linux/drivers/usb/core/usb.c

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/*
* drivers/usb/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/config.h>
#ifdef CONFIG_USB_DEBUG
#define DEBUG
#else
#undef DEBUG
#endif
#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/rwsem.h>
#include <linux/usb.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 */
/* Not honored on modular build */
static DECLARE_RWSEM(usb_all_devices_rwsem);
static int generic_probe (struct device *dev)
{
return 0;
}
static int generic_remove (struct device *dev)
{
return 0;
}
static struct device_driver usb_generic_driver = {
.owner = THIS_MODULE,
.name = "usb",
.bus = &usb_bus_type,
.probe = generic_probe,
.remove = generic_remove,
};
static int usb_generic_driver_data;
/* called from driver core with usb_bus_type.subsys writelock */
static int usb_probe_interface(struct device *dev)
{
struct usb_interface * intf = to_usb_interface(dev);
struct usb_driver * driver = to_usb_driver(dev->driver);
const struct usb_device_id *id;
int error = -ENODEV;
dev_dbg(dev, "%s\n", __FUNCTION__);
if (!driver->probe)
return error;
/* FIXME we'd much prefer to just resume it ... */
if (interface_to_usbdev(intf)->state == USB_STATE_SUSPENDED)
return -EHOSTUNREACH;
id = usb_match_id (intf, driver->id_table);
if (id) {
dev_dbg (dev, "%s - got id\n", __FUNCTION__);
intf->condition = USB_INTERFACE_BINDING;
error = driver->probe (intf, id);
intf->condition = error ? USB_INTERFACE_UNBOUND :
USB_INTERFACE_BOUND;
}
return error;
}
/* called from driver core with usb_bus_type.subsys writelock */
static int usb_unbind_interface(struct device *dev)
{
struct usb_interface *intf = to_usb_interface(dev);
struct usb_driver *driver = to_usb_driver(intf->dev.driver);
intf->condition = USB_INTERFACE_UNBINDING;
/* release all urbs for this interface */
usb_disable_interface(interface_to_usbdev(intf), intf);
if (driver && driver->disconnect)
driver->disconnect(intf);
/* reset other interface state */
usb_set_interface(interface_to_usbdev(intf),
intf->altsetting[0].desc.bInterfaceNumber,
0);
usb_set_intfdata(intf, NULL);
intf->condition = USB_INTERFACE_UNBOUND;
return 0;
}
/**
* usb_register - register a USB driver
* @new_driver: USB operations for the driver
*
* Registers a USB driver with the USB core. The list of unattached
* interfaces will be rescanned whenever a new driver is added, allowing
* the new driver to attach to any recognized devices.
* Returns a negative error code on failure and 0 on success.
*
* NOTE: if you want your driver to use the USB major number, you must call
* usb_register_dev() to enable that functionality. This function no longer
* takes care of that.
*/
int usb_register(struct usb_driver *new_driver)
{
int retval = 0;
if (nousb)
return -ENODEV;
new_driver->driver.name = (char *)new_driver->name;
new_driver->driver.bus = &usb_bus_type;
new_driver->driver.probe = usb_probe_interface;
new_driver->driver.remove = usb_unbind_interface;
new_driver->driver.owner = new_driver->owner;
usb_lock_all_devices();
retval = driver_register(&new_driver->driver);
usb_unlock_all_devices();
if (!retval) {
pr_info("%s: registered new driver %s\n",
usbcore_name, new_driver->name);
usbfs_update_special();
} else {
printk(KERN_ERR "%s: error %d registering driver %s\n",
usbcore_name, retval, new_driver->name);
}
return retval;
}
/**
* usb_deregister - unregister a USB driver
* @driver: USB operations of the driver to unregister
* Context: must be able to sleep
*
* Unlinks the specified driver from the internal USB driver list.
*
* NOTE: If you called usb_register_dev(), you still need to call
* usb_deregister_dev() to clean up your driver's allocated minor numbers,
* this * call will no longer do it for you.
