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 /* To disable USB, kernel command line is 'nousb' not 'usbcore.nousb' */
54 module_param(nousb, bool, 0444);
56 core_param(nousb, nousb, bool, 0444);
60 * for external read access to <nousb>
62 int usb_disabled(void)
66 EXPORT_SYMBOL_GPL(usb_disabled);
69 static int usb_autosuspend_delay = 2; /* Default delay value,
71 module_param_named(autosuspend, usb_autosuspend_delay, int, 0644);
72 MODULE_PARM_DESC(autosuspend, "default autosuspend delay");
75 #define usb_autosuspend_delay 0
80 * usb_find_common_endpoints() -- look up common endpoint descriptors
81 * @alt: alternate setting to search
82 * @bulk_in: pointer to descriptor pointer, or NULL
83 * @bulk_out: pointer to descriptor pointer, or NULL
84 * @int_in: pointer to descriptor pointer, or NULL
85 * @int_out: pointer to descriptor pointer, or NULL
87 * Search the alternate setting's endpoint descriptors for the first bulk-in,
88 * bulk-out, interrupt-in and interrupt-out endpoints and return them in the
89 * provided pointers (unless they are NULL).
91 * If a requested endpoint is not found, the corresponding pointer is set to
94 * Return: Zero if all requested descriptors were found, or -ENXIO otherwise.
96 int usb_find_common_endpoints(struct usb_host_interface *alt,
97 struct usb_endpoint_descriptor **bulk_in,
98 struct usb_endpoint_descriptor **bulk_out,
99 struct usb_endpoint_descriptor **int_in,
100 struct usb_endpoint_descriptor **int_out)
102 struct usb_endpoint_descriptor *epd;
114 for (i = 0; i < alt->desc.bNumEndpoints; ++i) {
115 epd = &alt->endpoint[i].desc;
117 switch (usb_endpoint_type(epd)) {
118 case USB_ENDPOINT_XFER_BULK:
119 if (usb_endpoint_dir_in(epd)) {
120 if (bulk_in && !*bulk_in) {
125 if (bulk_out && !*bulk_out) {
132 case USB_ENDPOINT_XFER_INT:
133 if (usb_endpoint_dir_in(epd)) {
134 if (int_in && !*int_in) {
139 if (int_out && !*int_out) {
150 if ((!bulk_in || *bulk_in) &&
151 (!bulk_out || *bulk_out) &&
152 (!int_in || *int_in) &&
153 (!int_out || *int_out)) {
160 EXPORT_SYMBOL_GPL(usb_find_common_endpoints);
163 * usb_find_alt_setting() - Given a configuration, find the alternate setting
164 * for the given interface.
165 * @config: the configuration to search (not necessarily the current config).
166 * @iface_num: interface number to search in
167 * @alt_num: alternate interface setting number to search for.
169 * Search the configuration's interface cache for the given alt setting.
171 * Return: The alternate setting, if found. %NULL otherwise.
173 struct usb_host_interface *usb_find_alt_setting(
174 struct usb_host_config *config,
175 unsigned int iface_num,
176 unsigned int alt_num)
178 struct usb_interface_cache *intf_cache = NULL;
183 for (i = 0; i < config->desc.bNumInterfaces; i++) {
184 if (config->intf_cache[i]->altsetting[0].desc.bInterfaceNumber
186 intf_cache = config->intf_cache[i];
192 for (i = 0; i < intf_cache->num_altsetting; i++)
193 if (intf_cache->altsetting[i].desc.bAlternateSetting == alt_num)
194 return &intf_cache->altsetting[i];
196 printk(KERN_DEBUG "Did not find alt setting %u for intf %u, "
197 "config %u\n", alt_num, iface_num,
198 config->desc.bConfigurationValue);
201 EXPORT_SYMBOL_GPL(usb_find_alt_setting);
204 * usb_ifnum_to_if - get the interface object with a given interface number
205 * @dev: the device whose current configuration is considered
206 * @ifnum: the desired interface
208 * This walks the device descriptor for the currently active configuration
209 * to find the interface object with the particular interface number.
211 * Note that configuration descriptors are not required to assign interface
212 * numbers sequentially, so that it would be incorrect to assume that
213 * the first interface in that descriptor corresponds to interface zero.
214 * This routine helps device drivers avoid such mistakes.
