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linux/drivers/usb/core/usb.c

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/*
* drivers/usb/core/usb.c
*
* (C) Copyright Linus Torvalds 1999
* (C) Copyright Johannes Erdfelt 1999-2001
* (C) Copyright Andreas Gal 1999
* (C) Copyright Gregory P. Smith 1999
* (C) Copyright Deti Fliegl 1999 (new USB architecture)
* (C) Copyright Randy Dunlap 2000
* (C) Copyright David Brownell 2000-2004
* (C) Copyright Yggdrasil Computing, Inc. 2000
* (usb_device_id matching changes by Adam J. Richter)
* (C) Copyright Greg Kroah-Hartman 2002-2003
*
* NOTE! This is not actually a driver at all, rather this is
* just a collection of helper routines that implement the
* generic USB things that the real drivers can use..
*
* Think of this as a "USB library" rather than anything else.
* It should be considered a slave, with no callbacks. Callbacks
* are evil.
*/
#include <linux/module.h>
#include <linux/string.h>
#include <linux/bitops.h>
#include <linux/slab.h>
#include <linux/interrupt.h> /* for in_interrupt() */
#include <linux/kmod.h>
#include <linux/init.h>
#include <linux/spinlock.h>
#include <linux/errno.h>
#include <linux/smp_lock.h>
#include <linux/usb.h>
#include <linux/mutex.h>
#include <linux/workqueue.h>
#include <asm/io.h>
#include <asm/scatterlist.h>
#include <linux/mm.h>
#include <linux/dma-mapping.h>
#include "hcd.h"
#include "usb.h"
const char *usbcore_name = "usbcore";
static int nousb; /* Disable USB when built into kernel image */
struct workqueue_struct *ksuspend_usb_wq; /* For autosuspend */
/**
* usb_ifnum_to_if - get the interface object with a given interface number
* @dev: the device whose current configuration is considered
* @ifnum: the desired interface
*
* This walks the device descriptor for the currently active configuration
* and returns a pointer to the interface with that particular interface
* number, or null.
*
* Note that configuration descriptors are not required to assign interface
* numbers sequentially, so that it would be incorrect to assume that
* the first interface in that descriptor corresponds to interface zero.
* This routine helps device drivers avoid such mistakes.
* However, you should make sure that you do the right thing with any
* alternate settings available for this interfaces.
*
* Don't call this function unless you are bound to one of the interfaces
* on this device or you have locked the device!
*/
struct usb_interface *usb_ifnum_to_if(const struct usb_device *dev,
unsigned ifnum)
{
struct usb_host_config *config = dev->actconfig;
int i;
if (!config)
return NULL;
for (i = 0; i < config->desc.bNumInterfaces; i++)
if (config->interface[i]->altsetting[0]
.desc.bInterfaceNumber == ifnum)
return config->interface[i];
return NULL;
}
/**
* usb_altnum_to_altsetting - get the altsetting structure with a given
* alternate setting number.
* @intf: the interface containing the altsetting in question
* @altnum: the desired alternate setting number
*
* This searches the altsetting array of the specified interface for
* an entry with the correct bAlternateSetting value and returns a pointer
* to that entry, or null.
*
* Note that altsettings need not be stored sequentially by number, so
* it would be incorrect to assume that the first altsetting entry in
* the array corresponds to altsetting zero. This routine helps device
* drivers avoid such mistakes.
*
* Don't call this function unless you are bound to the intf interface
* or you have locked the device!
*/
struct usb_host_interface *usb_altnum_to_altsetting(const struct usb_interface *intf,
unsigned int altnum)
{
int i;
for (i = 0; i < intf->num_altsetting; i++) {
if (intf->altsetting[i].desc.bAlternateSetting == altnum)
return &intf->altsetting[i];
}
return NULL;
}
struct find_interface_arg {
int minor;
struct usb_interface *interface;
};
static int __find_interface(struct device * dev, void * data)
{
struct find_interface_arg *arg = data;
struct usb_interface *intf;
/* can't look at usb devices, only interfaces */
if (is_usb_device(dev))
return 0;
intf = to_usb_interface(dev);
if (intf->minor != -1 && intf->minor == arg->minor) {
arg->interface = intf;
return 1;
}
return 0;
}
/**
* usb_find_interface - find usb_interface pointer for driver and device
* @drv: the driver whose current configuration is considered
* @minor: the minor number of the desired device
*
* This walks the driver device list and returns a pointer to the interface
* with the matching minor. Note, this only works for devices that share the
* USB major number.
