ops usb_device_pm_ops = {
361 .prepare = usb_dev_prepare,
362 .complete = usb_dev_complete,
363 .suspend = usb_dev_suspend,
364 .resume = usb_dev_resume,
365 .freeze = usb_dev_freeze,
366 .thaw = usb_dev_thaw,
367 .poweroff = usb_dev_poweroff,
368 .restore = usb_dev_restore,
369 .runtime_suspend = usb_runtime_suspend,
370 .runtime_resume = usb_runtime_resume,
371 .runtime_idle = usb_runtime_idle,
374 #endif /* CONFIG_PM */
377 static char *usb_devnode(struct device *dev,
378 umode_t *mode, kuid_t *uid, kgid_t *gid)
380 struct usb_device *usb_dev;
382 usb_dev = to_usb_device(dev);
383 return kasprintf(GFP_KERNEL, "bus/usb/%03d/%03d",
384 usb_dev->bus->busnum, usb_dev->devnum);
387 struct device_type usb_device_type = {
388 .name = "usb_device",
389 .release = usb_release_dev,
390 .uevent = usb_dev_uevent,
391 .devnode = usb_devnode,
393 .pm = &usb_device_pm_ops,
398 /* Returns 1 if @usb_bus is WUSB, 0 otherwise */
399 static unsigned usb_bus_is_wusb(struct usb_bus *bus)
401 struct usb_hcd *hcd = bus_to_hcd(bus);
402 return hcd->wireless;
407 * usb_alloc_dev - usb device constructor (usbcore-internal)
408 * @parent: hub to which device is connected; null to allocate a root hub
409 * @bus: bus used to access the device
410 * @port1: one-based index of port; ignored for root hubs
411 * Context: !in_interrupt()
413 * Only hub drivers (including virtual root hub drivers for host
414 * controllers) should ever call this.
416 * This call may not be used in a non-sleeping context.
418 * Return: On success, a pointer to the allocated usb device. %NULL on
421 struct usb_device *usb_alloc_dev(struct usb_device *parent,
422 struct usb_bus *bus, unsigned port1)
424 struct usb_device *dev;
425 struct usb_hcd *usb_hcd = bus_to_hcd(bus);
426 unsigned root_hub = 0;
427 unsigned raw_port = port1;
429 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
433 if (!usb_get_hcd(usb_hcd)) {
437 /* Root hubs aren't true devices, so don't allocate HCD resources */
438 if (usb_hcd->driver->alloc_dev && parent &&
439 !usb_hcd->driver->alloc_dev(usb_hcd, dev)) {
440 usb_put_hcd(bus_to_hcd(bus));
445 device_initialize(&dev->dev);
446 dev->dev.bus = &usb_bus_type;
447 dev->dev.type = &usb_device_type;
448 dev->dev.groups = usb_device_groups;
449 dev->dev.dma_mask = bus->controller->dma_mask;
450 set_dev_node(&dev->dev, dev_to_node(bus->controller));
451 dev->state = USB_STATE_ATTACHED;
452 dev->lpm_disable_count = 1;
453 atomic_set(&dev->urbnum, 0);
455 INIT_LIST_HEAD(&dev->ep0.urb_list);
456 dev->ep0.desc.bLength = USB_DT_ENDPOINT_SIZE;
457 dev->ep0.desc.bDescriptorType = USB_DT_ENDPOINT;
458 /* ep0 maxpacket comes later, from device descriptor */
459 usb_enable_endpoint(dev, &dev->ep0, false);
462 /* Save readable and stable topology id, distinguishing devices
463 * by location for diagnostics, tools, driver model, etc. The
464 * string is a path along hub ports, from the root. Each device's
465 * dev->devpath will be stable until USB is re-cabled, and hubs
466 * are often labeled with these port numbers. The name isn't
467 * as stable: bus->busnum changes easily from modprobe order,
468 * cardbus or pci hotplugging, and so on.
