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_common_endpoints() -- look up common endpoint descriptors
77 * @alt: alternate setting to search
78 * @bulk_in: pointer to descriptor pointer, or NULL
79 * @bulk_out: pointer to descriptor pointer, or NULL
80 * @int_in: pointer to descriptor pointer, or NULL
81 * @int_out: pointer to descriptor pointer, or NULL
83 * Search the alternate setting's endpoint descriptors for the first bulk-in,
84 * bulk-out, interrupt-in and interrupt-out endpoints and return them in the
85 * provided pointers (unless they are NULL).
87 * If a requested endpoint is not found, the corresponding pointer is set to
90 * Return: Zero if all requested descriptors were found, or -ENXIO otherwise.
92 int usb_find_common_endpoints(struct usb_host_interface *alt,
93 struct usb_endpoint_descriptor **bulk_in,
94 struct usb_endpoint_descriptor **bulk_out,
95 struct usb_endpoint_descriptor **int_in,
96 struct usb_endpoint_descriptor **int_out)
98 struct usb_endpoint_descriptor *epd;
110 for (i = 0; i < alt->desc.bNumEndpoints; ++i) {
111 epd = &alt->endpoint[i].desc;
113 switch (usb_endpoint_type(epd)) {
114 case USB_ENDPOINT_XFER_BULK:
115 if (usb_endpoint_dir_in(epd)) {
116 if (bulk_in && !*bulk_in) {
121 if (bulk_out && !*bulk_out) {
128 case USB_ENDPOINT_XFER_INT:
129 if (usb_endpoint_dir_in(epd)) {
130 if (int_in && !*int_in) {
135 if (int_out && !*int_out) {
146 if ((!bulk_in || *bulk_in) &&
147 (!bulk_out || *bulk_out) &&
148 (!int_in || *int_in) &&
149 (!int_out || *int_out)) {
156 EXPORT_SYMBOL_GPL(usb_find_common_endpoints);
159 * usb_find_alt_setting() - Given a configuration, find the alternate setting
160 * for the given interface.
161 * @config: the configuration to search (not necessarily the current config).
162 * @iface_num: interface number to search in
163 * @alt_num: alternate interface setting number to search for.
165 * Search the configuration's interface cache for the given alt setting.
167 * Return: The alternate setting, if found. %NULL otherwise.
169 struct usb_host_interface *usb_find_alt_setting(
170 struct usb_host_config *config,
171 unsigned int iface_num,
172 unsigned int alt_num)
174 struct usb_interface_cache *intf_cache = NULL;
179 for (i = 0; i < config->desc.bNumInterfaces; i++) {
180 if (config->intf_cache[i]->altsetting[0].desc.bInterfaceNumber
182 intf_cache = config->intf_cache[i];
188 for (i = 0; i < intf_cache->num_altsetting; i++)
189 if (intf_cache->altsetting[i].desc.bAlternateSetting == alt_num)
190 return &intf_cache->altsetting[i];
192 printk(KERN_DEBUG "Did not find alt setting %u for intf %u, "
193 "config %u\n", alt_num, iface_num,
194 config->desc.bConfigurationValue);
197 EXPORT_SYMBOL_GPL(usb_find_alt_setting);
200 * usb_ifnum_to_if - get the interface object with a given interface number
201 * @dev: the device whose current configuration is considered
202 * @ifnum: the desired interface
204 * This walks the device descriptor for the currently active configuration
205 * to find the interface object with the particular interface number.
207 * Note that configuration descriptors are not required to assign interface
208 * numbers sequentially, so that it would be incorrect to assume that
209 * the first interface in that descriptor corresponds to interface zero.
210 * This routine helps device drivers avoid such mistakes.
211 * However, you should make sure that you do the right thing with any
212 * alternate settings available for this interfaces.
214 * Don't call this function unless you are bound to one of the interfaces
215 * on this device or you have locked the device!
217 * Return: A pointer to the interface that has @ifnum as interface number,
218 * if found. %NULL otherwise.
220 struct usb_interface *usb_ifnum_to_if(const struct usb_device *dev,
223 struct usb_host_config *config = dev->actconfig;
228 for (i = 0; i < config->desc.bNumInterfaces; i++)
229 if (config->interface[i]->altsetting[0]
230 .desc.bInterfaceNumber == ifnum)
231 return config->interface[i];
235 EXPORT_SYMBOL_GPL(usb_ifnum_to_if);
238 * usb_altnum_to_altsetting - get the altsetting structure with a given alternate setting number.
