Linux-2.6.33.2/drivers/usb/core/driver.c
/*
* drivers/usb/driver.c - most of the driver model stuff for usb
*
* (C) Copyright 2005 Greg Kroah-Hartman <gregkh@suse.de>
*
* based on drivers/usb/usb.c which had the following copyrights:
* (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
* matching, probing, releasing, suspending and resuming for
* real drivers.
*
*/
#include <linux/device.h>
#include <linux/usb.h>
#include <linux/usb/quirks.h>
#include <linux/workqueue.h>
#include "hcd.h"
#include "usb.h"
#ifdef CONFIG_HOTPLUG
/*
* Adds a new dynamic USBdevice ID to this driver,
* and cause the driver to probe for all devices again.
*/
ssize_t usb_store_new_id(struct usb_dynids *dynids,
struct device_driver *driver,
const char *buf, size_t count)
{
struct usb_dynid *dynid;
u32 idVendor = 0;
u32 idProduct = 0;
int fields = 0;
int retval = 0;
fields = sscanf(buf, "%x %x", &idVendor, &idProduct);
if (fields < 2)
return -EINVAL;
dynid = kzalloc(sizeof(*dynid), GFP_KERNEL);
if (!dynid)
return -ENOMEM;
INIT_LIST_HEAD(&dynid->node);
dynid->id.idVendor = idVendor;
dynid->id.idProduct = idProduct;
dynid->id.match_flags = USB_DEVICE_ID_MATCH_DEVICE;
spin_lock(&dynids->lock);
list_add_tail(&dynid->node, &dynids->list);
spin_unlock(&dynids->lock);
if (get_driver(driver)) {
retval = driver_attach(driver);
put_driver(driver);
}
if (retval)
return retval;
return count;
}
EXPORT_SYMBOL_GPL(usb_store_new_id);
static ssize_t store_new_id(struct device_driver *driver,
const char *buf, size_t count)
{
struct usb_driver *usb_drv = to_usb_driver(driver);
return usb_store_new_id(&usb_drv->dynids, driver, buf, count);
}
static DRIVER_ATTR(new_id, S_IWUSR, NULL, store_new_id);
/**
* store_remove_id - remove a USB device ID from this driver
* @driver: target device driver
* @buf: buffer for scanning device ID data
* @count: input size
*
* Removes a dynamic usb device ID from this driver.
*/
static ssize_t
store_remove_id(struct device_driver *driver, const char *buf, size_t count)
{
struct usb_dynid *dynid, *n;
struct usb_driver *usb_driver = to_usb_driver(driver);
u32 idVendor = 0;
u32 idProduct = 0;
int fields = 0;
int retval = 0;
fields = sscanf(buf, "%x %x", &idVendor, &idProduct);
if (fields < 2)
return -EINVAL;
spin_lock(&usb_driver->dynids.lock);
list_for_each_entry_safe(dynid, n, &usb_driver->dynids.list, node) {
struct usb_device_id *id = &dynid->id;
if ((id->idVendor == idVendor) &&
(id->idProduct == idProduct)) {
list_del(&dynid->node);
kfree(dynid);
retval = 0;
break;
}
}
spin_unlock(&usb_driver->dynids.lock);
if (retval)
return retval;
return count;
}
static DRIVER_ATTR(remove_id, S_IWUSR, NULL, store_remove_id);
static int usb_create_newid_file(struct usb_driver *usb_drv)
{
int error = 0;
if (usb_drv->no_dynamic_id)
goto exit;
if (usb_drv->probe != NULL)
error = driver_create_file(&usb_drv->drvwrap.driver,
&driver_attr_new_id);
exit:
return error;
}
static void usb_remove_newid_file(struct usb_driver *usb_drv)
{
if (usb_drv->no_dynamic_id)
return;
if (usb_drv->probe != NULL)
driver_remove_file(&usb_drv->drvwrap.driver,
&driver_attr_new_id);
}
static int
usb_create_removeid_file(struct usb_driver *drv)
{
int error = 0;
if (drv->probe != NULL)
error = driver_create_file(&drv->drvwrap.driver,
&driver_attr_remove_id);
return error;
}
static void usb_remove_removeid_file(struct usb_driver *drv)
{
driver_remove_file(&drv->drvwrap.driver, &driver_attr_remove_id);
}
static void usb_free_dynids(struct usb_driver *usb_drv)
{
struct usb_dynid *dynid, *n;
spin_lock(&usb_drv->dynids.lock);
list_for_each_entry_safe(dynid, n, &usb_drv->dynids.list, node) {
list_del(&dynid->node);
kfree(dynid);
}
spin_unlock(&usb_drv->dynids.lock);
}
#else
static inline int usb_create_newid_file(struct usb_driver *usb_drv)
{
return 0;
}
static void usb_remove_newid_file(struct usb_driver *usb_drv)
{
}
static int
usb_create_removeid_file(struct usb_driver *drv)
{
return 0;
}
static void usb_remove_removeid_file(struct usb_driver *drv)
{
}
static inline void usb_free_dynids(struct usb_driver *usb_drv)
{
}
#endif
static const struct usb_device_id *usb_match_dynamic_id(struct usb_interface *intf,
struct usb_driver *drv)
{
struct usb_dynid *dynid;
spin_lock(&drv->dynids.lock);
list_for_each_entry(dynid, &drv->dynids.list, node) {
if (usb_match_one_id(intf, &dynid->id)) {
spin_unlock(&drv->dynids.lock);
return &dynid->id;
}
}
spin_unlock(&drv->dynids.lock);
return NULL;
}
/* called from driver core with dev locked */
static int usb_probe_device(struct device *dev)
{
struct usb_device_driver *udriver = to_usb_device_driver(dev->driver);
struct usb_device *udev = to_usb_device(dev);
int error = -ENODEV;
dev_dbg(dev, "%s\n", __func__);
/* TODO: Add real matching code */
/* The device should always appear to be in use
* unless the driver suports autosuspend.
*/
udev->pm_usage_cnt = !(udriver->supports_autosuspend);
error = udriver->probe(udev);
return error;
}
/* called from driver core with dev locked */
static int usb_unbind_device(struct device *dev)
{
struct usb_device_driver *udriver = to_usb_device_driver(dev->driver);
udriver->disconnect(to_usb_device(dev));
return 0;
}
/*
* Cancel any pending scheduled resets
*
* [see usb_queue_reset_device()]
*
* Called after unconfiguring / when releasing interfaces. See
* comments in __usb_queue_reset_device() regarding
* udev->reset_running.