470 if (unlikely(!parent)) {
471 dev->devpath[0] = '0';
474 dev->dev.parent = bus->controller;
475 dev_set_name(&dev->dev, "usb%d", bus->busnum);
478 /* match any labeling on the hubs; it's one-based */
479 if (parent->devpath[0] == '0') {
480 snprintf(dev->devpath, sizeof dev->devpath,
482 /* Root ports are not counted in route string */
485 snprintf(dev->devpath, sizeof dev->devpath,
486 "%s.%d", parent->devpath, port1);
487 /* Route string assumes hubs have less than 16 ports */
489 dev->route = parent->route +
490 (port1 << ((parent->level - 1)*4));
492 dev->route = parent->route +
493 (15 << ((parent->level - 1)*4));
496 dev->dev.parent = &parent->dev;
497 dev_set_name(&dev->dev, "%d-%s", bus->busnum, dev->devpath);
499 if (!parent->parent) {
500 /* device under root hub's port */
501 raw_port = usb_hcd_find_raw_port_number(usb_hcd,
504 dev->dev.of_node = usb_of_get_child_node(parent->dev.of_node,
507 /* hub driver sets up TT records */
510 dev->portnum = port1;
512 dev->parent = parent;
513 INIT_LIST_HEAD(&dev->filelist);
516 pm_runtime_set_autosuspend_delay(&dev->dev,
517 usb_autosuspend_delay * 1000);
518 dev->connect_time = jiffies;
519 dev->active_duration = -jiffies;
521 if (root_hub) /* Root hub always ok [and always wired] */
524 dev->authorized = !!HCD_DEV_AUTHORIZED(usb_hcd);
525 dev->wusb = usb_bus_is_wusb(bus) ? 1 : 0;
529 EXPORT_SYMBOL_GPL(usb_alloc_dev);
532 * usb_get_dev - increments the reference count of the usb device structure
533 * @dev: the device being referenced
535 * Each live reference to a device should be refcounted.
537 * Drivers for USB interfaces should normally record such references in
538 * their probe() methods, when they bind to an interface, and release
539 * them by calling usb_put_dev(), in their disconnect() methods.
541 * Return: A pointer to the device with the incremented reference counter.
543 struct usb_device *usb_get_dev(struct usb_device *dev)
546 get_device(&dev->dev);
549 EXPORT_SYMBOL_GPL(usb_get_dev);
552 * usb_put_dev - release a use of the usb device structure
553 * @dev: device that's been disconnected
555 * Must be called when a user of a device is finished with it. When the last
556 * user of the device calls this function, the memory of the device is freed.
558 void usb_put_dev(struct usb_device *dev)
561 put_device(&dev->dev);
563 EXPORT_SYMBOL_GPL(usb_put_dev);
566 * usb_get_intf - increments the reference count of the usb interface structure
567 * @intf: the interface being referenced
569 * Each live reference to a interface must be refcounted.
571 * Drivers for USB interfaces should normally record such references in
572 * their probe() methods, when they bind to an interface, and release
573 * them by calling usb_put_intf(), in their disconnect() methods.
575 * Return: A pointer to the interface with the incremented reference counter.
577 struct usb_interface *usb_get_intf(struct usb_interface *intf)
580 get_device(&intf->dev);
583 EXPORT_SYMBOL_GPL(usb_get_intf);
586 * usb_put_intf - release a use of the usb interface structure
587 * @intf: interface that's been decremented
589 * Must be called when a user of an interface is finished with it. When the
590 * last user of the interface calls this function, the memory of the interface
593 void usb_put_intf(struct usb_interface *intf)
596 put_device(&intf->dev);
598 EXPORT_SYMBOL_GPL(usb_put_intf);
600 /* USB device locking
602 * USB devices and interfaces are locked using the semaphore in their
603 * embedded struct device. The hub driver guarantees that whenever a
604 * device is connected or disconnected, drivers are called with the
605 * USB device locked as well as their particular interface.
