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 #ifdef CONFIG_PM_RUNTIME
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 * Return: The alternate setting, if found. %NULL otherwise.
74 struct usb_host_interface *usb_find_alt_setting(
75 struct usb_host_config *config,
76 unsigned int iface_num,
79 struct usb_interface_cache *intf_cache = NULL;
82 for (i = 0; i < config->desc.bNumInterfaces; i++) {
83 if (config->intf_cache[i]->altsetting[0].desc.bInterfaceNumber
85 intf_cache = config->intf_cache[i];
91 for (i = 0; i < intf_cache->num_altsetting; i++)
92 if (intf_cache->altsetting[i].desc.bAlternateSetting == alt_num)
93 return &intf_cache->altsetting[i];
95 printk(KERN_DEBUG "Did not find alt setting %u for intf %u, "
96 "config %u\n", alt_num, iface_num,
97 config->desc.bConfigurationValue);
100 EXPORT_SYMBOL_GPL(usb_find_alt_setting);
103 * usb_ifnum_to_if - get the interface object with a given interface number
104 * @dev: the device whose current configuration is considered
105 * @ifnum: the desired interface
107 * This walks the device descriptor for the currently active configuration
108 * to find the interface object with the particular interface number.
110 * Note that configuration descriptors are not required to assign interface
111 * numbers sequentially, so that it would be incorrect to assume that
112 * the first interface in that descriptor corresponds to interface zero.
113 * This routine helps device drivers avoid such mistakes.
114 * However, you should make sure that you do the right thing with any
115 * alternate settings available for this interfaces.
117 * Don't call this function unless you are bound to one of the interfaces
118 * on this device or you have locked the device!
120 * Return: A pointer to the interface that has @ifnum as interface number,
121 * if found. %NULL otherwise.
123 struct usb_interface *usb_ifnum_to_if(const struct usb_device *dev,
126 struct usb_host_config *config = dev->actconfig;
131 for (i = 0; i < config->desc.bNumInterfaces; i++)
132 if (config->interface[i]->altsetting[0]
133 .desc.bInterfaceNumber == ifnum)
134 return config->interface[i];
138 EXPORT_SYMBOL_GPL(usb_ifnum_to_if);
141 * usb_altnum_to_altsetting - get the altsetting structure with a given alternate setting number.
142 * @intf: the interface containing the altsetting in question
143 * @altnum: the desired alternate setting number
145 * This searches the altsetting array of the specified interface for
146 * an entry with the correct bAlternateSetting value.
148 * Note that altsettings need not be stored sequentially by number, so
149 * it would be incorrect to assume that the first altsetting entry in
150 * the array corresponds to altsetting zero. This routine helps device
151 * drivers avoid such mistakes.
153 * Don't call this function unless you are bound to the intf interface
154 * or you have locked the device!
156 * Return: A pointer to the entry of the altsetting array of @intf that
157 * has @altnum as the alternate setting number. %NULL if not found.
159 struct usb_host_interface *usb_altnum_to_altsetting(
160 const struct usb_interface *intf,
165 for (i = 0; i < intf->num_altsetting; i++) {
166 if (intf->altsetting[i].desc.bAlternateSetting == altnum)
167 return &intf->altsetting[i];
171 EXPORT_SYMBOL_GPL(usb_altnum_to_altsetting);
173 struct find_interface_arg {
175 struct device_driver *drv;
178 static int __find_interface(struct device *dev, void *data)
180 struct find_interface_arg *arg = data;
181 struct usb_interface *intf;
183 if (!is_usb_interface(dev))
186 if (dev->driver != arg->drv)
188 intf = to_usb_interface(dev);
189 return intf->minor == arg->minor;
193 * usb_find_interface - find usb_interface pointer for driver and device
194 * @drv: the driver whose current configuration is considered
195 * @minor: the minor number of the desired device
197 * This walks the bus device list and returns a pointer to the interface
198 * with the matching minor and driver. Note, this only works for devices
199 * that share the USB major number.
201 * Return: A pointer to the interface with the matching major and @minor.
