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 module_param(nousb
, bool, 0444);
55 * for external read access to <nousb>
57 int usb_disabled(void)
61 EXPORT_SYMBOL_GPL(usb_disabled
);
64 static int usb_autosuspend_delay
= 2; /* Default delay value,
66 module_param_named(autosuspend
, usb_autosuspend_delay
, int, 0644);
67 MODULE_PARM_DESC(autosuspend
, "default autosuspend delay");
70 #define usb_autosuspend_delay 0
75 * usb_find_alt_setting() - Given a configuration, find the alternate setting
76 * for the given interface.
77 * @config: the configuration to search (not necessarily the current config).
78 * @iface_num: interface number to search in
79 * @alt_num: alternate interface setting number to search for.
81 * Search the configuration's interface cache for the given alt setting.
83 * Return: The alternate setting, if found. %NULL otherwise.
85 struct usb_host_interface
*usb_find_alt_setting(
86 struct usb_host_config
*config
,
87 unsigned int iface_num
,
90 struct usb_interface_cache
*intf_cache
= NULL
;
93 for (i
= 0; i
< config
->desc
.bNumInterfaces
; i
++) {
94 if (config
->intf_cache
[i
]->altsetting
[0].desc
.bInterfaceNumber
96 intf_cache
= config
->intf_cache
[i
];
102 for (i
= 0; i
< intf_cache
->num_altsetting
; i
++)
103 if (intf_cache
->altsetting
[i
].desc
.bAlternateSetting
== alt_num
)
104 return &intf_cache
->altsetting
[i
];
106 printk(KERN_DEBUG
"Did not find alt setting %u for intf %u, "
107 "config %u\n", alt_num
, iface_num
,
108 config
->desc
.bConfigurationValue
);
111 EXPORT_SYMBOL_GPL(usb_find_alt_setting
);
114 * usb_ifnum_to_if - get the interface object with a given interface number
115 * @dev: the device whose current configuration is considered
116 * @ifnum: the desired interface
118 * This walks the device descriptor for the currently active configuration
119 * to find the interface object with the particular interface number.
121 * Note that configuration descriptors are not required to assign interface
122 * numbers sequentially, so that it would be incorrect to assume that
123 * the first interface in that descriptor corresponds to interface zero.
124 * This routine helps device drivers avoid such mistakes.
125 * However, you should make sure that you do the right thing with any
126 * alternate settings available for this interfaces.
128 * Don't call this function unless you are bound to one of the interfaces
129 * on this device or you have locked the device!
131 * Return: A pointer to the interface that has @ifnum as interface number,
132 * if found. %NULL otherwise.
134 struct usb_interface
*usb_ifnum_to_if(const struct usb_device
*dev
,
137 struct usb_host_config
*config
= dev
->actconfig
;
142 for (i
= 0; i
< config
->desc
.bNumInterfaces
; i
++)
143 if (config
->interface
[i
]->altsetting
[0]
144 .desc
.bInterfaceNumber
== ifnum
)
145 return config
->interface
[i
];
149 EXPORT_SYMBOL_GPL(usb_ifnum_to_if
);
152 * usb_altnum_to_altsetting - get the altsetting structure with a given alternate setting number.
153 * @intf: the interface containing the altsetting in question
154 * @altnum: the desired alternate setting number
156 * This searches the altsetting array of the specified interface for
157 * an entry with the correct bAlternateSetting value.
159 * Note that altsettings need not be stored sequentially by number, so
160 * it would be incorrect to assume that the first altsetting entry in
161 * the array corresponds to altsetting zero. This routine helps device
162 * drivers avoid such mistakes.
164 * Don't call this function unless you are bound to the intf interface
165 * or you have locked the device!
167 * Return: A pointer to the entry of the altsetting array of @intf that
168 * has @altnum as the alternate setting number. %NULL if not found.