*/
void usb_deregister(struct usb_driver *driver)
{
pr_info("%s: deregistering driver %s\n", usbcore_name, driver->name);
usb_lock_all_devices();
driver_unregister (&driver->driver);
usb_unlock_all_devices();
usbfs_update_special();
}
/**
* 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(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(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;
}
/**
* usb_driver_claim_interface - bind a driver to an interface
* @driver: the driver to be bound
* @iface: the interface to which it will be bound; must be in the
* usb device's active configuration
* @priv: driver data associated with that interface
*
* This is used by usb device drivers that need to claim more than one
* interface on a device when probing (audio and acm are current examples).
* No device driver should directly modify internal usb_interface or
* usb_device structure members.
*
* Few drivers should need to use this routine, since the most natural
* way to bind to an interface is to return the private data from
* the driver's probe() method.
*
* Callers must own the device lock and the driver model's usb_bus_type.subsys
* writelock. So driver probe() entries don't need extra locking,
* but other call contexts may need to explicitly claim those locks.
*/
int usb_driver_claim_interface(struct usb_driver *driver,
struct usb_interface *iface, void* priv)
{
struct device *dev = &iface->dev;
if (dev->driver)
return -EBUSY;
dev->driver = &driver->driver;
usb_set_intfdata(iface, priv);
iface->condition = USB_INTERFACE_BOUND;
/* if interface was already added, bind now; else let
* the future device_add() bind it, bypassing probe()
*/
if (klist_node_attached(&dev->knode_bus))
device_bind_driver(dev);
return 0;
}
/**
* usb_driver_release_interface - unbind a driver from an interface
* @driver: the driver to be unbound
* @iface: the interface from which it will be unbound
*
* This can be used by drivers to release an interface without waiting
* for their disconnect() methods to be called. In typical cases this
* also causes the driver disconnect() method to be called.
*
* This call is synchronous, and may not be used in an interrupt context.
* Callers must own the device lock and the driver model's usb_bus_type.subsys
* writelock. So driver disconnect() entries don't need extra locking,
* but other call contexts may need to explicitly claim those locks.
*/
void usb_driver_release_interface(struct usb_driver *driver,
struct usb_interface *iface)
{
struct device *dev = &iface->dev;
/* this should never happen, don't release something that's not ours */
if (!dev->driver || dev->driver != &driver->driver)
return;
/* don't release from within disconnect() */
if (iface->condition != USB_INTERFACE_BOUND)
return;
/* release only after device_add() */
if (klist_node_attached(&dev->knode_bus)) {
iface->condition = USB_INTERFACE_UNBINDING;
device_release_driver(dev);
}
dev->driver = NULL;
usb_set_intfdata(iface, NULL);
iface->condition = USB_INTERFACE_UNBOUND;
}
/**
* usb_match_id - find first usb_device_id matching device or interface
* @interface: the interface of interest
* @id: array of usb_device_id structures, terminated by zero entry
*
* usb_match_id searches an array of usb_device_id's and returns
* the first one matching the device or interface, or null.
* This is used when binding (or rebinding) a driver to an interface.
* Most USB device drivers will use this indirectly, through the usb core,
* but some layered driver frameworks use it directly.
* These device tables are exported with MODULE_DEVICE_TABLE, through
* modutils and "modules.usbmap", to support the driver loading
* functionality of USB hotplugging.
*
* What Matches:
*
* The "match_flags" element in a usb_device_id controls which
* members are used. If the corresponding bit is set, the
* value in the device_id must match its corresponding member
* in the device or interface descriptor, or else the device_id
* does not match.
*
* "driver_info" is normally used only by device drivers,
* but you can create a wildcard "matches anything" usb_device_id
* as a driver's "modules.usbmap" entry if you provide an id with
* only a nonzero "driver_info" field. If you do this, the USB device
* driver's probe() routine should use additional intelligence to
* decide whether to bind to the specified interface.