*/
static void usb_cancel_queued_reset(struct usb_interface *iface)
{
if (iface->reset_running == 0)
cancel_work_sync(&iface->reset_ws);
}
/* called from driver core with dev locked */
static int usb_probe_interface(struct device *dev)
{
struct usb_driver *driver = to_usb_driver(dev->driver);
struct usb_interface *intf = to_usb_interface(dev);
struct usb_device *udev = interface_to_usbdev(intf);
const struct usb_device_id *id;
int error = -ENODEV;
dev_dbg(dev, "%s\n", __func__);
intf->needs_binding = 0;
if (usb_device_is_owned(udev))
return -ENODEV;
if (udev->authorized == 0) {
dev_err(&intf->dev, "Device is not authorized for usage\n");
return -ENODEV;
}
id = usb_match_id(intf, driver->id_table);
if (!id)
id = usb_match_dynamic_id(intf, driver);
if (id) {
dev_dbg(dev, "%s - got id\n", __func__);
error = usb_autoresume_device(udev);
if (error)
return error;
/* Interface "power state" doesn't correspond to any hardware
* state whatsoever. We use it to record when it's bound to
* a driver that may start I/0: it's not frozen/quiesced.
*/
mark_active(intf);
intf->condition = USB_INTERFACE_BINDING;
/* The interface should always appear to be in use
* unless the driver suports autosuspend.
*/
atomic_set(&intf->pm_usage_cnt, !driver->supports_autosuspend);
/* Carry out a deferred switch to altsetting 0 */
if (intf->needs_altsetting0) {
error = usb_set_interface(udev, intf->altsetting[0].
desc.bInterfaceNumber, 0);
if (error < 0)
goto err;
intf->needs_altsetting0 = 0;
}
error = driver->probe(intf, id);
if (error)
goto err;
intf->condition = USB_INTERFACE_BOUND;
usb_autosuspend_device(udev);
}
return error;
err:
mark_quiesced(intf);
intf->needs_remote_wakeup = 0;
intf->condition = USB_INTERFACE_UNBOUND;
usb_cancel_queued_reset(intf);
usb_autosuspend_device(udev);
return error;
}
/* called from driver core with dev locked */
static int usb_unbind_interface(struct device *dev)
{
struct usb_driver *driver = to_usb_driver(dev->driver);
struct usb_interface *intf = to_usb_interface(dev);
struct usb_device *udev;
int error, r;
intf->condition = USB_INTERFACE_UNBINDING;
/* Autoresume for set_interface call below */
udev = interface_to_usbdev(intf);
error = usb_autoresume_device(udev);
/* Terminate all URBs for this interface unless the driver
* supports "soft" unbinding.
*/
if (!driver->soft_unbind)
usb_disable_interface(udev, intf, false);
driver->disconnect(intf);
usb_cancel_queued_reset(intf);
/* Reset other interface state.
* We cannot do a Set-Interface if the device is suspended or
* if it is prepared for a system sleep (since installing a new
* altsetting means creating new endpoint device entries).
* When either of these happens, defer the Set-Interface.
*/
if (intf->cur_altsetting->desc.bAlternateSetting == 0) {
/* Already in altsetting 0 so skip Set-Interface.
* Just re-enable it without affecting the endpoint toggles.
*/
usb_enable_interface(udev, intf, false);
} else if (!error && intf->dev.power.status == DPM_ON) {
r = usb_set_interface(udev, intf->altsetting[0].
desc.bInterfaceNumber, 0);
if (r < 0)
intf->needs_altsetting0 = 1;
} else {
intf->needs_altsetting0 = 1;
}
usb_set_intfdata(intf, NULL);
intf->condition = USB_INTERFACE_UNBOUND;
mark_quiesced(intf);
intf->needs_remote_wakeup = 0;
if (!error)
usb_autosuspend_device(udev);
return 0;
}
/**
* 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, so driver probe() entries don't need
* extra locking, but other call contexts may need to explicitly claim that
* lock.
*/
int usb_driver_claim_interface(struct usb_driver *driver,
struct usb_interface *iface, void *priv)
{
struct device *dev = &iface->dev;
struct usb_device *udev = interface_to_usbdev(iface);
int retval = 0;
if (dev->driver)
return -EBUSY;
dev->driver = &driver->drvwrap.driver;
usb_set_intfdata(iface, priv);
iface->needs_binding = 0;
usb_pm_lock(udev);
iface->condition = USB_INTERFACE_BOUND;
mark_active(iface);
atomic_set(&iface->pm_usage_cnt, !driver->supports_autosuspend);
usb_pm_unlock(udev);
/* if interface was already added, bind now; else let
* the future device_add() bind it, bypassing probe()
*/
if (device_is_registered(dev))
retval = device_bind_driver(dev);
return retval;
}
EXPORT_SYMBOL_GPL(usb_driver_claim_interface);
/**
* 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, so driver disconnect() entries don't
* need extra locking, but other call contexts may need to explicitly claim
* that lock.
*/
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->drvwrap.driver)
return;
/* don't release from within disconnect() */
if (iface->condition != USB_INTERFACE_BOUND)
return;
iface->condition = USB_INTERFACE_UNBINDING;
/* Release via the driver core only if the interface
* has already been registered
*/
if (device_is_registered(dev)) {
device_release_driver(dev);
} else {
down(&dev->sem);
usb_unbind_interface(dev);
dev->driver = NULL;
up(&dev->sem);
}
}
EXPORT_SYMBOL_GPL(usb_driver_release_interface);
/* returns 0 if no match, 1 if match */
int usb_match_device(struct usb_device *dev, const struct usb_device_id *id)
{
if ((id->match_flags & USB_DEVICE_ID_MATCH_VENDOR) &&
id->idVendor != le16_to_cpu(dev->descriptor.idVendor))
return 0;
if ((id->match_flags & USB_DEVICE_ID_MATCH_PRODUCT) &&
id->idProduct != le16_to_cpu(dev->descriptor.idProduct))
return 0;
/* 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)))
return 0;
if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_HI) &&
(id->bcdDevice_hi < le16_to_cpu(dev->descriptor.bcdDevice)))
return 0;
if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_CLASS) &&
(id->bDeviceClass != dev->descriptor.bDeviceClass))
return 0;
if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_SUBCLASS) &&
(id->bDeviceSubClass != dev->descriptor.bDeviceSubClass))
return 0;
if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_PROTOCOL) &&
(id->bDeviceProtocol != dev->descriptor.bDeviceProtocol))
return 0;
return 1;
}
/* returns 0 if no match, 1 if match */
int usb_match_one_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 0;
intf = interface->cur_altsetting;
dev = interface_to_usbdev(interface);
if (!usb_match_device(dev, id))
return 0;
/* The interface class, subclass, and protocol should never be
* checked for a match if the device class is Vendor Specific,
* unless the match record specifies the Vendor ID. */
if (dev->descriptor.bDeviceClass == USB_CLASS_VENDOR_SPEC &&
!(id->match_flags & USB_DEVICE_ID_MATCH_VENDOR) &&
(id->match_flags & (USB_DEVICE_ID_MATCH_INT_CLASS |
USB_DEVICE_ID_MATCH_INT_SUBCLASS |
USB_DEVICE_ID_MATCH_INT_PROTOCOL)))
return 0;
if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_CLASS) &&
(id->bInterfaceClass != intf->desc.bInterfaceClass))
return 0;
if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_SUBCLASS) &&
(id->bInterfaceSubClass != intf->desc.bInterfaceSubClass))
return 0;
if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_PROTOCOL) &&
(id->bInterfaceProtocol != intf->desc.bInterfaceProtocol))
return 0;
return 1;
}
EXPORT_SYMBOL_GPL(usb_match_one_id);
/**
* 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, 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 bInterfaceClass).