203 struct usb_interface *usb_find_interface(struct usb_driver *drv, int minor)
205 struct find_interface_arg argb;
209 argb.drv = &drv->drvwrap.driver;
211 dev = bus_find_device(&usb_bus_type, NULL, &argb, __find_interface);
213 /* Drop reference count from bus_find_device */
216 return dev ? to_usb_interface(dev) : NULL;
218 EXPORT_SYMBOL_GPL(usb_find_interface);
220 struct each_dev_arg {
222 int (*fn)(struct usb_device *, void *);
225 static int __each_dev(struct device *dev, void *data)
227 struct each_dev_arg *arg = (struct each_dev_arg *)data;
229 /* There are struct usb_interface on the same bus, filter them out */
230 if (!is_usb_device(dev))
233 return arg->fn(container_of(dev, struct usb_device, dev), arg->data);
237 * usb_for_each_dev - iterate over all USB devices in the system
238 * @data: data pointer that will be handed to the callback function
239 * @fn: callback function to be called for each USB device
241 * Iterate over all USB devices and call @fn for each, passing it @data. If it
242 * returns anything other than 0, we break the iteration prematurely and return
245 int usb_for_each_dev(void *data, int (*fn)(struct usb_device *, void *))
247 struct each_dev_arg arg = {data, fn};
249 return bus_for_each_dev(&usb_bus_type, NULL, &arg, __each_dev);
251 EXPORT_SYMBOL_GPL(usb_for_each_dev);
254 * usb_release_dev - free a usb device structure when all users of it are finished.
255 * @dev: device that's been disconnected
257 * Will be called only by the device core when all users of this usb device are
260 static void usb_release_dev(struct device *dev)
262 struct usb_device *udev;
265 udev = to_usb_device(dev);
266 hcd = bus_to_hcd(udev->bus);
268 usb_destroy_configuration(udev);
269 usb_release_bos_descriptor(udev);
271 kfree(udev->product);
272 kfree(udev->manufacturer);
277 static int usb_dev_uevent(struct device *dev, struct kobj_uevent_env *env)
279 struct usb_device *usb_dev;
281 usb_dev = to_usb_device(dev);
283 if (add_uevent_var(env, "BUSNUM=%03d", usb_dev->bus->busnum))
286 if (add_uevent_var(env, "DEVNUM=%03d", usb_dev->devnum))
294 /* USB device Power-Management thunks.
295 * There's no need to distinguish here between quiescing a USB device
296 * and powering it down; the generic_suspend() routine takes care of
297 * it by skipping the usb_port_suspend() call for a quiesce. And for
298 * USB interfaces there's no difference at all.
301 static int usb_dev_prepare(struct device *dev)
303 return 0; /* Implement eventually? */
306 static void usb_dev_complete(struct device *dev)
308 /* Currently used only for rebinding interfaces */
309 usb_resume_complete(dev);
312 static int usb_dev_suspend(struct device *dev)
314 return usb_suspend(dev, PMSG_SUSPEND);
317 static int usb_dev_resume(struct device *dev)
319 return usb_resume(dev, PMSG_RESUME);
322 static int usb_dev_freeze(struct device *dev)
324 return usb_suspend(dev, PMSG_FREEZE);
327 static int usb_dev_thaw(struct device *dev)
329 return usb_resume(dev, PMSG_THAW);
332 static int usb_dev_poweroff(struct device *dev)
334 return usb_suspend(dev, PMSG_HIBERNATE);
337 static int usb_dev_restore(struct device *dev)
339 return usb_resume(dev, PMSG_RESTORE);
342 static const struct dev_pm_ops usb_device_pm_ops = {
343 .prepare = usb_dev_prepare,
344 .complete = usb_dev_complete,
345 .suspend = usb_dev_suspend,
346 .resume = usb_dev_resume,
347 .freeze = usb_dev_freeze,
348 .thaw = usb_dev_thaw,
349 .poweroff = usb_dev_poweroff,
350 .restore = usb_dev_restore,
351 #ifdef CONFIG_PM_RUNTIME
352 .runtime_suspend = usb_runtime_suspend,
353 .runtime_resume = usb_runtime_resume,
354 .runtime_idle = usb_runtime_idle,
358 #endif /* CONFIG_PM */
361 static char *usb_devnode(struct device *dev,
362 umode_t *mode, kuid_t *uid, kgid_t *gid)
364 struct usb_device *usb_dev;
366 usb_dev = to_usb_device(dev);
367 return kasprintf(GFP_KERNEL, "bus/usb/%03d/%03d",
368 usb_dev->bus->busnum, usb_dev->devnum);
371 struct device_type usb_device_type = {
372 .name = "usb_device",
373 .release = usb_release_dev,
374 .uevent = usb_dev_uevent,
375 .devnode = usb_devnode,
377 .pm = &usb_device_pm_ops,
382 /* Returns 1 if @usb_bus is WUSB, 0 otherwise */
383 static unsigned usb_bus_is_wusb(struct usb_bus *bus)
385 struct usb_hcd *hcd = container_of(bus, struct usb_hcd, self);
386 return hcd->wireless;
391 * usb_alloc_dev - usb device constructor (usbcore-internal)
392 * @parent: hub to which device is connected; null to allocate a root hub
393 * @bus: bus used to access the device
394 * @port1: one-based index of port; ignored for root hubs
395 * Context: !in_interrupt()
397 * Only hub drivers (including virtual root hub drivers for host
398 * controllers) should ever call this.