239 * @intf: the interface containing the altsetting in question
240 * @altnum: the desired alternate setting number
242 * This searches the altsetting array of the specified interface for
243 * an entry with the correct bAlternateSetting value.
245 * Note that altsettings need not be stored sequentially by number, so
246 * it would be incorrect to assume that the first altsetting entry in
247 * the array corresponds to altsetting zero. This routine helps device
248 * drivers avoid such mistakes.
250 * Don't call this function unless you are bound to the intf interface
251 * or you have locked the device!
253 * Return: A pointer to the entry of the altsetting array of @intf that
254 * has @altnum as the alternate setting number. %NULL if not found.
256 struct usb_host_interface *usb_altnum_to_altsetting(
257 const struct usb_interface *intf,
262 for (i = 0; i < intf->num_altsetting; i++) {
263 if (intf->altsetting[i].desc.bAlternateSetting == altnum)
264 return &intf->altsetting[i];
268 EXPORT_SYMBOL_GPL(usb_altnum_to_altsetting);
270 struct find_interface_arg {
272 struct device_driver *drv;
275 static int __find_interface(struct device *dev, void *data)
277 struct find_interface_arg *arg = data;
278 struct usb_interface *intf;
280 if (!is_usb_interface(dev))
283 if (dev->driver != arg->drv)
285 intf = to_usb_interface(dev);
286 return intf->minor == arg->minor;
290 * usb_find_interface - find usb_interface pointer for driver and device
291 * @drv: the driver whose current configuration is considered
292 * @minor: the minor number of the desired device
294 * This walks the bus device list and returns a pointer to the interface
295 * with the matching minor and driver. Note, this only works for devices
296 * that share the USB major number.
298 * Return: A pointer to the interface with the matching major and @minor.
300 struct usb_interface *usb_find_interface(struct usb_driver *drv, int minor)
302 struct find_interface_arg argb;
306 argb.drv = &drv->drvwrap.driver;
308 dev = bus_find_device(&usb_bus_type, NULL, &argb, __find_interface);
310 /* Drop reference count from bus_find_device */
313 return dev ? to_usb_interface(dev) : NULL;
315 EXPORT_SYMBOL_GPL(usb_find_interface);
317 struct each_dev_arg {
319 int (*fn)(struct usb_device *, void *);
322 static int __each_dev(struct device *dev, void *data)
324 struct each_dev_arg *arg = (struct each_dev_arg *)data;
326 /* There are struct usb_interface on the same bus, filter them out */
327 if (!is_usb_device(dev))
330 return arg->fn(to_usb_device(dev), arg->data);
334 * usb_for_each_dev - iterate over all USB devices in the system
335 * @data: data pointer that will be handed to the callback function
336 * @fn: callback function to be called for each USB device
338 * Iterate over all USB devices and call @fn for each, passing it @data. If it
339 * returns anything other than 0, we break the iteration prematurely and return
342 int usb_for_each_dev(void *data, int (*fn)(struct usb_device *, void *))
344 struct each_dev_arg arg = {data, fn};
346 return bus_for_each_dev(&usb_bus_type, NULL, &arg, __each_dev);
348 EXPORT_SYMBOL_GPL(usb_for_each_dev);
351 * usb_release_dev - free a usb device structure when all users of it are finished.
352 * @dev: device that's been disconnected
354 * Will be called only by the device core when all users of this usb device are
357 static void usb_release_dev(struct device *dev)
359 struct usb_device *udev;
362 udev = to_usb_device(dev);
363 hcd = bus_to_hcd(udev->bus);
365 usb_destroy_configuration(udev);
366 usb_release_bos_descriptor(udev);
368 of_node_put(dev->of_node);
370 kfree(udev->product);
371 kfree(udev->manufacturer);
376 static int usb_dev_uevent(struct device *dev, struct kobj_uevent_env *env)
378 struct usb_device *usb_dev;
380 usb_dev = to_usb_device(dev);
382 if (add_uevent_var(env, "BUSNUM=%03d", usb_dev->bus->busnum))
385 if (add_uevent_var(env, "DEVNUM=%03d", usb_dev->devnum))
393 /* USB device Power-Management thunks.
