PRCM: 34XX: Fix wrong shift value used in dpll4_m4x2_ck enable bit
[linux-ginger.git] / drivers / usb / core / usb.c
blob325774375837e5f1c578c7c402fd7bffaf18960a
1 /*
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
21 * are evil.
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/mutex.h>
36 #include <linux/workqueue.h>
38 #include <asm/io.h>
39 #include <linux/scatterlist.h>
40 #include <linux/mm.h>
41 #include <linux/dma-mapping.h>
43 #include "hcd.h"
44 #include "usb.h"
47 const char *usbcore_name = "usbcore";
49 static int nousb; /* Disable USB when built into kernel image */
51 /* Workqueue for autosuspend and for remote wakeup of root hubs */
52 struct workqueue_struct *ksuspend_usb_wq;
54 #ifdef CONFIG_USB_SUSPEND
55 static int usb_autosuspend_delay = 2; /* Default delay value,
56 * in seconds */
57 module_param_named(autosuspend, usb_autosuspend_delay, int, 0644);
58 MODULE_PARM_DESC(autosuspend, "default autosuspend delay");
60 #else
61 #define usb_autosuspend_delay 0
62 #endif
65 /**
66 * usb_ifnum_to_if - get the interface object with a given interface number
67 * @dev: the device whose current configuration is considered
68 * @ifnum: the desired interface
70 * This walks the device descriptor for the currently active configuration
71 * and returns a pointer to the interface with that particular interface
72 * number, or null.
74 * Note that configuration descriptors are not required to assign interface
75 * numbers sequentially, so that it would be incorrect to assume that
76 * the first interface in that descriptor corresponds to interface zero.
77 * This routine helps device drivers avoid such mistakes.
78 * However, you should make sure that you do the right thing with any
79 * alternate settings available for this interfaces.
81 * Don't call this function unless you are bound to one of the interfaces
82 * on this device or you have locked the device!
84 struct usb_interface *usb_ifnum_to_if(const struct usb_device *dev,
85 unsigned ifnum)
87 struct usb_host_config *config = dev->actconfig;
88 int i;
90 if (!config)
91 return NULL;
92 for (i = 0; i < config->desc.bNumInterfaces; i++)
93 if (config->interface[i]->altsetting[0]
94 .desc.bInterfaceNumber == ifnum)
95 return config->interface[i];
97 return NULL;
99 EXPORT_SYMBOL_GPL(usb_ifnum_to_if);
102 * usb_altnum_to_altsetting - get the altsetting structure with a given alternate setting number.
103 * @intf: the interface containing the altsetting in question
104 * @altnum: the desired alternate setting number
106 * This searches the altsetting array of the specified interface for
107 * an entry with the correct bAlternateSetting value and returns a pointer
108 * to that entry, or null.
110 * Note that altsettings need not be stored sequentially by number, so
111 * it would be incorrect to assume that the first altsetting entry in
112 * the array corresponds to altsetting zero. This routine helps device
113 * drivers avoid such mistakes.
115 * Don't call this function unless you are bound to the intf interface
116 * or you have locked the device!
118 struct usb_host_interface *usb_altnum_to_altsetting(
119 const struct usb_interface *intf,
120 unsigned int altnum)
122 int i;
124 for (i = 0; i < intf->num_altsetting; i++) {
125 if (intf->altsetting[i].desc.bAlternateSetting == altnum)
126 return &intf->altsetting[i];
128 return NULL;
130 EXPORT_SYMBOL_GPL(usb_altnum_to_altsetting);
132 struct find_interface_arg {
133 int minor;
134 struct usb_interface *interface;
137 static int __find_interface(struct device *dev, void *data)
139 struct find_interface_arg *arg = data;
140 struct usb_interface *intf;
142 /* can't look at usb devices, only interfaces */
143 if (is_usb_device(dev))
144 return 0;
146 intf = to_usb_interface(dev);
147 if (intf->minor != -1 && intf->minor == arg->minor) {
148 arg->interface = intf;
149 return 1;
151 return 0;
155 * usb_find_interface - find usb_interface pointer for driver and device
156 * @drv: the driver whose current configuration is considered
157 * @minor: the minor number of the desired device
159 * This walks the driver device list and returns a pointer to the interface
160 * with the matching minor. Note, this only works for devices that share the
161 * USB major number.