*
* Note that an entry created by USB_INTERFACE_INFO won't match
* any interface if the device class is set to Vendor-Specific.
* This is deliberate; according to the USB spec the meanings of
* the interface class/subclass/protocol for these devices are also
* vendor-specific, and hence matching against a standard product
* class wouldn't work anyway. If you really want to use an
* interface-based match for such a device, create a match record
* that also specifies the vendor ID. (Unforunately there isn't a
* standard macro for creating records like this.)
*
* 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)
{
/* proc_connectinfo in devio.c may call us with id == NULL. */
if (id == NULL)
return NULL;
/* 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->idProduct || id->bDeviceClass ||
id->bInterfaceClass || id->driver_info; id++) {
if (usb_match_one_id(interface, id))
return id;
}
return NULL;
}
EXPORT_SYMBOL_GPL(usb_match_id);
static int usb_device_match(struct device *dev, struct device_driver *drv)
{
/* devices and interfaces are handled separately */
if (is_usb_device(dev)) {
/* interface drivers never match devices */
if (!is_usb_device_driver(drv))
return 0;
/* TODO: Add real matching code */
return 1;
} else if (is_usb_interface(dev)) {
struct usb_interface *intf;
struct usb_driver *usb_drv;
const struct usb_device_id *id;
/* device drivers never match interfaces */
if (is_usb_device_driver(drv))
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;
id = usb_match_dynamic_id(intf, usb_drv);
if (id)
return 1;
}
return 0;
}
#ifdef CONFIG_HOTPLUG
static int usb_uevent(struct device *dev, struct kobj_uevent_env *env)
{
struct usb_device *usb_dev;
if (is_usb_device(dev)) {
usb_dev = to_usb_device(dev);
} else if (is_usb_interface(dev)) {
struct usb_interface *intf = to_usb_interface(dev);
usb_dev = interface_to_usbdev(intf);
} else {
return 0;
}
if (usb_dev->devnum < 0) {
/* driver is often null here; dev_dbg() would oops */
pr_debug("usb %s: already deleted?\n", dev_name(dev));
return -ENODEV;
}
if (!usb_dev->bus) {
pr_debug("usb %s: bus removed?\n", dev_name(dev));
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
* act as usermode drivers.
*/
if (add_uevent_var(env, "DEVICE=/proc/bus/usb/%03d/%03d",
usb_dev->bus->busnum, usb_dev->devnum))
return -ENOMEM;
#endif
/* per-device configurations are common */
if (add_uevent_var(env, "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_uevent_var(env, "TYPE=%d/%d/%d",
usb_dev->descriptor.bDeviceClass,
usb_dev->descriptor.bDeviceSubClass,
usb_dev->descriptor.bDeviceProtocol))
return -ENOMEM;
return 0;
}
#else
static int usb_uevent(struct device *dev, struct kobj_uevent_env *env)
{
return -ENODEV;
}
#endif /* CONFIG_HOTPLUG */
/**
* usb_register_device_driver - register a USB device (not interface) driver
* @new_udriver: USB operations for the device driver
* @owner: module owner of this driver.
*
* Registers a USB device driver with the USB core. The list of
* unattached devices 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.
*/
int usb_register_device_driver(struct usb_device_driver *new_udriver,
struct module *owner)
{
int retval = 0;
if (usb_disabled())
return -ENODEV;
new_udriver->drvwrap.for_devices = 1;
new_udriver->drvwrap.driver.name = (char *) new_udriver->name;
new_udriver->drvwrap.driver.bus = &usb_bus_type;
new_udriver->drvwrap.driver.probe = usb_probe_device;
new_udriver->drvwrap.driver.remove = usb_unbind_device;
new_udriver->drvwrap.driver.owner = owner;
retval = driver_register(&new_udriver->drvwrap.driver);
if (!retval) {
pr_info("%s: registered new device driver %s\n",
usbcore_name, new_udriver->name);
usbfs_update_special();
} else {
printk(KERN_ERR "%s: error %d registering device "
" driver %s\n",
usbcore_name, retval, new_udriver->name);
}
return retval;
}
EXPORT_SYMBOL_GPL(usb_register_device_driver);
/**
* usb_deregister_device_driver - unregister a USB device (not interface) driver
* @udriver: USB operations of the device driver to unregister
* Context: must be able to sleep
*
* Unlinks the specified driver from the internal USB driver list.
*/
void usb_deregister_device_driver(struct usb_device_driver *udriver)
{
pr_info("%s: deregistering device driver %s\n",
usbcore_name, udriver->name);
driver_unregister(&udriver->drvwrap.driver);
usbfs_update_special();
}
EXPORT_SYMBOL_GPL(usb_deregister_device_driver);
/**
* usb_register_driver - register a USB interface driver
* @new_driver: USB operations for the interface driver
* @owner: module owner of this driver.
* @mod_name: module name string
*
* Registers a USB interface 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 interfaces.