*
* What Makes Good usb_device_id Tables:
*
* The match algorithm is very simple, so that intelligence in
* driver selection must come from smart driver id records.
* Unless you have good reasons to use another selection policy,
* provide match elements only in related groups, and order match
* specifiers from specific to general. Use the macros provided
* for that purpose if you can.
*
* The most specific match specifiers use device descriptor
* data. These are commonly used with product-specific matches;
* the USB_DEVICE macro lets you provide vendor and product IDs,
* and you can also match against ranges of product revisions.
* These are widely used for devices with application or vendor
* specific bDeviceClass values.
*
* Matches based on device class/subclass/protocol specifications
* are slightly more general; use the USB_DEVICE_INFO macro, or
* its siblings. These are used with single-function devices
* where bDeviceClass doesn't specify that each interface has
* its own class.
*
* Matches based on interface class/subclass/protocol are the
* most general; they let drivers bind to any interface on a
* multiple-function device. Use the USB_INTERFACE_INFO
* macro, or its siblings, to match class-per-interface style
* devices (as recorded in bDeviceClass).
*
* Within those groups, remember that not all combinations are
* meaningful. For example, don't give a product version range
* without vendor and product IDs; or specify a protocol without
* its associated class and subclass.
*/
const struct usb_device_id *
usb_match_id(struct usb_interface *interface, const struct usb_device_id *id)
{
struct usb_host_interface *intf;
struct usb_device *dev;
/* proc_connectinfo in devio.c may call us with id == NULL. */
if (id == NULL)
return NULL;
intf = interface->cur_altsetting;
dev = interface_to_usbdev(interface);
/* It is important to check that id->driver_info is nonzero,
since an entry that is all zeroes except for a nonzero
id->driver_info is the way to create an entry that
indicates that the driver want to examine every
device and interface. */
for (; id->idVendor || id->bDeviceClass || id->bInterfaceClass ||
id->driver_info; id++) {
if ((id->match_flags & USB_DEVICE_ID_MATCH_VENDOR) &&
id->idVendor != le16_to_cpu(dev->descriptor.idVendor))
continue;
if ((id->match_flags & USB_DEVICE_ID_MATCH_PRODUCT) &&
id->idProduct != le16_to_cpu(dev->descriptor.idProduct))
continue;
/* No need to test id->bcdDevice_lo != 0, since 0 is never
greater than any unsigned number. */
if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_LO) &&
(id->bcdDevice_lo > le16_to_cpu(dev->descriptor.bcdDevice)))
continue;
if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_HI) &&
(id->bcdDevice_hi < le16_to_cpu(dev->descriptor.bcdDevice)))
continue;
if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_CLASS) &&
(id->bDeviceClass != dev->descriptor.bDeviceClass))
continue;
if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_SUBCLASS) &&
(id->bDeviceSubClass!= dev->descriptor.bDeviceSubClass))
continue;
if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_PROTOCOL) &&
(id->bDeviceProtocol != dev->descriptor.bDeviceProtocol))
continue;
if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_CLASS) &&
(id->bInterfaceClass != intf->desc.bInterfaceClass))
continue;
if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_SUBCLASS) &&
(id->bInterfaceSubClass != intf->desc.bInterfaceSubClass))
continue;
if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_PROTOCOL) &&
(id->bInterfaceProtocol != intf->desc.bInterfaceProtocol))
continue;
return id;
}
return NULL;
}
static int __find_interface(struct device * dev, void * data)
{
struct usb_interface ** ret = (struct usb_interface **)data;
struct usb_interface * intf = *ret;
int *minor = (int *)data;
/* can't look at usb devices, only interfaces */
if (dev->driver == &usb_generic_driver)
return 0;
intf = to_usb_interface(dev);
if (intf->minor != -1 && intf->minor == *minor) {
*ret = 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 usb_interface *intf = (struct usb_interface *)(long)minor;
int ret;
ret = driver_for_each_device(&drv->driver, NULL, &intf, __find_interface);
return ret ? intf : NULL;
}
static int usb_device_match (struct device *dev, struct device_driver *drv)
{
struct usb_interface *intf;
struct usb_driver *usb_drv;
const struct usb_device_id *id;
/* check for generic driver, which we don't match any device with */
if (drv == &usb_generic_driver)
return 0;
intf = to_usb_interface(dev);
usb_drv = to_usb_driver(drv);
id = usb_match_id (intf, usb_drv->id_table);
if (id)
return 1;
return 0;
}
#ifdef CONFIG_HOTPLUG
/*
* USB hotplugging invokes what /proc/sys/kernel/hotplug says
* (normally /sbin/hotplug) when USB devices get added or removed.