170 struct usb_host_interface
*usb_altnum_to_altsetting(
171 const struct usb_interface
*intf
,
176 for (i
= 0; i
< intf
->num_altsetting
; i
++) {
177 if (intf
->altsetting
[i
].desc
.bAlternateSetting
== altnum
)
178 return &intf
->altsetting
[i
];
182 EXPORT_SYMBOL_GPL(usb_altnum_to_altsetting
);
184 struct find_interface_arg
{
186 struct device_driver
*drv
;
189 static int __find_interface(struct device
*dev
, void *data
)
191 struct find_interface_arg
*arg
= data
;
192 struct usb_interface
*intf
;
194 if (!is_usb_interface(dev
))
197 if (dev
->driver
!= arg
->drv
)
199 intf
= to_usb_interface(dev
);
200 return intf
->minor
== arg
->minor
;
204 * usb_find_interface - find usb_interface pointer for driver and device
205 * @drv: the driver whose current configuration is considered
206 * @minor: the minor number of the desired device
208 * This walks the bus device list and returns a pointer to the interface
209 * with the matching minor and driver. Note, this only works for devices
210 * that share the USB major number.
212 * Return: A pointer to the interface with the matching major and @minor.
214 struct usb_interface
*usb_find_interface(struct usb_driver
*drv
, int minor
)
216 struct find_interface_arg argb
;
220 argb
.drv
= &drv
->drvwrap
.driver
;
222 dev
= bus_find_device(&usb_bus_type
, NULL
, &argb
, __find_interface
);
224 /* Drop reference count from bus_find_device */
227 return dev
? to_usb_interface(dev
) : NULL
;
229 EXPORT_SYMBOL_GPL(usb_find_interface
);
231 struct each_dev_arg
{
233 int (*fn
)(struct usb_device
*, void *);
236 static int __each_dev(struct device
*dev
, void *data
)
238 struct each_dev_arg
*arg
= (struct each_dev_arg
*)data
;
240 /* There are struct usb_interface on the same bus, filter them out */
241 if (!is_usb_device(dev
))
244 return arg
->fn(container_of(dev
, struct usb_device
, dev
), arg
->data
);
248 * usb_for_each_dev - iterate over all USB devices in the system
249 * @data: data pointer that will be handed to the callback function
250 * @fn: callback function to be called for each USB device
252 * Iterate over all USB devices and call @fn for each, passing it @data. If it
253 * returns anything other than 0, we break the iteration prematurely and return
256 int usb_for_each_dev(void *data
, int (*fn
)(struct usb_device
*, void *))
258 struct each_dev_arg arg
= {data
, fn
};
260 return bus_for_each_dev(&usb_bus_type
, NULL
, &arg
, __each_dev
);
262 EXPORT_SYMBOL_GPL(usb_for_each_dev
);
265 * usb_release_dev - free a usb device structure when all users of it are finished.
266 * @dev: device that's been disconnected
268 * Will be called only by the device core when all users of this usb device are
271 static void usb_release_dev(struct device
*dev
)
273 struct usb_device
*udev
;
276 udev
= to_usb_device(dev
);
277 hcd
= bus_to_hcd(udev
->bus
);
279 usb_destroy_configuration(udev
);
280 usb_release_bos_descriptor(udev
);
282 kfree(udev
->product
);
283 kfree(udev
->manufacturer
);
288 static int usb_dev_uevent(struct device
*dev
, struct kobj_uevent_env
*env
)
290 struct usb_device
*usb_dev
;
292 usb_dev
= to_usb_device(dev
);
294 if (add_uevent_var(env
, "BUSNUM=%03d", usb_dev
->bus
->busnum
))
297 if (add_uevent_var(env
, "DEVNUM=%03d", usb_dev
->devnum
))
305 /* USB device Power-Management thunks.
306 * There's no need to distinguish here between quiescing a USB device
307 * and powering it down; the generic_suspend() routine takes care of
308 * it by skipping the usb_port_suspend() call for a quiesce. And for
309 * USB interfaces there's no difference at all.
