OpenSDV
/
linux-stable-rt
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity
linux-stable-rt/drivers/usb/core/usb.c

1576 lines
46 KiB
C
Raw Blame History

/*
* 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,
int 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)
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;
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:
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();
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(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");
Reference in New Issue View Git Blame Copy Permalink