*
* This invokes a user mode policy agent, typically helping to load driver
* or other modules, configure the device, and more. Drivers can provide
* a MODULE_DEVICE_TABLE to help with module loading subtasks.
*
* We're called either from khubd (the typical case) or from root hub
* (init, kapmd, modprobe, rmmod, etc), but the agents need to handle
* delays in event delivery. Use sysfs (and DEVPATH) to make sure the
* device (and this configuration!) are still present.
*/
static int usb_hotplug (struct device *dev, char **envp, int num_envp,
char *buffer, int buffer_size)
{
struct usb_interface *intf;
struct usb_device *usb_dev;
int i = 0;
int length = 0;
if (!dev)
return -ENODEV;
/* driver is often null here; dev_dbg() would oops */
pr_debug ("usb %s: hotplug\n", dev->bus_id);
/* Must check driver_data here, as on remove driver is always NULL */
if ((dev->driver == &usb_generic_driver) ||
(dev->driver_data == &usb_generic_driver_data))
return 0;
intf = to_usb_interface(dev);
usb_dev = interface_to_usbdev (intf);
if (usb_dev->devnum < 0) {
pr_debug ("usb %s: already deleted?\n", dev->bus_id);
return -ENODEV;
}
if (!usb_dev->bus) {
pr_debug ("usb %s: bus removed?\n", dev->bus_id);
return -ENODEV;
}
#ifdef CONFIG_USB_DEVICEFS
/* If this is available, userspace programs can directly read
* all the device descriptors we don't tell them about. Or
* even act as usermode drivers.
*
* FIXME reduce hardwired intelligence here
*/
if (add_hotplug_env_var(envp, num_envp, &i,
buffer, buffer_size, &length,
"DEVICE=/proc/bus/usb/%03d/%03d",
usb_dev->bus->busnum, usb_dev->devnum))
return -ENOMEM;
#endif
/* per-device configurations are common */
if (add_hotplug_env_var(envp, num_envp, &i,
buffer, buffer_size, &length,
"PRODUCT=%x/%x/%x",
le16_to_cpu(usb_dev->descriptor.idVendor),
le16_to_cpu(usb_dev->descriptor.idProduct),
le16_to_cpu(usb_dev->descriptor.bcdDevice)))
return -ENOMEM;
/* class-based driver binding models */
if (add_hotplug_env_var(envp, num_envp, &i,
buffer, buffer_size, &length,
"TYPE=%d/%d/%d",
usb_dev->descriptor.bDeviceClass,
usb_dev->descriptor.bDeviceSubClass,
usb_dev->descriptor.bDeviceProtocol))
return -ENOMEM;
if (usb_dev->descriptor.bDeviceClass == 0) {
struct usb_host_interface *alt = intf->cur_altsetting;
/* 2.4 only exposed interface zero. in 2.5, hotplug
* agents are called for all interfaces, and can use
* $DEVPATH/bInterfaceNumber if necessary.