215 * However, you should make sure that you do the right thing with any
216 * alternate settings available for this interfaces.
218 * Don't call this function unless you are bound to one of the interfaces
219 * on this device or you have locked the device!
221 * Return: A pointer to the interface that has @ifnum as interface number,
222 * if found. %NULL otherwise.
224 struct usb_interface *usb_ifnum_to_if(const struct usb_device *dev,
227 struct usb_host_config *config = dev->actconfig;
232 for (i = 0; i < config->desc.bNumInterfaces; i++)
233 if (config->interface[i]->altsetting[0]
234 .desc.bInterfaceNumber == ifnum)
235 return config->interface[i];
239 EXPORT_SYMBOL_GPL(usb_ifnum_to_if);
242 * usb_altnum_to_altsetting - get the altsetting structure with a given alternate setting number.
243 * @intf: the interface containing the altsetting in question
244 * @altnum: the desired alternate setting number
246 * This searches the altsetting array of the specified interface for
247 * an entry with the correct bAlternateSetting value.
249 * Note that altsettings need not be stored sequentially by number, so
250 * it would be incorrect to assume that the first altsetting entry in
251 * the array corresponds to altsetting zero. This routine helps device
252 * drivers avoid such mistakes.
254 * Don't call this function unless you are bound to the intf interface
255 * or you have locked the device!
257 * Return: A pointer to the entry of the altsetting array of @intf that
258 * has @altnum as the alternate setting number. %NULL if not found.
260 struct usb_host_interface *usb_altnum_to_altsetting(
261 const struct usb_interface *intf,
266 for (i = 0; i < intf->num_altsetting; i++) {
267 if (intf->altsetting[i].desc.bAlternateSetting == altnum)
268 return &intf->altsetting[i];
272 EXPORT_SYMBOL_GPL(usb_altnum_to_altsetting);
274 struct find_interface_arg {
276 struct device_driver *drv;
279 static int __find_interface(struct device *dev, void *data)
281 struct find_interface_arg *arg = data;
282 struct usb_interface *intf;
284 if (!is_usb_interface(dev))
287 if (dev->driver != arg->drv)
289 intf = to_usb_interface(dev);
290 return intf->minor == arg->minor;
294 * usb_find_interface - find usb_interface pointer for driver and device
295 * @drv: the driver whose current configuration is considered
296 * @minor: the minor number of the desired device
298 * This walks the bus device list and returns a pointer to the interface
299 * with the matching minor and driver. Note, this only works for devices
300 * that share the USB major number.
302 * Return: A pointer to the interface with the matching major and @minor.
304 struct usb_interface *usb_find_interface(struct usb_driver *drv, int minor)
306 struct find_interface_arg argb;
310 argb.drv = &drv->drvwrap.driver;
312 dev = bus_find_device(&usb_bus_type, NULL, &argb, __find_interface);
314 /* Drop reference count from bus_find_device */
317 return dev ? to_usb_interface(dev) : NULL;
319 EXPORT_SYMBOL_GPL(usb_find_interface);
321 struct each_dev_arg {
323 int (*fn)(struct usb_device *, void *);
326 static int __each_dev(struct device *dev, void *data)
328 struct each_dev_arg *arg = (struct each_dev_arg *)data;
330 /* There are struct usb_interface on the same bus, filter them out */
331 if (!is_usb_device(dev))
334 return arg->fn(container_of(dev, struct usb_device, dev), arg->data);
338 * usb_for_each_dev - iterate over all USB devices in the system
339 * @data: data pointer that will be handed to the callback function
340 * @fn: callback function to be called for each USB device
342 * Iterate over all USB devices and call @fn for each, passing it @data. If it
343 * returns anything other than 0, we break the iteration prematurely and return
346 int usb_for_each_dev(void *data, int (*fn)(struct usb_device *, void *))
348 struct each_dev_arg arg = {data, fn};
350 return bus_for_each_dev(&usb_bus_type, NULL, &arg, __each_dev);
352 EXPORT_SYMBOL_GPL(usb_for_each_dev);
355 * usb_release_dev - free a usb device structure when all users of it are finished.