*/
struct usb_interface *usb_find_interface(struct usb_driver *drv, int minor)
{
struct find_interface_arg argb;
int retval;
argb.minor = minor;
argb.interface = NULL;
/* eat the error, it will be in argb.interface */
retval = driver_for_each_device(&drv->drvwrap.driver, NULL, &argb,
__find_interface);
return argb.interface;
}
/**
* usb_release_dev - free a usb device structure when all users of it are finished.
* @dev: device that's been disconnected
*
* Will be called only by the device core when all users of this usb device are
* done.
*/
static void usb_release_dev(struct device *dev)
{
struct usb_device *udev;
udev = to_usb_device(dev);
#ifdef CONFIG_USB_SUSPEND
cancel_delayed_work(&udev->autosuspend);
flush_workqueue(ksuspend_usb_wq);
#endif
usb_destroy_configuration(udev);
usb_put_hcd(bus_to_hcd(udev->bus));
kfree(udev->product);
kfree(udev->manufacturer);
kfree(udev->serial);
kfree(udev);
}
#ifdef CONFIG_PM
static int ksuspend_usb_init(void)
{
ksuspend_usb_wq = create_singlethread_workqueue("ksuspend_usbd");
if (!ksuspend_usb_wq)
return -ENOMEM;
return 0;
}
static void ksuspend_usb_cleanup(void)
{
destroy_workqueue(ksuspend_usb_wq);
}
#ifdef CONFIG_USB_SUSPEND
/* usb_autosuspend_work - callback routine to autosuspend a USB device */
static void usb_autosuspend_work(struct work_struct *work)
{
struct usb_device *udev =
container_of(work, struct usb_device, autosuspend.work);
usb_pm_lock(udev);
udev->auto_pm = 1;
usb_suspend_both(udev, PMSG_SUSPEND);
usb_pm_unlock(udev);
}
#else
static void usb_autosuspend_work(struct work_struct *work)
{}
#endif /* CONFIG_USB_SUSPEND */
#else
#define ksuspend_usb_init() 0
#define ksuspend_usb_cleanup() do {} while (0)
#endif /* CONFIG_PM */
/**
* usb_alloc_dev - usb device constructor (usbcore-internal)
* @parent: hub to which device is connected; null to allocate a root hub
* @bus: bus used to access the device
* @port1: one-based index of port; ignored for root hubs
* Context: !in_interrupt ()
*
* Only hub drivers (including virtual root hub drivers for host
* controllers) should ever call this.
*
* This call may not be used in a non-sleeping context.
*/
struct usb_device *
usb_alloc_dev(struct usb_device *parent, struct usb_bus *bus, unsigned port1)
{
struct usb_device *dev;
dev = kzalloc(sizeof(*dev), GFP_KERNEL);
if (!dev)
return NULL;
if (!usb_get_hcd(bus_to_hcd(bus))) {
kfree(dev);
return NULL;
}
device_initialize(&dev->dev);
dev->dev.bus = &usb_bus_type;
dev->dev.dma_mask = bus->controller->dma_mask;
dev->dev.release = usb_release_dev;
dev->state = USB_STATE_ATTACHED;
/* This magic assignment distinguishes devices from interfaces */
dev->dev.platform_data = &usb_generic_driver;
INIT_LIST_HEAD(&dev->ep0.urb_list);
dev->ep0.desc.bLength = USB_DT_ENDPOINT_SIZE;
dev->ep0.desc.bDescriptorType = USB_DT_ENDPOINT;
/* ep0 maxpacket comes later, from device descriptor */
dev->ep_in[0] = dev->ep_out[0] = &dev->ep0;
/* Save readable and stable topology id, distinguishing devices
* by location for diagnostics, tools, driver model, etc. The
* string is a path along hub ports, from the root. Each device's
* dev->devpath will be stable until USB is re-cabled, and hubs
* are often labeled with these port numbers. The bus_id isn't
* as stable: bus->busnum changes easily from modprobe order,
* cardbus or pci hotplugging, and so on.