163 struct usb_interface *usb_find_interface(struct usb_driver *drv, int minor)
165 struct find_interface_arg argb;
166 int retval;
168 argb.minor = minor;
169 argb.interface = NULL;
170 /* eat the error, it will be in argb.interface */
171 retval = driver_for_each_device(&drv->drvwrap.driver, NULL, &argb,
172 __find_interface);
173 return argb.interface;
175 EXPORT_SYMBOL_GPL(usb_find_interface);
178 * usb_release_dev - free a usb device structure when all users of it are finished.
179 * @dev: device that's been disconnected
181 * Will be called only by the device core when all users of this usb device are
182 * done.
184 static void usb_release_dev(struct device *dev)
186 struct usb_device *udev;
188 udev = to_usb_device(dev);
190 usb_destroy_configuration(udev);
191 usb_put_hcd(bus_to_hcd(udev->bus));
192 kfree(udev->product);
193 kfree(udev->manufacturer);
194 kfree(udev->serial);
195 kfree(udev);
198 #ifdef CONFIG_HOTPLUG
199 static int usb_dev_uevent(struct device *dev, struct kobj_uevent_env *env)
201 struct usb_device *usb_dev;
203 usb_dev = to_usb_device(dev);
205 if (add_uevent_var(env, "BUSNUM=%03d", usb_dev->bus->busnum))
206 return -ENOMEM;
208 if (add_uevent_var(env, "DEVNUM=%03d", usb_dev->devnum))
209 return -ENOMEM;
211 return 0;
214 #else
216 static int usb_dev_uevent(struct device *dev, struct kobj_uevent_env *env)
218 return -ENODEV;
220 #endif /* CONFIG_HOTPLUG */
222 struct device_type usb_device_type = {
223 .name = "usb_device",
224 .release = usb_release_dev,
225 .uevent = usb_dev_uevent,
228 #ifdef CONFIG_PM
230 static int ksuspend_usb_init(void)
232 /* This workqueue is supposed to be both freezable and
233 * singlethreaded. Its job doesn't justify running on more
234 * than one CPU.
236 ksuspend_usb_wq = create_freezeable_workqueue("ksuspend_usbd");
237 if (!ksuspend_usb_wq)
238 return -ENOMEM;
239 return 0;
242 static void ksuspend_usb_cleanup(void)
244 destroy_workqueue(ksuspend_usb_wq);
247 #else
249 #define ksuspend_usb_init() 0
250 #define ksuspend_usb_cleanup() do {} while (0)
252 #endif /* CONFIG_PM */
255 /* Returns 1 if @usb_bus is WUSB, 0 otherwise */
256 static unsigned usb_bus_is_wusb(struct usb_bus *bus)
258 struct usb_hcd *hcd = container_of(bus, struct usb_hcd, self);
259 return hcd->wireless;
264 * usb_alloc_dev - usb device constructor (usbcore-internal)
265 * @parent: hub to which device is connected; null to allocate a root hub
266 * @bus: bus used to access the device
267 * @port1: one-based index of port; ignored for root hubs
268 * Context: !in_interrupt()
270 * Only hub drivers (including virtual root hub drivers for host
271 * controllers) should ever call this.
273 * This call may not be used in a non-sleeping context.