356 * @dev: device that's been disconnected
358 * Will be called only by the device core when all users of this usb device are
361 static void usb_release_dev(struct device *dev)
363 struct usb_device *udev;
366 udev = to_usb_device(dev);
367 hcd = bus_to_hcd(udev->bus);
369 usb_destroy_configuration(udev);
370 usb_release_bos_descriptor(udev);
372 kfree(udev->product);
373 kfree(udev->manufacturer);
378 static int usb_dev_uevent(struct device *dev, struct kobj_uevent_env *env)
380 struct usb_device *usb_dev;
382 usb_dev = to_usb_device(dev);
384 if (add_uevent_var(env, "BUSNUM=%03d", usb_dev->bus->busnum))
387 if (add_uevent_var(env, "DEVNUM=%03d", usb_dev->devnum))
395 /* USB device Power-Management thunks.
396 * There's no need to distinguish here between quiescing a USB device
397 * and powering it down; the generic_suspend() routine takes care of
398 * it by skipping the usb_port_suspend() call for a quiesce. And for
399 * USB interfaces there's no difference at all.
402 static int usb_dev_prepare(struct device *dev)
404 return 0; /* Implement eventually? */
407 static void usb_dev_complete(struct device *dev)
409 /* Currently used only for rebinding interfaces */
410 usb_resume_complete(dev);
413 static int usb_dev_suspend(struct device *dev)
415 return usb_suspend(dev, PMSG_SUSPEND);
418 static int usb_dev_resume(struct device *dev)
420 return usb_resume(dev, PMSG_RESUME);
423 static int usb_dev_freeze(struct device *dev)
425 return usb_suspend(dev, PMSG_FREEZE);
428 static int usb_dev_thaw(struct device *dev)
430 return usb_resume(dev, PMSG_THAW);
433 static int usb_dev_poweroff(struct device *dev)
435 return usb_suspend(dev, PMSG_HIBERNATE);
438 static int usb_dev_restore(struct device *dev)
440 return usb_resume(dev, PMSG_RESTORE);
443 static const struct dev_pm_ops usb_device_pm_ops = {
444 .prepare = usb_dev_prepare,
445 .complete = usb_dev_complete,
446 .suspend = usb_dev_suspend,
447 .resume = usb_dev_resume,
448 .freeze = usb_dev_freeze,
449 .thaw = usb_dev_thaw,
450 .poweroff = usb_dev_poweroff,
451 .restore = usb_dev_restore,
452 .runtime_suspend = usb_runtime_suspend,
453 .runtime_resume = usb_runtime_resume,
454 .runtime_idle = usb_runtime_idle,
457 #endif /* CONFIG_PM */
460 static char *usb_devnode(struct device *dev,
461 umode_t *mode, kuid_t *uid, kgid_t *gid)
463 struct usb_device *usb_dev;
465 usb_dev = to_usb_device(dev);
466 return kasprintf(GFP_KERNEL, "bus/usb/%03d/%03d",
467 usb_dev->bus->busnum, usb_dev->devnum);
470 struct device_type usb_device_type = {
471 .name = "usb_device",
472 .release = usb_release_dev,
473 .uevent = usb_dev_uevent,
474 .devnode = usb_devnode,
476 .pm = &usb_device_pm_ops,
481 /* Returns 1 if @usb_bus is WUSB, 0 otherwise */
482 static unsigned usb_bus_is_wusb(struct usb_bus *bus)
484 struct usb_hcd *hcd = container_of(bus, struct usb_hcd, self);
485 return hcd->wireless;
490 * usb_alloc_dev - usb device constructor (usbcore-internal)
491 * @parent: hub to which device is connected; null to allocate a root hub
492 * @bus: bus used to access the device
493 * @port1: one-based index of port; ignored for root hubs
494 * Context: !in_interrupt()
496 * Only hub drivers (including virtual root hub drivers for host
497 * controllers) should ever call this.
499 * This call may not be used in a non-sleeping context.