312 static int usb_dev_prepare(struct device
*dev
)
314 struct usb_device
*udev
= to_usb_device(dev
);
316 /* Return 0 if the current wakeup setting is wrong, otherwise 1 */
317 if (udev
->do_remote_wakeup
!= device_may_wakeup(dev
))
323 static void usb_dev_complete(struct device
*dev
)
325 /* Currently used only for rebinding interfaces */
326 usb_resume_complete(dev
);
329 static int usb_dev_suspend(struct device
*dev
)
331 return usb_suspend(dev
, PMSG_SUSPEND
);
334 static int usb_dev_resume(struct device
*dev
)
336 return usb_resume(dev
, PMSG_RESUME
);
339 static int usb_dev_freeze(struct device
*dev
)
341 return usb_suspend(dev
, PMSG_FREEZE
);
344 static int usb_dev_thaw(struct device
*dev
)
346 return usb_resume(dev
, PMSG_THAW
);
349 static int usb_dev_poweroff(struct device
*dev
)
351 return usb_suspend(dev
, PMSG_HIBERNATE
);
354 static int usb_dev_restore(struct device
*dev
)
356 return usb_resume(dev
, PMSG_RESTORE
);
359 static const struct dev_pm_ops usb_device_pm_ops
= {
360 .prepare
= usb_dev_prepare
,
361 .complete
= usb_dev_complete
,
362 .suspend
= usb_dev_suspend
,
363 .resume
= usb_dev_resume
,
364 .freeze
= usb_dev_freeze
,
365 .thaw
= usb_dev_thaw
,
366 .poweroff
= usb_dev_poweroff
,
367 .restore
= usb_dev_restore
,
368 .runtime_suspend
= usb_runtime_suspend
,
369 .runtime_resume
= usb_runtime_resume
,
370 .runtime_idle
= usb_runtime_idle
,
373 #endif /* CONFIG_PM */
376 static char *usb_devnode(struct device
*dev
,
377 umode_t
*mode
, kuid_t
*uid
, kgid_t
*gid
)
379 struct usb_device
*usb_dev
;
381 usb_dev
= to_usb_device(dev
);
382 return kasprintf(GFP_KERNEL
, "bus/usb/%03d/%03d",
383 usb_dev
->bus
->busnum
, usb_dev
->devnum
);
386 struct device_type usb_device_type
= {
387 .name
= "usb_device",
388 .release
= usb_release_dev
,
389 .uevent
= usb_dev_uevent
,
390 .devnode
= usb_devnode
,
392 .pm
= &usb_device_pm_ops
,
397 /* Returns 1 if @usb_bus is WUSB, 0 otherwise */
398 static unsigned usb_bus_is_wusb(struct usb_bus
*bus
)
400 struct usb_hcd
*hcd
= container_of(bus
, struct usb_hcd
, self
);
401 return hcd
->wireless
;
406 * usb_alloc_dev - usb device constructor (usbcore-internal)
407 * @parent: hub to which device is connected; null to allocate a root hub
408 * @bus: bus used to access the device
409 * @port1: one-based index of port; ignored for root hubs
410 * Context: !in_interrupt()
412 * Only hub drivers (including virtual root hub drivers for host
413 * controllers) should ever call this.
415 * This call may not be used in a non-sleeping context.
417 * Return: On success, a pointer to the allocated usb device. %NULL on
420 struct usb_device
*usb_alloc_dev(struct usb_device
*parent
,
421 struct usb_bus
*bus
, unsigned port1
)
423 struct usb_device
*dev
;
424 struct usb_hcd
*usb_hcd
= bus_to_hcd(bus
);
425 unsigned root_hub
= 0;
427 dev
= kzalloc(sizeof(*dev
), GFP_KERNEL
);
431 if (!usb_get_hcd(usb_hcd
)) {
435 /* Root hubs aren't true devices, so don't allocate HCD resources */
436 if (usb_hcd
->driver
->alloc_dev
&& parent
&&
437 !usb_hcd
->driver
->alloc_dev(usb_hcd
, dev
)) {
438 usb_put_hcd(bus_to_hcd(bus
));
443 device_initialize(&dev
->dev
);
444 dev
->dev
.bus
= &usb_bus_type
;
445 dev
->dev
.type
= &usb_device_type
;
446 dev
->dev
.groups
= usb_device_groups
;
447 dev
->dev
.dma_mask
= bus
->controller
->dma_mask
;
448 set_dev_node(&dev
->dev
, dev_to_node(bus
->controller
));
449 dev
->state
= USB_STATE_ATTACHED
;
450 dev
->lpm_disable_count
= 1;
451 atomic_set(&dev
->urbnum
, 0);
453 INIT_LIST_HEAD(&dev
->ep0
.urb_list
);
454 dev
->ep0
.desc
.bLength
= USB_DT_ENDPOINT_SIZE
;
455 dev
->ep0
.desc
.bDescriptorType
= USB_DT_ENDPOINT
;
456 /* ep0 maxpacket comes later, from device descriptor */
457 usb_enable_endpoint(dev
, &dev
->ep0
, false);
460 /* Save readable and stable topology id, distinguishing devices
461 * by location for diagnostics, tools, driver model, etc. The
462 * string is a path along hub ports, from the root. Each device's
463 * dev->devpath will be stable until USB is re-cabled, and hubs
464 * are often labeled with these port numbers. The name isn't
465 * as stable: bus->busnum changes easily from modprobe order,
466 * cardbus or pci hotplugging, and so on.
