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/config.h>
26 #ifdef CONFIG_USB_DEBUG
32 #include <linux/module.h>
33 #include <linux/string.h>
34 #include <linux/bitops.h>
35 #include <linux/slab.h>
36 #include <linux/interrupt.h> /* for in_interrupt() */
37 #include <linux/kmod.h>
38 #include <linux/init.h>
39 #include <linux/spinlock.h>
40 #include <linux/errno.h>
41 #include <linux/smp_lock.h>
42 #include <linux/rwsem.h>
43 #include <linux/usb.h>
46 #include <asm/scatterlist.h>
48 #include <linux/dma-mapping.h>
54 const char *usbcore_name = "usbcore";
56 static int nousb; /* Disable USB when built into kernel image */
57 /* Not honored on modular build */
59 static DECLARE_RWSEM(usb_all_devices_rwsem);
62 static int generic_probe (struct device *dev)
66 static int generic_remove (struct device *dev)
71 static struct device_driver usb_generic_driver = {
75 .probe = generic_probe,
76 .remove = generic_remove,
79 static int usb_generic_driver_data;
81 /* called from driver core with usb_bus_type.subsys writelock */
82 static int usb_probe_interface(struct device *dev)
84 struct usb_interface * intf = to_usb_interface(dev);
85 struct usb_driver * driver = to_usb_driver(dev->driver);
86 const struct usb_device_id *id;
89 dev_dbg(dev, "%s\n", __FUNCTION__);
93 /* FIXME we'd much prefer to just resume it ... */
94 if (interface_to_usbdev(intf)->state == USB_STATE_SUSPENDED)
97 id = usb_match_id (intf, driver->id_table);
99 dev_dbg (dev, "%s - got id\n", __FUNCTION__);
100 intf->condition = USB_INTERFACE_BINDING;
101 error = driver->probe (intf, id);
102 intf->condition = error ? USB_INTERFACE_UNBOUND :
109 /* called from driver core with usb_bus_type.subsys writelock */
110 static int usb_unbind_interface(struct device *dev)
112 struct usb_interface *intf = to_usb_interface(dev);
113 struct usb_driver *driver = to_usb_driver(intf->dev.driver);
115 intf->condition = USB_INTERFACE_UNBINDING;
117 /* release all urbs for this interface */
118 usb_disable_interface(interface_to_usbdev(intf), intf);
120 if (driver && driver->disconnect)
121 driver->disconnect(intf);
123 /* reset other interface state */
124 usb_set_interface(interface_to_usbdev(intf),
125 intf->altsetting[0].desc.bInterfaceNumber,
127 usb_set_intfdata(intf, NULL);
128 intf->condition = USB_INTERFACE_UNBOUND;
134 * usb_register - register a USB driver
135 * @new_driver: USB operations for the driver
137 * Registers a USB driver with the USB core. The list of unattached
138 * interfaces will be rescanned whenever a new driver is added, allowing
139 * the new driver to attach to any recognized devices.
140 * Returns a negative error code on failure and 0 on success.
142 * NOTE: if you want your driver to use the USB major number, you must call
143 * usb_register_dev() to enable that functionality. This function no longer
144 * takes care of that.
146 int usb_register(struct usb_driver *new_driver)
153 new_driver->driver.name = (char *)new_driver->name;
154 new_driver->driver.bus = &usb_bus_type;
155 new_driver->driver.probe = usb_probe_interface;
156 new_driver->driver.remove = usb_unbind_interface;
157 new_driver->driver.owner = new_driver->owner;
159 usb_lock_all_devices();
160 retval = driver_register(&new_driver->driver);
161 usb_unlock_all_devices();
164 pr_info("%s: registered new driver %s\n",
165 usbcore_name, new_driver->name);
166 usbfs_update_special();
168 printk(KERN_ERR "%s: error %d registering driver %s\n",
169 usbcore_name, retval, new_driver->name);
176 * usb_deregister - unregister a USB driver
177 * @driver: USB operations of the driver to unregister
178 * Context: must be able to sleep
180 * Unlinks the specified driver from the internal USB driver list.
182 * NOTE: If you called usb_register_dev(), you still need to call
183 * usb_deregister_dev() to clean up your driver's allocated minor numbers,
184 * this * call will no longer do it for you.
186 void usb_deregister(struct usb_driver *driver)
188 pr_info("%s: deregistering driver %s\n", usbcore_name, driver->name);
190 usb_lock_all_devices();
191 driver_unregister (&driver->driver);
192 usb_unlock_all_devices();
194 usbfs_update_special();
198 * usb_ifnum_to_if - get the interface object with a given interface number
199 * @dev: the device whose current configuration is considered
200 * @ifnum: the desired interface
202 * This walks the device descriptor for the currently active configuration
203 * and returns a pointer to the interface with that particular interface
206 * Note that configuration descriptors are not required to assign interface
207 * numbers sequentially, so that it would be incorrect to assume that
208 * the first interface in that descriptor corresponds to interface zero.
209 * This routine helps device drivers avoid such mistakes.
210 * However, you should make sure that you do the right thing with any
211 * alternate settings available for this interfaces.
213 * Don't call this function unless you are bound to one of the interfaces
214 * on this device or you have locked the device!
216 struct usb_interface *usb_ifnum_to_if(struct usb_device *dev, unsigned ifnum)
218 struct usb_host_config *config = dev->actconfig;
223 for (i = 0; i < config->desc.bNumInterfaces; i++)
224 if (config->interface[i]->altsetting[0]
225 .desc.bInterfaceNumber == ifnum)
226 return config->interface[i];
232 * usb_altnum_to_altsetting - get the altsetting structure with a given
233 * alternate setting number.
234 * @intf: the interface containing the altsetting in question
235 * @altnum: the desired alternate setting number
237 * This searches the altsetting array of the specified interface for
238 * an entry with the correct bAlternateSetting value and returns a pointer
239 * to that entry, or null.
