/*
* 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/slab.h>
#include <linux/export.h>
#include <linux/usb.h>
#include <linux/usb/quirks.h>
#include <linux/usb/hcd.h>
#include "usb.h"
/*
* 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;
unsigned int bInterfaceClass = 0;
int fields = 0;
int retval = 0;
fields = sscanf(buf, "%x %x %x", &idVendor, &idProduct,
&bInterfaceClass);
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;
if (fields == 3) {
dynid->id.bInterfaceClass = (u8)bInterfaceClass;
dynid->id.match_flags |= USB_DEVICE_ID_MATCH_INT_CLASS;
}
spin_lock(&dynids->lock);
list_add_tail(&dynid->node, &dynids->list);
spin_unlock(&dynids->lock);
retval = driver_attach(driver);
if (retval)
return retval;
return count;
}
EXPORT_SYMBOL_GPL(usb_store_new_id);
ssize_t usb_show_dynids(struct usb_dynids *dynids, char *buf)
{
struct usb_dynid *dynid;
size_t count = 0;
list_for_each_entry(dynid, &dynids->list, node)
if (dynid->id.bInterfaceClass != 0)
count += scnprintf(&buf[count], PAGE_SIZE - count, "%04x %04x %02x\n",
dynid->id.idVendor, dynid->id.idProduct,
dynid->id.bInterfaceClass);
else
count += scnprintf(&buf[count], PAGE_SIZE - count, "%04x %04x\n",
dynid->id.idVendor, dynid->id.idProduct);
return count;
}
EXPORT_SYMBOL_GPL(usb_show_dynids);
static ssize_t show_dynids(struct device_driver *driver, char *buf)
{
struct usb_driver *usb_drv = to_usb_driver(driver);
return usb_show_dynids(&usb_drv->dynids, buf);
}
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_IRUGO | S_IWUSR, show_dynids, 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;
u32 idProduct;
int fields;
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);
break;
}
}
spin_unlock(&usb_driver->dynids.lock);
return count;
}
static DRIVER_ATTR(remove_id, S_IRUGO | S_IWUSR, show_dynids, store_remove_id);
static int usb_create_newid_files(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);
if (error == 0) {
error = driver_create_file(&usb_drv->drvwrap.driver,
&driver_attr_remove_id);
if (error)
driver_remove_file(&usb_drv->drvwrap.driver,
&driver_attr_new_id);
}
}
exit:
return error;
}
static void usb_remove_newid_files(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_remove_id);
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);
}
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 = 0;
dev_dbg(dev, "%s\n", __func__);
/* TODO: Add real matching code */
/* The device should always appear to be in use
* unless the driver supports autosuspend.
*/
if (!udriver->supports_autosuspend)
error = usb_autoresume_device(udev);
if (!error)
error = udriver->probe(udev);
return error;
}
/* called from driver core with dev locked */
static int usb_unbind_device(struct device *dev)
{
struct usb_device *udev = to_usb_device(dev);
struct usb_device_driver *udriver = to_usb_device_driver(dev->driver);
udriver->disconnect(udev);
if (!udriver->supports_autosuspend)
usb_autosuspend_device(udev);
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;
int lpm_disable_error;
dev_dbg(dev, "%s\n", __func__);
intf->needs_binding = 0;
if (usb_device_is_owned(udev))
return error;
if (udev->authorized == 0) {
dev_err(&intf->dev, "Device is not authorized for usage\n");
return error;
}
id = usb_match_id(intf, driver->id_table);
if (!id)
id = usb_match_dynamic_id(intf, driver);
if (!id)
return error;
dev_dbg(dev, "%s - got id\n", __func__);
error = usb_autoresume_device(udev);
if (error)
return error;
intf->condition = USB_INTERFACE_BINDING;
/* Probed interfaces are initially active. They are
* runtime-PM-enabled only if the driver has autosuspend support.
* They are sensitive to their children's power states.
*/
pm_runtime_set_active(dev);
pm_suspend_ignore_children(dev, false);
if (driver->supports_autosuspend)
pm_runtime_enable(dev);
/* If the new driver doesn't allow hub-initiated LPM, and we can't
* disable hub-initiated LPM, then fail the probe.
*
* Otherwise, leaving LPM enabled should be harmless, because the
* endpoint intervals should remain the same, and the U1/U2 timeouts
* should remain the same.