*/
if (unlikely (!parent)) {
dev->devpath [0] = '0';
dev->dev.parent = bus->controller;
sprintf (&dev->dev.bus_id[0], "usb%d", bus->busnum);
} else {
/* match any labeling on the hubs; it's one-based */
if (parent->devpath [0] == '0')
snprintf (dev->devpath, sizeof dev->devpath,
"%d", port1);
else
snprintf (dev->devpath, sizeof dev->devpath,
"%s.%d", parent->devpath, port1);
dev->dev.parent = &parent->dev;
sprintf (&dev->dev.bus_id[0], "%d-%s",
bus->busnum, dev->devpath);
/* hub driver sets up TT records */
}
dev->portnum = port1;
dev->bus = bus;
dev->parent = parent;
INIT_LIST_HEAD(&dev->filelist);
#ifdef CONFIG_PM
mutex_init(&dev->pm_mutex);
INIT_DELAYED_WORK(&dev->autosuspend, usb_autosuspend_work);
#endif
return dev;
}
/**
* usb_get_dev - increments the reference count of the usb device structure
* @dev: the device being referenced
*
* Each live reference to a device should be refcounted.
*
* Drivers for USB interfaces should normally record such references in
* their probe() methods, when they bind to an interface, and release
* them by calling usb_put_dev(), in their disconnect() methods.
*
* A pointer to the device with the incremented reference counter is returned.
*/
struct usb_device *usb_get_dev(struct usb_device *dev)
{
if (dev)
get_device(&dev->dev);
return dev;
}
/**
* usb_put_dev - release a use of the usb device structure
* @dev: device that's been disconnected
*
* Must be called when a user of a device is finished with it. When the last
* user of the device calls this function, the memory of the device is freed.
*/
void usb_put_dev(struct usb_device *dev)
{
if (dev)
put_device(&dev->dev);
}
/**
* usb_get_intf - increments the reference count of the usb interface structure
* @intf: the interface being referenced
*
* Each live reference to a interface must be refcounted.
*
* Drivers for USB interfaces should normally record such references in
* their probe() methods, when they bind to an interface, and release
* them by calling usb_put_intf(), in their disconnect() methods.
*
* A pointer to the interface with the incremented reference counter is
* returned.
*/
struct usb_interface *usb_get_intf(struct usb_interface *intf)
{
if (intf)
get_device(&intf->dev);
return intf;
}
/**
* usb_put_intf - release a use of the usb interface structure
* @intf: interface that's been decremented
*
* Must be called when a user of an interface is finished with it. When the
* last user of the interface calls this function, the memory of the interface
* is freed.
*/
void usb_put_intf(struct usb_interface *intf)
{
if (intf)
put_device(&intf->dev);
}
/* USB device locking
*
* USB devices and interfaces are locked using the semaphore in their
* embedded struct device. The hub driver guarantees that whenever a
* device is connected or disconnected, drivers are called with the
* USB device locked as well as their particular interface.
*
* Complications arise when several devices are to be locked at the same
* time. Only hub-aware drivers that are part of usbcore ever have to
* do this; nobody else needs to worry about it. The rule for locking
* is simple:
*
* When locking both a device and its parent, always lock the
* the parent first.
*/
/**
* usb_lock_device_for_reset - cautiously acquire the lock for a
* usb device structure
* @udev: device that's being locked
* @iface: interface bound to the driver making the request (optional)
*
* Attempts to acquire the device lock, but fails if the device is
* NOTATTACHED or SUSPENDED, or if iface is specified and the interface
* is neither BINDING nor BOUND. Rather than sleeping to wait for the
* lock, the routine polls repeatedly. This is to prevent deadlock with
* disconnect; in some drivers (such as usb-storage) the disconnect()
* or suspend() method will block waiting for a device reset to complete.
*
* Returns a negative error code for failure, otherwise 1 or 0 to indicate
* that the device will or will not have to be unlocked. (0 can be
* returned when an interface is given and is BINDING, because in that
* case the driver already owns the device lock.)