607 * Complications arise when several devices are to be locked at the same
608 * time. Only hub-aware drivers that are part of usbcore ever have to
609 * do this; nobody else needs to worry about it. The rule for locking
612 * When locking both a device and its parent, always lock the
617 * usb_lock_device_for_reset - cautiously acquire the lock for a usb device structure
618 * @udev: device that's being locked
619 * @iface: interface bound to the driver making the request (optional)
621 * Attempts to acquire the device lock, but fails if the device is
622 * NOTATTACHED or SUSPENDED, or if iface is specified and the interface
623 * is neither BINDING nor BOUND. Rather than sleeping to wait for the
624 * lock, the routine polls repeatedly. This is to prevent deadlock with
625 * disconnect; in some drivers (such as usb-storage) the disconnect()
626 * or suspend() method will block waiting for a device reset to complete.
628 * Return: A negative error code for failure, otherwise 0.
630 int usb_lock_device_for_reset(struct usb_device *udev,
631 const struct usb_interface *iface)
633 unsigned long jiffies_expire = jiffies + HZ;
635 if (udev->state == USB_STATE_NOTATTACHED)
637 if (udev->state == USB_STATE_SUSPENDED)
638 return -EHOSTUNREACH;
639 if (iface && (iface->condition == USB_INTERFACE_UNBINDING ||
640 iface->condition == USB_INTERFACE_UNBOUND))
643 while (!usb_trylock_device(udev)) {
645 /* If we can't acquire the lock after waiting one second,
646 * we're probably deadlocked */
647 if (time_after(jiffies, jiffies_expire))
651 if (udev->state == USB_STATE_NOTATTACHED)
653 if (udev->state == USB_STATE_SUSPENDED)
654 return -EHOSTUNREACH;
655 if (iface && (iface->condition == USB_INTERFACE_UNBINDING ||
656 iface->condition == USB_INTERFACE_UNBOUND))
661 EXPORT_SYMBOL_GPL(usb_lock_device_for_reset);
664 * usb_get_current_frame_number - return current bus frame number
665 * @dev: the device whose bus is being queried
667 * Return: The current frame number for the USB host controller used
668 * with the given USB device. This can be used when scheduling
669 * isochronous requests.
671 * Note: Different kinds of host controller have different "scheduling
672 * horizons". While one type might support scheduling only 32 frames
673 * into the future, others could support scheduling up to 1024 frames
677 int usb_get_current_frame_number(struct usb_device *dev)
679 return usb_hcd_get_frame_number(dev);
681 EXPORT_SYMBOL_GPL(usb_get_current_frame_number);
683 /*-------------------------------------------------------------------*/
685 * __usb_get_extra_descriptor() finds a descriptor of specific type in the
686 * extra field of the interface and endpoint descriptor structs.
689 int __usb_get_extra_descriptor(char *buffer, unsigned size,
690 unsigned char type, void **ptr)
692 struct usb_descriptor_header *header;
694 while (size >= sizeof(struct usb_descriptor_header)) {
695 header = (struct usb_descriptor_header *)buffer;
697 if (header->bLength < 2) {
699 "%s: bogus descriptor, type %d length %d\n",
701 header->bDescriptorType,
706 if (header->bDescriptorType == type) {
711 buffer += header->bLength;
712 size -= header->bLength;
716 EXPORT_SYMBOL_GPL(__usb_get_extra_descriptor);
719 * usb_alloc_coherent - allocate dma-consistent buffer for URB_NO_xxx_DMA_MAP
720 * @dev: device the buffer will be used with
721 * @size: requested buffer size
722 * @mem_flags: affect whether allocation may block
723 * @dma: used to return DMA address of buffer
725 * Return: Either null (indicating no buffer could be allocated), or the
726 * cpu-space pointer to a buffer that may be used to perform DMA to the
727 * specified device. Such cpu-space buffers are returned along with the DMA
728 * address (through the pointer provided).