275 struct usb_device *usb_alloc_dev(struct usb_device *parent,
276 struct usb_bus *bus, unsigned port1)
278 struct usb_device *dev;
279 struct usb_hcd *usb_hcd = container_of(bus, struct usb_hcd, self);
280 unsigned root_hub = 0;
282 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
283 if (!dev)
284 return NULL;
286 if (!usb_get_hcd(bus_to_hcd(bus))) {
287 kfree(dev);
288 return NULL;
291 device_initialize(&dev->dev);
292 dev->dev.bus = &usb_bus_type;
293 dev->dev.type = &usb_device_type;
294 dev->dev.groups = usb_device_groups;
295 dev->dev.dma_mask = bus->controller->dma_mask;
296 set_dev_node(&dev->dev, dev_to_node(bus->controller));
297 dev->state = USB_STATE_ATTACHED;
298 atomic_set(&dev->urbnum, 0);
300 INIT_LIST_HEAD(&dev->ep0.urb_list);
301 dev->ep0.desc.bLength = USB_DT_ENDPOINT_SIZE;
302 dev->ep0.desc.bDescriptorType = USB_DT_ENDPOINT;
303 /* ep0 maxpacket comes later, from device descriptor */
304 usb_enable_endpoint(dev, &dev->ep0);
305 dev->can_submit = 1;
307 /* Save readable and stable topology id, distinguishing devices
308 * by location for diagnostics, tools, driver model, etc. The
309 * string is a path along hub ports, from the root. Each device's
310 * dev->devpath will be stable until USB is re-cabled, and hubs
311 * are often labeled with these port numbers. The bus_id isn't
312 * as stable: bus->busnum changes easily from modprobe order,
313 * cardbus or pci hotplugging, and so on.
315 if (unlikely(!parent)) {
316 dev->devpath[0] = '0';
318 dev->dev.parent = bus->controller;
319 sprintf(&dev->dev.bus_id[0], "usb%d", bus->busnum);
320 root_hub = 1;
321 } else {
322 /* match any labeling on the hubs; it's one-based */
323 if (parent->devpath[0] == '0')
324 snprintf(dev->devpath, sizeof dev->devpath,
325 "%d", port1);
326 else
327 snprintf(dev->devpath, sizeof dev->devpath,
328 "%s.%d", parent->devpath, port1);
330 dev->dev.parent = &parent->dev;
331 sprintf(&dev->dev.bus_id[0], "%d-%s",
332 bus->busnum, dev->devpath);
334 /* hub driver sets up TT records */
337 dev->portnum = port1;
338 dev->bus = bus;
339 dev->parent = parent;
340 INIT_LIST_HEAD(&dev->filelist);
342 #ifdef CONFIG_PM
343 mutex_init(&dev->pm_mutex);
344 INIT_DELAYED_WORK(&dev->autosuspend, usb_autosuspend_work);
345 dev->autosuspend_delay = usb_autosuspend_delay * HZ;
346 dev->connect_time = jiffies;
347 dev->active_duration = -jiffies;
348 #endif
349 if (root_hub) /* Root hub always ok [and always wired] */
350 dev->authorized = 1;
351 else {
352 dev->authorized = usb_hcd->authorized_default;
353 dev->wusb = usb_bus_is_wusb(bus)? 1 : 0;
355 return dev;
359 * usb_get_dev - increments the reference count of the usb device structure
360 * @dev: the device being referenced
362 * Each live reference to a device should be refcounted.
364 * Drivers for USB interfaces should normally record such references in
365 * their probe() methods, when they bind to an interface, and release
366 * them by calling usb_put_dev(), in their disconnect() methods.
368 * A pointer to the device with the incremented reference counter is returned.
370 struct usb_device *usb_get_dev(struct usb_device *dev)
372 if (dev)
373 get_device(&dev->dev);
374 return dev;
376 EXPORT_SYMBOL_GPL(usb_get_dev);
379 * usb_put_dev - release a use of the usb device structure
380 * @dev: device that's been disconnected
382 * Must be called when a user of a device is finished with it. When the last
383 * user of the device calls this function, the memory of the device is freed.
385 void usb_put_dev(struct usb_device *dev)
387 if (dev)
388 put_device(&dev->dev);
390 EXPORT_SYMBOL_GPL(usb_put_dev);
393 * usb_get_intf - increments the reference count of the usb interface structure
394 * @intf: the interface being referenced
396 * Each live reference to a interface must be refcounted.
398 * Drivers for USB interfaces should normally record such references in
399 * their probe() methods, when they bind to an interface, and release
400 * them by calling usb_put_intf(), in their disconnect() methods.
402 * A pointer to the interface with the incremented reference counter is
403 * returned.