*/
if (add_hotplug_env_var(envp, num_envp, &i,
buffer, buffer_size, &length,
"INTERFACE=%d/%d/%d",
alt->desc.bInterfaceClass,
alt->desc.bInterfaceSubClass,
alt->desc.bInterfaceProtocol))
return -ENOMEM;
if (add_hotplug_env_var(envp, num_envp, &i,
buffer, buffer_size, &length,
"MODALIAS=usb:v%04Xp%04Xd%04Xdc%02Xdsc%02Xdp%02Xic%02Xisc%02Xip%02X",
le16_to_cpu(usb_dev->descriptor.idVendor),
le16_to_cpu(usb_dev->descriptor.idProduct),
le16_to_cpu(usb_dev->descriptor.bcdDevice),
usb_dev->descriptor.bDeviceClass,
usb_dev->descriptor.bDeviceSubClass,
usb_dev->descriptor.bDeviceProtocol,
alt->desc.bInterfaceClass,
alt->desc.bInterfaceSubClass,
alt->desc.bInterfaceProtocol))
return -ENOMEM;
} else {
if (add_hotplug_env_var(envp, num_envp, &i,
buffer, buffer_size, &length,
"MODALIAS=usb:v%04Xp%04Xd%04Xdc%02Xdsc%02Xdp%02Xic*isc*ip*",
le16_to_cpu(usb_dev->descriptor.idVendor),
le16_to_cpu(usb_dev->descriptor.idProduct),
le16_to_cpu(usb_dev->descriptor.bcdDevice),
usb_dev->descriptor.bDeviceClass,
usb_dev->descriptor.bDeviceSubClass,
usb_dev->descriptor.bDeviceProtocol))
return -ENOMEM;
}
envp[i] = NULL;
return 0;
}
#else
static int usb_hotplug (struct device *dev, char **envp,
int num_envp, char *buffer, int buffer_size)
{
return -ENODEV;
}
#endif /* CONFIG_HOTPLUG */
/**
* 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);
usb_destroy_configuration(udev);
usb_bus_put(udev->bus);
kfree(udev->product);
kfree(udev->manufacturer);
kfree(udev->serial);
kfree(udev);
}
/**
* 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 = kmalloc(sizeof(*dev), GFP_KERNEL);
if (!dev)
return NULL;
memset(dev, 0, sizeof(*dev));
bus = usb_bus_get(bus);
if (!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.driver_data = &usb_generic_driver_data;
dev->dev.driver = &usb_generic_driver;
dev->dev.release = usb_release_dev;
dev->state = USB_STATE_ATTACHED;
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->bus = bus;
dev->parent = parent;
INIT_LIST_HEAD(&dev->filelist);
init_MUTEX(&dev->serialize);
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
*
* Although locking USB devices should be straightforward, it is
* complicated by the way the driver-model core works. When a new USB
* driver is registered or unregistered, the core will automatically
* probe or disconnect all matching interfaces on all USB devices while
* holding the USB subsystem writelock. There's no good way for us to
* tell which devices will be used or to lock them beforehand; our only
* option is to effectively lock all the USB devices.
*
* We do that by using a private rw-semaphore, usb_all_devices_rwsem.
* When locking an individual device you must first acquire the rwsem's
* readlock. When a driver is registered or unregistered the writelock
* must be held. These actions are encapsulated in the subroutines
* below, so all a driver needs to do is call usb_lock_device() and
* usb_unlock_device().
*
* 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 problem is that
* usb_lock_device() must not be called to lock a second device since it
* would acquire the rwsem's readlock reentrantly, leading to deadlock if
* another thread was waiting for the writelock. The solution is simple:
*
* When locking more than one device, call usb_lock_device()
* to lock the first one. Lock the others by calling
* down(&udev->serialize) directly.
*
* When unlocking multiple devices, use up(&udev->serialize)
* to unlock all but the last one. Unlock the last one by
* calling usb_unlock_device().
*
* When locking both a device and its parent, always lock the
* the parent first.
*/
/**
* usb_lock_device - acquire the lock for a usb device structure
* @udev: device that's being locked
*
* Use this routine when you don't hold any other device locks;
* to acquire nested inner locks call down(&udev->serialize) directly.
* This is necessary for proper interaction with usb_lock_all_devices().