*/
int usb_lock_device_for_reset(struct usb_device *udev,
const struct usb_interface *iface)
{
unsigned long jiffies_expire = jiffies + HZ;
if (udev->state == USB_STATE_NOTATTACHED)
return -ENODEV;
if (udev->state == USB_STATE_SUSPENDED)
return -EHOSTUNREACH;
if (iface) {
switch (iface->condition) {
case USB_INTERFACE_BINDING:
return 0;
case USB_INTERFACE_BOUND:
break;
default:
return -EINTR;
}
}
while (usb_trylock_device(udev) != 0) {
/* If we can't acquire the lock after waiting one second,
* we're probably deadlocked */
if (time_after(jiffies, jiffies_expire))
return -EBUSY;
msleep(15);
if (udev->state == USB_STATE_NOTATTACHED)
return -ENODEV;
if (udev->state == USB_STATE_SUSPENDED)
return -EHOSTUNREACH;
if (iface && iface->condition != USB_INTERFACE_BOUND)
return -EINTR;
}
return 1;
}
static struct usb_device *match_device(struct usb_device *dev,
u16 vendor_id, u16 product_id)
{
struct usb_device *ret_dev = NULL;
int child;
dev_dbg(&dev->dev, "check for vendor %04x, product %04x ...\n",
le16_to_cpu(dev->descriptor.idVendor),
le16_to_cpu(dev->descriptor.idProduct));
/* see if this device matches */
if ((vendor_id == le16_to_cpu(dev->descriptor.idVendor)) &&
(product_id == le16_to_cpu(dev->descriptor.idProduct))) {
dev_dbg (&dev->dev, "matched this device!\n");
ret_dev = usb_get_dev(dev);
goto exit;
}
/* look through all of the children of this device */
for (child = 0; child < dev->maxchild; ++child) {
if (dev->children[child]) {
usb_lock_device(dev->children[child]);
ret_dev = match_device(dev->children[child],
vendor_id, product_id);
usb_unlock_device(dev->children[child]);
if (ret_dev)
goto exit;
}
}
exit:
return ret_dev;
}
/**
* usb_find_device - find a specific usb device in the system
* @vendor_id: the vendor id of the device to find
* @product_id: the product id of the device to find
*
* Returns a pointer to a struct usb_device if such a specified usb
* device is present in the system currently. The usage count of the
* device will be incremented if a device is found. Make sure to call
* usb_put_dev() when the caller is finished with the device.
*
* If a device with the specified vendor and product id is not found,
* NULL is returned.
*/
struct usb_device *usb_find_device(u16 vendor_id, u16 product_id)
{
struct list_head *buslist;
struct usb_bus *bus;
struct usb_device *dev = NULL;
mutex_lock(&usb_bus_list_lock);
for (buslist = usb_bus_list.next;
buslist != &usb_bus_list;
buslist = buslist->next) {
bus = container_of(buslist, struct usb_bus, bus_list);
if (!bus->root_hub)
continue;
usb_lock_device(bus->root_hub);
dev = match_device(bus->root_hub, vendor_id, product_id);
usb_unlock_device(bus->root_hub);
if (dev)
goto exit;
}
exit:
mutex_unlock(&usb_bus_list_lock);
return dev;
}
/**
* usb_get_current_frame_number - return current bus frame number
* @dev: the device whose bus is being queried
*
* Returns the current frame number for the USB host controller
* used with the given USB device. This can be used when scheduling
* isochronous requests.
*
* Note that different kinds of host controller have different
* "scheduling horizons". While one type might support scheduling only
* 32 frames into the future, others could support scheduling up to
* 1024 frames into the future.
*/
int usb_get_current_frame_number(struct usb_device *dev)
{
return usb_hcd_get_frame_number (dev);
}
/*-------------------------------------------------------------------*/
/*
* __usb_get_extra_descriptor() finds a descriptor of specific type in the
* extra field of the interface and endpoint descriptor structs.
*/
int __usb_get_extra_descriptor(char *buffer, unsigned size,
unsigned char type, void **ptr)
{
struct usb_descriptor_header *header;
while (size >= sizeof(struct usb_descriptor_header)) {
header = (struct usb_descriptor_header *)buffer;
if (header->bLength < 2) {
printk(KERN_ERR
"%s: bogus descriptor, type %d length %d\n",
usbcore_name,
header->bDescriptorType,
header->bLength);
return -1;
}
if (header->bDescriptorType == type) {
*ptr = header;
return 0;
}
buffer += header->bLength;
size -= header->bLength;
}
return -1;
}
/**
* usb_buffer_alloc - allocate dma-consistent buffer for URB_NO_xxx_DMA_MAP
* @dev: device the buffer will be used with
* @size: requested buffer size
* @mem_flags: affect whether allocation may block
* @dma: used to return DMA address of buffer
*
* Return value is either null (indicating no buffer could be allocated), or
* the cpu-space pointer to a buffer that may be used to perform DMA to the
* specified device. Such cpu-space buffers are returned along with the DMA
* address (through the pointer provided).