468 if (unlikely(!parent
)) {
469 dev
->devpath
[0] = '0';
472 dev
->dev
.parent
= bus
->controller
;
473 dev_set_name(&dev
->dev
, "usb%d", bus
->busnum
);
476 /* match any labeling on the hubs; it's one-based */
477 if (parent
->devpath
[0] == '0') {
478 snprintf(dev
->devpath
, sizeof dev
->devpath
,
480 /* Root ports are not counted in route string */
483 snprintf(dev
->devpath
, sizeof dev
->devpath
,
484 "%s.%d", parent
->devpath
, port1
);
485 /* Route string assumes hubs have less than 16 ports */
487 dev
->route
= parent
->route
+
488 (port1
<< ((parent
->level
- 1)*4));
490 dev
->route
= parent
->route
+
491 (15 << ((parent
->level
- 1)*4));
494 dev
->dev
.parent
= &parent
->dev
;
495 dev_set_name(&dev
->dev
, "%d-%s", bus
->busnum
, dev
->devpath
);
497 /* hub driver sets up TT records */
500 dev
->portnum
= port1
;
502 dev
->parent
= parent
;
503 INIT_LIST_HEAD(&dev
->filelist
);
506 pm_runtime_set_autosuspend_delay(&dev
->dev
,
507 usb_autosuspend_delay
* 1000);
508 dev
->connect_time
= jiffies
;
509 dev
->active_duration
= -jiffies
;
511 if (root_hub
) /* Root hub always ok [and always wired] */
514 dev
->authorized
= !!HCD_DEV_AUTHORIZED(usb_hcd
);
515 dev
->wusb
= usb_bus_is_wusb(bus
) ? 1 : 0;
519 EXPORT_SYMBOL_GPL(usb_alloc_dev
);
522 * usb_get_dev - increments the reference count of the usb device structure
523 * @dev: the device being referenced
525 * Each live reference to a device should be refcounted.
527 * Drivers for USB interfaces should normally record such references in
528 * their probe() methods, when they bind to an interface, and release
529 * them by calling usb_put_dev(), in their disconnect() methods.
531 * Return: A pointer to the device with the incremented reference counter.
533 struct usb_device
*usb_get_dev(struct usb_device
*dev
)
536 get_device(&dev
->dev
);
539 EXPORT_SYMBOL_GPL(usb_get_dev
);
542 * usb_put_dev - release a use of the usb device structure
543 * @dev: device that's been disconnected
545 * Must be called when a user of a device is finished with it. When the last
546 * user of the device calls this function, the memory of the device is freed.
548 void usb_put_dev(struct usb_device
*dev
)
551 put_device(&dev
->dev
);
553 EXPORT_SYMBOL_GPL(usb_put_dev
);
556 * usb_get_intf - increments the reference count of the usb interface structure
557 * @intf: the interface being referenced
559 * Each live reference to a interface must be refcounted.
561 * Drivers for USB interfaces should normally record such references in
562 * their probe() methods, when they bind to an interface, and release
563 * them by calling usb_put_intf(), in their disconnect() methods.
565 * Return: A pointer to the interface with the incremented reference counter.
567 struct usb_interface
*usb_get_intf(struct usb_interface
*intf
)
570 get_device(&intf
->dev
);
573 EXPORT_SYMBOL_GPL(usb_get_intf
);
576 * usb_put_intf - release a use of the usb interface structure
577 * @intf: interface that's been decremented
579 * Must be called when a user of an interface is finished with it. When the
580 * last user of the interface calls this function, the memory of the interface
583 void usb_put_intf(struct usb_interface
*intf
)
586 put_device(&intf
->dev
);
588 EXPORT_SYMBOL_GPL(usb_put_intf
);
590 /* USB device locking
592 * USB devices and interfaces are locked using the semaphore in their
593 * embedded struct device. The hub driver guarantees that whenever a
594 * device is connected or disconnected, drivers are called with the
595 * USB device locked as well as their particular interface.