*
* If we need to install alt setting 0 before probe, or another alt
* setting during probe, that should also be fine. usb_set_interface()
* will attempt to disable LPM, and fail if it can't disable it.
*/
lpm_disable_error = usb_unlocked_disable_lpm(udev);
if (lpm_disable_error && driver->disable_hub_initiated_lpm) {
dev_err(&intf->dev, "%s Failed to disable LPM for driver %s\n.",
__func__, driver->name);
error = lpm_disable_error;
goto err;
}
/* 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;
/* If the LPM disable succeeded, balance the ref counts. */
if (!lpm_disable_error)
usb_unlocked_enable_lpm(udev);
usb_autosuspend_device(udev);
return error;
err:
usb_set_intfdata(intf, NULL);
intf->needs_remote_wakeup = 0;
intf->condition = USB_INTERFACE_UNBOUND;
usb_cancel_queued_reset(intf);
/* If the LPM disable succeeded, balance the ref counts. */
if (!lpm_disable_error)
usb_unlocked_enable_lpm(udev);
/* Unbound interfaces are always runtime-PM-disabled and -suspended */
if (driver->supports_autosuspend)
pm_runtime_disable(dev);
pm_runtime_set_suspended(dev);
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, lpm_disable_error;
intf->condition = USB_INTERFACE_UNBINDING;
/* Autoresume for set_interface call below */
udev = interface_to_usbdev(intf);
error = usb_autoresume_device(udev);
/* Hub-initiated LPM policy may change, so attempt to disable LPM until
* the driver is unbound. If LPM isn't disabled, that's fine because it
* wouldn't be enabled unless all the bound interfaces supported
* hub-initiated LPM.
*/
lpm_disable_error = usb_unlocked_disable_lpm(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.is_prepared) {
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;
intf->needs_remote_wakeup = 0;
/* Attempt to re-enable USB3 LPM, if the disable succeeded. */
if (!lpm_disable_error)
usb_unlocked_enable_lpm(udev);
/* Unbound interfaces are always runtime-PM-disabled and -suspended */
if (driver->supports_autosuspend)
pm_runtime_disable(dev);
pm_runtime_set_suspended(dev);
/* Undo any residual pm_autopm_get_interface_* calls */
for (r = atomic_read(&intf->pm_usage_cnt); r > 0; --r)
usb_autopm_put_interface_no_suspend(intf);
atomic_set(&intf->pm_usage_cnt, 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;
int retval = 0;
int lpm_disable_error;
if (dev->driver)
return -EBUSY;
udev = interface_to_usbdev(iface);
dev->driver = &driver->drvwrap.driver;
usb_set_intfdata(iface, priv);
iface->needs_binding = 0;
iface->condition = USB_INTERFACE_BOUND;
/* Disable LPM until this driver is bound. */
lpm_disable_error = usb_unlocked_disable_lpm(udev);
if (lpm_disable_error && driver->disable_hub_initiated_lpm) {
dev_err(&iface->dev, "%s Failed to disable LPM for driver %s\n.",
__func__, driver->name);
return -ENOMEM;
}
/* Claimed interfaces are initially inactive (suspended) and
* runtime-PM-enabled, but only if the driver has autosuspend
* support. Otherwise they are marked active, to prevent the
* device from being autosuspended, but left disabled. In either
* case they are sensitive to their children's power states.
*/
pm_suspend_ignore_children(dev, false);
if (driver->supports_autosuspend)
pm_runtime_enable(dev);
else
pm_runtime_set_active(dev);
/* 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);
/* Attempt to re-enable USB3 LPM, if the disable was successful. */
if (!lpm_disable_error)
usb_unlocked_enable_lpm(udev);
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 {
device_lock(dev);
usb_unbind_interface(dev);
dev->driver = NULL;
device_unlock(dev);
}
}
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_intf(struct usb_device *dev,
struct usb_host_interface *intf,
const struct usb_device_id *id)
{
/* The interface class, subclass, protocol and number 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 |
USB_DEVICE_ID_MATCH_INT_NUMBER)))
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;
if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_NUMBER) &&
(id->bInterfaceNumber != intf->desc.bInterfaceNumber))
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;
return usb_match_one_id_intf(dev, intf, id);
}
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;
}
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;
}
/* 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;
}
/**
* 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);
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);
}
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;
retval = usb_create_newid_files(new_driver);
if (retval)
goto out_newid;
pr_info("%s: registered new interface driver %s\n",
usbcore_name, new_driver->name);
out:
return retval;
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_newid_files(driver);
driver_unregister(&driver->drvwrap.driver);
usb_free_dynids(driver);
}
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)
usb_forced_unbind_intf(intf);
/* Try to rebind the interface */
if (!intf->dev.power.is_prepared) {
intf->needs_binding = 0;
rc = device_attach(&intf->dev);
if (rc < 0)
dev_warn(&intf->dev, "rebind failed: %d\n", rc);
}
}
#ifdef CONFIG_PM
/* Unbind drivers for @udev's interfaces that don't support suspend/resume
* There is no check for reset_resume here because it can be determined
* only during resume whether reset_resume is needed.