731 * These buffers are used with URB_NO_xxx_DMA_MAP set in urb->transfer_flags
732 * to avoid behaviors like using "DMA bounce buffers", or thrashing IOMMU
733 * hardware during URB completion/resubmit. The implementation varies between
734 * platforms, depending on details of how DMA will work to this device.
735 * Using these buffers also eliminates cacheline sharing problems on
736 * architectures where CPU caches are not DMA-coherent. On systems without
737 * bus-snooping caches, these buffers are uncached.
739 * When the buffer is no longer used, free it with usb_free_coherent().
741 void *usb_alloc_coherent(struct usb_device *dev, size_t size, gfp_t mem_flags,
744 if (!dev || !dev->bus)
746 return hcd_buffer_alloc(dev->bus, size, mem_flags, dma);
748 EXPORT_SYMBOL_GPL(usb_alloc_coherent);
751 * usb_free_coherent - free memory allocated with usb_alloc_coherent()
752 * @dev: device the buffer was used with
753 * @size: requested buffer size
754 * @addr: CPU address of buffer
755 * @dma: DMA address of buffer
757 * This reclaims an I/O buffer, letting it be reused. The memory must have
758 * been allocated using usb_alloc_coherent(), and the parameters must match
759 * those provided in that allocation request.
761 void usb_free_coherent(struct usb_device *dev, size_t size, void *addr,
764 if (!dev || !dev->bus)
768 hcd_buffer_free(dev->bus, size, addr, dma);
770 EXPORT_SYMBOL_GPL(usb_free_coherent);
773 * usb_buffer_map - create DMA mapping(s) for an urb
774 * @urb: urb whose transfer_buffer/setup_packet will be mapped
776 * URB_NO_TRANSFER_DMA_MAP is added to urb->transfer_flags if the operation
777 * succeeds. If the device is connected to this system through a non-DMA
778 * controller, this operation always succeeds.
780 * This call would normally be used for an urb which is reused, perhaps
781 * as the target of a large periodic transfer, with usb_buffer_dmasync()
782 * calls to synchronize memory and dma state.
784 * Reverse the effect of this call with usb_buffer_unmap().
786 * Return: Either %NULL (indicating no buffer could be mapped), or @urb.
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 /* FIXME generic api broken like pci, can't report errors */
807 /* if (urb->transfer_dma == DMA_ADDR_INVALID) return 0; */
809 urb->transfer_dma = ~0;
810 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
813 EXPORT_SYMBOL_GPL(usb_buffer_map);
816 /* XXX DISABLED, no users currently. If you wish to re-enable this
817 * XXX please determine whether the sync is to transfer ownership of
818 * XXX the buffer from device to cpu or vice verse, and thusly use the
819 * XXX appropriate _for_{cpu,device}() method. -DaveM
824 * usb_buffer_dmasync - synchronize DMA and CPU view of buffer(s)
825 * @urb: urb whose transfer_buffer/setup_packet will be synchronized
827 void usb_buffer_dmasync(struct urb *urb)
830 struct device *controller;
833 || !(urb->transfer_flags & URB_NO_TRANSFER_DMA_MAP)
835 || !(bus = urb->dev->bus)
836 || !(controller = bus->controller))
839 if (controller->dma_mask) {
840 dma_sync_single_for_cpu(controller,
841 urb->transfer_dma, urb->transfer_buffer_length,
842 usb_pipein(urb->pipe)
843 ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
844 if (usb_pipecontrol(urb->pipe))
845 dma_sync_single_for_cpu(controller,
847 sizeof(struct usb_ctrlrequest),
851 EXPORT_SYMBOL_GPL(usb_buffer_dmasync);
855 * usb_buffer_unmap - free DMA mapping(s) for an urb
856 * @urb: urb whose transfer_buffer will be unmapped
858 * Reverses the effect of usb_buffer_map().