241 * Note that altsettings need not be stored sequentially by number, so
242 * it would be incorrect to assume that the first altsetting entry in
243 * the array corresponds to altsetting zero. This routine helps device
244 * drivers avoid such mistakes.
246 * Don't call this function unless you are bound to the intf interface
247 * or you have locked the device!
249 struct usb_host_interface *usb_altnum_to_altsetting(struct usb_interface *intf,
254 for (i = 0; i < intf->num_altsetting; i++) {
255 if (intf->altsetting[i].desc.bAlternateSetting == altnum)
256 return &intf->altsetting[i];
262 * usb_driver_claim_interface - bind a driver to an interface
263 * @driver: the driver to be bound
264 * @iface: the interface to which it will be bound; must be in the
265 * usb device's active configuration
266 * @priv: driver data associated with that interface
268 * This is used by usb device drivers that need to claim more than one
269 * interface on a device when probing (audio and acm are current examples).
270 * No device driver should directly modify internal usb_interface or
271 * usb_device structure members.
273 * Few drivers should need to use this routine, since the most natural
274 * way to bind to an interface is to return the private data from
275 * the driver's probe() method.
277 * Callers must own the device lock and the driver model's usb_bus_type.subsys
278 * writelock. So driver probe() entries don't need extra locking,
279 * but other call contexts may need to explicitly claim those locks.
281 int usb_driver_claim_interface(struct usb_driver *driver,
282 struct usb_interface *iface, void* priv)
284 struct device *dev = &iface->dev;
289 dev->driver = &driver->driver;
290 usb_set_intfdata(iface, priv);
291 iface->condition = USB_INTERFACE_BOUND;
293 /* if interface was already added, bind now; else let
294 * the future device_add() bind it, bypassing probe()
296 if (!list_empty (&dev->bus_list))
297 device_bind_driver(dev);
303 * usb_driver_release_interface - unbind a driver from an interface
304 * @driver: the driver to be unbound
305 * @iface: the interface from which it will be unbound
307 * This can be used by drivers to release an interface without waiting
308 * for their disconnect() methods to be called. In typical cases this
309 * also causes the driver disconnect() method to be called.
311 * This call is synchronous, and may not be used in an interrupt context.
312 * Callers must own the device lock and the driver model's usb_bus_type.subsys
313 * writelock. So driver disconnect() entries don't need extra locking,
314 * but other call contexts may need to explicitly claim those locks.
316 void usb_driver_release_interface(struct usb_driver *driver,
317 struct usb_interface *iface)
319 struct device *dev = &iface->dev;
321 /* this should never happen, don't release something that's not ours */
322 if (!dev->driver || dev->driver != &driver->driver)
325 /* don't disconnect from disconnect(), or before dev_add() */
326 if (!list_empty (&dev->driver_list) && !list_empty (&dev->bus_list))
327 device_release_driver(dev);
330 usb_set_intfdata(iface, NULL);
331 iface->condition = USB_INTERFACE_UNBOUND;
335 * usb_match_id - find first usb_device_id matching device or interface
336 * @interface: the interface of interest
337 * @id: array of usb_device_id structures, terminated by zero entry
339 * usb_match_id searches an array of usb_device_id's and returns
340 * the first one matching the device or interface, or null.
341 * This is used when binding (or rebinding) a driver to an interface.
342 * Most USB device drivers will use this indirectly, through the usb core,
343 * but some layered driver frameworks use it directly.
344 * These device tables are exported with MODULE_DEVICE_TABLE, through
345 * modutils and "modules.usbmap", to support the driver loading
346 * functionality of USB hotplugging.
350 * The "match_flags" element in a usb_device_id controls which
351 * members are used. If the corresponding bit is set, the
352 * value in the device_id must match its corresponding member
353 * in the device or interface descriptor, or else the device_id
356 * "driver_info" is normally used only by device drivers,
357 * but you can create a wildcard "matches anything" usb_device_id
358 * as a driver's "modules.usbmap" entry if you provide an id with
359 * only a nonzero "driver_info" field. If you do this, the USB device
360 * driver's probe() routine should use additional intelligence to
361 * decide whether to bind to the specified interface.
363 * What Makes Good usb_device_id Tables:
365 * The match algorithm is very simple, so that intelligence in
366 * driver selection must come from smart driver id records.
367 * Unless you have good reasons to use another selection policy,
368 * provide match elements only in related groups, and order match
369 * specifiers from specific to general. Use the macros provided
370 * for that purpose if you can.
372 * The most specific match specifiers use device descriptor
373 * data. These are commonly used with product-specific matches;
374 * the USB_DEVICE macro lets you provide vendor and product IDs,
375 * and you can also match against ranges of product revisions.
376 * These are widely used for devices with application or vendor
377 * specific bDeviceClass values.
379 * Matches based on device class/subclass/protocol specifications
380 * are slightly more general; use the USB_DEVICE_INFO macro, or
381 * its siblings. These are used with single-function devices
382 * where bDeviceClass doesn't specify that each interface has
385 * Matches based on interface class/subclass/protocol are the
386 * most general; they let drivers bind to any interface on a
387 * multiple-function device. Use the USB_INTERFACE_INFO
388 * macro, or its siblings, to match class-per-interface style
389 * devices (as recorded in bDeviceClass).
391 * Within those groups, remember that not all combinations are
392 * meaningful. For example, don't give a product version range
393 * without vendor and product IDs; or specify a protocol without
394 * its associated class and subclass.