*
* The caller must hold @udev's device lock.
*/
static void unbind_no_pm_drivers_interfaces(struct usb_device *udev)
{
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];
if (intf->dev.driver) {
drv = to_usb_driver(intf->dev.driver);
if (!drv->suspend || !drv->resume)
usb_forced_unbind_intf(intf);
}
}
}
}
/* Unbind drivers for @udev's interfaces that failed to support reset-resume.
* These interfaces have the needs_binding flag set by usb_resume_interface().
*
* The caller must hold @udev's device lock.
*/
static void unbind_no_reset_resume_drivers_interfaces(struct usb_device *udev)
{
struct usb_host_config *config;
int i;
struct usb_interface *intf;
config = udev->actconfig;
if (config) {
for (i = 0; i < config->desc.bNumInterfaces; ++i) {
intf = config->interface[i];
if (intf->dev.driver && intf->needs_binding)
usb_forced_unbind_intf(intf);
}
}
}
static void do_rebind_interfaces(struct usb_device *udev)
{
struct usb_host_config *config;
int i;
struct usb_interface *intf;
config = udev->actconfig;
if (config) {
for (i = 0; i < config->desc.bNumInterfaces; ++i) {
intf = config->interface[i];
if (intf->needs_binding)
usb_rebind_intf(intf);
}
}
}
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;
}
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;
}
/* Non-root devices on a full/low-speed bus must wait for their
* companion high-speed root hub, in case a handoff is needed.
*/
if (!PMSG_IS_AUTO(msg) && udev->parent && udev->bus->hs_companion)
device_pm_wait_for_dev(&udev->dev,
&udev->bus->hs_companion->root_hub->dev);
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;
}
static int usb_suspend_interface(struct usb_device *udev,
struct usb_interface *intf, pm_message_t msg)
{
struct usb_driver *driver;
int status = 0;
if (udev->state == USB_STATE_NOTATTACHED ||
intf->condition == USB_INTERFACE_UNBOUND)
goto done;
driver = to_usb_driver(intf->dev.driver);
/* at this time we know the driver supports suspend */
status = driver->suspend(intf, msg);
if (status && !PMSG_IS_AUTO(msg))
dev_err(&intf->dev, "suspend error %d\n", status);
done:
dev_vdbg(&intf->dev, "%s: status %d\n", __func__, status);
return status;
}
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)
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.is_prepared) {
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 {
status = driver->resume(intf);
if (status)
dev_err(&intf->dev, "resume error %d\n", status);
}
done:
dev_vdbg(&intf->dev, "%s: status %d\n", __func__, status);
/* Later we will unbind the driver and/or reprobe, if necessary */
return status;
}
/**
* 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. When the routine is called in
* autosuspend, 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, but when called from system sleep, all error
* from suspend methods of interfaces and the non-root-hub device itself
* are simply ignored, so all suspended interfaces are only resumed
* to the device's state when @udev is root-hub and its suspend method
* returns failure.
*
* Autosuspend requests originating from a child device or an interface
* driver may be made without the protection of @udev's device lock, but
* all other suspend calls will hold the lock. Usbcore will insure that
* method calls do not arrive during bind, unbind, or reset operations.
* However drivers must be prepared to handle suspend calls arriving at
* unpredictable times.
*
* 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, n = 0;
struct usb_interface *intf;
if (udev->state == USB_STATE_NOTATTACHED ||
udev->state == USB_STATE_SUSPENDED)
goto done;
/* Suspend all the interfaces and then udev itself */
if (udev->actconfig) {
n = udev->actconfig->desc.bNumInterfaces;
for (i = n - 1; i >= 0; --i) {
intf = udev->actconfig->interface[i];
status = usb_suspend_interface(udev, intf, msg);
/* Ignore errors during system sleep transitions */
if (!PMSG_IS_AUTO(msg))
status = 0;
if (status != 0)
break;
}
}
if (status == 0) {
status = usb_suspend_device(udev, msg);
/*
* Ignore errors from non-root-hub devices during
* system sleep transitions. For the most part,
* these devices should go to low power anyway when
* the entire bus is suspended.