394 * There's no need to distinguish here between quiescing a USB device
395 * and powering it down; the generic_suspend() routine takes care of
396 * it by skipping the usb_port_suspend() call for a quiesce. And for
397 * USB interfaces there's no difference at all.
400 static int usb_dev_prepare(struct device *dev)
402 return 0; /* Implement eventually? */
405 static void usb_dev_complete(struct device *dev)
407 /* Currently used only for rebinding interfaces */
408 usb_resume_complete(dev);
411 static int usb_dev_suspend(struct device *dev)
413 return usb_suspend(dev, PMSG_SUSPEND);
416 static int usb_dev_resume(struct device *dev)
418 return usb_resume(dev, PMSG_RESUME);
421 static int usb_dev_freeze(struct device *dev)
423 return usb_suspend(dev, PMSG_FREEZE);
426 static int usb_dev_thaw(struct device *dev)
428 return usb_resume(dev, PMSG_THAW);
431 static int usb_dev_poweroff(struct device *dev)
433 return usb_suspend(dev, PMSG_HIBERNATE);
436 static int usb_dev_restore(struct device *dev)
438 return usb_resume(dev, PMSG_RESTORE);
441 static const struct dev_pm_ops usb_device_pm_ops = {
442 .prepare = usb_dev_prepare,
443 .complete = usb_dev_complete,
444 .suspend = usb_dev_suspend,
445 .resume = usb_dev_resume,
446 .freeze = usb_dev_freeze,
447 .thaw = usb_dev_thaw,
448 .poweroff = usb_dev_poweroff,
449 .restore = usb_dev_restore,
450 .runtime_suspend = usb_runtime_suspend,
451 .runtime_resume = usb_runtime_resume,
452 .runtime_idle = usb_runtime_idle,
455 #endif /* CONFIG_PM */
458 static char *usb_devnode(struct device *dev,
459 umode_t *mode, kuid_t *uid, kgid_t *gid)
461 struct usb_device *usb_dev;
463 usb_dev = to_usb_device(dev);
464 return kasprintf(GFP_KERNEL, "bus/usb/%03d/%03d",
465 usb_dev->bus->busnum, usb_dev->devnum);
468 struct device_type usb_device_type = {
469 .name = "usb_device",
470 .release = usb_release_dev,
471 .uevent = usb_dev_uevent,
472 .devnode = usb_devnode,
474 .pm = &usb_device_pm_ops,
479 /* Returns 1 if @usb_bus is WUSB, 0 otherwise */
480 static unsigned usb_bus_is_wusb(struct usb_bus *bus)
482 struct usb_hcd *hcd = bus_to_hcd(bus);
483 return hcd->wireless;
488 * usb_alloc_dev - usb device constructor (usbcore-internal)
489 * @parent: hub to which device is connected; null to allocate a root hub
490 * @bus: bus used to access the device
491 * @port1: one-based index of port; ignored for root hubs
492 * Context: !in_interrupt()
494 * Only hub drivers (including virtual root hub drivers for host
495 * controllers) should ever call this.
497 * This call may not be used in a non-sleeping context.
499 * Return: On success, a pointer to the allocated usb device. %NULL on
502 struct usb_device *usb_alloc_dev(struct usb_device *parent,
503 struct usb_bus *bus, unsigned port1)
505 struct usb_device *dev;
506 struct usb_hcd *usb_hcd = bus_to_hcd(bus);
507 unsigned root_hub = 0;
508 unsigned raw_port = port1;
510 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
514 if (!usb_get_hcd(usb_hcd)) {
518 /* Root hubs aren't true devices, so don't allocate HCD resources */
519 if (usb_hcd->driver->alloc_dev && parent &&
520 !usb_hcd->driver->alloc_dev(usb_hcd, dev)) {
521 usb_put_hcd(bus_to_hcd(bus));
526 device_initialize(&dev->dev);
527 dev->dev.bus = &usb_bus_type;
528 dev->dev.type = &usb_device_type;
529 dev->dev.groups = usb_device_groups;
531 * Fake a dma_mask/offset for the USB device:
532 * We cannot really use the dma-mapping API (dma_alloc_* and
533 * dma_map_*) for USB devices but instead need to use
534 * usb_alloc_coherent and pass data in 'urb's, but some subsystems
535 * manually look into the mask/offset pair to determine whether
536 * they need bounce buffers.