405 struct usb_interface *usb_get_intf(struct usb_interface *intf)
407 if (intf)
408 get_device(&intf->dev);
409 return intf;
411 EXPORT_SYMBOL_GPL(usb_get_intf);
414 * usb_put_intf - release a use of the usb interface structure
415 * @intf: interface that's been decremented
417 * Must be called when a user of an interface is finished with it. When the
418 * last user of the interface calls this function, the memory of the interface
419 * is freed.
421 void usb_put_intf(struct usb_interface *intf)
423 if (intf)
424 put_device(&intf->dev);
426 EXPORT_SYMBOL_GPL(usb_put_intf);
428 /* USB device locking
430 * USB devices and interfaces are locked using the semaphore in their
431 * embedded struct device. The hub driver guarantees that whenever a
432 * device is connected or disconnected, drivers are called with the
433 * USB device locked as well as their particular interface.
435 * Complications arise when several devices are to be locked at the same
436 * time. Only hub-aware drivers that are part of usbcore ever have to
437 * do this; nobody else needs to worry about it. The rule for locking
438 * is simple:
440 * When locking both a device and its parent, always lock the
441 * the parent first.
445 * usb_lock_device_for_reset - cautiously acquire the lock for a usb device structure
446 * @udev: device that's being locked
447 * @iface: interface bound to the driver making the request (optional)
449 * Attempts to acquire the device lock, but fails if the device is
450 * NOTATTACHED or SUSPENDED, or if iface is specified and the interface
451 * is neither BINDING nor BOUND. Rather than sleeping to wait for the
452 * lock, the routine polls repeatedly. This is to prevent deadlock with
453 * disconnect; in some drivers (such as usb-storage) the disconnect()
454 * or suspend() method will block waiting for a device reset to complete.
456 * Returns a negative error code for failure, otherwise 1 or 0 to indicate
457 * that the device will or will not have to be unlocked. (0 can be
458 * returned when an interface is given and is BINDING, because in that
459 * case the driver already owns the device lock.)
461 int usb_lock_device_for_reset(struct usb_device *udev,
462 const struct usb_interface *iface)
464 unsigned long jiffies_expire = jiffies + HZ;
466 if (udev->state == USB_STATE_NOTATTACHED)
467 return -ENODEV;
468 if (udev->state == USB_STATE_SUSPENDED)
469 return -EHOSTUNREACH;
470 if (iface) {
471 switch (iface->condition) {
472 case USB_INTERFACE_BINDING:
473 return 0;
474 case USB_INTERFACE_BOUND:
475 break;
476 default:
477 return -EINTR;
481 while (usb_trylock_device(udev) != 0) {
483 /* If we can't acquire the lock after waiting one second,
484 * we're probably deadlocked */
485 if (time_after(jiffies, jiffies_expire))
486 return -EBUSY;
488 msleep(15);
489 if (udev->state == USB_STATE_NOTATTACHED)
490 return -ENODEV;
491 if (udev->state == USB_STATE_SUSPENDED)
492 return -EHOSTUNREACH;
493 if (iface && iface->condition != USB_INTERFACE_BOUND)
494 return -EINTR;
496 return 1;
498 EXPORT_SYMBOL_GPL(usb_lock_device_for_reset);
500 static struct usb_device *match_device(struct usb_device *dev,
501 u16 vendor_id, u16 product_id)
503 struct usb_device *ret_dev = NULL;
504 int child;
506 dev_dbg(&dev->dev, "check for vendor %04x, product %04x ...\n",
507 le16_to_cpu(dev->descriptor.idVendor),
508 le16_to_cpu(dev->descriptor.idProduct));
510 /* see if this device matches */
511 if ((vendor_id == le16_to_cpu(dev->descriptor.idVendor)) &&
512 (product_id == le16_to_cpu(dev->descriptor.idProduct))) {
513 dev_dbg(&dev->dev, "matched this device!\n");
514 ret_dev = usb_get_dev(dev);
515 goto exit;
518 /* look through all of the children of this device */
519 for (child = 0; child < dev->maxchild; ++child) {
520 if (dev->children[child]) {
521 usb_lock_device(dev->children[child]);
522 ret_dev = match_device(dev->children[child],
523 vendor_id, product_id);
524 usb_unlock_device(dev->children[child]);
525 if (ret_dev)
526 goto exit;
529 exit:
530 return ret_dev;
534 * usb_find_device - find a specific usb device in the system
535 * @vendor_id: the vendor id of the device to find
536 * @product_id: the product id of the device to find
538 * Returns a pointer to a struct usb_device if such a specified usb
539 * device is present in the system currently. The usage count of the
540 * device will be incremented if a device is found. Make sure to call
541 * usb_put_dev() when the caller is finished with the device.