*/
if (udev->parent && !PMSG_IS_AUTO(msg))
status = 0;
}
/* If the suspend failed, resume interfaces that did get suspended */
if (status != 0) {
if (udev->actconfig) {
msg.event ^= (PM_EVENT_SUSPEND | PM_EVENT_RESUME);
while (++i < n) {
intf = udev->actconfig->interface[i];
usb_resume_interface(udev, intf, msg, 0);
}
}
/* If the suspend succeeded then prevent any more URB submissions
* and flush any outstanding URBs.
*/
} else {
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]);
}
}
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.
*
* Autoresume requests originating from a child device or an interface
* driver may be made without the protection of @udev's device lock, but
* all other resume calls will hold the lock. Usbcore will insure that
* method calls do not arrive during bind, unbind, or reset operations.
* However drivers must be prepared to handle resume calls arriving at
* unpredictable times.
*
* 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;
if (udev->state == USB_STATE_NOTATTACHED) {
status = -ENODEV;
goto done;
}
udev->can_submit = 1;
/* Resume the device */
if (udev->state == USB_STATE_SUSPENDED || udev->reset_resume)
status = usb_resume_device(udev, msg);
/* Resume the interfaces */
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);
}
}
usb_mark_last_busy(udev);
done:
dev_vdbg(&udev->dev, "%s: status %d\n", __func__, status);
if (!status)
udev->reset_resume = 0;
return status;
}
static void choose_wakeup(struct usb_device *udev, pm_message_t msg)
{
int w;
/* Remote wakeup is needed only when we actually go to sleep.
* For things like FREEZE and QUIESCE, if the device is already
* autosuspended then its current wakeup setting is okay.
*/
if (msg.event == PM_EVENT_FREEZE || msg.event == PM_EVENT_QUIESCE) {
if (udev->state != USB_STATE_SUSPENDED)
udev->do_remote_wakeup = 0;
return;
}
/* Enable remote wakeup if it is allowed, even if no interface drivers
* actually want it.
*/
w = device_may_wakeup(&udev->dev);
/* If the device is autosuspended with the wrong wakeup setting,
* autoresume now so the setting can be changed.
*/
if (udev->state == USB_STATE_SUSPENDED && w != udev->do_remote_wakeup)
pm_runtime_resume(&udev->dev);
udev->do_remote_wakeup = w;
}
/* The device lock is held by the PM core */
int usb_suspend(struct device *dev, pm_message_t msg)
{
struct usb_device *udev = to_usb_device(dev);
unbind_no_pm_drivers_interfaces(udev);
/* From now on we are sure all drivers support suspend/resume
* but not necessarily reset_resume()
* so we may still need to unbind and rebind upon resume
*/
choose_wakeup(udev, msg);
return usb_suspend_both(udev, msg);
}
/* The device lock is held by the PM core */
int usb_resume_complete(struct device *dev)
{
struct usb_device *udev = to_usb_device(dev);
/* For PM complete calls, all we do is rebind interfaces
* whose needs_binding flag is set
*/
if (udev->state != USB_STATE_NOTATTACHED)
do_rebind_interfaces(udev);
return 0;
}
/* The device lock is held by the PM core */
int usb_resume(struct device *dev, pm_message_t msg)
{
struct usb_device *udev = to_usb_device(dev);
int status;
/* For all calls, take the device back to full power and
* tell the PM core in case it was autosuspended previously.
* Unbind the interfaces that will need rebinding later,
* because they fail to support reset_resume.
* (This can't be done in usb_resume_interface()
* above because it doesn't own the right set of locks.)
*/
status = usb_resume_both(udev, msg);
if (status == 0) {
pm_runtime_disable(dev);
pm_runtime_set_active(dev);
pm_runtime_enable(dev);
unbind_no_reset_resume_drivers_interfaces(udev);
}
/* Avoid PM error messages for devices disconnected while suspended
* as we'll display regular disconnect messages just a bit later.