501 * Return: On success, a pointer to the allocated usb device. %NULL on
504 struct usb_device *usb_alloc_dev(struct usb_device *parent,
505 struct usb_bus *bus, unsigned port1)
507 struct usb_device *dev;
508 struct usb_hcd *usb_hcd = bus_to_hcd(bus);
509 unsigned root_hub = 0;
511 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
515 if (!usb_get_hcd(usb_hcd)) {
519 /* Root hubs aren't true devices, so don't allocate HCD resources */
520 if (usb_hcd->driver->alloc_dev && parent &&
521 !usb_hcd->driver->alloc_dev(usb_hcd, dev)) {
522 usb_put_hcd(bus_to_hcd(bus));
527 device_initialize(&dev->dev);
528 dev->dev.bus = &usb_bus_type;
529 dev->dev.type = &usb_device_type;
530 dev->dev.groups = usb_device_groups;
531 dev->dev.dma_mask = bus->controller->dma_mask;
532 set_dev_node(&dev->dev, dev_to_node(bus->controller));
533 dev->state = USB_STATE_ATTACHED;
534 dev->lpm_disable_count = 1;
535 atomic_set(&dev->urbnum, 0);
537 INIT_LIST_HEAD(&dev->ep0.urb_list);
538 dev->ep0.desc.bLength = USB_DT_ENDPOINT_SIZE;
539 dev->ep0.desc.bDescriptorType = USB_DT_ENDPOINT;
540 /* ep0 maxpacket comes later, from device descriptor */
541 usb_enable_endpoint(dev, &dev->ep0, false);
544 /* Save readable and stable topology id, distinguishing devices
545 * by location for diagnostics, tools, driver model, etc. The
546 * string is a path along hub ports, from the root. Each device's
547 * dev->devpath will be stable until USB is re-cabled, and hubs
548 * are often labeled with these port numbers. The name isn't
549 * as stable: bus->busnum changes easily from modprobe order,
550 * cardbus or pci hotplugging, and so on.
552 if (unlikely(!parent)) {
553 dev->devpath[0] = '0';
556 dev->dev.parent = bus->controller;
557 dev_set_name(&dev->dev, "usb%d", bus->busnum);
560 /* match any labeling on the hubs; it's one-based */
561 if (parent->devpath[0] == '0') {
562 snprintf(dev->devpath, sizeof dev->devpath,
564 /* Root ports are not counted in route string */
567 snprintf(dev->devpath, sizeof dev->devpath,
568 "%s.%d", parent->devpath, port1);
569 /* Route string assumes hubs have less than 16 ports */
571 dev->route = parent->route +
572 (port1 << ((parent->level - 1)*4));
574 dev->route = parent->route +
575 (15 << ((parent->level - 1)*4));
578 dev->dev.parent = &parent->dev;
579 dev_set_name(&dev->dev, "%d-%s", bus->busnum, dev->devpath);
581 /* hub driver sets up TT records */
584 dev->portnum = port1;
586 dev->parent = parent;
587 INIT_LIST_HEAD(&dev->filelist);
590 pm_runtime_set_autosuspend_delay(&dev->dev,
591 usb_autosuspend_delay * 1000);
592 dev->connect_time = jiffies;
593 dev->active_duration = -jiffies;
595 if (root_hub) /* Root hub always ok [and always wired] */
598 dev->authorized = !!HCD_DEV_AUTHORIZED(usb_hcd);
599 dev->wusb = usb_bus_is_wusb(bus) ? 1 : 0;
603 EXPORT_SYMBOL_GPL(usb_alloc_dev);
606 * usb_get_dev - increments the reference count of the usb device structure
607 * @dev: the device being referenced
609 * Each live reference to a device should be refcounted.
611 * Drivers for USB interfaces should normally record such references in
612 * their probe() methods, when they bind to an interface, and release
613 * them by calling usb_put_dev(), in their disconnect() methods.
615 * Return: A pointer to the device with the incremented reference counter.
617 struct usb_device *usb_get_dev(struct usb_device *dev)
620 get_device(&dev->dev);
623 EXPORT_SYMBOL_GPL(usb_get_dev);
626 * usb_put_dev - release a use of the usb device structure
627 * @dev: device that's been disconnected
629 * Must be called when a user of a device is finished with it. When the last
630 * user of the device calls this function, the memory of the device is freed.
632 void usb_put_dev(struct usb_device *dev)
635 put_device(&dev->dev);
637 EXPORT_SYMBOL_GPL(usb_put_dev);
640 * usb_get_intf - increments the reference count of the usb interface structure
641 * @intf: the interface being referenced
643 * Each live reference to a interface must be refcounted.
645 * Drivers for USB interfaces should normally record such references in
646 * their probe() methods, when they bind to an interface, and release
647 * them by calling usb_put_intf(), in their disconnect() methods.
649 * Return: A pointer to the interface with the incremented reference counter.