400 * This call may not be used in a non-sleeping context.
402 * Return: On success, a pointer to the allocated usb device. %NULL on
405 struct usb_device *usb_alloc_dev(struct usb_device *parent,
406 struct usb_bus *bus, unsigned port1)
408 struct usb_device *dev;
409 struct usb_hcd *usb_hcd = bus_to_hcd(bus);
410 unsigned root_hub = 0;
412 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
416 if (!usb_get_hcd(usb_hcd)) {
420 /* Root hubs aren't true devices, so don't allocate HCD resources */
421 if (usb_hcd->driver->alloc_dev && parent &&
422 !usb_hcd->driver->alloc_dev(usb_hcd, dev)) {
423 usb_put_hcd(bus_to_hcd(bus));
428 device_initialize(&dev->dev);
429 dev->dev.bus = &usb_bus_type;
430 dev->dev.type = &usb_device_type;
431 dev->dev.groups = usb_device_groups;
432 dev->dev.dma_mask = bus->controller->dma_mask;
433 set_dev_node(&dev->dev, dev_to_node(bus->controller));
434 dev->state = USB_STATE_ATTACHED;
435 dev->lpm_disable_count = 1;
436 atomic_set(&dev->urbnum, 0);
438 INIT_LIST_HEAD(&dev->ep0.urb_list);
439 dev->ep0.desc.bLength = USB_DT_ENDPOINT_SIZE;
440 dev->ep0.desc.bDescriptorType = USB_DT_ENDPOINT;
441 /* ep0 maxpacket comes later, from device descriptor */
442 usb_enable_endpoint(dev, &dev->ep0, false);
445 /* Save readable and stable topology id, distinguishing devices
446 * by location for diagnostics, tools, driver model, etc. The
447 * string is a path along hub ports, from the root. Each device's
448 * dev->devpath will be stable until USB is re-cabled, and hubs
449 * are often labeled with these port numbers. The name isn't
450 * as stable: bus->busnum changes easily from modprobe order,
451 * cardbus or pci hotplugging, and so on.
453 if (unlikely(!parent)) {
454 dev->devpath[0] = '0';
457 dev->dev.parent = bus->controller;
458 dev_set_name(&dev->dev, "usb%d", bus->busnum);
461 /* match any labeling on the hubs; it's one-based */
462 if (parent->devpath[0] == '0') {
463 snprintf(dev->devpath, sizeof dev->devpath,
465 /* Root ports are not counted in route string */
468 snprintf(dev->devpath, sizeof dev->devpath,
469 "%s.%d", parent->devpath, port1);
470 /* Route string assumes hubs have less than 16 ports */
472 dev->route = parent->route +
473 (port1 << ((parent->level - 1)*4));
475 dev->route = parent->route +
476 (15 << ((parent->level - 1)*4));
479 dev->dev.parent = &parent->dev;
480 dev_set_name(&dev->dev, "%d-%s", bus->busnum, dev->devpath);
482 /* hub driver sets up TT records */
485 dev->portnum = port1;
487 dev->parent = parent;
488 INIT_LIST_HEAD(&dev->filelist);
491 pm_runtime_set_autosuspend_delay(&dev->dev,
492 usb_autosuspend_delay * 1000);
493 dev->connect_time = jiffies;
494 dev->active_duration = -jiffies;
496 if (root_hub) /* Root hub always ok [and always wired] */
499 dev->authorized = usb_hcd->authorized_default;
500 dev->wusb = usb_bus_is_wusb(bus) ? 1 : 0;
504 EXPORT_SYMBOL_GPL(usb_alloc_dev);
507 * usb_get_dev - increments the reference count of the usb device structure
508 * @dev: the device being referenced
510 * Each live reference to a device should be refcounted.