537 * Note: calling dma_set_mask() on a USB device would set the
538 * mask for the entire HCD, so don't do that.
540 dev->dev.dma_mask = bus->controller->dma_mask;
541 dev->dev.dma_pfn_offset = bus->controller->dma_pfn_offset;
542 set_dev_node(&dev->dev, dev_to_node(bus->controller));
543 dev->state = USB_STATE_ATTACHED;
544 dev->lpm_disable_count = 1;
545 atomic_set(&dev->urbnum, 0);
547 INIT_LIST_HEAD(&dev->ep0.urb_list);
548 dev->ep0.desc.bLength = USB_DT_ENDPOINT_SIZE;
549 dev->ep0.desc.bDescriptorType = USB_DT_ENDPOINT;
550 /* ep0 maxpacket comes later, from device descriptor */
551 usb_enable_endpoint(dev, &dev->ep0, false);
554 /* Save readable and stable topology id, distinguishing devices
555 * by location for diagnostics, tools, driver model, etc. The
556 * string is a path along hub ports, from the root. Each device's
557 * dev->devpath will be stable until USB is re-cabled, and hubs
558 * are often labeled with these port numbers. The name isn't
559 * as stable: bus->busnum changes easily from modprobe order,
560 * cardbus or pci hotplugging, and so on.
562 if (unlikely(!parent)) {
563 dev->devpath[0] = '0';
566 dev->dev.parent = bus->controller;
567 dev_set_name(&dev->dev, "usb%d", bus->busnum);
570 /* match any labeling on the hubs; it's one-based */
571 if (parent->devpath[0] == '0') {
572 snprintf(dev->devpath, sizeof dev->devpath,
574 /* Root ports are not counted in route string */
577 snprintf(dev->devpath, sizeof dev->devpath,
578 "%s.%d", parent->devpath, port1);
579 /* Route string assumes hubs have less than 16 ports */
581 dev->route = parent->route +
582 (port1 << ((parent->level - 1)*4));
584 dev->route = parent->route +
585 (15 << ((parent->level - 1)*4));
588 dev->dev.parent = &parent->dev;
589 dev_set_name(&dev->dev, "%d-%s", bus->busnum, dev->devpath);
591 if (!parent->parent) {
592 /* device under root hub's port */
593 raw_port = usb_hcd_find_raw_port_number(usb_hcd,
596 dev->dev.of_node = usb_of_get_child_node(parent->dev.of_node,
599 /* hub driver sets up TT records */
602 dev->portnum = port1;
604 dev->parent = parent;
605 INIT_LIST_HEAD(&dev->filelist);
608 pm_runtime_set_autosuspend_delay(&dev->dev,
609 usb_autosuspend_delay * 1000);
610 dev->connect_time = jiffies;
611 dev->active_duration = -jiffies;
613 if (root_hub) /* Root hub always ok [and always wired] */
616 dev->authorized = !!HCD_DEV_AUTHORIZED(usb_hcd);
617 dev->wusb = usb_bus_is_wusb(bus) ? 1 : 0;
621 EXPORT_SYMBOL_GPL(usb_alloc_dev);
624 * usb_get_dev - increments the reference count of the usb device structure
625 * @dev: the device being referenced
627 * Each live reference to a device should be refcounted.
629 * Drivers for USB interfaces should normally record such references in
630 * their probe() methods, when they bind to an interface, and release
631 * them by calling usb_put_dev(), in their disconnect() methods.
633 * Return: A pointer to the device with the incremented reference counter.
635 struct usb_device *usb_get_dev(struct usb_device *dev)
638 get_device(&dev->dev);
641 EXPORT_SYMBOL_GPL(usb_get_dev);
644 * usb_put_dev - release a use of the usb device structure
645 * @dev: device that's been disconnected
647 * Must be called when a user of a device is finished with it. When the last
648 * user of the device calls this function, the memory of the device is freed.
650 void usb_put_dev(struct usb_device *dev)
653 put_device(&dev->dev);
655 EXPORT_SYMBOL_GPL(usb_put_dev);
658 * usb_get_intf - increments the reference count of the usb interface structure
659 * @intf: the interface being referenced
661 * Each live reference to a interface must be refcounted.
663 * Drivers for USB interfaces should normally record such references in
664 * their probe() methods, when they bind to an interface, and release
665 * them by calling usb_put_intf(), in their disconnect() methods.
667 * Return: A pointer to the interface with the incremented reference counter.