651 struct usb_interface *usb_get_intf(struct usb_interface *intf)
654 get_device(&intf->dev);
657 EXPORT_SYMBOL_GPL(usb_get_intf);
660 * usb_put_intf - release a use of the usb interface structure
661 * @intf: interface that's been decremented
663 * Must be called when a user of an interface is finished with it. When the
664 * last user of the interface calls this function, the memory of the interface
667 void usb_put_intf(struct usb_interface *intf)
670 put_device(&intf->dev);
672 EXPORT_SYMBOL_GPL(usb_put_intf);
674 /* USB device locking
676 * USB devices and interfaces are locked using the semaphore in their
677 * embedded struct device. The hub driver guarantees that whenever a
678 * device is connected or disconnected, drivers are called with the
679 * USB device locked as well as their particular interface.
681 * Complications arise when several devices are to be locked at the same
682 * time. Only hub-aware drivers that are part of usbcore ever have to
683 * do this; nobody else needs to worry about it. The rule for locking
686 * When locking both a device and its parent, always lock the
691 * usb_lock_device_for_reset - cautiously acquire the lock for a usb device structure
692 * @udev: device that's being locked
693 * @iface: interface bound to the driver making the request (optional)
695 * Attempts to acquire the device lock, but fails if the device is
696 * NOTATTACHED or SUSPENDED, or if iface is specified and the interface
697 * is neither BINDING nor BOUND. Rather than sleeping to wait for the
698 * lock, the routine polls repeatedly. This is to prevent deadlock with
699 * disconnect; in some drivers (such as usb-storage) the disconnect()
700 * or suspend() method will block waiting for a device reset to complete.
702 * Return: A negative error code for failure, otherwise 0.
704 int usb_lock_device_for_reset(struct usb_device *udev,
705 const struct usb_interface *iface)
707 unsigned long jiffies_expire = jiffies + HZ;
709 if (udev->state == USB_STATE_NOTATTACHED)
711 if (udev->state == USB_STATE_SUSPENDED)
712 return -EHOSTUNREACH;
713 if (iface && (iface->condition == USB_INTERFACE_UNBINDING ||
714 iface->condition == USB_INTERFACE_UNBOUND))
717 while (!usb_trylock_device(udev)) {
719 /* If we can't acquire the lock after waiting one second,
720 * we're probably deadlocked */
721 if (time_after(jiffies, jiffies_expire))
725 if (udev->state == USB_STATE_NOTATTACHED)
727 if (udev->state == USB_STATE_SUSPENDED)
728 return -EHOSTUNREACH;
729 if (iface && (iface->condition == USB_INTERFACE_UNBINDING ||
730 iface->condition == USB_INTERFACE_UNBOUND))
735 EXPORT_SYMBOL_GPL(usb_lock_device_for_reset);
738 * usb_get_current_frame_number - return current bus frame number
739 * @dev: the device whose bus is being queried
741 * Return: The current frame number for the USB host controller used
742 * with the given USB device. This can be used when scheduling
743 * isochronous requests.
745 * Note: Different kinds of host controller have different "scheduling
746 * horizons". While one type might support scheduling only 32 frames
747 * into the future, others could support scheduling up to 1024 frames
751 int usb_get_current_frame_number(struct usb_device *dev)
753 return usb_hcd_get_frame_number(dev);
755 EXPORT_SYMBOL_GPL(usb_get_current_frame_number);
757 /*-------------------------------------------------------------------*/
759 * __usb_get_extra_descriptor() finds a descriptor of specific type in the
760 * extra field of the interface and endpoint descriptor structs.
763 int __usb_get_extra_descriptor(char *buffer, unsigned size,
764 unsigned char type, void **ptr, size_t minsize)
766 struct usb_descriptor_header *header;
768 while (size >= sizeof(struct usb_descriptor_header)) {
769 header = (struct usb_descriptor_header *)buffer;
771 if (header->bLength < 2 || header->bLength > size) {
773 "%s: bogus descriptor, type %d length %d\n",
775 header->bDescriptorType,
780 if (header->bDescriptorType == type && header->bLength >= minsize) {
785 buffer += header->bLength;
786 size -= header->bLength;
790 EXPORT_SYMBOL_GPL(__usb_get_extra_descriptor);
793 * usb_alloc_coherent - allocate dma-consistent buffer for URB_NO_xxx_DMA_MAP
794 * @dev: device the buffer will be used with
795 * @size: requested buffer size
796 * @mem_flags: affect whether allocation may block
797 * @dma: used to return DMA address of buffer
799 * Return: Either null (indicating no buffer could be allocated), or the
800 * cpu-space pointer to a buffer that may be used to perform DMA to the
801 * specified device. Such cpu-space buffers are returned along with the DMA
802 * address (through the pointer provided).