*/
void usb_lock_device(struct usb_device *udev)
{
down_read(&usb_all_devices_rwsem);
down(&udev->serialize);
}
/**
* usb_trylock_device - attempt to acquire the lock for a usb device structure
* @udev: device that's being locked
*
* Don't use this routine if you already hold a device lock;
* use down_trylock(&udev->serialize) instead.
* This is necessary for proper interaction with usb_lock_all_devices().
*
* Returns 1 if successful, 0 if contention.
*/
int usb_trylock_device(struct usb_device *udev)
{
if (!down_read_trylock(&usb_all_devices_rwsem))
return 0;
if (down_trylock(&udev->serialize)) {
up_read(&usb_all_devices_rwsem);
return 0;
}
return 1;
}
/**
* 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()
* callback 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,
struct usb_interface *iface)
{
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)) {
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;
}
/**
* usb_unlock_device - release the lock for a usb device structure
* @udev: device that's being unlocked
*
* Use this routine when releasing the only device lock you hold;
* to release inner nested locks call up(&udev->serialize) directly.
* This is necessary for proper interaction with usb_lock_all_devices().
*/
void usb_unlock_device(struct usb_device *udev)
{
up(&udev->serialize);
up_read(&usb_all_devices_rwsem);
}
/**
* usb_lock_all_devices - acquire the lock for all usb device structures
*
* This is necessary when registering a new driver or probing a bus,
* since the driver-model core may try to use any usb_device.
*/
void usb_lock_all_devices(void)
{
down_write(&usb_all_devices_rwsem);
}
/**
* usb_unlock_all_devices - release the lock for all usb device structures
*/
void usb_unlock_all_devices(void)
{
up_write(&usb_all_devices_rwsem);
}
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]) {
down(&dev->children[child]->serialize);
ret_dev = match_device(dev->children[child],
vendor_id, product_id);
up(&dev->children[child]->serialize);
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;
down(&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:
up(&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 dev->bus->op->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,
unsigned mem_flags,
dma_addr_t *dma
)
{
if (!dev || !dev->bus || !dev->bus->op || !dev->bus->op->buffer_alloc)
return NULL;
return dev->bus->op->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 || !dev->bus->op || !dev->bus->op->buffer_free)
return;
dev->bus->op->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 (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 (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 (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);
}
static int usb_generic_suspend(struct device *dev, pm_message_t message)
{
struct usb_interface *intf;
struct usb_driver *driver;
if (dev->driver == &usb_generic_driver)
return usb_suspend_device (to_usb_device(dev), message);
if ((dev->driver == NULL) ||
(dev->driver_data == &usb_generic_driver_data))
return 0;
intf = to_usb_interface(dev);
driver = to_usb_driver(dev->driver);
/* there's only one USB suspend state */
if (intf->dev.power.power_state.event)
return 0;
if (driver->suspend)
return driver->suspend(intf, message);
return 0;
}
static int usb_generic_resume(struct device *dev)
{
struct usb_interface *intf;
struct usb_driver *driver;
/* devices resume through their hub */
if (dev->driver == &usb_generic_driver)
return usb_resume_device (to_usb_device(dev));
if ((dev->driver == NULL) ||
(dev->driver_data == &usb_generic_driver_data))