* 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_driver(struct usb_driver *new_driver, struct module *owner,
const char *mod_name)
{
int retval = 0;
if (usb_disabled())
return -ENODEV;
new_driver->drvwrap.for_devices = 0;
new_driver->drvwrap.driver.name = (char *) new_driver->name;
new_driver->drvwrap.driver.bus = &usb_bus_type;
new_driver->drvwrap.driver.probe = usb_probe_interface;
new_driver->drvwrap.driver.remove = usb_unbind_interface;
new_driver->drvwrap.driver.owner = owner;
new_driver->drvwrap.driver.mod_name = mod_name;
spin_lock_init(&new_driver->dynids.lock);
INIT_LIST_HEAD(&new_driver->dynids.list);
retval = driver_register(&new_driver->drvwrap.driver);
if (retval)
goto out;
usbfs_update_special();
retval = usb_create_newid_file(new_driver);
if (retval)
goto out_newid;
retval = usb_create_removeid_file(new_driver);
if (retval)
goto out_removeid;
pr_info("%s: registered new interface driver %s\n",
usbcore_name, new_driver->name);
out:
return retval;
out_removeid:
usb_remove_newid_file(new_driver);
out_newid:
driver_unregister(&new_driver->drvwrap.driver);
printk(KERN_ERR "%s: error %d registering interface "
" driver %s\n",
usbcore_name, retval, new_driver->name);
goto out;
}
EXPORT_SYMBOL_GPL(usb_register_driver);
/**
* usb_deregister - unregister a USB interface driver
* @driver: USB operations of the interface 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 interface driver %s\n",
usbcore_name, driver->name);
usb_remove_removeid_file(driver);
usb_remove_newid_file(driver);
usb_free_dynids(driver);
driver_unregister(&driver->drvwrap.driver);
usbfs_update_special();
}
EXPORT_SYMBOL_GPL(usb_deregister);
/* Forced unbinding of a USB interface driver, either because
* it doesn't support pre_reset/post_reset/reset_resume or
* because it doesn't support suspend/resume.
*
* The caller must hold @intf's device's lock, but not its pm_mutex
* and not @intf->dev.sem.
*/
void usb_forced_unbind_intf(struct usb_interface *intf)
{
struct usb_driver *driver = to_usb_driver(intf->dev.driver);
dev_dbg(&intf->dev, "forced unbind\n");
usb_driver_release_interface(driver, intf);
/* Mark the interface for later rebinding */
intf->needs_binding = 1;
}
/* Delayed forced unbinding of a USB interface driver and scan
* for rebinding.
*
* The caller must hold @intf's device's lock, but not its pm_mutex
* and not @intf->dev.sem.
*
* Note: Rebinds will be skipped if a system sleep transition is in
* progress and the PM "complete" callback hasn't occurred yet.
*/
void usb_rebind_intf(struct usb_interface *intf)
{
int rc;
/* Delayed unbind of an existing driver */
if (intf->dev.driver) {
struct usb_driver *driver =
to_usb_driver(intf->dev.driver);
dev_dbg(&intf->dev, "forced unbind\n");
usb_driver_release_interface(driver, intf);
}
/* Try to rebind the interface */
if (intf->dev.power.status == DPM_ON) {
intf->needs_binding = 0;
rc = device_attach(&intf->dev);
if (rc < 0)
dev_warn(&intf->dev, "rebind failed: %d\n", rc);
}
}
#ifdef CONFIG_PM
#define DO_UNBIND 0
#define DO_REBIND 1
/* Unbind drivers for @udev's interfaces that don't support suspend/resume,
* or rebind interfaces that have been unbound, according to @action.
*
* The caller must hold @udev's device lock.
*/
static void do_unbind_rebind(struct usb_device *udev, int action)
{
struct usb_host_config *config;
int i;
struct usb_interface *intf;
struct usb_driver *drv;
config = udev->actconfig;
if (config) {
for (i = 0; i < config->desc.bNumInterfaces; ++i) {
intf = config->interface[i];
switch (action) {
case DO_UNBIND:
if (intf->dev.driver) {
drv = to_usb_driver(intf->dev.driver);
if (!drv->suspend || !drv->resume)
usb_forced_unbind_intf(intf);
}
break;
case DO_REBIND:
if (intf->needs_binding)
usb_rebind_intf(intf);
break;
}
}
}
}
/* Caller has locked udev's pm_mutex */
static int usb_suspend_device(struct usb_device *udev, pm_message_t msg)
{
struct usb_device_driver *udriver;
int status = 0;
if (udev->state == USB_STATE_NOTATTACHED ||
udev->state == USB_STATE_SUSPENDED)
goto done;
/* For devices that don't have a driver, we do a generic suspend. */
if (udev->dev.driver)
udriver = to_usb_device_driver(udev->dev.driver);
else {
udev->do_remote_wakeup = 0;
udriver = &usb_generic_driver;
}
status = udriver->suspend(udev, msg);
done:
dev_vdbg(&udev->dev, "%s: status %d\n", __func__, status);
return status;
}
/* Caller has locked udev's pm_mutex */
static int usb_resume_device(struct usb_device *udev, pm_message_t msg)
{
struct usb_device_driver *udriver;
int status = 0;
if (udev->state == USB_STATE_NOTATTACHED)
goto done;
/* Can't resume it if it doesn't have a driver. */
if (udev->dev.driver == NULL) {
status = -ENOTCONN;
goto done;
}
if (udev->quirks & USB_QUIRK_RESET_RESUME)
udev->reset_resume = 1;
udriver = to_usb_device_driver(udev->dev.driver);
status = udriver->resume(udev, msg);
done:
dev_vdbg(&udev->dev, "%s: status %d\n", __func__, status);
return status;
}
/* Caller has locked intf's usb_device's pm mutex */
static int usb_suspend_interface(struct usb_device *udev,
struct usb_interface *intf, pm_message_t msg)
{
struct usb_driver *driver;
int status = 0;
/* with no hardware, USB interfaces only use FREEZE and ON states */
if (udev->state == USB_STATE_NOTATTACHED || !is_active(intf))
goto done;
/* This can happen; see usb_driver_release_interface() */
if (intf->condition == USB_INTERFACE_UNBOUND)
goto done;
driver = to_usb_driver(intf->dev.driver);
if (driver->suspend) {
status = driver->suspend(intf, msg);
if (status == 0)
mark_quiesced(intf);
else if (!(msg.event & PM_EVENT_AUTO))
dev_err(&intf->dev, "%s error %d\n",
"suspend", status);
} else {
/* Later we will unbind the driver and reprobe */
intf->needs_binding = 1;
dev_warn(&intf->dev, "no %s for driver %s?\n",
"suspend", driver->name);
mark_quiesced(intf);
}
done:
dev_vdbg(&intf->dev, "%s: status %d\n", __func__, status);
return status;
}
/* Caller has locked intf's usb_device's pm_mutex */
static int usb_resume_interface(struct usb_device *udev,
struct usb_interface *intf, pm_message_t msg, int reset_resume)
{
struct usb_driver *driver;
int status = 0;
if (udev->state == USB_STATE_NOTATTACHED || is_active(intf))
goto done;
/* Don't let autoresume interfere with unbinding */
if (intf->condition == USB_INTERFACE_UNBINDING)
goto done;
/* Can't resume it if it doesn't have a driver. */
if (intf->condition == USB_INTERFACE_UNBOUND) {
/* Carry out a deferred switch to altsetting 0 */
if (intf->needs_altsetting0 &&
intf->dev.power.status == DPM_ON) {
usb_set_interface(udev, intf->altsetting[0].