669 struct usb_interface *usb_get_intf(struct usb_interface *intf)
672 get_device(&intf->dev);
675 EXPORT_SYMBOL_GPL(usb_get_intf);
678 * usb_put_intf - release a use of the usb interface structure
679 * @intf: interface that's been decremented
681 * Must be called when a user of an interface is finished with it. When the
682 * last user of the interface calls this function, the memory of the interface
685 void usb_put_intf(struct usb_interface *intf)
688 put_device(&intf->dev);
690 EXPORT_SYMBOL_GPL(usb_put_intf);
692 /* USB device locking
694 * USB devices and interfaces are locked using the semaphore in their
695 * embedded struct device. The hub driver guarantees that whenever a
696 * device is connected or disconnected, drivers are called with the
697 * USB device locked as well as their particular interface.
699 * Complications arise when several devices are to be locked at the same
700 * time. Only hub-aware drivers that are part of usbcore ever have to
701 * do this; nobody else needs to worry about it. The rule for locking
704 * When locking both a device and its parent, always lock the
709 * usb_lock_device_for_reset - cautiously acquire the lock for a usb device structure
710 * @udev: device that's being locked
711 * @iface: interface bound to the driver making the request (optional)
713 * Attempts to acquire the device lock, but fails if the device is
714 * NOTATTACHED or SUSPENDED, or if iface is specified and the interface
715 * is neither BINDING nor BOUND. Rather than sleeping to wait for the
716 * lock, the routine polls repeatedly. This is to prevent deadlock with
717 * disconnect; in some drivers (such as usb-storage) the disconnect()
718 * or suspend() method will block waiting for a device reset to complete.
720 * Return: A negative error code for failure, otherwise 0.
722 int usb_lock_device_for_reset(struct usb_device *udev,
723 const struct usb_interface *iface)
725 unsigned long jiffies_expire = jiffies + HZ;
727 if (udev->state == USB_STATE_NOTATTACHED)
729 if (udev->state == USB_STATE_SUSPENDED)
730 return -EHOSTUNREACH;
731 if (iface && (iface->condition == USB_INTERFACE_UNBINDING ||
732 iface->condition == USB_INTERFACE_UNBOUND))
735 while (!usb_trylock_device(udev)) {
737 /* If we can't acquire the lock after waiting one second,
738 * we're probably deadlocked */
739 if (time_after(jiffies, jiffies_expire))
743 if (udev->state == USB_STATE_NOTATTACHED)
745 if (udev->state == USB_STATE_SUSPENDED)
746 return -EHOSTUNREACH;
747 if (iface && (iface->condition == USB_INTERFACE_UNBINDING ||
748 iface->condition == USB_INTERFACE_UNBOUND))
753 EXPORT_SYMBOL_GPL(usb_lock_device_for_reset);
756 * usb_get_current_frame_number - return current bus frame number
757 * @dev: the device whose bus is being queried
759 * Return: The current frame number for the USB host controller used
760 * with the given USB device. This can be used when scheduling
761 * isochronous requests.
763 * Note: Different kinds of host controller have different "scheduling
764 * horizons". While one type might support scheduling only 32 frames
765 * into the future, others could support scheduling up to 1024 frames
769 int usb_get_current_frame_number(struct usb_device *dev)
771 return usb_hcd_get_frame_number(dev);
773 EXPORT_SYMBOL_GPL(usb_get_current_frame_number);
775 /*-------------------------------------------------------------------*/
777 * __usb_get_extra_descriptor() finds a descriptor of specific type in the
778 * extra field of the interface and endpoint descriptor structs.
781 int __usb_get_extra_descriptor(char *buffer, unsigned size,
782 unsigned char type, void **ptr, size_t minsize)
784 struct usb_descriptor_header *header;
786 while (size >= sizeof(struct usb_descriptor_header)) {
787 header = (struct usb_descriptor_header *)buffer;
789 if (header->bLength < 2 || header->bLength > size) {
791 "%s: bogus descriptor, type %d length %d\n",
793 header->bDescriptorType,
798 if (header->bDescriptorType == type && header->bLength >= minsize) {
803 buffer += header->bLength;
804 size -= header->bLength;
808 EXPORT_SYMBOL_GPL(__usb_get_extra_descriptor);
811 * usb_alloc_coherent - allocate dma-consistent buffer for URB_NO_xxx_DMA_MAP
812 * @dev: device the buffer will be used with
813 * @size: requested buffer size
814 * @mem_flags: affect whether allocation may block
815 * @dma: used to return DMA address of buffer
817 * Return: Either null (indicating no buffer could be allocated), or the
818 * cpu-space pointer to a buffer that may be used to perform DMA to the
819 * specified device. Such cpu-space buffers are returned along with the DMA
820 * address (through the pointer provided).