512 * Drivers for USB interfaces should normally record such references in
513 * their probe() methods, when they bind to an interface, and release
514 * them by calling usb_put_dev(), in their disconnect() methods.
516 * Return: A pointer to the device with the incremented reference counter.
518 struct usb_device *usb_get_dev(struct usb_device *dev)
521 get_device(&dev->dev);
524 EXPORT_SYMBOL_GPL(usb_get_dev);
527 * usb_put_dev - release a use of the usb device structure
528 * @dev: device that's been disconnected
530 * Must be called when a user of a device is finished with it. When the last
531 * user of the device calls this function, the memory of the device is freed.
533 void usb_put_dev(struct usb_device *dev)
536 put_device(&dev->dev);
538 EXPORT_SYMBOL_GPL(usb_put_dev);
541 * usb_get_intf - increments the reference count of the usb interface structure
542 * @intf: the interface being referenced
544 * Each live reference to a interface must be refcounted.
546 * Drivers for USB interfaces should normally record such references in
547 * their probe() methods, when they bind to an interface, and release
548 * them by calling usb_put_intf(), in their disconnect() methods.
550 * Return: A pointer to the interface with the incremented reference counter.
552 struct usb_interface *usb_get_intf(struct usb_interface *intf)
555 get_device(&intf->dev);
558 EXPORT_SYMBOL_GPL(usb_get_intf);
561 * usb_put_intf - release a use of the usb interface structure
562 * @intf: interface that's been decremented
564 * Must be called when a user of an interface is finished with it. When the
565 * last user of the interface calls this function, the memory of the interface
568 void usb_put_intf(struct usb_interface *intf)
571 put_device(&intf->dev);
573 EXPORT_SYMBOL_GPL(usb_put_intf);
575 /* USB device locking
577 * USB devices and interfaces are locked using the semaphore in their
578 * embedded struct device. The hub driver guarantees that whenever a
579 * device is connected or disconnected, drivers are called with the
580 * USB device locked as well as their particular interface.
582 * Complications arise when several devices are to be locked at the same
583 * time. Only hub-aware drivers that are part of usbcore ever have to
584 * do this; nobody else needs to worry about it. The rule for locking
587 * When locking both a device and its parent, always lock the
592 * usb_lock_device_for_reset - cautiously acquire the lock for a usb device structure
593 * @udev: device that's being locked
594 * @iface: interface bound to the driver making the request (optional)
596 * Attempts to acquire the device lock, but fails if the device is
597 * NOTATTACHED or SUSPENDED, or if iface is specified and the interface
598 * is neither BINDING nor BOUND. Rather than sleeping to wait for the
599 * lock, the routine polls repeatedly. This is to prevent deadlock with
600 * disconnect; in some drivers (such as usb-storage) the disconnect()
601 * or suspend() method will block waiting for a device reset to complete.
603 * Return: A negative error code for failure, otherwise 0.
605 int usb_lock_device_for_reset(struct usb_device *udev,
606 const struct usb_interface *iface)
608 unsigned long jiffies_expire = jiffies + HZ;
610 if (udev->state == USB_STATE_NOTATTACHED)
612 if (udev->state == USB_STATE_SUSPENDED)
613 return -EHOSTUNREACH;
614 if (iface && (iface->condition == USB_INTERFACE_UNBINDING ||
615 iface->condition == USB_INTERFACE_UNBOUND))
618 while (!usb_trylock_device(udev)) {
620 /* If we can't acquire the lock after waiting one second,
621 * we're probably deadlocked */
622 if (time_after(jiffies, jiffies_expire))
626 if (udev->state == USB_STATE_NOTATTACHED)
628 if (udev->state == USB_STATE_SUSPENDED)
629 return -EHOSTUNREACH;
630 if (iface && (iface->condition == USB_INTERFACE_UNBINDING ||
631 iface->condition == USB_INTERFACE_UNBOUND))
636 EXPORT_SYMBOL_GPL(usb_lock_device_for_reset);
639 * usb_get_current_frame_number - return current bus frame number
640 * @dev: the device whose bus is being queried
642 * Return: The current frame number for the USB host controller used
643 * with the given USB device. This can be used when scheduling
644 * isochronous requests.