*/
if (status == -ENODEV || status == -ESHUTDOWN)
status = 0;
return status;
}
#endif /* CONFIG_PM */
#ifdef CONFIG_PM_RUNTIME
/**
* usb_enable_autosuspend - allow a USB device to be autosuspended
* @udev: the USB device which may be autosuspended
*
* This routine allows @udev to be autosuspended. An autosuspend won't
* take place until the autosuspend_delay has elapsed and all the other
* necessary conditions are satisfied.
*
* The caller must hold @udev's device lock.
*/
void usb_enable_autosuspend(struct usb_device *udev)
{
pm_runtime_allow(&udev->dev);
}
EXPORT_SYMBOL_GPL(usb_enable_autosuspend);
/**
* usb_disable_autosuspend - prevent a USB device from being autosuspended
* @udev: the USB device which may not be autosuspended
*
* This routine prevents @udev from being autosuspended and wakes it up
* if it is already autosuspended.
*
* The caller must hold @udev's device lock.
*/
void usb_disable_autosuspend(struct usb_device *udev)
{
pm_runtime_forbid(&udev->dev);
}
EXPORT_SYMBOL_GPL(usb_disable_autosuspend);
/**
* 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 drops to 0 and all the
* interfaces are inactive then a delayed autosuspend will be attempted.
* The attempt may fail (see autosuspend_check()).
*
* The caller must hold @udev's device lock.
*
* This routine can run only in process context.
*/
void usb_autosuspend_device(struct usb_device *udev)
{
int status;
usb_mark_last_busy(udev);
status = pm_runtime_put_sync_autosuspend(&udev->dev);
dev_vdbg(&udev->dev, "%s: cnt %d -> %d\n",
__func__, atomic_read(&udev->dev.power.usage_count),
status);
}
/**
* 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.
*
* The caller must hold @udev's device lock.
*
* This routine can run only in process context.
*/
int usb_autoresume_device(struct usb_device *udev)
{
int status;
status = pm_runtime_get_sync(&udev->dev);
if (status < 0)
pm_runtime_put_sync(&udev->dev);
dev_vdbg(&udev->dev, "%s: cnt %d -> %d\n",
__func__, atomic_read(&udev->dev.power.usage_count),
status);
if (status > 0)
status = 0;
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 attempted. The
* attempt may fail (see autosuspend_check()).
*
* This routine can run only in process context.
*/
void usb_autopm_put_interface(struct usb_interface *intf)
{
struct usb_device *udev = interface_to_usbdev(intf);
int status;
usb_mark_last_busy(udev);
atomic_dec(&intf->pm_usage_cnt);
status = pm_runtime_put_sync(&intf->dev);
dev_vdbg(&intf->dev, "%s: cnt %d -> %d\n",
__func__, atomic_read(&intf->dev.power.usage_count),
status);
}
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 much the same thing as usb_autopm_put_interface():
* It decrements @intf's usage counter and schedules a delayed
* autosuspend request if the counter is <= 0. The difference is that it
* does not perform any synchronization; callers should hold a private
* lock and 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;
usb_mark_last_busy(udev);
atomic_dec(&intf->pm_usage_cnt);
status = pm_runtime_put(&intf->dev);
dev_vdbg(&intf->dev, "%s: cnt %d -> %d\n",
__func__, atomic_read(&intf->dev.power.usage_count),
status);
}
EXPORT_SYMBOL_GPL(usb_autopm_put_interface_async);
/**
* usb_autopm_put_interface_no_suspend - decrement a USB interface's PM-usage counter
* @intf: the usb_interface whose counter should be decremented
*
* This routine decrements @intf's usage counter but does not carry out an
* autosuspend.
*
* This routine can run in atomic context.
*/
void usb_autopm_put_interface_no_suspend(struct usb_interface *intf)
{
struct usb_device *udev = interface_to_usbdev(intf);
usb_mark_last_busy(udev);
atomic_dec(&intf->pm_usage_cnt);
pm_runtime_put_noidle(&intf->dev);
}
EXPORT_SYMBOL_GPL(usb_autopm_put_interface_no_suspend);
/**
* 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.
*
* @intf's usage counter is incremented to prevent subsequent autosuspends.
* However if the autoresume fails then the counter is re-decremented.
*
* This routine can run only in process context.