return 0;
intf = to_usb_interface(dev);
driver = to_usb_driver(dev->driver);
if (driver->resume)
return driver->resume(intf);
return 0;
}
struct bus_type usb_bus_type = {
.name = "usb",
.match = usb_device_match,
.hotplug = usb_hotplug,
.suspend = usb_generic_suspend,
.resume = usb_generic_resume,
};
#ifndef MODULE
static int __init usb_setup_disable(char *str)
{
nousb = 1;
return 1;
}
/* format to disable USB on kernel command line is: nousb */
__setup("nousb", usb_setup_disable);
#endif
/*
* 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 = bus_register(&usb_bus_type);
if (retval)
goto out;
retval = usb_host_init();
if (retval)
goto host_init_failed;
retval = usb_major_init();
if (retval)
goto major_init_failed;
[PATCH] USB: real nodes instead of usbfs This patch introduces a /sys/class/usb_device/ class where every connected usb-device will show up: tree /sys/class/usb_device/ /sys/class/usb_device/ |-- usb1.1 | |-- dev | `-- device -> ../../../devices/pci0000:00/0000:00:1d.0/usb1 |-- usb2.1 | |-- dev | `-- device -> ../../../devices/pci0000:00/0000:00:1d.1/usb2 ... The presence of the "dev" file lets udev create real device nodes. kay@pim:~/src/linux-2.6> tree /dev/bus/usb/ /dev/bus/usb/ |-- 1 | `-- 1 |-- 2 | `-- 1 ... udev rule: SUBSYSTEM="usb_device", PROGRAM="/sbin/usb_device %k", NAME="%c" (echo $1 | /bin/sed 's/usb\([0-9]*\)\.\([0-9]*\)/bus\/usb\/\1\/\2/') This makes libusb pick up the real nodes instead of the mounted usbfs: export USB_DEVFS_PATH=/dev/bus/usb Background: All this makes it possible to manage usb devices with udev instead of the devfs solution. We are currently working on a pam_console/resmgr replacement driven by udev and a pam-helper. It applies ACL's to device nodes, which is required for modern desktop functionalty like "Fast User Switching" or multiple local login support. New patch with its own major. I've succesfully disabled usbfs and use real nodes only on my box. With: "export USB_DEVFS_PATH=/dev/bus/usb" libusb picks up the udev managed nodes instead of reading usbfs files. This makes udev to provide symlinks for libusb to pick up: SUBSYSTEM="usb_device", PROGRAM="/sbin/usbdevice %k", SYMLINK="%c" /sbin/usbdevice: #!/bin/sh echo $1 | /bin/sed 's/usbdev\([0-9]*\)\.\([0-9]*\)/bus\/usb\/\1\/\2/' Signed-off-by: Kay Sievers <kay.sievers@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2005-07-31 07:05:53 +08:00
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 = driver_register(&usb_generic_driver);
if (!retval)
goto out;
usb_hub_cleanup();
hub_init_failed:
usbfs_cleanup();
fs_init_failed:
[PATCH] USB: real nodes instead of usbfs This patch introduces a /sys/class/usb_device/ class where every connected usb-device will show up: tree /sys/class/usb_device/ /sys/class/usb_device/ |-- usb1.1 | |-- dev | `-- device -> ../../../devices/pci0000:00/0000:00:1d.0/usb1 |-- usb2.1 | |-- dev | `-- device -> ../../../devices/pci0000:00/0000:00:1d.1/usb2 ... The presence of the "dev" file lets udev create real device nodes. kay@pim:~/src/linux-2.6> tree /dev/bus/usb/ /dev/bus/usb/ |-- 1 | `-- 1 |-- 2 | `-- 1 ... udev rule: SUBSYSTEM="usb_device", PROGRAM="/sbin/usb_device %k", NAME="%c" (echo $1 | /bin/sed 's/usb\([0-9]*\)\.