823 * These buffers are used with URB_NO_xxx_DMA_MAP set in urb->transfer_flags
824 * to avoid behaviors like using "DMA bounce buffers", or thrashing IOMMU
825 * hardware during URB completion/resubmit. The implementation varies between
826 * platforms, depending on details of how DMA will work to this device.
827 * Using these buffers also eliminates cacheline sharing problems on
828 * architectures where CPU caches are not DMA-coherent. On systems without
829 * bus-snooping caches, these buffers are uncached.
831 * When the buffer is no longer used, free it with usb_free_coherent().
833 void *usb_alloc_coherent(struct usb_device *dev, size_t size, gfp_t mem_flags,
836 if (!dev || !dev->bus)
838 return hcd_buffer_alloc(dev->bus, size, mem_flags, dma);
840 EXPORT_SYMBOL_GPL(usb_alloc_coherent);
843 * usb_free_coherent - free memory allocated with usb_alloc_coherent()
844 * @dev: device the buffer was used with
845 * @size: requested buffer size
846 * @addr: CPU address of buffer
847 * @dma: DMA address of buffer
849 * This reclaims an I/O buffer, letting it be reused. The memory must have
850 * been allocated using usb_alloc_coherent(), and the parameters must match
851 * those provided in that allocation request.
853 void usb_free_coherent(struct usb_device *dev, size_t size, void *addr,
856 if (!dev || !dev->bus)
860 hcd_buffer_free(dev->bus, size, addr, dma);
862 EXPORT_SYMBOL_GPL(usb_free_coherent);
865 * usb_buffer_map - create DMA mapping(s) for an urb
866 * @urb: urb whose transfer_buffer/setup_packet will be mapped
868 * URB_NO_TRANSFER_DMA_MAP is added to urb->transfer_flags if the operation
869 * succeeds. If the device is connected to this system through a non-DMA
870 * controller, this operation always succeeds.
872 * This call would normally be used for an urb which is reused, perhaps
873 * as the target of a large periodic transfer, with usb_buffer_dmasync()
874 * calls to synchronize memory and dma state.
876 * Reverse the effect of this call with usb_buffer_unmap().
878 * Return: Either %NULL (indicating no buffer could be mapped), or @urb.
882 struct urb *usb_buffer_map(struct urb *urb)
885 struct device *controller;
889 || !(bus = urb->dev->bus)
890 || !(controller = bus->controller))
893 if (controller->dma_mask) {
894 urb->transfer_dma = dma_map_single(controller,
895 urb->transfer_buffer, urb->transfer_buffer_length,
896 usb_pipein(urb->pipe)
897 ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
898 /* FIXME generic api broken like pci, can't report errors */
899 /* if (urb->transfer_dma == DMA_ADDR_INVALID) return 0; */
901 urb->transfer_dma = ~0;
902 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
905 EXPORT_SYMBOL_GPL(usb_buffer_map);
908 /* XXX DISABLED, no users currently. If you wish to re-enable this
909 * XXX please determine whether the sync is to transfer ownership of
910 * XXX the buffer from device to cpu or vice verse, and thusly use the
911 * XXX appropriate _for_{cpu,device}() method. -DaveM
916 * usb_buffer_dmasync - synchronize DMA and CPU view of buffer(s)
917 * @urb: urb whose transfer_buffer/setup_packet will be synchronized
919 void usb_buffer_dmasync(struct urb *urb)
922 struct device *controller;
925 || !(urb->transfer_flags & URB_NO_TRANSFER_DMA_MAP)
927 || !(bus = urb->dev->bus)
928 || !(controller = bus->controller))
931 if (controller->dma_mask) {
932 dma_sync_single_for_cpu(controller,
933 urb->transfer_dma, urb->transfer_buffer_length,
934 usb_pipein(urb->pipe)
935 ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
936 if (usb_pipecontrol(urb->pipe))
937 dma_sync_single_for_cpu(controller,
939 sizeof(struct usb_ctrlrequest),
943 EXPORT_SYMBOL_GPL(usb_buffer_dmasync);
947 * usb_buffer_unmap - free DMA mapping(s) for an urb
948 * @urb: urb whose transfer_buffer will be unmapped
950 * Reverses the effect of usb_buffer_map().