396 const struct usb_device_id *
397 usb_match_id(struct usb_interface *interface, const struct usb_device_id *id)
399 struct usb_host_interface *intf;
400 struct usb_device *dev;
402 /* proc_connectinfo in devio.c may call us with id == NULL. */
406 intf = interface->cur_altsetting;
407 dev = interface_to_usbdev(interface);
409 /* It is important to check that id->driver_info is nonzero,
410 since an entry that is all zeroes except for a nonzero
411 id->driver_info is the way to create an entry that
412 indicates that the driver want to examine every
413 device and interface. */
414 for (; id->idVendor || id->bDeviceClass || id->bInterfaceClass ||
415 id->driver_info; id++) {
417 if ((id->match_flags & USB_DEVICE_ID_MATCH_VENDOR) &&
418 id->idVendor != le16_to_cpu(dev->descriptor.idVendor))
421 if ((id->match_flags & USB_DEVICE_ID_MATCH_PRODUCT) &&
422 id->idProduct != le16_to_cpu(dev->descriptor.idProduct))
425 /* No need to test id->bcdDevice_lo != 0, since 0 is never
426 greater than any unsigned number. */
427 if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_LO) &&
428 (id->bcdDevice_lo > le16_to_cpu(dev->descriptor.bcdDevice)))
431 if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_HI) &&
432 (id->bcdDevice_hi < le16_to_cpu(dev->descriptor.bcdDevice)))
435 if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_CLASS) &&
436 (id->bDeviceClass != dev->descriptor.bDeviceClass))
439 if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_SUBCLASS) &&
440 (id->bDeviceSubClass!= dev->descriptor.bDeviceSubClass))
443 if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_PROTOCOL) &&
444 (id->bDeviceProtocol != dev->descriptor.bDeviceProtocol))
447 if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_CLASS) &&
448 (id->bInterfaceClass != intf->desc.bInterfaceClass))
451 if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_SUBCLASS) &&
452 (id->bInterfaceSubClass != intf->desc.bInterfaceSubClass))
455 if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_PROTOCOL) &&
456 (id->bInterfaceProtocol != intf->desc.bInterfaceProtocol))
466 * usb_find_interface - find usb_interface pointer for driver and device
467 * @drv: the driver whose current configuration is considered
468 * @minor: the minor number of the desired device
470 * This walks the driver device list and returns a pointer to the interface
471 * with the matching minor. Note, this only works for devices that share the
474 struct usb_interface *usb_find_interface(struct usb_driver *drv, int minor)
476 struct list_head *entry;
478 struct usb_interface *intf;
480 list_for_each(entry, &drv->driver.devices) {
481 dev = container_of(entry, struct device, driver_list);
483 /* can't look at usb devices, only interfaces */
484 if (dev->driver == &usb_generic_driver)
487 intf = to_usb_interface(dev);
488 if (intf->minor == -1)
490 if (intf->minor == minor)
494 /* no device found that matches */
498 static int usb_device_match (struct device *dev, struct device_driver *drv)
500 struct usb_interface *intf;
501 struct usb_driver *usb_drv;
502 const struct usb_device_id *id;
504 /* check for generic driver, which we don't match any device with */
505 if (drv == &usb_generic_driver)
508 intf = to_usb_interface(dev);
509 usb_drv = to_usb_driver(drv);
511 id = usb_match_id (intf, usb_drv->id_table);
519 #ifdef CONFIG_HOTPLUG
522 * USB hotplugging invokes what /proc/sys/kernel/hotplug says
523 * (normally /sbin/hotplug) when USB devices get added or removed.
525 * This invokes a user mode policy agent, typically helping to load driver
526 * or other modules, configure the device, and more. Drivers can provide
527 * a MODULE_DEVICE_TABLE to help with module loading subtasks.
529 * We're called either from khubd (the typical case) or from root hub
530 * (init, kapmd, modprobe, rmmod, etc), but the agents need to handle
531 * delays in event delivery. Use sysfs (and DEVPATH) to make sure the
532 * device (and this configuration!) are still present.
534 static int usb_hotplug (struct device *dev, char **envp, int num_envp,
535 char *buffer, int buffer_size)
537 struct usb_interface *intf;
538 struct usb_device *usb_dev;
545 /* driver is often null here; dev_dbg() would oops */
546 pr_debug ("usb %s: hotplug\n", dev->bus_id);
548 /* Must check driver_data here, as on remove driver is always NULL */
549 if ((dev->driver == &usb_generic_driver) ||
550 (dev->driver_data == &usb_generic_driver_data))
553 intf = to_usb_interface(dev);
554 usb_dev = interface_to_usbdev (intf);
556 if (usb_dev->devnum < 0) {
557 pr_debug ("usb %s: already deleted?\n", dev->bus_id);
561 pr_debug ("usb %s: bus removed?\n", dev->bus_id);
565 #ifdef CONFIG_USB_DEVICEFS
566 /* If this is available, userspace programs can directly read
567 * all the device descriptors we don't tell them about. Or
568 * even act as usermode drivers.
570 * FIXME reduce hardwired intelligence here
572 if (add_hotplug_env_var(envp, num_envp, &i,
573 buffer, buffer_size, &length,
574 "DEVICE=/proc/bus/usb/%03d/%03d",
575 usb_dev->bus->busnum, usb_dev->devnum))
579 /* per-device configurations are common */
580 if (add_hotplug_env_var(envp, num_envp, &i,
581 buffer, buffer_size, &length,
583 le16_to_cpu(usb_dev->descriptor.idVendor),
584 le16_to_cpu(usb_dev->descriptor.idProduct),
585 le16_to_cpu(usb_dev->descriptor.bcdDevice)))
588 /* class-based driver binding models */
589 if (add_hotplug_env_var(envp, num_envp, &i,
590 buffer, buffer_size, &length,
592 usb_dev->descriptor.bDeviceClass,
593 usb_dev->descriptor.bDeviceSubClass,
594 usb_dev->descriptor.bDeviceProtocol))
597 if (usb_dev->descriptor.bDeviceClass == 0) {
598 struct usb_host_interface *alt = intf->cur_altsetting;
600 /* 2.4 only exposed interface zero. in 2.5, hotplug
601 * agents are called for all interfaces, and can use
602 * $DEVPATH/bInterfaceNumber if necessary.
