linux/drivers/usb/core/driver.c
Alan Stern ddeac4e75f USB: fix toggle mismatch in disable_endpoint paths
This patch (as1200) finishes some fixes that were left incomplete by
an earlier patch.

Although nobody has addressed this issue in the past, it turns out
that we need to distinguish between two different modes of disabling
and enabling endpoints.  In one mode only the data structures in
usbcore are affected, and in the other mode the host controller and
device hardware states are affected as well.

The earlier patch added an extra argument to the routines in the
enable_endpoint pathways to reflect this difference.  This patch adds
corresponding arguments to the disable_endpoint pathways.  Without
this change, the endpoint toggle state can get out of sync between
the host and the device.  The exact mechanism depends on the details
of the host controller (whether or not it stores its own copy of the
toggle values).

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Reported-by: Dan Streetman <ddstreet@ieee.org>
Tested-by: Dan Streetman <ddstreet@ieee.org>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-01-27 16:15:32 -08:00

1784 lines
54 KiB
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);
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 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 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;
int error = -ENODEV;
dev_dbg(dev, "%s\n", __func__);
if (!is_usb_device(dev)) /* Sanity check */
return error;
udev = to_usb_device(dev);
/* 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;
struct usb_device *udev;
const struct usb_device_id *id;
int error = -ENODEV;
dev_dbg(dev, "%s\n", __func__);
if (is_usb_device(dev)) /* Sanity check */
return error;
intf = to_usb_interface(dev);
udev = interface_to_usbdev(intf);
intf->needs_binding = 0;
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.
*/
intf->pm_usage_cnt = !(driver->supports_autosuspend);
/* Carry out a deferred switch to altsetting 0 */
if (intf->needs_altsetting0) {
usb_set_interface(udev, intf->altsetting[0].
desc.bInterfaceNumber, 0);
intf->needs_altsetting0 = 0;
}
error = driver->probe(intf, id);
if (error) {
mark_quiesced(intf);
intf->needs_remote_wakeup = 0;
intf->condition = USB_INTERFACE_UNBOUND;
usb_cancel_queued_reset(intf);
} else
intf->condition = USB_INTERFACE_BOUND;
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;
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)
usb_set_interface(udev, intf->altsetting[0].
desc.bInterfaceNumber, 0);
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);
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;
struct usb_device *udev = interface_to_usbdev(iface);
/* 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;
/* don't release if the interface hasn't been added yet */
if (device_is_registered(dev)) {
iface->condition = USB_INTERFACE_UNBINDING;
device_release_driver(dev);
} else {
iface->condition = USB_INTERFACE_UNBOUND;
usb_cancel_queued_reset(iface);
}
dev->driver = NULL;
usb_set_intfdata(iface, NULL);
usb_pm_lock(udev);
iface->condition = USB_INTERFACE_UNBOUND;
mark_quiesced(iface);
iface->needs_remote_wakeup = 0;
usb_pm_unlock(udev);
}
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 {
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;
/* driver is often null here; dev_dbg() would oops */
pr_debug("usb %s: uevent\n", dev_name(dev));
if (is_usb_device(dev))
usb_dev = to_usb_device(dev);
else {
struct usb_interface *intf = to_usb_interface(dev);
usb_dev = interface_to_usbdev(intf);
}
if (usb_dev->devnum < 0) {
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) {
pr_info("%s: registered new interface driver %s\n",
usbcore_name, new_driver->name);
usbfs_update_special();
usb_create_newid_file(new_driver);
} else {
printk(KERN_ERR "%s: error %d registering interface "
" driver %s\n",
usbcore_name, retval, new_driver->name);
}
return retval;
}
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_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);
if (status == 0)
udev->autoresume_disabled = 0;
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 (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 ((msg.event & PM_EVENT_AUTO) &&
udev->autoresume_disabled) {
status = -EPERM;
goto done;
}
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->auto_pm = 1;
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 {
udev->auto_pm = 1;
intf->pm_usage_cnt += inc_usage_cnt;
udev->last_busy = jiffies;
if (inc_usage_cnt >= 0 && intf->pm_usage_cnt > 0) {
if (udev->state == USB_STATE_SUSPENDED)
status = usb_resume_both(udev,
PMSG_AUTO_RESUME);
if (status != 0)
intf->pm_usage_cnt -= inc_usage_cnt;
else
udev->last_busy = jiffies;
} else if (inc_usage_cnt <= 0 && 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, 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;
--intf->pm_usage_cnt;
if (udev->autosuspend_disabled || udev->autosuspend_delay < 0)
status = -EPERM;
else if (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, 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, 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 if (udev->autoresume_disabled)
status = -EPERM;
else if (++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, intf->pm_usage_cnt);
return status;
}
EXPORT_SYMBOL_GPL(usb_autopm_get_interface_async);
/**
* usb_autopm_set_interface - set a USB interface's autosuspend state
* @intf: the usb_interface whose state should be set
*
* This routine sets the autosuspend state of @intf's device according
* to @intf's usage counter, which the caller must have set previously.
* If the counter is <= 0, the device is autosuspended (if it isn't
* already suspended and if nothing else prevents the autosuspend). If
* the counter is > 0, the device is autoresumed (if it isn't already
* awake).
*/
int usb_autopm_set_interface(struct usb_interface *intf)
{
int status;
status = usb_autopm_do_interface(intf, 0);
dev_vdbg(&intf->dev, "%s: status %d cnt %d\n",
__func__, status, intf->pm_usage_cnt);
return status;
}
EXPORT_SYMBOL_GPL(usb_autopm_set_interface);
#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);
udev->auto_pm = 0;
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);
udev->auto_pm = 0;
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;
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;
return usb_external_resume_device(udev, msg);
}
#endif /* CONFIG_PM */
struct bus_type usb_bus_type = {
.name = "usb",
.match = usb_device_match,
.uevent = usb_uevent,
};