805 * These buffers are used with URB_NO_xxx_DMA_MAP set in urb->transfer_flags
806 * to avoid behaviors like using "DMA bounce buffers", or thrashing IOMMU
807 * hardware during URB completion/resubmit. The implementation varies between
808 * platforms, depending on details of how DMA will work to this device.
809 * Using these buffers also eliminates cacheline sharing problems on
810 * architectures where CPU caches are not DMA-coherent. On systems without
811 * bus-snooping caches, these buffers are uncached.
813 * When the buffer is no longer used, free it with usb_free_coherent().
815 void *usb_alloc_coherent(struct usb_device *dev, size_t size, gfp_t mem_flags,
818 if (!dev || !dev->bus)
820 return hcd_buffer_alloc(dev->bus, size, mem_flags, dma);
822 EXPORT_SYMBOL_GPL(usb_alloc_coherent);
825 * usb_free_coherent - free memory allocated with usb_alloc_coherent()
826 * @dev: device the buffer was used with
827 * @size: requested buffer size
828 * @addr: CPU address of buffer
829 * @dma: DMA address of buffer
831 * This reclaims an I/O buffer, letting it be reused. The memory must have
832 * been allocated using usb_alloc_coherent(), and the parameters must match
833 * those provided in that allocation request.
835 void usb_free_coherent(struct usb_device *dev, size_t size, void *addr,
838 if (!dev || !dev->bus)
842 hcd_buffer_free(dev->bus, size, addr, dma);
844 EXPORT_SYMBOL_GPL(usb_free_coherent);
847 * usb_buffer_map - create DMA mapping(s) for an urb
848 * @urb: urb whose transfer_buffer/setup_packet will be mapped
850 * URB_NO_TRANSFER_DMA_MAP is added to urb->transfer_flags if the operation
851 * succeeds. If the device is connected to this system through a non-DMA
852 * controller, this operation always succeeds.
854 * This call would normally be used for an urb which is reused, perhaps
855 * as the target of a large periodic transfer, with usb_buffer_dmasync()
856 * calls to synchronize memory and dma state.
858 * Reverse the effect of this call with usb_buffer_unmap().
860 * Return: Either %NULL (indicating no buffer could be mapped), or @urb.
864 struct urb *usb_buffer_map(struct urb *urb)
867 struct device *controller;
871 || !(bus = urb->dev->bus)
872 || !(controller = bus->controller))
875 if (controller->dma_mask) {
876 urb->transfer_dma = dma_map_single(controller,
877 urb->transfer_buffer, urb->transfer_buffer_length,
878 usb_pipein(urb->pipe)
879 ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
880 /* FIXME generic api broken like pci, can't report errors */
881 /* if (urb->transfer_dma == DMA_ADDR_INVALID) return 0; */
883 urb->transfer_dma = ~0;
884 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
887 EXPORT_SYMBOL_GPL(usb_buffer_map);
890 /* XXX DISABLED, no users currently. If you wish to re-enable this
891 * XXX please determine whether the sync is to transfer ownership of
892 * XXX the buffer from device to cpu or vice verse, and thusly use the
893 * XXX appropriate _for_{cpu,device}() method. -DaveM
898 * usb_buffer_dmasync - synchronize DMA and CPU view of buffer(s)
899 * @urb: urb whose transfer_buffer/setup_packet will be synchronized
901 void usb_buffer_dmasync(struct urb *urb)
904 struct device *controller;
907 || !(urb->transfer_flags & URB_NO_TRANSFER_DMA_MAP)
909 || !(bus = urb->dev->bus)
910 || !(controller = bus->controller))
913 if (controller->dma_mask) {
914 dma_sync_single_for_cpu(controller,
915 urb->transfer_dma, urb->transfer_buffer_length,
916 usb_pipein(urb->pipe)
917 ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
918 if (usb_pipecontrol(urb->pipe))
919 dma_sync_single_for_cpu(controller,
921 sizeof(struct usb_ctrlrequest),
925 EXPORT_SYMBOL_GPL(usb_buffer_dmasync);
929 * usb_buffer_unmap - free DMA mapping(s) for an urb
930 * @urb: urb whose transfer_buffer will be unmapped
932 * Reverses the effect of usb_buffer_map().