543 * If a device with the specified vendor and product id is not found,
544 * NULL is returned.
546 struct usb_device *usb_find_device(u16 vendor_id, u16 product_id)
548 struct list_head *buslist;
549 struct usb_bus *bus;
550 struct usb_device *dev = NULL;
552 mutex_lock(&usb_bus_list_lock);
553 for (buslist = usb_bus_list.next;
554 buslist != &usb_bus_list;
555 buslist = buslist->next) {
556 bus = container_of(buslist, struct usb_bus, bus_list);
557 if (!bus->root_hub)
558 continue;
559 usb_lock_device(bus->root_hub);
560 dev = match_device(bus->root_hub, vendor_id, product_id);
561 usb_unlock_device(bus->root_hub);
562 if (dev)
563 goto exit;
565 exit:
566 mutex_unlock(&usb_bus_list_lock);
567 return dev;
571 * usb_get_current_frame_number - return current bus frame number
572 * @dev: the device whose bus is being queried
574 * Returns the current frame number for the USB host controller
575 * used with the given USB device. This can be used when scheduling
576 * isochronous requests.
578 * Note that different kinds of host controller have different
579 * "scheduling horizons". While one type might support scheduling only
580 * 32 frames into the future, others could support scheduling up to
581 * 1024 frames into the future.
583 int usb_get_current_frame_number(struct usb_device *dev)
585 return usb_hcd_get_frame_number(dev);
587 EXPORT_SYMBOL_GPL(usb_get_current_frame_number);
589 /*-------------------------------------------------------------------*/
591 * __usb_get_extra_descriptor() finds a descriptor of specific type in the
592 * extra field of the interface and endpoint descriptor structs.
595 int __usb_get_extra_descriptor(char *buffer, unsigned size,
596 unsigned char type, void **ptr)
598 struct usb_descriptor_header *header;
600 while (size >= sizeof(struct usb_descriptor_header)) {
601 header = (struct usb_descriptor_header *)buffer;
603 if (header->bLength < 2) {
604 printk(KERN_ERR
605 "%s: bogus descriptor, type %d length %d\n",
606 usbcore_name,
607 header->bDescriptorType,
608 header->bLength);
609 return -1;
612 if (header->bDescriptorType == type) {
613 *ptr = header;
614 return 0;
617 buffer += header->bLength;
618 size -= header->bLength;
620 return -1;
622 EXPORT_SYMBOL_GPL(__usb_get_extra_descriptor);
625 * usb_buffer_alloc - allocate dma-consistent buffer for URB_NO_xxx_DMA_MAP
626 * @dev: device the buffer will be used with
627 * @size: requested buffer size
628 * @mem_flags: affect whether allocation may block
629 * @dma: used to return DMA address of buffer
631 * Return value is either null (indicating no buffer could be allocated), or
632 * the cpu-space pointer to a buffer that may be used to perform DMA to the
633 * specified device. Such cpu-space buffers are returned along with the DMA
634 * address (through the pointer provided).
636 * These buffers are used with URB_NO_xxx_DMA_MAP set in urb->transfer_flags
637 * to avoid behaviors like using "DMA bounce buffers", or thrashing IOMMU
638 * hardware during URB completion/resubmit. The implementation varies between
639 * platforms, depending on details of how DMA will work to this device.
640 * Using these buffers also eliminates cacheline sharing problems on
641 * architectures where CPU caches are not DMA-coherent. On systems without
642 * bus-snooping caches, these buffers are uncached.