646 * Note: Different kinds of host controller have different "scheduling
647 * horizons". While one type might support scheduling only 32 frames
648 * into the future, others could support scheduling up to 1024 frames
652 int usb_get_current_frame_number(struct usb_device *dev)
654 return usb_hcd_get_frame_number(dev);
656 EXPORT_SYMBOL_GPL(usb_get_current_frame_number);
658 /*-------------------------------------------------------------------*/
660 * __usb_get_extra_descriptor() finds a descriptor of specific type in the
661 * extra field of the interface and endpoint descriptor structs.
664 int __usb_get_extra_descriptor(char *buffer, unsigned size,
665 unsigned char type, void **ptr)
667 struct usb_descriptor_header *header;
669 while (size >= sizeof(struct usb_descriptor_header)) {
670 header = (struct usb_descriptor_header *)buffer;
672 if (header->bLength < 2) {
674 "%s: bogus descriptor, type %d length %d\n",
676 header->bDescriptorType,
681 if (header->bDescriptorType == type) {
686 buffer += header->bLength;
687 size -= header->bLength;
691 EXPORT_SYMBOL_GPL(__usb_get_extra_descriptor);
694 * usb_alloc_coherent - allocate dma-consistent buffer for URB_NO_xxx_DMA_MAP
695 * @dev: device the buffer will be used with
696 * @size: requested buffer size
697 * @mem_flags: affect whether allocation may block
698 * @dma: used to return DMA address of buffer
700 * Return: Either null (indicating no buffer could be allocated), or the
701 * cpu-space pointer to a buffer that may be used to perform DMA to the
702 * specified device. Such cpu-space buffers are returned along with the DMA
703 * address (through the pointer provided).
706 * These buffers are used with URB_NO_xxx_DMA_MAP set in urb->transfer_flags
707 * to avoid behaviors like using "DMA bounce buffers", or thrashing IOMMU
708 * hardware during URB completion/resubmit. The implementation varies between
709 * platforms, depending on details of how DMA will work to this device.
710 * Using these buffers also eliminates cacheline sharing problems on
711 * architectures where CPU caches are not DMA-coherent. On systems without
712 * bus-snooping caches, these buffers are uncached.
714 * When the buffer is no longer used, free it with usb_free_coherent().
716 void *usb_alloc_coherent(struct usb_device *dev, size_t size, gfp_t mem_flags,
719 if (!dev || !dev->bus)
721 return hcd_buffer_alloc(dev->bus, size, mem_flags, dma);
723 EXPORT_SYMBOL_GPL(usb_alloc_coherent);
726 * usb_free_coherent - free memory allocated with usb_alloc_coherent()
727 * @dev: device the buffer was used with
728 * @size: requested buffer size
729 * @addr: CPU address of buffer
730 * @dma: DMA address of buffer
732 * This reclaims an I/O buffer, letting it be reused. The memory must have
733 * been allocated using usb_alloc_coherent(), and the parameters must match
734 * those provided in that allocation request.
736 void usb_free_coherent(struct usb_device *dev, size_t size, void *addr,
739 if (!dev || !dev->bus)
743 hcd_buffer_free(dev->bus, size, addr, dma);
745 EXPORT_SYMBOL_GPL(usb_free_coherent);
748 * usb_buffer_map - create DMA mapping(s) for an urb
749 * @urb: urb whose transfer_buffer/setup_packet will be mapped
751 * URB_NO_TRANSFER_DMA_MAP is added to urb->transfer_flags if the operation
752 * succeeds. If the device is connected to this system through a non-DMA
753 * controller, this operation always succeeds.
755 * This call would normally be used for an urb which is reused, perhaps
756 * as the target of a large periodic transfer, with usb_buffer_dmasync()
757 * calls to synchronize memory and dma state.
759 * Reverse the effect of this call with usb_buffer_unmap().