*
* These buffers are used with URB_NO_xxx_DMA_MAP set in urb->transfer_flags
* to avoid behaviors like using "DMA bounce buffers", or tying down I/O
* mapping hardware for long idle periods. The implementation varies between
* platforms, depending on details of how DMA will work to this device.
* Using these buffers also helps prevent cacheline sharing problems on
* architectures where CPU caches are not DMA-coherent.
*
* When the buffer is no longer used, free it with usb_buffer_free().
*/
void *usb_buffer_alloc (
struct usb_device *dev,
size_t size,
gfp_t mem_flags,
dma_addr_t *dma
)
{
if (!dev || !dev->bus)
return NULL;
return hcd_buffer_alloc (dev->bus, size, mem_flags, dma);
}
/**
* usb_buffer_free - free memory allocated with usb_buffer_alloc()
* @dev: device the buffer was used with
* @size: requested buffer size
* @addr: CPU address of buffer
* @dma: DMA address of buffer
*
* This reclaims an I/O buffer, letting it be reused. The memory must have
* been allocated using usb_buffer_alloc(), and the parameters must match
* those provided in that allocation request.
*/
void usb_buffer_free (
struct usb_device *dev,
size_t size,
void *addr,
dma_addr_t dma
)
{
if (!dev || !dev->bus)
return;
if (!addr)
return;
hcd_buffer_free (dev->bus, size, addr, dma);
}
/**
* usb_buffer_map - create DMA mapping(s) for an urb
* @urb: urb whose transfer_buffer/setup_packet will be mapped
*
* Return value is either null (indicating no buffer could be mapped), or
* the parameter. URB_NO_TRANSFER_DMA_MAP and URB_NO_SETUP_DMA_MAP are
* added to urb->transfer_flags if the operation succeeds. If the device
* is connected to this system through a non-DMA controller, this operation
* always succeeds.
*
* This call would normally be used for an urb which is reused, perhaps
* as the target of a large periodic transfer, with usb_buffer_dmasync()
* calls to synchronize memory and dma state.
*
* Reverse the effect of this call with usb_buffer_unmap().
*/
#if 0
struct urb *usb_buffer_map (struct urb *urb)
{
struct usb_bus *bus;
struct device *controller;
if (!urb
|| !urb->dev
|| !(bus = urb->dev->bus)
|| !(controller = bus->controller))
return NULL;
if (controller->dma_mask) {
urb->transfer_dma = dma_map_single (controller,
urb->transfer_buffer, urb->transfer_buffer_length,
usb_pipein (urb->pipe)
? DMA_FROM_DEVICE : DMA_TO_DEVICE);
if (usb_pipecontrol (urb->pipe))
urb->setup_dma = dma_map_single (controller,
urb->setup_packet,
sizeof (struct usb_ctrlrequest),
DMA_TO_DEVICE);
// FIXME generic api broken like pci, can't report errors
// if (urb->transfer_dma == DMA_ADDR_INVALID) return 0;
} else
urb->transfer_dma = ~0;
urb->transfer_flags |= (URB_NO_TRANSFER_DMA_MAP
| URB_NO_SETUP_DMA_MAP);
return urb;
}
#endif /* 0 */
/* XXX DISABLED, no users currently. If you wish to re-enable this
* XXX please determine whether the sync is to transfer ownership of
* XXX the buffer from device to cpu or vice verse, and thusly use the
* XXX appropriate _for_{cpu,device}() method. -DaveM
*/
#if 0
/**
* usb_buffer_dmasync - synchronize DMA and CPU view of buffer(s)
* @urb: urb whose transfer_buffer/setup_packet will be synchronized
*/
void usb_buffer_dmasync (struct urb *urb)
{
struct usb_bus *bus;
struct device *controller;
if (!urb
|| !(urb->transfer_flags & URB_NO_TRANSFER_DMA_MAP)
|| !urb->dev
|| !(bus = urb->dev->bus)
|| !(controller = bus->controller))
return;
if (controller->dma_mask) {
dma_sync_single (controller,
urb->transfer_dma, urb->transfer_buffer_length,
usb_pipein (urb->pipe)
? DMA_FROM_DEVICE : DMA_TO_DEVICE);
if (usb_pipecontrol (urb->pipe))
dma_sync_single (controller,
urb->setup_dma,
sizeof (struct usb_ctrlrequest),
DMA_TO_DEVICE);
}
}
#endif
/**
* usb_buffer_unmap - free DMA mapping(s) for an urb
* @urb: urb whose transfer_buffer will be unmapped
*
* Reverses the effect of usb_buffer_map().