desc.bInterfaceNumber, 0);
intf->needs_altsetting0 = 0;
}
goto done;
}
/* Don't resume if the interface is marked for rebinding */
if (intf->needs_binding)
goto done;
driver = to_usb_driver(intf->dev.driver);
if (reset_resume) {
if (driver->reset_resume) {
status = driver->reset_resume(intf);
if (status)
dev_err(&intf->dev, "%s error %d\n",
"reset_resume", status);
} else {
intf->needs_binding = 1;
dev_warn(&intf->dev, "no %s for driver %s?\n",
"reset_resume", driver->name);
}
} else {
if (driver->resume) {
status = driver->resume(intf);
if (status)
dev_err(&intf->dev, "%s error %d\n",
"resume", status);
} else {
intf->needs_binding = 1;
dev_warn(&intf->dev, "no %s for driver %s?\n",
"resume", driver->name);
}
}
done:
dev_vdbg(&intf->dev, "%s: status %d\n", __func__, status);
if (status == 0 && intf->condition == USB_INTERFACE_BOUND)
mark_active(intf);
/* Later we will unbind the driver and/or reprobe, if necessary */
return status;
}
#ifdef CONFIG_USB_SUSPEND
/* Internal routine to check whether we may autosuspend a device. */
static int autosuspend_check(struct usb_device *udev, int reschedule)
{
int i;
struct usb_interface *intf;
unsigned long suspend_time, j;
/* For autosuspend, fail fast if anything is in use or autosuspend
* is disabled. Also fail if any interfaces require remote wakeup
* but it isn't available.
*/
if (udev->pm_usage_cnt > 0)
return -EBUSY;
if (udev->autosuspend_delay < 0 || udev->autosuspend_disabled)
return -EPERM;
suspend_time = udev->last_busy + udev->autosuspend_delay;
if (udev->actconfig) {
for (i = 0; i < udev->actconfig->desc.bNumInterfaces; i++) {
intf = udev->actconfig->interface[i];
if (!is_active(intf))
continue;
if (atomic_read(&intf->pm_usage_cnt) > 0)
return -EBUSY;
if (intf->needs_remote_wakeup &&
!udev->do_remote_wakeup) {
dev_dbg(&udev->dev, "remote wakeup needed "
"for autosuspend\n");
return -EOPNOTSUPP;
}
/* Don't allow autosuspend if the device will need
* a reset-resume and any of its interface drivers
* doesn't include support.
*/
if (udev->quirks & USB_QUIRK_RESET_RESUME) {
struct usb_driver *driver;
driver = to_usb_driver(intf->dev.driver);
if (!driver->reset_resume ||
intf->needs_remote_wakeup)
return -EOPNOTSUPP;
}
}
}
/* If everything is okay but the device hasn't been idle for long
* enough, queue a delayed autosuspend request. If the device
* _has_ been idle for long enough and the reschedule flag is set,
* likewise queue a delayed (1 second) autosuspend request.
*/
j = jiffies;
if (time_before(j, suspend_time))
reschedule = 1;
else
suspend_time = j + HZ;
if (reschedule) {
if (!timer_pending(&udev->autosuspend.timer)) {
queue_delayed_work(ksuspend_usb_wq, &udev->autosuspend,
round_jiffies_up_relative(suspend_time - j));
}
return -EAGAIN;
}
return 0;
}
#else
static inline int autosuspend_check(struct usb_device *udev, int reschedule)
{
return 0;
}
#endif /* CONFIG_USB_SUSPEND */
/**
* usb_suspend_both - suspend a USB device and its interfaces
* @udev: the usb_device to suspend
* @msg: Power Management message describing this state transition
*
* This is the central routine for suspending USB devices. It calls the
* suspend methods for all the interface drivers in @udev and then calls
* the suspend method for @udev itself. If an error occurs at any stage,
* all the interfaces which were suspended are resumed so that they remain
* in the same state as the device.
*
* If an autosuspend is in progress the routine checks first to make sure
* that neither the device itself or any of its active interfaces is in use
* (pm_usage_cnt is greater than 0). If they are, the autosuspend fails.
*
* If the suspend succeeds, the routine recursively queues an autosuspend
* request for @udev's parent device, thereby propagating the change up
* the device tree. If all of the parent's children are now suspended,
* the parent will autosuspend in turn.
*
* The suspend method calls are subject to mutual exclusion under control
* of @udev's pm_mutex. Many of these calls are also under the protection
* of @udev's device lock (including all requests originating outside the
* USB subsystem), but autosuspend requests generated by a child device or
* interface driver may not be. Usbcore will insure that the method calls
* do not arrive during bind, unbind, or reset operations. However, drivers
* must be prepared to handle suspend calls arriving at unpredictable times.
* The only way to block such calls is to do an autoresume (preventing
* autosuspends) while holding @udev's device lock (preventing outside
* suspends).
*
* The caller must hold @udev->pm_mutex.
*
* This routine can run only in process context.