761 * Return: Either %NULL (indicating no buffer could be mapped), or @urb.
765 struct urb *usb_buffer_map(struct urb *urb)
768 struct device *controller;
772 || !(bus = urb->dev->bus)
773 || !(controller = bus->controller))
776 if (controller->dma_mask) {
777 urb->transfer_dma = dma_map_single(controller,
778 urb->transfer_buffer, urb->transfer_buffer_length,
779 usb_pipein(urb->pipe)
780 ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
781 /* FIXME generic api broken like pci, can't report errors */
782 /* if (urb->transfer_dma == DMA_ADDR_INVALID) return 0; */
784 urb->transfer_dma = ~0;
785 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
788 EXPORT_SYMBOL_GPL(usb_buffer_map);
791 /* XXX DISABLED, no users currently. If you wish to re-enable this
792 * XXX please determine whether the sync is to transfer ownership of
793 * XXX the buffer from device to cpu or vice verse, and thusly use the
794 * XXX appropriate _for_{cpu,device}() method. -DaveM
799 * usb_buffer_dmasync - synchronize DMA and CPU view of buffer(s)
800 * @urb: urb whose transfer_buffer/setup_packet will be synchronized
802 void usb_buffer_dmasync(struct urb *urb)
805 struct device *controller;
808 || !(urb->transfer_flags & URB_NO_TRANSFER_DMA_MAP)
810 || !(bus = urb->dev->bus)
811 || !(controller = bus->controller))
814 if (controller->dma_mask) {
815 dma_sync_single_for_cpu(controller,
816 urb->transfer_dma, urb->transfer_buffer_length,
817 usb_pipein(urb->pipe)
818 ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
819 if (usb_pipecontrol(urb->pipe))
820 dma_sync_single_for_cpu(controller,
822 sizeof(struct usb_ctrlrequest),
826 EXPORT_SYMBOL_GPL(usb_buffer_dmasync);
830 * usb_buffer_unmap - free DMA mapping(s) for an urb
831 * @urb: urb whose transfer_buffer will be unmapped
833 * Reverses the effect of usb_buffer_map().
836 void usb_buffer_unmap(struct urb *urb)
839 struct device *controller;
842 || !(urb->transfer_flags & URB_NO_TRANSFER_DMA_MAP)
844 || !(bus = urb->dev->bus)
845 || !(controller = bus->controller))
848 if (controller->dma_mask) {
849 dma_unmap_single(controller,
850 urb->transfer_dma, urb->transfer_buffer_length,
851 usb_pipein(urb->pipe)
852 ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
854 urb->transfer_flags &= ~URB_NO_TRANSFER_DMA_MAP;
856 EXPORT_SYMBOL_GPL(usb_buffer_unmap);
861 * usb_buffer_map_sg - create scatterlist DMA mapping(s) for an endpoint
862 * @dev: device to which the scatterlist will be mapped
863 * @is_in: mapping transfer direction
864 * @sg: the scatterlist to map
865 * @nents: the number of entries in the scatterlist
867 * Return: Either < 0 (indicating no buffers could be mapped), or the
868 * number of DMA mapping array entries in the scatterlist.
871 * The caller is responsible for placing the resulting DMA addresses from
872 * the scatterlist into URB transfer buffer pointers, and for setting the
873 * URB_NO_TRANSFER_DMA_MAP transfer flag in each of those URBs.
875 * Top I/O rates come from queuing URBs, instead of waiting for each one
876 * to complete before starting the next I/O. This is particularly easy
877 * to do with scatterlists. Just allocate and submit one URB for each DMA
878 * mapping entry returned, stopping on the first error or when all succeed.
879 * Better yet, use the usb_sg_*() calls, which do that (and more) for you.
881 * This call would normally be used when translating scatterlist requests,
882 * rather than usb_buffer_map(), since on some hardware (with IOMMUs) it
883 * may be able to coalesce mappings for improved I/O efficiency.
885 * Reverse the effect of this call with usb_buffer_unmap_sg().