861 void usb_buffer_unmap(struct urb *urb)
864 struct device *controller;
867 || !(urb->transfer_flags & URB_NO_TRANSFER_DMA_MAP)
869 || !(bus = urb->dev->bus)
870 || !(controller = bus->controller))
873 if (controller->dma_mask) {
874 dma_unmap_single(controller,
875 urb->transfer_dma, urb->transfer_buffer_length,
876 usb_pipein(urb->pipe)
877 ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
879 urb->transfer_flags &= ~URB_NO_TRANSFER_DMA_MAP;
881 EXPORT_SYMBOL_GPL(usb_buffer_unmap);
886 * usb_buffer_map_sg - create scatterlist DMA mapping(s) for an endpoint
887 * @dev: device to which the scatterlist will be mapped
888 * @is_in: mapping transfer direction
889 * @sg: the scatterlist to map
890 * @nents: the number of entries in the scatterlist
892 * Return: Either < 0 (indicating no buffers could be mapped), or the
893 * number of DMA mapping array entries in the scatterlist.
896 * The caller is responsible for placing the resulting DMA addresses from
897 * the scatterlist into URB transfer buffer pointers, and for setting the
898 * URB_NO_TRANSFER_DMA_MAP transfer flag in each of those URBs.
900 * Top I/O rates come from queuing URBs, instead of waiting for each one
901 * to complete before starting the next I/O. This is particularly easy
902 * to do with scatterlists. Just allocate and submit one URB for each DMA
903 * mapping entry returned, stopping on the first error or when all succeed.
904 * Better yet, use the usb_sg_*() calls, which do that (and more) for you.
906 * This call would normally be used when translating scatterlist requests,
907 * rather than usb_buffer_map(), since on some hardware (with IOMMUs) it
908 * may be able to coalesce mappings for improved I/O efficiency.
910 * Reverse the effect of this call with usb_buffer_unmap_sg().
912 int usb_buffer_map_sg(const struct usb_device *dev, int is_in,
913 struct scatterlist *sg, int nents)
916 struct device *controller;
920 || !(controller = bus->controller)
921 || !controller->dma_mask)
924 /* FIXME generic api broken like pci, can't report errors */
925 return dma_map_sg(controller, sg, nents,
926 is_in ? DMA_FROM_DEVICE : DMA_TO_DEVICE) ? : -ENOMEM;
928 EXPORT_SYMBOL_GPL(usb_buffer_map_sg);
931 /* XXX DISABLED, no users currently. If you wish to re-enable this
932 * XXX please determine whether the sync is to transfer ownership of
933 * XXX the buffer from device to cpu or vice verse, and thusly use the
934 * XXX appropriate _for_{cpu,device}() method. -DaveM
939 * usb_buffer_dmasync_sg - synchronize DMA and CPU view of scatterlist buffer(s)
940 * @dev: device to which the scatterlist will be mapped
941 * @is_in: mapping transfer direction
942 * @sg: the scatterlist to synchronize
943 * @n_hw_ents: the positive return value from usb_buffer_map_sg
945 * Use this when you are re-using a scatterlist's data buffers for
946 * another USB request.
948 void usb_buffer_dmasync_sg(const struct usb_device *dev, int is_in,
949 struct scatterlist *sg, int n_hw_ents)
952 struct device *controller;
956 || !(controller = bus->controller)
957 || !controller->dma_mask)
960 dma_sync_sg_for_cpu(controller, sg, n_hw_ents,
961 is_in ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
963 EXPORT_SYMBOL_GPL(usb_buffer_dmasync_sg);
968 * usb_buffer_unmap_sg - free DMA mapping(s) for a scatterlist
969 * @dev: device to which the scatterlist will be mapped
970 * @is_in: mapping transfer direction
971 * @sg: the scatterlist to unmap
972 * @n_hw_ents: the positive return value from usb_buffer_map_sg
974 * Reverses the effect of usb_buffer_map_sg().