597 * Complications arise when several devices are to be locked at the same
598 * time. Only hub-aware drivers that are part of usbcore ever have to
599 * do this; nobody else needs to worry about it. The rule for locking
602 * When locking both a device and its parent, always lock the
607 * usb_lock_device_for_reset - cautiously acquire the lock for a usb device structure
608 * @udev: device that's being locked
609 * @iface: interface bound to the driver making the request (optional)
611 * Attempts to acquire the device lock, but fails if the device is
612 * NOTATTACHED or SUSPENDED, or if iface is specified and the interface
613 * is neither BINDING nor BOUND. Rather than sleeping to wait for the
614 * lock, the routine polls repeatedly. This is to prevent deadlock with
615 * disconnect; in some drivers (such as usb-storage) the disconnect()
616 * or suspend() method will block waiting for a device reset to complete.
618 * Return: A negative error code for failure, otherwise 0.
620 int usb_lock_device_for_reset(struct usb_device
*udev
,
621 const struct usb_interface
*iface
)
623 unsigned long jiffies_expire
= jiffies
+ HZ
;
625 if (udev
->state
== USB_STATE_NOTATTACHED
)
627 if (udev
->state
== USB_STATE_SUSPENDED
)
628 return -EHOSTUNREACH
;
629 if (iface
&& (iface
->condition
== USB_INTERFACE_UNBINDING
||
630 iface
->condition
== USB_INTERFACE_UNBOUND
))
633 while (!usb_trylock_device(udev
)) {
635 /* If we can't acquire the lock after waiting one second,
636 * we're probably deadlocked */
637 if (time_after(jiffies
, jiffies_expire
))
641 if (udev
->state
== USB_STATE_NOTATTACHED
)
643 if (udev
->state
== USB_STATE_SUSPENDED
)
644 return -EHOSTUNREACH
;
645 if (iface
&& (iface
->condition
== USB_INTERFACE_UNBINDING
||
646 iface
->condition
== USB_INTERFACE_UNBOUND
))
651 EXPORT_SYMBOL_GPL(usb_lock_device_for_reset
);
654 * usb_get_current_frame_number - return current bus frame number
655 * @dev: the device whose bus is being queried
657 * Return: The current frame number for the USB host controller used
658 * with the given USB device. This can be used when scheduling
659 * isochronous requests.
661 * Note: Different kinds of host controller have different "scheduling
662 * horizons". While one type might support scheduling only 32 frames
663 * into the future, others could support scheduling up to 1024 frames
667 int usb_get_current_frame_number(struct usb_device
*dev
)
669 return usb_hcd_get_frame_number(dev
);
671 EXPORT_SYMBOL_GPL(usb_get_current_frame_number
);
673 /*-------------------------------------------------------------------*/
675 * __usb_get_extra_descriptor() finds a descriptor of specific type in the
676 * extra field of the interface and endpoint descriptor structs.
679 int __usb_get_extra_descriptor(char *buffer
, unsigned size
,
680 unsigned char type
, void **ptr
)
682 struct usb_descriptor_header
*header
;
684 while (size
>= sizeof(struct usb_descriptor_header
)) {
685 header
= (struct usb_descriptor_header
*)buffer
;
687 if (header
->bLength
< 2) {
689 "%s: bogus descriptor, type %d length %d\n",
691 header
->bDescriptorType
,
696 if (header
->bDescriptorType
== type
) {
701 buffer
+= header
->bLength
;
702 size
-= header
->bLength
;
706 EXPORT_SYMBOL_GPL(__usb_get_extra_descriptor
);
709 * usb_alloc_coherent - allocate dma-consistent buffer for URB_NO_xxx_DMA_MAP
710 * @dev: device the buffer will be used with
711 * @size: requested buffer size
712 * @mem_flags: affect whether allocation may block
713 * @dma: used to return DMA address of buffer
715 * Return: Either null (indicating no buffer could be allocated), or the
716 * cpu-space pointer to a buffer that may be used to perform DMA to the
717 * specified device. Such cpu-space buffers are returned along with the DMA
718 * address (through the pointer provided).
721 * These buffers are used with URB_NO_xxx_DMA_MAP set in urb->transfer_flags
722 * to avoid behaviors like using "DMA bounce buffers", or thrashing IOMMU
723 * hardware during URB completion/resubmit. The implementation varies between
724 * platforms, depending on details of how DMA will work to this device.