604 if (add_hotplug_env_var(envp, num_envp, &i,
605 buffer, buffer_size, &length,
606 "INTERFACE=%d/%d/%d",
607 alt->desc.bInterfaceClass,
608 alt->desc.bInterfaceSubClass,
609 alt->desc.bInterfaceProtocol))
612 if (add_hotplug_env_var(envp, num_envp, &i,
613 buffer, buffer_size, &length,
614 "MODALIAS=usb:v%04Xp%04Xd%04Xdc%02Xdsc%02Xdp%02Xic%02Xisc%02Xip%02X",
615 le16_to_cpu(usb_dev->descriptor.idVendor),
616 le16_to_cpu(usb_dev->descriptor.idProduct),
617 le16_to_cpu(usb_dev->descriptor.bcdDevice),
618 usb_dev->descriptor.bDeviceClass,
619 usb_dev->descriptor.bDeviceSubClass,
620 usb_dev->descriptor.bDeviceProtocol,
621 alt->desc.bInterfaceClass,
622 alt->desc.bInterfaceSubClass,
623 alt->desc.bInterfaceProtocol))
626 if (add_hotplug_env_var(envp, num_envp, &i,
627 buffer, buffer_size, &length,
628 "MODALIAS=usb:v%04Xp%04Xd%04Xdc%02Xdsc%02Xdp%02Xic*isc*ip*",
629 le16_to_cpu(usb_dev->descriptor.idVendor),
630 le16_to_cpu(usb_dev->descriptor.idProduct),
631 le16_to_cpu(usb_dev->descriptor.bcdDevice),
632 usb_dev->descriptor.bDeviceClass,
633 usb_dev->descriptor.bDeviceSubClass,
634 usb_dev->descriptor.bDeviceProtocol))
645 static int usb_hotplug (struct device *dev, char **envp,
646 int num_envp, char *buffer, int buffer_size)
651 #endif /* CONFIG_HOTPLUG */
654 * usb_release_dev - free a usb device structure when all users of it are finished.
655 * @dev: device that's been disconnected
657 * Will be called only by the device core when all users of this usb device are
660 static void usb_release_dev(struct device *dev)
662 struct usb_device *udev;
664 udev = to_usb_device(dev);
666 usb_destroy_configuration(udev);
667 usb_bus_put(udev->bus);
668 kfree(udev->product);
669 kfree(udev->manufacturer);
675 * usb_alloc_dev - usb device constructor (usbcore-internal)
676 * @parent: hub to which device is connected; null to allocate a root hub
677 * @bus: bus used to access the device
678 * @port1: one-based index of port; ignored for root hubs
679 * Context: !in_interrupt ()
681 * Only hub drivers (including virtual root hub drivers for host
682 * controllers) should ever call this.
684 * This call may not be used in a non-sleeping context.
687 usb_alloc_dev(struct usb_device *parent, struct usb_bus *bus, unsigned port1)
689 struct usb_device *dev;
691 dev = kmalloc(sizeof(*dev), GFP_KERNEL);
695 memset(dev, 0, sizeof(*dev));
697 bus = usb_bus_get(bus);
703 device_initialize(&dev->dev);
704 dev->dev.bus = &usb_bus_type;
705 dev->dev.dma_mask = bus->controller->dma_mask;
706 dev->dev.driver_data = &usb_generic_driver_data;
707 dev->dev.driver = &usb_generic_driver;
708 dev->dev.release = usb_release_dev;
709 dev->state = USB_STATE_ATTACHED;
711 INIT_LIST_HEAD(&dev->ep0.urb_list);
712 dev->ep0.desc.bLength = USB_DT_ENDPOINT_SIZE;
713 dev->ep0.desc.bDescriptorType = USB_DT_ENDPOINT;
714 /* ep0 maxpacket comes later, from device descriptor */
715 dev->ep_in[0] = dev->ep_out[0] = &dev->ep0;
717 /* Save readable and stable topology id, distinguishing devices
718 * by location for diagnostics, tools, driver model, etc. The
719 * string is a path along hub ports, from the root. Each device's
720 * dev->devpath will be stable until USB is re-cabled, and hubs
721 * are often labeled with these port numbers. The bus_id isn't
722 * as stable: bus->busnum changes easily from modprobe order,
723 * cardbus or pci hotplugging, and so on.
725 if (unlikely (!parent)) {
726 dev->devpath [0] = '0';
728 dev->dev.parent = bus->controller;
729 sprintf (&dev->dev.bus_id[0], "usb%d", bus->busnum);
731 /* match any labeling on the hubs; it's one-based */
732 if (parent->devpath [0] == '0')
733 snprintf (dev->devpath, sizeof dev->devpath,
736 snprintf (dev->devpath, sizeof dev->devpath,
737 "%s.%d", parent->devpath, port1);
739 dev->dev.parent = &parent->dev;
740 sprintf (&dev->dev.bus_id[0], "%d-%s",
741 bus->busnum, dev->devpath);
743 /* hub driver sets up TT records */
747 dev->parent = parent;
748 INIT_LIST_HEAD(&dev->filelist);
750 init_MUTEX(&dev->serialize);
756 * usb_get_dev - increments the reference count of the usb device structure
757 * @dev: the device being referenced
759 * Each live reference to a device should be refcounted.
761 * Drivers for USB interfaces should normally record such references in
762 * their probe() methods, when they bind to an interface, and release
763 * them by calling usb_put_dev(), in their disconnect() methods.
765 * A pointer to the device with the incremented reference counter is returned.
767 struct usb_device *usb_get_dev(struct usb_device *dev)
770 get_device(&dev->dev);
775 * usb_put_dev - release a use of the usb device structure
776 * @dev: device that's been disconnected
778 * Must be called when a user of a device is finished with it. When the last
779 * user of the device calls this function, the memory of the device is freed.