*/
static int usb_suspend_both(struct usb_device *udev, pm_message_t msg)
{
int status = 0;
int i = 0;
struct usb_interface *intf;
struct usb_device *parent = udev->parent;
if (udev->state == USB_STATE_NOTATTACHED ||
udev->state == USB_STATE_SUSPENDED)
goto done;
udev->do_remote_wakeup = device_may_wakeup(&udev->dev);
if (msg.event & PM_EVENT_AUTO) {
status = autosuspend_check(udev, 0);
if (status < 0)
goto done;
}
/* Suspend all the interfaces and then udev itself */
if (udev->actconfig) {
for (; i < udev->actconfig->desc.bNumInterfaces; i++) {
intf = udev->actconfig->interface[i];
status = usb_suspend_interface(udev, intf, msg);
if (status != 0)
break;
}
}
if (status == 0)
status = usb_suspend_device(udev, msg);
/* If the suspend failed, resume interfaces that did get suspended */
if (status != 0) {
pm_message_t msg2;
msg2.event = msg.event ^ (PM_EVENT_SUSPEND | PM_EVENT_RESUME);
while (--i >= 0) {
intf = udev->actconfig->interface[i];
usb_resume_interface(udev, intf, msg2, 0);
}
/* Try another autosuspend when the interfaces aren't busy */
if (msg.event & PM_EVENT_AUTO)
autosuspend_check(udev, status == -EBUSY);
/* If the suspend succeeded then prevent any more URB submissions,
* flush any outstanding URBs, and propagate the suspend up the tree.
*/
} else {
cancel_delayed_work(&udev->autosuspend);
udev->can_submit = 0;
for (i = 0; i < 16; ++i) {
usb_hcd_flush_endpoint(udev, udev->ep_out[i]);
usb_hcd_flush_endpoint(udev, udev->ep_in[i]);
}
/* If this is just a FREEZE or a PRETHAW, udev might
* not really be suspended. Only true suspends get
* propagated up the device tree.
*/
if (parent && udev->state == USB_STATE_SUSPENDED)
usb_autosuspend_device(parent);
}
done:
dev_vdbg(&udev->dev, "%s: status %d\n", __func__, status);
return status;
}
/**
* usb_resume_both - resume a USB device and its interfaces
* @udev: the usb_device to resume
* @msg: Power Management message describing this state transition
*
* This is the central routine for resuming USB devices. It calls the
* the resume method for @udev and then calls the resume methods for all
* the interface drivers in @udev.
*
* Before starting the resume, the routine calls itself recursively for
* the parent device of @udev, thereby propagating the change up the device
* tree and assuring that @udev will be able to resume. If the parent is
* unable to resume successfully, the routine fails.
*
* The resume method calls are subject to mutual exclusion under control
* of @udev's pm_mutex. Many of these calls are also under the protection
* of @udev's device lock (including all requests originating outside the
* USB subsystem), but autoresume requests generated by a child device or
* interface driver may not be. Usbcore will insure that the method calls
* do not arrive during bind, unbind, or reset operations. However, drivers
* must be prepared to handle resume calls arriving at unpredictable times.
* The only way to block such calls is to do an autoresume (preventing
* other autoresumes) while holding @udev's device lock (preventing outside
* resumes).
*
* The caller must hold @udev->pm_mutex.
*
* This routine can run only in process context.
*/
static int usb_resume_both(struct usb_device *udev, pm_message_t msg)
{
int status = 0;
int i;
struct usb_interface *intf;
struct usb_device *parent = udev->parent;
cancel_delayed_work(&udev->autosuspend);
if (udev->state == USB_STATE_NOTATTACHED) {
status = -ENODEV;
goto done;
}
udev->can_submit = 1;
/* Propagate the resume up the tree, if necessary */
if (udev->state == USB_STATE_SUSPENDED) {
if (parent) {
status = usb_autoresume_device(parent);
if (status == 0) {
status = usb_resume_device(udev, msg);
if (status || udev->state ==
USB_STATE_NOTATTACHED) {
usb_autosuspend_device(parent);
/* It's possible usb_resume_device()
* failed after the port was
* unsuspended, causing udev to be
* logically disconnected. We don't
* want usb_disconnect() to autosuspend
* the parent again, so tell it that
* udev disconnected while still
* suspended. */
if (udev->state ==
USB_STATE_NOTATTACHED)
udev->discon_suspended = 1;
}
}
} else {
/* We can't progagate beyond the USB subsystem,
* so if a root hub's controller is suspended
* then we're stuck. */
status = usb_resume_device(udev, msg);
}
} else if (udev->reset_resume)
status = usb_resume_device(udev, msg);
if (status == 0 && udev->actconfig) {
for (i = 0; i < udev->actconfig->desc.bNumInterfaces; i++) {
intf = udev->actconfig->interface[i];
usb_resume_interface(udev, intf, msg,
udev->reset_resume);
}
}
done:
dev_vdbg(&udev->dev, "%s: status %d\n", __func__, status);
if (!status)
udev->reset_resume = 0;
return status;
}
#ifdef CONFIG_USB_SUSPEND
/* Internal routine to adjust a device's usage counter and change
* its autosuspend state.
*/
static int usb_autopm_do_device(struct usb_device *udev, int inc_usage_cnt)
{
int status = 0;
usb_pm_lock(udev);
udev->pm_usage_cnt += inc_usage_cnt;
WARN_ON(udev->pm_usage_cnt < 0);
if (inc_usage_cnt)
udev->last_busy = jiffies;
if (inc_usage_cnt >= 0 && udev->pm_usage_cnt > 0) {
if (udev->state == USB_STATE_SUSPENDED)
status = usb_resume_both(udev, PMSG_AUTO_RESUME);
if (status != 0)
udev->pm_usage_cnt -= inc_usage_cnt;
else if (inc_usage_cnt)
udev->last_busy = jiffies;
} else if (inc_usage_cnt <= 0 && udev->pm_usage_cnt <= 0) {
status = usb_suspend_both(udev, PMSG_AUTO_SUSPEND);
}
usb_pm_unlock(udev);
return status;
}
/* usb_autosuspend_work - callback routine to autosuspend a USB device */
void usb_autosuspend_work(struct work_struct *work)
{
struct usb_device *udev =
container_of(work, struct usb_device, autosuspend.work);
usb_autopm_do_device(udev, 0);
}
/* usb_autoresume_work - callback routine to autoresume a USB device */
void usb_autoresume_work(struct work_struct *work)
{
struct usb_device *udev =
container_of(work, struct usb_device, autoresume);
/* Wake it up, let the drivers do their thing, and then put it
* back to sleep.
*/
if (usb_autopm_do_device(udev, 1) == 0)
usb_autopm_do_device(udev, -1);
}
/**
* usb_autosuspend_device - delayed autosuspend of a USB device and its interfaces
* @udev: the usb_device to autosuspend
*
* This routine should be called when a core subsystem is finished using
* @udev and wants to allow it to autosuspend. Examples would be when
* @udev's device file in usbfs is closed or after a configuration change.