644 * When the buffer is no longer used, free it with usb_buffer_free().
646 void *usb_buffer_alloc(struct usb_device *dev, size_t size, gfp_t mem_flags,
647 dma_addr_t *dma)
649 if (!dev || !dev->bus)
650 return NULL;
651 return hcd_buffer_alloc(dev->bus, size, mem_flags, dma);
653 EXPORT_SYMBOL_GPL(usb_buffer_alloc);
656 * usb_buffer_free - free memory allocated with usb_buffer_alloc()
657 * @dev: device the buffer was used with
658 * @size: requested buffer size
659 * @addr: CPU address of buffer
660 * @dma: DMA address of buffer
662 * This reclaims an I/O buffer, letting it be reused. The memory must have
663 * been allocated using usb_buffer_alloc(), and the parameters must match
664 * those provided in that allocation request.
666 void usb_buffer_free(struct usb_device *dev, size_t size, void *addr,
667 dma_addr_t dma)
669 if (!dev || !dev->bus)
670 return;
671 if (!addr)
672 return;
673 hcd_buffer_free(dev->bus, size, addr, dma);
675 EXPORT_SYMBOL_GPL(usb_buffer_free);
678 * usb_buffer_map - create DMA mapping(s) for an urb
679 * @urb: urb whose transfer_buffer/setup_packet will be mapped
681 * Return value is either null (indicating no buffer could be mapped), or
682 * the parameter. URB_NO_TRANSFER_DMA_MAP and URB_NO_SETUP_DMA_MAP are
683 * added to urb->transfer_flags if the operation succeeds. If the device
684 * is connected to this system through a non-DMA controller, this operation
685 * always succeeds.
687 * This call would normally be used for an urb which is reused, perhaps
688 * as the target of a large periodic transfer, with usb_buffer_dmasync()
689 * calls to synchronize memory and dma state.
691 * Reverse the effect of this call with usb_buffer_unmap().
693 #if 0
694 struct urb *usb_buffer_map(struct urb *urb)
696 struct usb_bus *bus;
697 struct device *controller;
699 if (!urb
700 || !urb->dev
701 || !(bus = urb->dev->bus)
702 || !(controller = bus->controller))
703 return NULL;
705 if (controller->dma_mask) {
706 urb->transfer_dma = dma_map_single(controller,
707 urb->transfer_buffer, urb->transfer_buffer_length,
708 usb_pipein(urb->pipe)
709 ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
710 if (usb_pipecontrol(urb->pipe))
711 urb->setup_dma = dma_map_single(controller,
712 urb->setup_packet,
713 sizeof(struct usb_ctrlrequest),
714 DMA_TO_DEVICE);
715 /* FIXME generic api broken like pci, can't report errors */
716 /* if (urb->transfer_dma == DMA_ADDR_INVALID) return 0; */
717 } else
718 urb->transfer_dma = ~0;
719 urb->transfer_flags |= (URB_NO_TRANSFER_DMA_MAP
720 | URB_NO_SETUP_DMA_MAP);
721 return urb;
723 EXPORT_SYMBOL_GPL(usb_buffer_map);
724 #endif /* 0 */
726 /* XXX DISABLED, no users currently. If you wish to re-enable this
727 * XXX please determine whether the sync is to transfer ownership of
728 * XXX the buffer from device to cpu or vice verse, and thusly use the
729 * XXX appropriate _for_{cpu,device}() method. -DaveM
731 #if 0
734 * usb_buffer_dmasync - synchronize DMA and CPU view of buffer(s)
735 * @urb: urb whose transfer_buffer/setup_packet will be synchronized
737 void usb_buffer_dmasync(struct urb *urb)
739 struct usb_bus *bus;
740 struct device *controller;
742 if (!urb
743 || !(urb->transfer_flags & URB_NO_TRANSFER_DMA_MAP)
744 || !urb->dev
745 || !(bus = urb->dev->bus)
746 || !(controller = bus->controller))
747 return;
749 if (controller->dma_mask) {
750 dma_sync_single(controller,
751 urb->transfer_dma, urb->transfer_buffer_length,
752 usb_pipein(urb->pipe)
753 ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
754 if (usb_pipecontrol(urb->pipe))
755 dma_sync_single(controller,
756 urb->setup_dma,
757 sizeof(struct usb_ctrlrequest),
758 DMA_TO_DEVICE);
761 EXPORT_SYMBOL_GPL(usb_buffer_dmasync);
762 #endif
765 * usb_buffer_unmap - free DMA mapping(s) for an urb
766 * @urb: urb whose transfer_buffer will be unmapped
768 * Reverses the effect of usb_buffer_map().