887 int usb_buffer_map_sg(const struct usb_device *dev, int is_in,
888 struct scatterlist *sg, int nents)
891 struct device *controller;
895 || !(controller = bus->controller)
896 || !controller->dma_mask)
899 /* FIXME generic api broken like pci, can't report errors */
900 return dma_map_sg(controller, sg, nents,
901 is_in ? DMA_FROM_DEVICE : DMA_TO_DEVICE) ? : -ENOMEM;
903 EXPORT_SYMBOL_GPL(usb_buffer_map_sg);
906 /* XXX DISABLED, no users currently. If you wish to re-enable this
907 * XXX please determine whether the sync is to transfer ownership of
908 * XXX the buffer from device to cpu or vice verse, and thusly use the
909 * XXX appropriate _for_{cpu,device}() method. -DaveM
914 * usb_buffer_dmasync_sg - synchronize DMA and CPU view of scatterlist buffer(s)
915 * @dev: device to which the scatterlist will be mapped
916 * @is_in: mapping transfer direction
917 * @sg: the scatterlist to synchronize
918 * @n_hw_ents: the positive return value from usb_buffer_map_sg
920 * Use this when you are re-using a scatterlist's data buffers for
921 * another USB request.
923 void usb_buffer_dmasync_sg(const struct usb_device *dev, int is_in,
924 struct scatterlist *sg, int n_hw_ents)
927 struct device *controller;
931 || !(controller = bus->controller)
932 || !controller->dma_mask)
935 dma_sync_sg_for_cpu(controller, sg, n_hw_ents,
936 is_in ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
938 EXPORT_SYMBOL_GPL(usb_buffer_dmasync_sg);
943 * usb_buffer_unmap_sg - free DMA mapping(s) for a scatterlist
944 * @dev: device to which the scatterlist will be mapped
945 * @is_in: mapping transfer direction
946 * @sg: the scatterlist to unmap
947 * @n_hw_ents: the positive return value from usb_buffer_map_sg
949 * Reverses the effect of usb_buffer_map_sg().
951 void usb_buffer_unmap_sg(const struct usb_device *dev, int is_in,
952 struct scatterlist *sg, int n_hw_ents)
955 struct device *controller;
959 || !(controller = bus->controller)
960 || !controller->dma_mask)
963 dma_unmap_sg(controller, sg, n_hw_ents,
964 is_in ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
966 EXPORT_SYMBOL_GPL(usb_buffer_unmap_sg);
969 /* To disable USB, kernel command line is 'nousb' not 'usbcore.nousb' */
971 module_param(nousb, bool, 0444);
973 core_param(nousb, nousb, bool, 0444);
977 * for external read access to <nousb>
979 int usb_disabled(void)
983 EXPORT_SYMBOL_GPL(usb_disabled);
986 * Notifications of device and interface registration
988 static int usb_bus_notify(struct notifier_block *nb, unsigned long action,
991 struct device *dev = data;
994 case BUS_NOTIFY_ADD_DEVICE:
995 if (dev->type == &usb_device_type)
996 (void) usb_create_sysfs_dev_files(to_usb_device(dev));
997 else if (dev->type == &usb_if_device_type)
998 usb_create_sysfs_intf_files(to_usb_interface(dev));
1001 case BUS_NOTIFY_DEL_DEVICE:
1002 if (dev->type == &usb_device_type)
1003 usb_remove_sysfs_dev_files(to_usb_device(dev));
1004 else if (dev->type == &usb_if_device_type)
1005 usb_remove_sysfs_intf_files(to_usb_interface(dev));
1011 static struct notifier_block usb_bus_nb = {
1012 .notifier_call = usb_bus_notify,
1015 struct dentry *usb_debug_root;
1016 EXPORT_SYMBOL_GPL(usb_debug_root);
1018 static struct dentry *usb_debug_devices;
1020 static int usb_debugfs_init(void)
1022 usb_debug_root = debugfs_create_dir("usb", NULL);
1023 if (!usb_debug_root)
1026 usb_debug_devices = debugfs_create_file("devices", 0444,
1027 usb_debug_root, NULL,
1028 &usbfs_devices_fops);
1029 if (!usb_debug_devices) {
1030 debugfs_remove(usb_debug_root);
1031 usb_debug_root = NULL;
1038 static void usb_debugfs_cleanup(void)
1040 debugfs_remove(usb_debug_devices);
1041 debugfs_remove(usb_debug_root);
1047 static int __init usb_init(void)
1051 pr_info("%s: USB support disabled\n", usbcore_name);
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");