935 void usb_buffer_unmap(struct urb *urb)
938 struct device *controller;
941 || !(urb->transfer_flags & URB_NO_TRANSFER_DMA_MAP)
943 || !(bus = urb->dev->bus)
944 || !(controller = bus->controller))
947 if (controller->dma_mask) {
948 dma_unmap_single(controller,
949 urb->transfer_dma, urb->transfer_buffer_length,
950 usb_pipein(urb->pipe)
951 ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
953 urb->transfer_flags &= ~URB_NO_TRANSFER_DMA_MAP;
955 EXPORT_SYMBOL_GPL(usb_buffer_unmap);
960 * usb_buffer_map_sg - create scatterlist DMA mapping(s) for an endpoint
961 * @dev: device to which the scatterlist will be mapped
962 * @is_in: mapping transfer direction
963 * @sg: the scatterlist to map
964 * @nents: the number of entries in the scatterlist
966 * Return: Either < 0 (indicating no buffers could be mapped), or the
967 * number of DMA mapping array entries in the scatterlist.
970 * The caller is responsible for placing the resulting DMA addresses from
971 * the scatterlist into URB transfer buffer pointers, and for setting the
972 * URB_NO_TRANSFER_DMA_MAP transfer flag in each of those URBs.
974 * Top I/O rates come from queuing URBs, instead of waiting for each one
975 * to complete before starting the next I/O. This is particularly easy
976 * to do with scatterlists. Just allocate and submit one URB for each DMA
977 * mapping entry returned, stopping on the first error or when all succeed.
978 * Better yet, use the usb_sg_*() calls, which do that (and more) for you.
980 * This call would normally be used when translating scatterlist requests,
981 * rather than usb_buffer_map(), since on some hardware (with IOMMUs) it
982 * may be able to coalesce mappings for improved I/O efficiency.
984 * Reverse the effect of this call with usb_buffer_unmap_sg().
986 int usb_buffer_map_sg(const struct usb_device *dev, int is_in,
987 struct scatterlist *sg, int nents)
990 struct device *controller;
994 || !(controller = bus->controller)
995 || !controller->dma_mask)
998 /* FIXME generic api broken like pci, can't report errors */
999 return dma_map_sg(controller, sg, nents,
1000 is_in ? DMA_FROM_DEVICE : DMA_TO_DEVICE) ? : -ENOMEM;
1002 EXPORT_SYMBOL_GPL(usb_buffer_map_sg);
1005 /* XXX DISABLED, no users currently. If you wish to re-enable this
1006 * XXX please determine whether the sync is to transfer ownership of
1007 * XXX the buffer from device to cpu or vice verse, and thusly use the
1008 * XXX appropriate _for_{cpu,device}() method. -DaveM
1013 * usb_buffer_dmasync_sg - synchronize DMA and CPU view of scatterlist buffer(s)
1014 * @dev: device to which the scatterlist will be mapped
1015 * @is_in: mapping transfer direction
1016 * @sg: the scatterlist to synchronize
1017 * @n_hw_ents: the positive return value from usb_buffer_map_sg
1019 * Use this when you are re-using a scatterlist's data buffers for
1020 * another USB request.
1022 void usb_buffer_dmasync_sg(const struct usb_device *dev, int is_in,
1023 struct scatterlist *sg, int n_hw_ents)
1025 struct usb_bus *bus;
1026 struct device *controller;
1029 || !(bus = dev->bus)
1030 || !(controller = bus->controller)
1031 || !controller->dma_mask)
1034 dma_sync_sg_for_cpu(controller, sg, n_hw_ents,
1035 is_in ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
1037 EXPORT_SYMBOL_GPL(usb_buffer_dmasync_sg);
1042 * usb_buffer_unmap_sg - free DMA mapping(s) for a scatterlist
1043 * @dev: device to which the scatterlist will be mapped
1044 * @is_in: mapping transfer direction
1045 * @sg: the scatterlist to unmap
1046 * @n_hw_ents: the positive return value from usb_buffer_map_sg
1048 * Reverses the effect of usb_buffer_map_sg().