976 void usb_buffer_unmap_sg(const struct usb_device *dev, int is_in,
977 struct scatterlist *sg, int n_hw_ents)
980 struct device *controller;
984 || !(controller = bus->controller)
985 || !controller->dma_mask)
988 dma_unmap_sg(controller, sg, n_hw_ents,
989 is_in ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
991 EXPORT_SYMBOL_GPL(usb_buffer_unmap_sg);
995 * Notifications of device and interface registration
997 static int usb_bus_notify(struct notifier_block *nb, unsigned long action,
1000 struct device *dev = data;
1003 case BUS_NOTIFY_ADD_DEVICE:
1004 if (dev->type == &usb_device_type)
1005 (void) usb_create_sysfs_dev_files(to_usb_device(dev));
1006 else if (dev->type == &usb_if_device_type)
1007 usb_create_sysfs_intf_files(to_usb_interface(dev));
1010 case BUS_NOTIFY_DEL_DEVICE:
1011 if (dev->type == &usb_device_type)
1012 usb_remove_sysfs_dev_files(to_usb_device(dev));
1013 else if (dev->type == &usb_if_device_type)
1014 usb_remove_sysfs_intf_files(to_usb_interface(dev));
1020 static struct notifier_block usb_bus_nb = {
1021 .notifier_call = usb_bus_notify,
1024 struct dentry *usb_debug_root;
1025 EXPORT_SYMBOL_GPL(usb_debug_root);
1027 static struct dentry *usb_debug_devices;
1029 static int usb_debugfs_init(void)
1031 usb_debug_root = debugfs_create_dir("usb", NULL);
1032 if (!usb_debug_root)
1035 usb_debug_devices = debugfs_create_file("devices", 0444,
1036 usb_debug_root, NULL,
1037 &usbfs_devices_fops);
1038 if (!usb_debug_devices) {
1039 debugfs_remove(usb_debug_root);
1040 usb_debug_root = NULL;
1047 static void usb_debugfs_cleanup(void)
1049 debugfs_remove(usb_debug_devices);
1050 debugfs_remove(usb_debug_root);
1056 static int __init usb_init(void)
1059 if (usb_disabled()) {
1060 pr_info("%s: USB support disabled\n", usbcore_name);
1063 usb_init_pool_max();
1065 retval = usb_debugfs_init();
1069 usb_acpi_register();
1070 retval = bus_register(&usb_bus_type);
1072 goto bus_register_failed;
1073 retval = bus_register_notifier(&usb_bus_type, &usb_bus_nb);
1075 goto bus_notifier_failed;
1076 retval = usb_major_init();
1078 goto major_init_failed;
1079 retval = usb_register(&usbfs_driver);
1081 goto driver_register_failed;
1082 retval = usb_devio_init();
1084 goto usb_devio_init_failed;
1085 retval = usb_hub_init();
1087 goto hub_init_failed;
1088 retval = usb_register_device_driver(&usb_generic_driver, THIS_MODULE);
1094 usb_devio_cleanup();
1095 usb_devio_init_failed:
1096 usb_deregister(&usbfs_driver);
1097 driver_register_failed:
1098 usb_major_cleanup();
1100 bus_unregister_notifier(&usb_bus_type, &usb_bus_nb);
1101 bus_notifier_failed:
1102 bus_unregister(&usb_bus_type);
1103 bus_register_failed:
1104 usb_acpi_unregister();
1105 usb_debugfs_cleanup();
1113 static void __exit usb_exit(void)
1115 /* This will matter if shutdown/reboot does exitcalls. */
1119 usb_deregister_device_driver(&usb_generic_driver);
1120 usb_major_cleanup();
1121 usb_deregister(&usbfs_driver);
1122 usb_devio_cleanup();
1124 bus_unregister_notifier(&usb_bus_type, &usb_bus_nb);
1125 bus_unregister(&usb_bus_type);
1126 usb_acpi_unregister();
1127 usb_debugfs_cleanup();
1128 idr_destroy(&usb_bus_idr);
1131 subsys_initcall(usb_init);
1132 module_exit(usb_exit);
1133 MODULE_LICENSE("GPL");