725 * Using these buffers also eliminates cacheline sharing problems on
726 * architectures where CPU caches are not DMA-coherent. On systems without
727 * bus-snooping caches, these buffers are uncached.
729 * When the buffer is no longer used, free it with usb_free_coherent().
731 void *usb_alloc_coherent(struct usb_device
*dev
, size_t size
, gfp_t mem_flags
,
734 if (!dev
|| !dev
->bus
)
736 return hcd_buffer_alloc(dev
->bus
, size
, mem_flags
, dma
);
738 EXPORT_SYMBOL_GPL(usb_alloc_coherent
);
741 * usb_free_coherent - free memory allocated with usb_alloc_coherent()
742 * @dev: device the buffer was used with
743 * @size: requested buffer size
744 * @addr: CPU address of buffer
745 * @dma: DMA address of buffer
747 * This reclaims an I/O buffer, letting it be reused. The memory must have
748 * been allocated using usb_alloc_coherent(), and the parameters must match
749 * those provided in that allocation request.
751 void usb_free_coherent(struct usb_device
*dev
, size_t size
, void *addr
,
754 if (!dev
|| !dev
->bus
)
758 hcd_buffer_free(dev
->bus
, size
, addr
, dma
);
760 EXPORT_SYMBOL_GPL(usb_free_coherent
);
763 * usb_buffer_map - create DMA mapping(s) for an urb
764 * @urb: urb whose transfer_buffer/setup_packet will be mapped
766 * URB_NO_TRANSFER_DMA_MAP is added to urb->transfer_flags if the operation
767 * succeeds. If the device is connected to this system through a non-DMA
768 * controller, this operation always succeeds.
770 * This call would normally be used for an urb which is reused, perhaps
771 * as the target of a large periodic transfer, with usb_buffer_dmasync()
772 * calls to synchronize memory and dma state.
774 * Reverse the effect of this call with usb_buffer_unmap().
776 * Return: Either %NULL (indicating no buffer could be mapped), or @urb.
780 struct urb
*usb_buffer_map(struct urb
*urb
)
783 struct device
*controller
;
787 || !(bus
= urb
->dev
->bus
)
788 || !(controller
= bus
->controller
))
791 if (controller
->dma_mask
) {
792 urb
->transfer_dma
= dma_map_single(controller
,
793 urb
->transfer_buffer
, urb
->transfer_buffer_length
,
794 usb_pipein(urb
->pipe
)
795 ? DMA_FROM_DEVICE
: DMA_TO_DEVICE
);
796 /* FIXME generic api broken like pci, can't report errors */
797 /* if (urb->transfer_dma == DMA_ADDR_INVALID) return 0; */
799 urb
->transfer_dma
= ~0;
800 urb
->transfer_flags
|= URB_NO_TRANSFER_DMA_MAP
;
803 EXPORT_SYMBOL_GPL(usb_buffer_map
);
806 /* XXX DISABLED, no users currently. If you wish to re-enable this
807 * XXX please determine whether the sync is to transfer ownership of
808 * XXX the buffer from device to cpu or vice verse, and thusly use the
809 * XXX appropriate _for_{cpu,device}() method. -DaveM
814 * usb_buffer_dmasync - synchronize DMA and CPU view of buffer(s)
815 * @urb: urb whose transfer_buffer/setup_packet will be synchronized
817 void usb_buffer_dmasync(struct urb
*urb
)
820 struct device
*controller
;
823 || !(urb
->transfer_flags
& URB_NO_TRANSFER_DMA_MAP
)
825 || !(bus
= urb
->dev
->bus
)
826 || !(controller
= bus
->controller
))
829 if (controller
->dma_mask
) {
830 dma_sync_single_for_cpu(controller
,
831 urb
->transfer_dma
, urb
->transfer_buffer_length
,
832 usb_pipein(urb
->pipe
)
833 ? DMA_FROM_DEVICE
: DMA_TO_DEVICE
);
834 if (usb_pipecontrol(urb
->pipe
))
835 dma_sync_single_for_cpu(controller
,
837 sizeof(struct usb_ctrlrequest
),
841 EXPORT_SYMBOL_GPL(usb_buffer_dmasync
);
845 * usb_buffer_unmap - free DMA mapping(s) for an urb
846 * @urb: urb whose transfer_buffer will be unmapped
848 * Reverses the effect of usb_buffer_map().