770 #if 0
771 void usb_buffer_unmap(struct urb *urb)
773 struct usb_bus *bus;
774 struct device *controller;
776 if (!urb
777 || !(urb->transfer_flags & URB_NO_TRANSFER_DMA_MAP)
778 || !urb->dev
779 || !(bus = urb->dev->bus)
780 || !(controller = bus->controller))
781 return;
783 if (controller->dma_mask) {
784 dma_unmap_single(controller,
785 urb->transfer_dma, urb->transfer_buffer_length,
786 usb_pipein(urb->pipe)
787 ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
788 if (usb_pipecontrol(urb->pipe))
789 dma_unmap_single(controller,
790 urb->setup_dma,
791 sizeof(struct usb_ctrlrequest),
792 DMA_TO_DEVICE);
794 urb->transfer_flags &= ~(URB_NO_TRANSFER_DMA_MAP
795 | URB_NO_SETUP_DMA_MAP);
797 EXPORT_SYMBOL_GPL(usb_buffer_unmap);
798 #endif /* 0 */
801 * usb_buffer_map_sg - create scatterlist DMA mapping(s) for an endpoint
802 * @dev: device to which the scatterlist will be mapped
803 * @is_in: mapping transfer direction
804 * @sg: the scatterlist to map
805 * @nents: the number of entries in the scatterlist
807 * Return value is either < 0 (indicating no buffers could be mapped), or
808 * the number of DMA mapping array entries in the scatterlist.
810 * The caller is responsible for placing the resulting DMA addresses from
811 * the scatterlist into URB transfer buffer pointers, and for setting the
812 * URB_NO_TRANSFER_DMA_MAP transfer flag in each of those URBs.
814 * Top I/O rates come from queuing URBs, instead of waiting for each one
815 * to complete before starting the next I/O. This is particularly easy
816 * to do with scatterlists. Just allocate and submit one URB for each DMA
817 * mapping entry returned, stopping on the first error or when all succeed.
818 * Better yet, use the usb_sg_*() calls, which do that (and more) for you.
820 * This call would normally be used when translating scatterlist requests,
821 * rather than usb_buffer_map(), since on some hardware (with IOMMUs) it
822 * may be able to coalesce mappings for improved I/O efficiency.
824 * Reverse the effect of this call with usb_buffer_unmap_sg().
826 int usb_buffer_map_sg(const struct usb_device *dev, int is_in,
827 struct scatterlist *sg, int nents)
829 struct usb_bus *bus;
830 struct device *controller;
832 if (!dev
833 || !(bus = dev->bus)
834 || !(controller = bus->controller)
835 || !controller->dma_mask)
836 return -1;
838 /* FIXME generic api broken like pci, can't report errors */
839 return dma_map_sg(controller, sg, nents,
840 is_in ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
842 EXPORT_SYMBOL_GPL(usb_buffer_map_sg);
844 /* XXX DISABLED, no users currently. If you wish to re-enable this
845 * XXX please determine whether the sync is to transfer ownership of
846 * XXX the buffer from device to cpu or vice verse, and thusly use the
847 * XXX appropriate _for_{cpu,device}() method. -DaveM
849 #if 0
852 * usb_buffer_dmasync_sg - synchronize DMA and CPU view of scatterlist buffer(s)
853 * @dev: device to which the scatterlist will be mapped
854 * @is_in: mapping transfer direction
855 * @sg: the scatterlist to synchronize
856 * @n_hw_ents: the positive return value from usb_buffer_map_sg
858 * Use this when you are re-using a scatterlist's data buffers for
859 * another USB request.