953 void usb_buffer_unmap(struct urb *urb)
956 struct device *controller;
959 || !(urb->transfer_flags & URB_NO_TRANSFER_DMA_MAP)
961 || !(bus = urb->dev->bus)
962 || !(controller = bus->controller))
965 if (controller->dma_mask) {
966 dma_unmap_single(controller,
967 urb->transfer_dma, urb->transfer_buffer_length,
968 usb_pipein(urb->pipe)
969 ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
971 urb->transfer_flags &= ~URB_NO_TRANSFER_DMA_MAP;
973 EXPORT_SYMBOL_GPL(usb_buffer_unmap);
978 * usb_buffer_map_sg - create scatterlist DMA mapping(s) for an endpoint
979 * @dev: device to which the scatterlist will be mapped
980 * @is_in: mapping transfer direction
981 * @sg: the scatterlist to map
982 * @nents: the number of entries in the scatterlist
984 * Return: Either < 0 (indicating no buffers could be mapped), or the
985 * number of DMA mapping array entries in the scatterlist.
988 * The caller is responsible for placing the resulting DMA addresses from
989 * the scatterlist into URB transfer buffer pointers, and for setting the
990 * URB_NO_TRANSFER_DMA_MAP transfer flag in each of those URBs.
992 * Top I/O rates come from queuing URBs, instead of waiting for each one
993 * to complete before starting the next I/O. This is particularly easy
994 * to do with scatterlists. Just allocate and submit one URB for each DMA
995 * mapping entry returned, stopping on the first error or when all succeed.
996 * Better yet, use the usb_sg_*() calls, which do that (and more) for you.
998 * This call would normally be used when translating scatterlist requests,
999 * rather than usb_buffer_map(), since on some hardware (with IOMMUs) it
1000 * may be able to coalesce mappings for improved I/O efficiency.
1002 * Reverse the effect of this call with usb_buffer_unmap_sg().
1004 int usb_buffer_map_sg(const struct usb_device *dev, int is_in,
1005 struct scatterlist *sg, int nents)
1007 struct usb_bus *bus;
1008 struct device *controller;
1011 || !(bus = dev->bus)
1012 || !(controller = bus->controller)
1013 || !controller->dma_mask)
1016 /* FIXME generic api broken like pci, can't report errors */
1017 return dma_map_sg(controller, sg, nents,
1018 is_in ? DMA_FROM_DEVICE : DMA_TO_DEVICE) ? : -ENOMEM;
1020 EXPORT_SYMBOL_GPL(usb_buffer_map_sg);
1023 /* XXX DISABLED, no users currently. If you wish to re-enable this
1024 * XXX please determine whether the sync is to transfer ownership of
1025 * XXX the buffer from device to cpu or vice verse, and thusly use the
1026 * XXX appropriate _for_{cpu,device}() method. -DaveM
1031 * usb_buffer_dmasync_sg - synchronize DMA and CPU view of scatterlist buffer(s)
1032 * @dev: device to which the scatterlist will be mapped
1033 * @is_in: mapping transfer direction
1034 * @sg: the scatterlist to synchronize
1035 * @n_hw_ents: the positive return value from usb_buffer_map_sg
1037 * Use this when you are re-using a scatterlist's data buffers for
1038 * another USB request.
1040 void usb_buffer_dmasync_sg(const struct usb_device *dev, int is_in,
1041 struct scatterlist *sg, int n_hw_ents)
1043 struct usb_bus *bus;
1044 struct device *controller;
1047 || !(bus = dev->bus)
1048 || !(controller = bus->controller)
1049 || !controller->dma_mask)
1052 dma_sync_sg_for_cpu(controller, sg, n_hw_ents,
1053 is_in ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
1055 EXPORT_SYMBOL_GPL(usb_buffer_dmasync_sg);
1060 * usb_buffer_unmap_sg - free DMA mapping(s) for a scatterlist
1061 * @dev: device to which the scatterlist will be mapped
1062 * @is_in: mapping transfer direction
1063 * @sg: the scatterlist to unmap
1064 * @n_hw_ents: the positive return value from usb_buffer_map_sg
1066 * Reverses the effect of usb_buffer_map_sg().