851 void usb_buffer_unmap(struct urb
*urb
)
854 struct device
*controller
;
857 || !(urb
->transfer_flags
& URB_NO_TRANSFER_DMA_MAP
)
859 || !(bus
= urb
->dev
->bus
)
860 || !(controller
= bus
->controller
))
863 if (controller
->dma_mask
) {
864 dma_unmap_single(controller
,
865 urb
->transfer_dma
, urb
->transfer_buffer_length
,
866 usb_pipein(urb
->pipe
)
867 ? DMA_FROM_DEVICE
: DMA_TO_DEVICE
);
869 urb
->transfer_flags
&= ~URB_NO_TRANSFER_DMA_MAP
;
871 EXPORT_SYMBOL_GPL(usb_buffer_unmap
);
876 * usb_buffer_map_sg - create scatterlist DMA mapping(s) for an endpoint
877 * @dev: device to which the scatterlist will be mapped
878 * @is_in: mapping transfer direction
879 * @sg: the scatterlist to map
880 * @nents: the number of entries in the scatterlist
882 * Return: Either < 0 (indicating no buffers could be mapped), or the
883 * number of DMA mapping array entries in the scatterlist.
886 * The caller is responsible for placing the resulting DMA addresses from
887 * the scatterlist into URB transfer buffer pointers, and for setting the
888 * URB_NO_TRANSFER_DMA_MAP transfer flag in each of those URBs.
890 * Top I/O rates come from queuing URBs, instead of waiting for each one
891 * to complete before starting the next I/O. This is particularly easy
892 * to do with scatterlists. Just allocate and submit one URB for each DMA
893 * mapping entry returned, stopping on the first error or when all succeed.
894 * Better yet, use the usb_sg_*() calls, which do that (and more) for you.
896 * This call would normally be used when translating scatterlist requests,
897 * rather than usb_buffer_map(), since on some hardware (with IOMMUs) it
898 * may be able to coalesce mappings for improved I/O efficiency.
900 * Reverse the effect of this call with usb_buffer_unmap_sg().
902 int usb_buffer_map_sg(const struct usb_device
*dev
, int is_in
,
903 struct scatterlist
*sg
, int nents
)
906 struct device
*controller
;
910 || !(controller
= bus
->controller
)
911 || !controller
->dma_mask
)
914 /* FIXME generic api broken like pci, can't report errors */
915 return dma_map_sg(controller
, sg
, nents
,
916 is_in
? DMA_FROM_DEVICE
: DMA_TO_DEVICE
) ? : -ENOMEM
;
918 EXPORT_SYMBOL_GPL(usb_buffer_map_sg
);
921 /* XXX DISABLED, no users currently. If you wish to re-enable this
922 * XXX please determine whether the sync is to transfer ownership of
923 * XXX the buffer from device to cpu or vice verse, and thusly use the
924 * XXX appropriate _for_{cpu,device}() method. -DaveM
929 * usb_buffer_dmasync_sg - synchronize DMA and CPU view of scatterlist buffer(s)
930 * @dev: device to which the scatterlist will be mapped
931 * @is_in: mapping transfer direction
932 * @sg: the scatterlist to synchronize
933 * @n_hw_ents: the positive return value from usb_buffer_map_sg
935 * Use this when you are re-using a scatterlist's data buffers for
936 * another USB request.
938 void usb_buffer_dmasync_sg(const struct usb_device
*dev
, int is_in
,
939 struct scatterlist
*sg
, int n_hw_ents
)
942 struct device
*controller
;
946 || !(controller
= bus
->controller
)
947 || !controller
->dma_mask
)
950 dma_sync_sg_for_cpu(controller
, sg
, n_hw_ents
,
951 is_in
? DMA_FROM_DEVICE
: DMA_TO_DEVICE
);
953 EXPORT_SYMBOL_GPL(usb_buffer_dmasync_sg
);
958 * usb_buffer_unmap_sg - free DMA mapping(s) for a scatterlist
959 * @dev: device to which the scatterlist will be mapped
960 * @is_in: mapping transfer direction
961 * @sg: the scatterlist to unmap
962 * @n_hw_ents: the positive return value from usb_buffer_map_sg
964 * Reverses the effect of usb_buffer_map_sg().