781 void usb_put_dev(struct usb_device *dev)
784 put_device(&dev->dev);
788 * usb_get_intf - increments the reference count of the usb interface structure
789 * @intf: the interface being referenced
791 * Each live reference to a interface must be refcounted.
793 * Drivers for USB interfaces should normally record such references in
794 * their probe() methods, when they bind to an interface, and release
795 * them by calling usb_put_intf(), in their disconnect() methods.
797 * A pointer to the interface with the incremented reference counter is
800 struct usb_interface *usb_get_intf(struct usb_interface *intf)
803 get_device(&intf->dev);
808 * usb_put_intf - release a use of the usb interface structure
809 * @intf: interface that's been decremented
811 * Must be called when a user of an interface is finished with it. When the
812 * last user of the interface calls this function, the memory of the interface
815 void usb_put_intf(struct usb_interface *intf)
818 put_device(&intf->dev);
822 /* USB device locking
824 * Although locking USB devices should be straightforward, it is
825 * complicated by the way the driver-model core works. When a new USB
826 * driver is registered or unregistered, the core will automatically
827 * probe or disconnect all matching interfaces on all USB devices while
828 * holding the USB subsystem writelock. There's no good way for us to
829 * tell which devices will be used or to lock them beforehand; our only
830 * option is to effectively lock all the USB devices.
832 * We do that by using a private rw-semaphore, usb_all_devices_rwsem.
833 * When locking an individual device you must first acquire the rwsem's
834 * readlock. When a driver is registered or unregistered the writelock
835 * must be held. These actions are encapsulated in the subroutines
836 * below, so all a driver needs to do is call usb_lock_device() and
837 * usb_unlock_device().
839 * Complications arise when several devices are to be locked at the same
840 * time. Only hub-aware drivers that are part of usbcore ever have to
841 * do this; nobody else needs to worry about it. The problem is that
842 * usb_lock_device() must not be called to lock a second device since it
843 * would acquire the rwsem's readlock reentrantly, leading to deadlock if
844 * another thread was waiting for the writelock. The solution is simple:
846 * When locking more than one device, call usb_lock_device()
847 * to lock the first one. Lock the others by calling
848 * down(&udev->serialize) directly.
850 * When unlocking multiple devices, use up(&udev->serialize)
851 * to unlock all but the last one. Unlock the last one by
852 * calling usb_unlock_device().
854 * When locking both a device and its parent, always lock the
859 * usb_lock_device - acquire the lock for a usb device structure
860 * @udev: device that's being locked
862 * Use this routine when you don't hold any other device locks;
863 * to acquire nested inner locks call down(&udev->serialize) directly.
864 * This is necessary for proper interaction with usb_lock_all_devices().
866 void usb_lock_device(struct usb_device *udev)
868 down_read(&usb_all_devices_rwsem);
869 down(&udev->serialize);
873 * usb_trylock_device - attempt to acquire the lock for a usb device structure
874 * @udev: device that's being locked
876 * Don't use this routine if you already hold a device lock;
877 * use down_trylock(&udev->serialize) instead.
878 * This is necessary for proper interaction with usb_lock_all_devices().
880 * Returns 1 if successful, 0 if contention.
882 int usb_trylock_device(struct usb_device *udev)
884 if (!down_read_trylock(&usb_all_devices_rwsem))
886 if (down_trylock(&udev->serialize)) {
887 up_read(&usb_all_devices_rwsem);
894 * usb_lock_device_for_reset - cautiously acquire the lock for a
895 * usb device structure
896 * @udev: device that's being locked
897 * @iface: interface bound to the driver making the request (optional)
899 * Attempts to acquire the device lock, but fails if the device is
900 * NOTATTACHED or SUSPENDED, or if iface is specified and the interface
901 * is neither BINDING nor BOUND. Rather than sleeping to wait for the
902 * lock, the routine polls repeatedly. This is to prevent deadlock with
903 * disconnect; in some drivers (such as usb-storage) the disconnect()
904 * callback will block waiting for a device reset to complete.
906 * Returns a negative error code for failure, otherwise 1 or 0 to indicate
907 * that the device will or will not have to be unlocked. (0 can be
908 * returned when an interface is given and is BINDING, because in that
909 * case the driver already owns the device lock.)
911 int usb_lock_device_for_reset(struct usb_device *udev,
912 struct usb_interface *iface)
914 if (udev->state == USB_STATE_NOTATTACHED)
916 if (udev->state == USB_STATE_SUSPENDED)
917 return -EHOSTUNREACH;
919 switch (iface->condition) {
920 case USB_INTERFACE_BINDING:
922 case USB_INTERFACE_BOUND:
929 while (!usb_trylock_device(udev)) {
931 if (udev->state == USB_STATE_NOTATTACHED)
933 if (udev->state == USB_STATE_SUSPENDED)
934 return -EHOSTUNREACH;
935 if (iface && iface->condition != USB_INTERFACE_BOUND)
942 * usb_unlock_device - release the lock for a usb device structure
943 * @udev: device that's being unlocked
945 * Use this routine when releasing the only device lock you hold;
946 * to release inner nested locks call up(&udev->serialize) directly.
947 * This is necessary for proper interaction with usb_lock_all_devices().
949 void usb_unlock_device(struct usb_device *udev)
951 up(&udev->serialize);
952 up_read(&usb_all_devices_rwsem);
956 * usb_lock_all_devices - acquire the lock for all usb device structures
958 * This is necessary when registering a new driver or probing a bus,
959 * since the driver-model core may try to use any usb_device.