*
* @udev's usage counter is decremented. If it or any of the usage counters
* for an active interface is greater than 0, no autosuspend request will be
* queued. (If an interface driver does not support autosuspend then its
* usage counter is permanently positive.) Furthermore, if an interface
* driver requires remote-wakeup capability during autosuspend but remote
* wakeup is disabled, the autosuspend will fail.
*
* Often the caller will hold @udev's device lock, but this is not
* necessary.
*
* This routine can run only in process context.
*/
void usb_autosuspend_device(struct usb_device *udev)
{
int status;
status = usb_autopm_do_device(udev, -1);
dev_vdbg(&udev->dev, "%s: cnt %d\n",
__func__, udev->pm_usage_cnt);
}
/**
* usb_try_autosuspend_device - attempt an autosuspend of a USB device and its interfaces
* @udev: the usb_device to autosuspend
*
* This routine should be called when a core subsystem thinks @udev may
* be ready to autosuspend.
*
* @udev's usage counter left unchanged. If it or any of the usage counters
* for an active interface is greater than 0, or autosuspend is not allowed
* for any other reason, no autosuspend request will be queued.
*
* This routine can run only in process context.
*/
void usb_try_autosuspend_device(struct usb_device *udev)
{
usb_autopm_do_device(udev, 0);
dev_vdbg(&udev->dev, "%s: cnt %d\n",
__func__, udev->pm_usage_cnt);
}
/**
* usb_autoresume_device - immediately autoresume a USB device and its interfaces
* @udev: the usb_device to autoresume
*
* This routine should be called when a core subsystem wants to use @udev
* and needs to guarantee that it is not suspended. No autosuspend will
* occur until usb_autosuspend_device is called. (Note that this will not
* prevent suspend events originating in the PM core.) Examples would be
* when @udev's device file in usbfs is opened or when a remote-wakeup
* request is received.
*
* @udev's usage counter is incremented to prevent subsequent autosuspends.
* However if the autoresume fails then the usage counter is re-decremented.
*
* Often the caller will hold @udev's device lock, but this is not
* necessary (and attempting it might cause deadlock).
*
* This routine can run only in process context.
*/
int usb_autoresume_device(struct usb_device *udev)
{
int status;
status = usb_autopm_do_device(udev, 1);
dev_vdbg(&udev->dev, "%s: status %d cnt %d\n",
__func__, status, udev->pm_usage_cnt);
return status;
}
/* Internal routine to adjust an interface's usage counter and change
* its device's autosuspend state.
*/
static int usb_autopm_do_interface(struct usb_interface *intf,
int inc_usage_cnt)
{
struct usb_device *udev = interface_to_usbdev(intf);
int status = 0;
usb_pm_lock(udev);
if (intf->condition == USB_INTERFACE_UNBOUND)
status = -ENODEV;
else {
atomic_add(inc_usage_cnt, &intf->pm_usage_cnt);
udev->last_busy = jiffies;
if (inc_usage_cnt >= 0 &&
atomic_read(&intf->pm_usage_cnt) > 0) {
if (udev->state == USB_STATE_SUSPENDED)
status = usb_resume_both(udev,
PMSG_AUTO_RESUME);
if (status != 0)
atomic_sub(inc_usage_cnt, &intf->pm_usage_cnt);
else
udev->last_busy = jiffies;
} else if (inc_usage_cnt <= 0 &&
atomic_read(&intf->pm_usage_cnt) <= 0) {
status = usb_suspend_both(udev, PMSG_AUTO_SUSPEND);
}
}
usb_pm_unlock(udev);
return status;
}
/**
* usb_autopm_put_interface - decrement a USB interface's PM-usage counter
* @intf: the usb_interface whose counter should be decremented
*
* This routine should be called by an interface driver when it is
* finished using @intf and wants to allow it to autosuspend. A typical
* example would be a character-device driver when its device file is
* closed.
*
* The routine decrements @intf's usage counter. When the counter reaches
* 0, a delayed autosuspend request for @intf's device is queued. When
* the delay expires, if @intf->pm_usage_cnt is still <= 0 along with all
* the other usage counters for the sibling interfaces and @intf's
* usb_device, the device and all its interfaces will be autosuspended.
*
* Note that @intf->pm_usage_cnt is owned by the interface driver. The
* core will not change its value other than the increment and decrement
* in usb_autopm_get_interface and usb_autopm_put_interface. The driver
* may use this simple counter-oriented discipline or may set the value
* any way it likes.
*
* If the driver has set @intf->needs_remote_wakeup then autosuspend will
* take place only if the device's remote-wakeup facility is enabled.
*
* Suspend method calls queued by this routine can arrive at any time
* while @intf is resumed and its usage counter is equal to 0. They are
* not protected by the usb_device's lock but only by its pm_mutex.
* Drivers must provide their own synchronization.
*
* This routine can run only in process context.
*/
void usb_autopm_put_interface(struct usb_interface *intf)
{
int status;
status = usb_autopm_do_interface(intf, -1);
dev_vdbg(&intf->dev, "%s: status %d cnt %d\n",
__func__, status, atomic_read(&intf->pm_usage_cnt));
}
EXPORT_SYMBOL_GPL(usb_autopm_put_interface);
/**
* usb_autopm_put_interface_async - decrement a USB interface's PM-usage counter
* @intf: the usb_interface whose counter should be decremented
*
* This routine does essentially the same thing as
* usb_autopm_put_interface(): it decrements @intf's usage counter and
* queues a delayed autosuspend request if the counter is <= 0. The
* difference is that it does not acquire the device's pm_mutex;
* callers must handle all synchronization issues themselves.
*
* Typically a driver would call this routine during an URB's completion
* handler, if no more URBs were pending.
*
* This routine can run in atomic context.
*/
void usb_autopm_put_interface_async(struct usb_interface *intf)
{
struct usb_device *udev = interface_to_usbdev(intf);
int status = 0;
if (intf->condition == USB_INTERFACE_UNBOUND) {
status = -ENODEV;
} else {
udev->last_busy = jiffies;
atomic_dec(&intf->pm_usage_cnt);
if (udev->autosuspend_disabled || udev->autosuspend_delay < 0)
status = -EPERM;
else if (atomic_read(&intf->pm_usage_cnt) <= 0 &&
!timer_pending(&udev->autosuspend.timer)) {
queue_delayed_work(ksuspend_usb_wq, &udev->autosuspend,
round_jiffies_up_relative(
udev->autosuspend_delay));
}
}
dev_vdbg(&intf->dev, "%s: status %d cnt %d\n",
__func__, status, atomic_read(&intf->pm_usage_cnt));
}
EXPORT_SYMBOL_GPL(usb_autopm_put_interface_async);
/**
* usb_autopm_get_interface - increment a USB interface's PM-usage counter
* @intf: the usb_interface whose counter should be incremented
*
* This routine should be called by an interface driver when it wants to
* use @intf and needs to guarantee that it is not suspended. In addition,
* the routine prevents @intf from being autosuspended subsequently. (Note
* that this will not prevent suspend events originating in the PM core.)