*/
#if 0
void usb_buffer_unmap (struct urb *urb)
{
struct usb_bus *bus;
struct device *controller;
if (!urb
|| !(urb->transfer_flags & URB_NO_TRANSFER_DMA_MAP)
|| !urb->dev
|| !(bus = urb->dev->bus)
|| !(controller = bus->controller))
return;
if (controller->dma_mask) {
dma_unmap_single (controller,
urb->transfer_dma, urb->transfer_buffer_length,
usb_pipein (urb->pipe)
? DMA_FROM_DEVICE : DMA_TO_DEVICE);
if (usb_pipecontrol (urb->pipe))
dma_unmap_single (controller,
urb->setup_dma,
sizeof (struct usb_ctrlrequest),
DMA_TO_DEVICE);
}
urb->transfer_flags &= ~(URB_NO_TRANSFER_DMA_MAP
| URB_NO_SETUP_DMA_MAP);
}
#endif /* 0 */
/**
* usb_buffer_map_sg - create scatterlist DMA mapping(s) for an endpoint
* @dev: device to which the scatterlist will be mapped
* @pipe: endpoint defining the mapping direction
* @sg: the scatterlist to map
* @nents: the number of entries in the scatterlist
*
* Return value is either < 0 (indicating no buffers could be mapped), or
* the number of DMA mapping array entries in the scatterlist.
*
* The caller is responsible for placing the resulting DMA addresses from
* the scatterlist into URB transfer buffer pointers, and for setting the
* URB_NO_TRANSFER_DMA_MAP transfer flag in each of those URBs.
*
* Top I/O rates come from queuing URBs, instead of waiting for each one
* to complete before starting the next I/O. This is particularly easy
* to do with scatterlists. Just allocate and submit one URB for each DMA
* mapping entry returned, stopping on the first error or when all succeed.
* Better yet, use the usb_sg_*() calls, which do that (and more) for you.
*
* This call would normally be used when translating scatterlist requests,
* rather than usb_buffer_map(), since on some hardware (with IOMMUs) it
* may be able to coalesce mappings for improved I/O efficiency.
*
* Reverse the effect of this call with usb_buffer_unmap_sg().
*/
int usb_buffer_map_sg(const struct usb_device *dev, unsigned pipe,
struct scatterlist *sg, int nents)
{
struct usb_bus *bus;
struct device *controller;
if (!dev
|| usb_pipecontrol (pipe)
|| !(bus = dev->bus)
|| !(controller = bus->controller)
|| !controller->dma_mask)
return -1;
// FIXME generic api broken like pci, can't report errors
return dma_map_sg (controller, sg, nents,
usb_pipein (pipe) ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
}
/* XXX DISABLED, no users currently. If you wish to re-enable this
* XXX please determine whether the sync is to transfer ownership of
* XXX the buffer from device to cpu or vice verse, and thusly use the
* XXX appropriate _for_{cpu,device}() method. -DaveM
*/
#if 0
/**
* usb_buffer_dmasync_sg - synchronize DMA and CPU view of scatterlist buffer(s)
* @dev: device to which the scatterlist will be mapped
* @pipe: endpoint defining the mapping direction
* @sg: the scatterlist to synchronize
* @n_hw_ents: the positive return value from usb_buffer_map_sg
*
* Use this when you are re-using a scatterlist's data buffers for
* another USB request.
*/
void usb_buffer_dmasync_sg(const struct usb_device *dev, unsigned pipe,
struct scatterlist *sg, int n_hw_ents)
{
struct usb_bus *bus;
struct device *controller;
if (!dev
|| !(bus = dev->bus)
|| !(controller = bus->controller)
|| !controller->dma_mask)
return;
dma_sync_sg (controller, sg, n_hw_ents,
usb_pipein (pipe) ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
}
#endif
/**
* usb_buffer_unmap_sg - free DMA mapping(s) for a scatterlist
* @dev: device to which the scatterlist will be mapped
* @pipe: endpoint defining the mapping direction
* @sg: the scatterlist to unmap
* @n_hw_ents: the positive return value from usb_buffer_map_sg
*
* Reverses the effect of usb_buffer_map_sg().