961 void usb_lock_all_devices(void)
963 down_write(&usb_all_devices_rwsem);
967 * usb_unlock_all_devices - release the lock for all usb device structures
969 void usb_unlock_all_devices(void)
971 up_write(&usb_all_devices_rwsem);
975 static struct usb_device *match_device(struct usb_device *dev,
976 u16 vendor_id, u16 product_id)
978 struct usb_device *ret_dev = NULL;
981 dev_dbg(&dev->dev, "check for vendor %04x, product %04x ...\n",
982 le16_to_cpu(dev->descriptor.idVendor),
983 le16_to_cpu(dev->descriptor.idProduct));
985 /* see if this device matches */
986 if ((vendor_id == le16_to_cpu(dev->descriptor.idVendor)) &&
987 (product_id == le16_to_cpu(dev->descriptor.idProduct))) {
988 dev_dbg (&dev->dev, "matched this device!\n");
989 ret_dev = usb_get_dev(dev);
993 /* look through all of the children of this device */
994 for (child = 0; child < dev->maxchild; ++child) {
995 if (dev->children[child]) {
996 down(&dev->children[child]->serialize);
997 ret_dev = match_device(dev->children[child],
998 vendor_id, product_id);
999 up(&dev->children[child]->serialize);
1009 * usb_find_device - find a specific usb device in the system
1010 * @vendor_id: the vendor id of the device to find
1011 * @product_id: the product id of the device to find
1013 * Returns a pointer to a struct usb_device if such a specified usb
1014 * device is present in the system currently. The usage count of the
1015 * device will be incremented if a device is found. Make sure to call
1016 * usb_put_dev() when the caller is finished with the device.
1018 * If a device with the specified vendor and product id is not found,
1021 struct usb_device *usb_find_device(u16 vendor_id, u16 product_id)
1023 struct list_head *buslist;
1024 struct usb_bus *bus;
1025 struct usb_device *dev = NULL;
1027 down(&usb_bus_list_lock);
1028 for (buslist = usb_bus_list.next;
1029 buslist != &usb_bus_list;
1030 buslist = buslist->next) {
1031 bus = container_of(buslist, struct usb_bus, bus_list);
1034 usb_lock_device(bus->root_hub);
1035 dev = match_device(bus->root_hub, vendor_id, product_id);
1036 usb_unlock_device(bus->root_hub);
1041 up(&usb_bus_list_lock);
1046 * usb_get_current_frame_number - return current bus frame number
1047 * @dev: the device whose bus is being queried
1049 * Returns the current frame number for the USB host controller
1050 * used with the given USB device. This can be used when scheduling
1051 * isochronous requests.
1053 * Note that different kinds of host controller have different
1054 * "scheduling horizons". While one type might support scheduling only
1055 * 32 frames into the future, others could support scheduling up to
1056 * 1024 frames into the future.
1058 int usb_get_current_frame_number(struct usb_device *dev)
1060 return dev->bus->op->get_frame_number (dev);
1063 /*-------------------------------------------------------------------*/
1065 * __usb_get_extra_descriptor() finds a descriptor of specific type in the
1066 * extra field of the interface and endpoint descriptor structs.
1069 int __usb_get_extra_descriptor(char *buffer, unsigned size,
1070 unsigned char type, void **ptr)
1072 struct usb_descriptor_header *header;
1074 while (size >= sizeof(struct usb_descriptor_header)) {
1075 header = (struct usb_descriptor_header *)buffer;
1077 if (header->bLength < 2) {
1079 "%s: bogus descriptor, type %d length %d\n",
1081 header->bDescriptorType,
1086 if (header->bDescriptorType == type) {
1091 buffer += header->bLength;
1092 size -= header->bLength;
1098 * usb_buffer_alloc - allocate dma-consistent buffer for URB_NO_xxx_DMA_MAP
1099 * @dev: device the buffer will be used with
1100 * @size: requested buffer size
1101 * @mem_flags: affect whether allocation may block
1102 * @dma: used to return DMA address of buffer
1104 * Return value is either null (indicating no buffer could be allocated), or
1105 * the cpu-space pointer to a buffer that may be used to perform DMA to the
1106 * specified device. Such cpu-space buffers are returned along with the DMA
1107 * address (through the pointer provided).
1109 * These buffers are used with URB_NO_xxx_DMA_MAP set in urb->transfer_flags
1110 * to avoid behaviors like using "DMA bounce buffers", or tying down I/O
1111 * mapping hardware for long idle periods. The implementation varies between
1112 * platforms, depending on details of how DMA will work to this device.
1113 * Using these buffers also helps prevent cacheline sharing problems on
1114 * architectures where CPU caches are not DMA-coherent.
1116 * When the buffer is no longer used, free it with usb_buffer_free().
1118 void *usb_buffer_alloc (
1119 struct usb_device *dev,
1125 if (!dev || !dev->bus || !dev->bus->op || !dev->bus->op->buffer_alloc)
1127 return dev->bus->op->buffer_alloc (dev->bus, size, mem_flags, dma);
1131 * usb_buffer_free - free memory allocated with usb_buffer_alloc()
1132 * @dev: device the buffer was used with
1133 * @size: requested buffer size
1134 * @addr: CPU address of buffer
1135 * @dma: DMA address of buffer
1137 * This reclaims an I/O buffer, letting it be reused. The memory must have
1138 * been allocated using usb_buffer_alloc(), and the parameters must match
1139 * those provided in that allocation request.
1141 void usb_buffer_free (
1142 struct usb_device *dev,
1148 if (!dev || !dev->bus || !dev->bus->op || !dev->bus->op->buffer_free)
1150 dev->bus->op->buffer_free (dev->bus, size, addr, dma);
1154 * usb_buffer_map - create DMA mapping(s) for an urb
1155 * @urb: urb whose transfer_buffer/setup_packet will be mapped
1157 * Return value is either null (indicating no buffer could be mapped), or
1158 * the parameter. URB_NO_TRANSFER_DMA_MAP and URB_NO_SETUP_DMA_MAP are
1159 * added to urb->transfer_flags if the operation succeeds. If the device
1160 * is connected to this system through a non-DMA controller, this operation
1163 * This call would normally be used for an urb which is reused, perhaps
1164 * as the target of a large periodic transfer, with usb_buffer_dmasync()
1165 * calls to synchronize memory and dma state.