1068 void usb_buffer_unmap_sg(const struct usb_device *dev, int is_in,
1069 struct scatterlist *sg, int n_hw_ents)
1071 struct usb_bus *bus;
1072 struct device *controller;
1075 || !(bus = dev->bus)
1076 || !(controller = bus->controller)
1077 || !controller->dma_mask)
1080 dma_unmap_sg(controller, sg, n_hw_ents,
1081 is_in ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
1083 EXPORT_SYMBOL_GPL(usb_buffer_unmap_sg);
1087 * Notifications of device and interface registration
1089 static int usb_bus_notify(struct notifier_block *nb, unsigned long action,
1092 struct device *dev = data;
1095 case BUS_NOTIFY_ADD_DEVICE:
1096 if (dev->type == &usb_device_type)
1097 (void) usb_create_sysfs_dev_files(to_usb_device(dev));
1098 else if (dev->type == &usb_if_device_type)
1099 usb_create_sysfs_intf_files(to_usb_interface(dev));
1102 case BUS_NOTIFY_DEL_DEVICE:
1103 if (dev->type == &usb_device_type)
1104 usb_remove_sysfs_dev_files(to_usb_device(dev));
1105 else if (dev->type == &usb_if_device_type)
1106 usb_remove_sysfs_intf_files(to_usb_interface(dev));
1112 static struct notifier_block usb_bus_nb = {
1113 .notifier_call = usb_bus_notify,
1116 struct dentry *usb_debug_root;
1117 EXPORT_SYMBOL_GPL(usb_debug_root);
1119 static struct dentry *usb_debug_devices;
1121 static int usb_debugfs_init(void)
1123 usb_debug_root = debugfs_create_dir("usb", NULL);
1124 if (!usb_debug_root)
1127 usb_debug_devices = debugfs_create_file("devices", 0444,
1128 usb_debug_root, NULL,
1129 &usbfs_devices_fops);
1130 if (!usb_debug_devices) {
1131 debugfs_remove(usb_debug_root);
1132 usb_debug_root = NULL;
1139 static void usb_debugfs_cleanup(void)
1141 debugfs_remove(usb_debug_devices);
1142 debugfs_remove(usb_debug_root);
1148 static int __init usb_init(void)
1151 if (usb_disabled()) {
1152 pr_info("%s: USB support disabled\n", usbcore_name);
1155 usb_init_pool_max();
1157 retval = usb_debugfs_init();
1161 usb_acpi_register();
1162 retval = bus_register(&usb_bus_type);
1164 goto bus_register_failed;
1165 retval = bus_register_notifier(&usb_bus_type, &usb_bus_nb);
1167 goto bus_notifier_failed;
1168 retval = usb_major_init();
1170 goto major_init_failed;
1171 retval = usb_register(&usbfs_driver);
1173 goto driver_register_failed;
1174 retval = usb_devio_init();
1176 goto usb_devio_init_failed;
1177 retval = usb_hub_init();
1179 goto hub_init_failed;
1180 retval = usb_register_device_driver(&usb_generic_driver, THIS_MODULE);
1186 usb_devio_cleanup();
1187 usb_devio_init_failed:
1188 usb_deregister(&usbfs_driver);
1189 driver_register_failed:
1190 usb_major_cleanup();
1192 bus_unregister_notifier(&usb_bus_type, &usb_bus_nb);
1193 bus_notifier_failed:
1194 bus_unregister(&usb_bus_type);
1195 bus_register_failed:
1196 usb_acpi_unregister();
1197 usb_debugfs_cleanup();
1205 static void __exit usb_exit(void)
1207 /* This will matter if shutdown/reboot does exitcalls. */
1211 usb_deregister_device_driver(&usb_generic_driver);
1212 usb_major_cleanup();
1213 usb_deregister(&usbfs_driver);
1214 usb_devio_cleanup();
1216 bus_unregister_notifier(&usb_bus_type, &usb_bus_nb);
1217 bus_unregister(&usb_bus_type);
1218 usb_acpi_unregister();
1219 usb_debugfs_cleanup();
1220 idr_destroy(&usb_bus_idr);
1223 subsys_initcall(usb_init);
1224 module_exit(usb_exit);
1225 MODULE_LICENSE("GPL");