1050 void usb_buffer_unmap_sg(const struct usb_device *dev, int is_in,
1051 struct scatterlist *sg, int n_hw_ents)
1053 struct usb_bus *bus;
1054 struct device *controller;
1057 || !(bus = dev->bus)
1058 || !(controller = bus->controller)
1059 || !controller->dma_mask)
1062 dma_unmap_sg(controller, sg, n_hw_ents,
1063 is_in ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
1065 EXPORT_SYMBOL_GPL(usb_buffer_unmap_sg);
1069 * Notifications of device and interface registration
1071 static int usb_bus_notify(struct notifier_block *nb, unsigned long action,
1074 struct device *dev = data;
1077 case BUS_NOTIFY_ADD_DEVICE:
1078 if (dev->type == &usb_device_type)
1079 (void) usb_create_sysfs_dev_files(to_usb_device(dev));
1080 else if (dev->type == &usb_if_device_type)
1081 usb_create_sysfs_intf_files(to_usb_interface(dev));
1084 case BUS_NOTIFY_DEL_DEVICE:
1085 if (dev->type == &usb_device_type)
1086 usb_remove_sysfs_dev_files(to_usb_device(dev));
1087 else if (dev->type == &usb_if_device_type)
1088 usb_remove_sysfs_intf_files(to_usb_interface(dev));
1094 static struct notifier_block usb_bus_nb = {
1095 .notifier_call = usb_bus_notify,
1098 struct dentry *usb_debug_root;
1099 EXPORT_SYMBOL_GPL(usb_debug_root);
1101 static struct dentry *usb_debug_devices;
1103 static int usb_debugfs_init(void)
1105 usb_debug_root = debugfs_create_dir("usb", NULL);
1106 if (!usb_debug_root)
1109 usb_debug_devices = debugfs_create_file("devices", 0444,
1110 usb_debug_root, NULL,
1111 &usbfs_devices_fops);
1112 if (!usb_debug_devices) {
1113 debugfs_remove(usb_debug_root);
1114 usb_debug_root = NULL;
1121 static void usb_debugfs_cleanup(void)
1123 debugfs_remove(usb_debug_devices);
1124 debugfs_remove(usb_debug_root);
1130 static int __init usb_init(void)
1133 if (usb_disabled()) {
1134 pr_info("%s: USB support disabled\n", usbcore_name);
1137 usb_init_pool_max();
1139 retval = usb_debugfs_init();
1143 usb_acpi_register();
1144 retval = bus_register(&usb_bus_type);
1146 goto bus_register_failed;
1147 retval = bus_register_notifier(&usb_bus_type, &usb_bus_nb);
1149 goto bus_notifier_failed;
1150 retval = usb_major_init();
1152 goto major_init_failed;
1153 retval = usb_register(&usbfs_driver);
1155 goto driver_register_failed;
1156 retval = usb_devio_init();
1158 goto usb_devio_init_failed;
1159 retval = usb_hub_init();
1161 goto hub_init_failed;
1162 retval = usb_register_device_driver(&usb_generic_driver, THIS_MODULE);
1168 usb_devio_cleanup();
1169 usb_devio_init_failed:
1170 usb_deregister(&usbfs_driver);
1171 driver_register_failed:
1172 usb_major_cleanup();
1174 bus_unregister_notifier(&usb_bus_type, &usb_bus_nb);
1175 bus_notifier_failed:
1176 bus_unregister(&usb_bus_type);
1177 bus_register_failed:
1178 usb_acpi_unregister();
1179 usb_debugfs_cleanup();
1187 static void __exit usb_exit(void)
1189 /* This will matter if shutdown/reboot does exitcalls. */
1193 usb_deregister_device_driver(&usb_generic_driver);
1194 usb_major_cleanup();
1195 usb_deregister(&usbfs_driver);
1196 usb_devio_cleanup();
1198 bus_unregister_notifier(&usb_bus_type, &usb_bus_nb);
1199 bus_unregister(&usb_bus_type);
1200 usb_acpi_unregister();
1201 usb_debugfs_cleanup();
1204 subsys_initcall(usb_init);
1205 module_exit(usb_exit);
1206 MODULE_LICENSE("GPL");