*/
void usb_buffer_unmap_sg(const struct usb_device *dev, unsigned pipe,
struct scatterlist *sg, int n_hw_ents)
{
struct usb_bus *bus;
struct device *controller;
if (!dev
|| !(bus = dev->bus)
|| !(controller = bus->controller)
|| !controller->dma_mask)
return;
dma_unmap_sg (controller, sg, n_hw_ents,
usb_pipein (pipe) ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
}
/* format to disable USB on kernel command line is: nousb */
__module_param_call("", nousb, param_set_bool, param_get_bool, &nousb, 0444);
/*
* for external read access to <nousb>
*/
int usb_disabled(void)
{
return nousb;
}
/*
* Init
*/
static int __init usb_init(void)
{
int retval;
if (nousb) {
pr_info ("%s: USB support disabled\n", usbcore_name);
return 0;
}
retval = ksuspend_usb_init();
if (retval)
goto out;
retval = bus_register(&usb_bus_type);
if (retval)
goto bus_register_failed;
retval = usb_host_init();
if (retval)
goto host_init_failed;
retval = usb_major_init();
if (retval)
goto major_init_failed;
retval = usb_register(&usbfs_driver);
if (retval)
goto driver_register_failed;
retval = usbdev_init();
if (retval)
goto usbdevice_init_failed;
retval = usbfs_init();
if (retval)
goto fs_init_failed;
retval = usb_hub_init();
if (retval)
goto hub_init_failed;
retval = usb_register_device_driver(&usb_generic_driver, THIS_MODULE);
if (!retval)
goto out;
usb_hub_cleanup();
hub_init_failed:
usbfs_cleanup();
fs_init_failed:
usbdev_cleanup();
usbdevice_init_failed:
usb_deregister(&usbfs_driver);
driver_register_failed:
usb_major_cleanup();
major_init_failed:
usb_host_cleanup();
host_init_failed:
bus_unregister(&usb_bus_type);
bus_register_failed:
ksuspend_usb_cleanup();
out:
return retval;
}
/*
* Cleanup
*/
static void __exit usb_exit(void)
{
/* This will matter if shutdown/reboot does exitcalls. */
if (nousb)
return;
usb_deregister_device_driver(&usb_generic_driver);
usb_major_cleanup();
usbfs_cleanup();
usb_deregister(&usbfs_driver);
usbdev_cleanup();
usb_hub_cleanup();
usb_host_cleanup();
bus_unregister(&usb_bus_type);
ksuspend_usb_cleanup();
}
subsys_initcall(usb_init);
module_exit(usb_exit);
/*
* USB may be built into the kernel or be built as modules.
* These symbols are exported for device (or host controller)
* driver modules to use.
*/
EXPORT_SYMBOL(usb_disabled);
EXPORT_SYMBOL_GPL(usb_get_intf);
EXPORT_SYMBOL_GPL(usb_put_intf);
EXPORT_SYMBOL(usb_put_dev);
EXPORT_SYMBOL(usb_get_dev);
EXPORT_SYMBOL(usb_hub_tt_clear_buffer);
EXPORT_SYMBOL(usb_lock_device_for_reset);
EXPORT_SYMBOL(usb_find_interface);
EXPORT_SYMBOL(usb_ifnum_to_if);
EXPORT_SYMBOL(usb_altnum_to_altsetting);
EXPORT_SYMBOL(__usb_get_extra_descriptor);
EXPORT_SYMBOL(usb_find_device);
EXPORT_SYMBOL(usb_get_current_frame_number);
EXPORT_SYMBOL (usb_buffer_alloc);
EXPORT_SYMBOL (usb_buffer_free);
#if 0
EXPORT_SYMBOL (usb_buffer_map);
EXPORT_SYMBOL (usb_buffer_dmasync);
EXPORT_SYMBOL (usb_buffer_unmap);
#endif
EXPORT_SYMBOL (usb_buffer_map_sg);
#if 0
EXPORT_SYMBOL (usb_buffer_dmasync_sg);
#endif
EXPORT_SYMBOL (usb_buffer_unmap_sg);
MODULE_LICENSE("GPL");
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