1167 * Reverse the effect of this call with usb_buffer_unmap().
1170 struct urb *usb_buffer_map (struct urb *urb)
1172 struct usb_bus *bus;
1173 struct device *controller;
1177 || !(bus = urb->dev->bus)
1178 || !(controller = bus->controller))
1181 if (controller->dma_mask) {
1182 urb->transfer_dma = dma_map_single (controller,
1183 urb->transfer_buffer, urb->transfer_buffer_length,
1184 usb_pipein (urb->pipe)
1185 ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
1186 if (usb_pipecontrol (urb->pipe))
1187 urb->setup_dma = dma_map_single (controller,
1189 sizeof (struct usb_ctrlrequest),
1191 // FIXME generic api broken like pci, can't report errors
1192 // if (urb->transfer_dma == DMA_ADDR_INVALID) return 0;
1194 urb->transfer_dma = ~0;
1195 urb->transfer_flags |= (URB_NO_TRANSFER_DMA_MAP
1196 | URB_NO_SETUP_DMA_MAP);
1201 /* XXX DISABLED, no users currently. If you wish to re-enable this
1202 * XXX please determine whether the sync is to transfer ownership of
1203 * XXX the buffer from device to cpu or vice verse, and thusly use the
1204 * XXX appropriate _for_{cpu,device}() method. -DaveM
1209 * usb_buffer_dmasync - synchronize DMA and CPU view of buffer(s)
1210 * @urb: urb whose transfer_buffer/setup_packet will be synchronized
1212 void usb_buffer_dmasync (struct urb *urb)
1214 struct usb_bus *bus;
1215 struct device *controller;
1218 || !(urb->transfer_flags & URB_NO_TRANSFER_DMA_MAP)
1220 || !(bus = urb->dev->bus)
1221 || !(controller = bus->controller))
1224 if (controller->dma_mask) {
1225 dma_sync_single (controller,
1226 urb->transfer_dma, urb->transfer_buffer_length,
1227 usb_pipein (urb->pipe)
1228 ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
1229 if (usb_pipecontrol (urb->pipe))
1230 dma_sync_single (controller,
1232 sizeof (struct usb_ctrlrequest),
1239 * usb_buffer_unmap - free DMA mapping(s) for an urb
1240 * @urb: urb whose transfer_buffer will be unmapped
1242 * Reverses the effect of usb_buffer_map().
1245 void usb_buffer_unmap (struct urb *urb)
1247 struct usb_bus *bus;
1248 struct device *controller;
1251 || !(urb->transfer_flags & URB_NO_TRANSFER_DMA_MAP)
1253 || !(bus = urb->dev->bus)
1254 || !(controller = bus->controller))
1257 if (controller->dma_mask) {
1258 dma_unmap_single (controller,
1259 urb->transfer_dma, urb->transfer_buffer_length,
1260 usb_pipein (urb->pipe)
1261 ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
1262 if (usb_pipecontrol (urb->pipe))
1263 dma_unmap_single (controller,
1265 sizeof (struct usb_ctrlrequest),
1268 urb->transfer_flags &= ~(URB_NO_TRANSFER_DMA_MAP
1269 | URB_NO_SETUP_DMA_MAP);
1274 * usb_buffer_map_sg - create scatterlist DMA mapping(s) for an endpoint
1275 * @dev: device to which the scatterlist will be mapped
1276 * @pipe: endpoint defining the mapping direction
1277 * @sg: the scatterlist to map
1278 * @nents: the number of entries in the scatterlist
1280 * Return value is either < 0 (indicating no buffers could be mapped), or
1281 * the number of DMA mapping array entries in the scatterlist.
1283 * The caller is responsible for placing the resulting DMA addresses from
1284 * the scatterlist into URB transfer buffer pointers, and for setting the
1285 * URB_NO_TRANSFER_DMA_MAP transfer flag in each of those URBs.
1287 * Top I/O rates come from queuing URBs, instead of waiting for each one
1288 * to complete before starting the next I/O. This is particularly easy
1289 * to do with scatterlists. Just allocate and submit one URB for each DMA
1290 * mapping entry returned, stopping on the first error or when all succeed.
1291 * Better yet, use the usb_sg_*() calls, which do that (and more) for you.
1293 * This call would normally be used when translating scatterlist requests,
1294 * rather than usb_buffer_map(), since on some hardware (with IOMMUs) it
1295 * may be able to coalesce mappings for improved I/O efficiency.
1297 * Reverse the effect of this call with usb_buffer_unmap_sg().
1299 int usb_buffer_map_sg (struct usb_device *dev, unsigned pipe,
1300 struct scatterlist *sg, int nents)
1302 struct usb_bus *bus;
1303 struct device *controller;
1306 || usb_pipecontrol (pipe)
1307 || !(bus = dev->bus)
1308 || !(controller = bus->controller)
1309 || !controller->dma_mask)
1312 // FIXME generic api broken like pci, can't report errors
1313 return dma_map_sg (controller, sg, nents,
1314 usb_pipein (pipe) ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
1317 /* XXX DISABLED, no users currently. If you wish to re-enable this
1318 * XXX please determine whether the sync is to transfer ownership of
1319 * XXX the buffer from device to cpu or vice verse, and thusly use the
1320 * XXX appropriate _for_{cpu,device}() method. -DaveM
1325 * usb_buffer_dmasync_sg - synchronize DMA and CPU view of scatterlist buffer(s)
1326 * @dev: device to which the scatterlist will be mapped
1327 * @pipe: endpoint defining the mapping direction
1328 * @sg: the scatterlist to synchronize
1329 * @n_hw_ents: the positive return value from usb_buffer_map_sg
1331 * Use this when you are re-using a scatterlist's data buffers for
1332 * another USB request.