966 void usb_buffer_unmap_sg(const struct usb_device
*dev
, int is_in
,
967 struct scatterlist
*sg
, int n_hw_ents
)
970 struct device
*controller
;
974 || !(controller
= bus
->controller
)
975 || !controller
->dma_mask
)
978 dma_unmap_sg(controller
, sg
, n_hw_ents
,
979 is_in
? DMA_FROM_DEVICE
: DMA_TO_DEVICE
);
981 EXPORT_SYMBOL_GPL(usb_buffer_unmap_sg
);
985 * Notifications of device and interface registration
987 static int usb_bus_notify(struct notifier_block
*nb
, unsigned long action
,
990 struct device
*dev
= data
;
993 case BUS_NOTIFY_ADD_DEVICE
:
994 if (dev
->type
== &usb_device_type
)
995 (void) usb_create_sysfs_dev_files(to_usb_device(dev
));
996 else if (dev
->type
== &usb_if_device_type
)
997 usb_create_sysfs_intf_files(to_usb_interface(dev
));
1000 case BUS_NOTIFY_DEL_DEVICE
:
1001 if (dev
->type
== &usb_device_type
)
1002 usb_remove_sysfs_dev_files(to_usb_device(dev
));
1003 else if (dev
->type
== &usb_if_device_type
)
1004 usb_remove_sysfs_intf_files(to_usb_interface(dev
));
1010 static struct notifier_block usb_bus_nb
= {
1011 .notifier_call
= usb_bus_notify
,
1014 struct dentry
*usb_debug_root
;
1015 EXPORT_SYMBOL_GPL(usb_debug_root
);
1017 static struct dentry
*usb_debug_devices
;
1019 static int usb_debugfs_init(void)
1021 usb_debug_root
= debugfs_create_dir("usb", NULL
);
1022 if (!usb_debug_root
)
1025 usb_debug_devices
= debugfs_create_file("devices", 0444,
1026 usb_debug_root
, NULL
,
1027 &usbfs_devices_fops
);
1028 if (!usb_debug_devices
) {
1029 debugfs_remove(usb_debug_root
);
1030 usb_debug_root
= NULL
;
1037 static void usb_debugfs_cleanup(void)
1039 debugfs_remove(usb_debug_devices
);
1040 debugfs_remove(usb_debug_root
);
1046 static int __init
usb_init(void)
1049 if (usb_disabled()) {
1050 pr_info("%s: USB support disabled\n", usbcore_name
);
1053 usb_init_pool_max();
1055 retval
= usb_debugfs_init();
1059 usb_acpi_register();
1060 retval
= bus_register(&usb_bus_type
);
1062 goto bus_register_failed
;
1063 retval
= bus_register_notifier(&usb_bus_type
, &usb_bus_nb
);
1065 goto bus_notifier_failed
;
1066 retval
= usb_major_init();
1068 goto major_init_failed
;
1069 retval
= usb_register(&usbfs_driver
);
1071 goto driver_register_failed
;
1072 retval
= usb_devio_init();
1074 goto usb_devio_init_failed
;
1075 retval
= usb_hub_init();
1077 goto hub_init_failed
;
1078 retval
= usb_register_device_driver(&usb_generic_driver
, THIS_MODULE
);
1084 usb_devio_cleanup();
1085 usb_devio_init_failed
:
1086 usb_deregister(&usbfs_driver
);
1087 driver_register_failed
:
1088 usb_major_cleanup();
1090 bus_unregister_notifier(&usb_bus_type
, &usb_bus_nb
);
1091 bus_notifier_failed
:
1092 bus_unregister(&usb_bus_type
);
1093 bus_register_failed
:
1094 usb_acpi_unregister();
1095 usb_debugfs_cleanup();
1103 static void __exit
usb_exit(void)
1105 /* This will matter if shutdown/reboot does exitcalls. */
1109 usb_deregister_device_driver(&usb_generic_driver
);
1110 usb_major_cleanup();
1111 usb_deregister(&usbfs_driver
);
1112 usb_devio_cleanup();
1114 bus_unregister_notifier(&usb_bus_type
, &usb_bus_nb
);
1115 bus_unregister(&usb_bus_type
);
1116 usb_acpi_unregister();
1117 usb_debugfs_cleanup();
1120 subsys_initcall(usb_init
);
1121 module_exit(usb_exit
);
1122 MODULE_LICENSE("GPL");