\([0-9]*\)/bus\/usb\/\1\/\2/') This makes libusb pick up the real nodes instead of the mounted usbfs: export USB_DEVFS_PATH=/dev/bus/usb Background: All this makes it possible to manage usb devices with udev instead of the devfs solution. We are currently working on a pam_console/resmgr replacement driven by udev and a pam-helper. It applies ACL's to device nodes, which is required for modern desktop functionalty like "Fast User Switching" or multiple local login support. New patch with its own major. I've succesfully disabled usbfs and use real nodes only on my box. With: "export USB_DEVFS_PATH=/dev/bus/usb" libusb picks up the udev managed nodes instead of reading usbfs files. This makes udev to provide symlinks for libusb to pick up: SUBSYSTEM="usb_device", PROGRAM="/sbin/usbdevice %k", SYMLINK="%c" /sbin/usbdevice: #!/bin/sh echo $1 | /bin/sed 's/usbdev\([0-9]*\)\.\([0-9]*\)/bus\/usb\/\1\/\2/' Signed-off-by: Kay Sievers <kay.sievers@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2005-07-31 07:05:53 +08:00
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);
out:
return retval;
}
/*
* Cleanup
*/
static void __exit usb_exit(void)
{
/* This will matter if shutdown/reboot does exitcalls. */
if (nousb)
return;
driver_unregister(&usb_generic_driver);
usb_major_cleanup();
usbfs_cleanup();
[PATCH] USB: real nodes instead of usbfs This patch introduces a /sys/class/usb_device/ class where every connected usb-device will show up: tree /sys/class/usb_device/ /sys/class/usb_device/ |-- usb1.1 | |-- dev | `-- device -> ../../../devices/pci0000:00/0000:00:1d.0/usb1 |-- usb2.1 | |-- dev | `-- device -> ../../../devices/pci0000:00/0000:00:1d.1/usb2 ... The presence of the "dev" file lets udev create real device nodes. kay@pim:~/src/linux-2.6> tree /dev/bus/usb/ /dev/bus/usb/ |-- 1 | `-- 1 |-- 2 | `-- 1 ... udev rule: SUBSYSTEM="usb_device", PROGRAM="/sbin/usb_device %k", NAME="%c" (echo $1 | /bin/sed 's/usb\([0-9]*\)\.\([0-9]*\)/bus\/usb\/\1\/\2/') This makes libusb pick up the real nodes instead of the mounted usbfs: export USB_DEVFS_PATH=/dev/bus/usb Background: All this makes it possible to manage usb devices with udev instead of the devfs solution. We are currently working on a pam_console/resmgr replacement driven by udev and a pam-helper. It applies ACL's to device nodes, which is required for modern desktop functionalty like "Fast User Switching" or multiple local login support. New patch with its own major. I've succesfully disabled usbfs and use real nodes only on my box. With: "export USB_DEVFS_PATH=/dev/bus/usb" libusb picks up the udev managed nodes instead of reading usbfs files. This makes udev to provide symlinks for libusb to pick up: SUBSYSTEM="usb_device", PROGRAM="/sbin/usbdevice %k", SYMLINK="%c" /sbin/usbdevice: #!/bin/sh echo $1 | /bin/sed 's/usbdev\([0-9]*\)\.\([0-9]*\)/bus\/usb\/\1\/\2/' Signed-off-by: Kay Sievers <kay.sievers@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2005-07-31 07:05:53 +08:00
usb_deregister(&usbfs_driver);
usbdev_cleanup();
usb_hub_cleanup();
usb_host_cleanup();
bus_unregister(&usb_bus_type);
}
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_register);
EXPORT_SYMBOL(usb_deregister);
EXPORT_SYMBOL(usb_disabled);
EXPORT_SYMBOL_GPL(usb_get_intf);
EXPORT_SYMBOL_GPL(usb_put_intf);
EXPORT_SYMBOL(usb_alloc_dev);
EXPORT_SYMBOL(usb_put_dev);
EXPORT_SYMBOL(usb_get_dev);
EXPORT_SYMBOL(usb_hub_tt_clear_buffer);
EXPORT_SYMBOL(usb_lock_device);
EXPORT_SYMBOL(usb_trylock_device);
EXPORT_SYMBOL(usb_lock_device_for_reset);
EXPORT_SYMBOL(usb_unlock_device);
EXPORT_SYMBOL(usb_driver_claim_interface);
EXPORT_SYMBOL(usb_driver_release_interface);
EXPORT_SYMBOL(usb_match_id);
EXPORT_SYMBOL(usb_find_interface);
EXPORT_SYMBOL(usb_ifnum_to_if);
EXPORT_SYMBOL(usb_altnum_to_altsetting);
EXPORT_SYMBOL(usb_reset_device);
EXPORT_SYMBOL(usb_disconnect);
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");