1334 void usb_buffer_dmasync_sg (struct usb_device *dev, unsigned pipe,
1335 struct scatterlist *sg, int n_hw_ents)
1337 struct usb_bus *bus;
1338 struct device *controller;
1341 || !(bus = dev->bus)
1342 || !(controller = bus->controller)
1343 || !controller->dma_mask)
1346 dma_sync_sg (controller, sg, n_hw_ents,
1347 usb_pipein (pipe) ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
1352 * usb_buffer_unmap_sg - free DMA mapping(s) for a scatterlist
1353 * @dev: device to which the scatterlist will be mapped
1354 * @pipe: endpoint defining the mapping direction
1355 * @sg: the scatterlist to unmap
1356 * @n_hw_ents: the positive return value from usb_buffer_map_sg
1358 * Reverses the effect of usb_buffer_map_sg().
1360 void usb_buffer_unmap_sg (struct usb_device *dev, unsigned pipe,
1361 struct scatterlist *sg, int n_hw_ents)
1363 struct usb_bus *bus;
1364 struct device *controller;
1367 || !(bus = dev->bus)
1368 || !(controller = bus->controller)
1369 || !controller->dma_mask)
1372 dma_unmap_sg (controller, sg, n_hw_ents,
1373 usb_pipein (pipe) ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
1376 static int usb_generic_suspend(struct device *dev, pm_message_t message)
1378 struct usb_interface *intf;
1379 struct usb_driver *driver;
1381 if (dev->driver == &usb_generic_driver)
1382 return usb_suspend_device (to_usb_device(dev), message);
1384 if ((dev->driver == NULL) ||
1385 (dev->driver_data == &usb_generic_driver_data))
1388 intf = to_usb_interface(dev);
1389 driver = to_usb_driver(dev->driver);
1391 /* there's only one USB suspend state */
1392 if (intf->dev.power.power_state)
1395 if (driver->suspend)
1396 return driver->suspend(intf, message);
1400 static int usb_generic_resume(struct device *dev)
1402 struct usb_interface *intf;
1403 struct usb_driver *driver;
1405 /* devices resume through their hub */
1406 if (dev->driver == &usb_generic_driver)
1407 return usb_resume_device (to_usb_device(dev));
1409 if ((dev->driver == NULL) ||
1410 (dev->driver_data == &usb_generic_driver_data))
1413 intf = to_usb_interface(dev);
1414 driver = to_usb_driver(dev->driver);
1417 return driver->resume(intf);
1421 struct bus_type usb_bus_type = {
1423 .match = usb_device_match,
1424 .hotplug = usb_hotplug,
1425 .suspend = usb_generic_suspend,
1426 .resume = usb_generic_resume,
1431 static int __init usb_setup_disable(char *str)
1437 /* format to disable USB on kernel command line is: nousb */
1438 __setup("nousb", usb_setup_disable);
1443 * for external read access to <nousb>
1445 int usb_disabled(void)
1453 static int __init usb_init(void)
1457 pr_info ("%s: USB support disabled\n", usbcore_name);
1461 retval = bus_register(&usb_bus_type);
1464 retval = usb_host_init();
1466 goto host_init_failed;
1467 retval = usb_major_init();
1469 goto major_init_failed;
1470 retval = usbfs_init();
1472 goto fs_init_failed;
1473 retval = usb_hub_init();
1475 goto hub_init_failed;
1477 retval = driver_register(&usb_generic_driver);
1485 usb_major_cleanup();
1489 bus_unregister(&usb_bus_type);
1497 static void __exit usb_exit(void)
1499 /* This will matter if shutdown/reboot does exitcalls. */
1503 driver_unregister(&usb_generic_driver);
1504 usb_major_cleanup();
1508 bus_unregister(&usb_bus_type);
1511 subsys_initcall(usb_init);
1512 module_exit(usb_exit);
1515 * USB may be built into the kernel or be built as modules.
1516 * These symbols are exported for device (or host controller)
1517 * driver modules to use.
1520 EXPORT_SYMBOL(usb_register);
1521 EXPORT_SYMBOL(usb_deregister);
1522 EXPORT_SYMBOL(usb_disabled);
1524 EXPORT_SYMBOL(usb_alloc_dev);
1525 EXPORT_SYMBOL(usb_put_dev);
1526 EXPORT_SYMBOL(usb_get_dev);
1527 EXPORT_SYMBOL(usb_hub_tt_clear_buffer);
1529 EXPORT_SYMBOL(usb_lock_device);
1530 EXPORT_SYMBOL(usb_trylock_device);
1531 EXPORT_SYMBOL(usb_lock_device_for_reset);
1532 EXPORT_SYMBOL(usb_unlock_device);
1534 EXPORT_SYMBOL(usb_driver_claim_interface);
1535 EXPORT_SYMBOL(usb_driver_release_interface);
1536 EXPORT_SYMBOL(usb_match_id);
1537 EXPORT_SYMBOL(usb_find_interface);
1538 EXPORT_SYMBOL(usb_ifnum_to_if);
1539 EXPORT_SYMBOL(usb_altnum_to_altsetting);
1541 EXPORT_SYMBOL(usb_reset_device);
1542 EXPORT_SYMBOL(usb_disconnect);
1544 EXPORT_SYMBOL(__usb_get_extra_descriptor);
1546 EXPORT_SYMBOL(usb_find_device);
1547 EXPORT_SYMBOL(usb_get_current_frame_number);
1549 EXPORT_SYMBOL (usb_buffer_alloc);
1550 EXPORT_SYMBOL (usb_buffer_free);
1553 EXPORT_SYMBOL (usb_buffer_map);
1554 EXPORT_SYMBOL (usb_buffer_dmasync);
1555 EXPORT_SYMBOL (usb_buffer_unmap);
1558 EXPORT_SYMBOL (usb_buffer_map_sg);
1560 EXPORT_SYMBOL (usb_buffer_dmasync_sg);
1562 EXPORT_SYMBOL (usb_buffer_unmap_sg);
1564 MODULE_LICENSE("GPL");