861 void usb_buffer_dmasync_sg(const struct usb_device *dev, int is_in,
862 struct scatterlist *sg, int n_hw_ents)
864 struct usb_bus *bus;
865 struct device *controller;
867 if (!dev
868 || !(bus = dev->bus)
869 || !(controller = bus->controller)
870 || !controller->dma_mask)
871 return;
873 dma_sync_sg(controller, sg, n_hw_ents,
874 is_in ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
876 EXPORT_SYMBOL_GPL(usb_buffer_dmasync_sg);
877 #endif
880 * usb_buffer_unmap_sg - free DMA mapping(s) for a scatterlist
881 * @dev: device to which the scatterlist will be mapped
882 * @is_in: mapping transfer direction
883 * @sg: the scatterlist to unmap
884 * @n_hw_ents: the positive return value from usb_buffer_map_sg
886 * Reverses the effect of usb_buffer_map_sg().
888 void usb_buffer_unmap_sg(const struct usb_device *dev, int is_in,
889 struct scatterlist *sg, int n_hw_ents)
891 struct usb_bus *bus;
892 struct device *controller;
894 if (!dev
895 || !(bus = dev->bus)
896 || !(controller = bus->controller)
897 || !controller->dma_mask)
898 return;
900 dma_unmap_sg(controller, sg, n_hw_ents,
901 is_in ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
903 EXPORT_SYMBOL_GPL(usb_buffer_unmap_sg);
905 /* format to disable USB on kernel command line is: nousb */
906 __module_param_call("", nousb, param_set_bool, param_get_bool, &nousb, 0444);
909 * for external read access to <nousb>
911 int usb_disabled(void)
913 return nousb;
915 EXPORT_SYMBOL_GPL(usb_disabled);
918 * Init
920 static int __init usb_init(void)
922 int retval;
923 if (nousb) {
924 pr_info("%s: USB support disabled\n", usbcore_name);
925 return 0;
928 retval = ksuspend_usb_init();
929 if (retval)
930 goto out;
931 retval = bus_register(&usb_bus_type);
932 if (retval)
933 goto bus_register_failed;
934 retval = usb_host_init();
935 if (retval)
936 goto host_init_failed;
937 retval = usb_major_init();
938 if (retval)
939 goto major_init_failed;
940 retval = usb_register(&usbfs_driver);
941 if (retval)
942 goto driver_register_failed;
943 retval = usb_devio_init();
944 if (retval)
945 goto usb_devio_init_failed;
946 retval = usbfs_init();
947 if (retval)
948 goto fs_init_failed;
949 retval = usb_hub_init();
950 if (retval)
951 goto hub_init_failed;
952 retval = usb_register_device_driver(&usb_generic_driver, THIS_MODULE);
953 if (!retval)
954 goto out;
956 usb_hub_cleanup();
957 hub_init_failed:
958 usbfs_cleanup();
959 fs_init_failed:
960 usb_devio_cleanup();
961 usb_devio_init_failed:
962 usb_deregister(&usbfs_driver);
963 driver_register_failed:
964 usb_major_cleanup();
965 major_init_failed:
966 usb_host_cleanup();
967 host_init_failed:
968 bus_unregister(&usb_bus_type);
969 bus_register_failed:
970 ksuspend_usb_cleanup();
971 out:
972 return retval;
976 * Cleanup
978 static void __exit usb_exit(void)
980 /* This will matter if shutdown/reboot does exitcalls. */
981 if (nousb)
982 return;
984 usb_deregister_device_driver(&usb_generic_driver);
985 usb_major_cleanup();
986 usbfs_cleanup();
987 usb_deregister(&usbfs_driver);
988 usb_devio_cleanup();
989 usb_hub_cleanup();
990 usb_host_cleanup();
991 bus_unregister(&usb_bus_type);
992 ksuspend_usb_cleanup();
995 subsys_initcall(usb_init);
996 module_exit(usb_exit);
997 MODULE_LICENSE("GPL");