* This prevention will persist until usb_autopm_put_interface() is called
* or @intf is unbound. A typical example would be a character-device
* driver when its device file is opened.
*
*
* The routine increments @intf's usage counter. (However if the
* autoresume fails then the counter is re-decremented.) So long as the
* counter is greater than 0, autosuspend will not be allowed for @intf
* or its usb_device. When the driver is finished using @intf it should
* call usb_autopm_put_interface() to decrement the usage counter and
* queue a delayed autosuspend request (if the counter is <= 0).
*
*
* Note that @intf->pm_usage_cnt is owned by the interface driver. The
* core will not change its value other than the increment and decrement
* in usb_autopm_get_interface and usb_autopm_put_interface. The driver
* may use this simple counter-oriented discipline or may set the value
* any way it likes.
*
* Resume method calls generated by this routine can arrive at any time
* while @intf is suspended. They are not protected by the usb_device's
* lock but only by its pm_mutex. Drivers must provide their own
* synchronization.
*
* This routine can run only in process context.
*/
int usb_autopm_get_interface(struct usb_interface *intf)
{
int status;
status = usb_autopm_do_interface(intf, 1);
dev_vdbg(&intf->dev, "%s: status %d cnt %d\n",
__func__, status, atomic_read(&intf->pm_usage_cnt));
return status;
}
EXPORT_SYMBOL_GPL(usb_autopm_get_interface);
/**
* usb_autopm_get_interface_async - increment a USB interface's PM-usage counter
* @intf: the usb_interface whose counter should be incremented
*
* This routine does much the same thing as
* usb_autopm_get_interface(): it increments @intf's usage counter and
* queues an autoresume request if the result is > 0. The differences
* are that it does not acquire the device's pm_mutex (callers must
* handle all synchronization issues themselves), and it does not
* autoresume the device directly (it only queues a request). After a
* successful call, the device will generally not yet be resumed.
*
* This routine can run in atomic context.
*/
int usb_autopm_get_interface_async(struct usb_interface *intf)
{
struct usb_device *udev = interface_to_usbdev(intf);
int status = 0;
if (intf->condition == USB_INTERFACE_UNBOUND)
status = -ENODEV;
else {
atomic_inc(&intf->pm_usage_cnt);
if (atomic_read(&intf->pm_usage_cnt) > 0 &&
udev->state == USB_STATE_SUSPENDED)
queue_work(ksuspend_usb_wq, &udev->autoresume);
}
dev_vdbg(&intf->dev, "%s: status %d cnt %d\n",
__func__, status, atomic_read(&intf->pm_usage_cnt));
return status;
}
EXPORT_SYMBOL_GPL(usb_autopm_get_interface_async);
#else
void usb_autosuspend_work(struct work_struct *work)
{}
void usb_autoresume_work(struct work_struct *work)
{}
#endif /* CONFIG_USB_SUSPEND */
/**
* usb_external_suspend_device - external suspend of a USB device and its interfaces
* @udev: the usb_device to suspend
* @msg: Power Management message describing this state transition
*
* This routine handles external suspend requests: ones not generated
* internally by a USB driver (autosuspend) but rather coming from the user
* (via sysfs) or the PM core (system sleep). The suspend will be carried
* out regardless of @udev's usage counter or those of its interfaces,
* and regardless of whether or not remote wakeup is enabled. Of course,
* interface drivers still have the option of failing the suspend (if
* there are unsuspended children, for example).
*
* The caller must hold @udev's device lock.
*/
int usb_external_suspend_device(struct usb_device *udev, pm_message_t msg)
{
int status;
do_unbind_rebind(udev, DO_UNBIND);
usb_pm_lock(udev);
status = usb_suspend_both(udev, msg);
usb_pm_unlock(udev);
return status;
}
/**
* usb_external_resume_device - external resume of a USB device and its interfaces
* @udev: the usb_device to resume
* @msg: Power Management message describing this state transition
*
* This routine handles external resume requests: ones not generated
* internally by a USB driver (autoresume) but rather coming from the user
* (via sysfs), the PM core (system resume), or the device itself (remote
* wakeup). @udev's usage counter is unaffected.
*
* The caller must hold @udev's device lock.
*/
int usb_external_resume_device(struct usb_device *udev, pm_message_t msg)
{
int status;
usb_pm_lock(udev);
status = usb_resume_both(udev, msg);
udev->last_busy = jiffies;
usb_pm_unlock(udev);
if (status == 0)
do_unbind_rebind(udev, DO_REBIND);
/* Now that the device is awake, we can start trying to autosuspend
* it again. */
if (status == 0)
usb_try_autosuspend_device(udev);
return status;
}
int usb_suspend(struct device *dev, pm_message_t msg)
{
struct usb_device *udev;
udev = to_usb_device(dev);
/* If udev is already suspended, we can skip this suspend and
* we should also skip the upcoming system resume. High-speed
* root hubs are an exception; they need to resume whenever the
* system wakes up in order for USB-PERSIST port handover to work
* properly.
*/
if (udev->state == USB_STATE_SUSPENDED) {
if (udev->parent || udev->speed != USB_SPEED_HIGH)
udev->skip_sys_resume = 1;
return 0;
}
udev->skip_sys_resume = 0;
return usb_external_suspend_device(udev, msg);
}
int usb_resume(struct device *dev, pm_message_t msg)
{
struct usb_device *udev;
int status;
udev = to_usb_device(dev);
/* If udev->skip_sys_resume is set then udev was already suspended
* when the system sleep started, so we don't want to resume it
* during this system wakeup.
*/
if (udev->skip_sys_resume)
return 0;
status = usb_external_resume_device(udev, msg);
/* Avoid PM error messages for devices disconnected while suspended
* as we'll display regular disconnect messages just a bit later.
*/
if (status == -ENODEV)
return 0;
return status;
}
#endif /* CONFIG_PM */
struct bus_type usb_bus_type = {
.name = "usb",
.match = usb_device_match,
.uevent = usb_uevent,
};