*/
int usb_autopm_get_interface(struct usb_interface *intf)
{
int status;
status = pm_runtime_get_sync(&intf->dev);
if (status < 0)
pm_runtime_put_sync(&intf->dev);
else
atomic_inc(&intf->pm_usage_cnt);
dev_vdbg(&intf->dev, "%s: cnt %d -> %d\n",
__func__, atomic_read(&intf->dev.power.usage_count),
status);
if (status > 0)
status = 0;
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 device is suspended. The
* differences are that it does not perform any synchronization (callers
* should hold a private lock and handle all synchronization issues
* themselves), and it does not autoresume the device directly (it only
* queues a request). After a successful call, the device may not yet be
* resumed.
*
* This routine can run in atomic context.
*/
int usb_autopm_get_interface_async(struct usb_interface *intf)
{
int status;
status = pm_runtime_get(&intf->dev);
if (status < 0 && status != -EINPROGRESS)
pm_runtime_put_noidle(&intf->dev);
else
atomic_inc(&intf->pm_usage_cnt);
dev_vdbg(&intf->dev, "%s: cnt %d -> %d\n",
__func__, atomic_read(&intf->dev.power.usage_count),
status);
if (status > 0 || status == -EINPROGRESS)
status = 0;
return status;
}
EXPORT_SYMBOL_GPL(usb_autopm_get_interface_async);
/**
* usb_autopm_get_interface_no_resume - increment a USB interface's PM-usage counter
* @intf: the usb_interface whose counter should be incremented
*
* This routine increments @intf's usage counter but does not carry out an
* autoresume.
*
* This routine can run in atomic context.
*/
void usb_autopm_get_interface_no_resume(struct usb_interface *intf)
{
struct usb_device *udev = interface_to_usbdev(intf);
usb_mark_last_busy(udev);
atomic_inc(&intf->pm_usage_cnt);
pm_runtime_get_noresume(&intf->dev);
}
EXPORT_SYMBOL_GPL(usb_autopm_get_interface_no_resume);
/* Internal routine to check whether we may autosuspend a device. */
static int autosuspend_check(struct usb_device *udev)
{
int w, i;
struct usb_interface *intf;
/* Fail if autosuspend is disabled, or any interfaces are in use, or
* any interface drivers require remote wakeup but it isn't available.
*/
w = 0;
if (udev->actconfig) {
for (i = 0; i < udev->actconfig->desc.bNumInterfaces; i++) {
intf = udev->actconfig->interface[i];
/* We don't need to check interfaces that are
* disabled for runtime PM. Either they are unbound
* or else their drivers don't support autosuspend
* and so they are permanently active.
*/
if (intf->dev.power.disable_depth)
continue;
if (atomic_read(&intf->dev.power.usage_count) > 0)
return -EBUSY;
w |= intf->needs_remote_wakeup;
/* Don't allow autosuspend if the device will need
* a reset-resume and any of its interface drivers
* doesn't include support or needs remote wakeup.
*/
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 (w && !device_can_wakeup(&udev->dev)) {
dev_dbg(&udev->dev, "remote wakeup needed for autosuspend\n");
return -EOPNOTSUPP;
}
udev->do_remote_wakeup = w;
return 0;
}
int usb_runtime_suspend(struct device *dev)
{
struct usb_device *udev = to_usb_device(dev);
int status;
/* A USB device can be suspended if it passes the various autosuspend
* checks. Runtime suspend for a USB device means suspending all the
* interfaces and then the device itself.
*/
if (autosuspend_check(udev) != 0)
return -EAGAIN;
status = usb_suspend_both(udev, PMSG_AUTO_SUSPEND);
/* Allow a retry if autosuspend failed temporarily */
if (status == -EAGAIN || status == -EBUSY)
usb_mark_last_busy(udev);
/* The PM core reacts badly unless the return code is 0,
* -EAGAIN, or -EBUSY, so always return -EBUSY on an error.
*/
if (status != 0)
return -EBUSY;
return status;
}
int usb_runtime_resume(struct device *dev)
{
struct usb_device *udev = to_usb_device(dev);
int status;
/* Runtime resume for a USB device means resuming both the device
* and all its interfaces.
*/
status = usb_resume_both(udev, PMSG_AUTO_RESUME);
return status;
}
int usb_runtime_idle(struct device *dev)
{
struct usb_device *udev = to_usb_device(dev);
/* An idle USB device can be suspended if it passes the various
* autosuspend checks.
*/
if (autosuspend_check(udev) == 0)
pm_runtime_autosuspend(dev);
return 0;
}
int usb_set_usb2_hardware_lpm(struct usb_device *udev, int enable)
{
struct usb_hcd *hcd = bus_to_hcd(udev->bus);
int ret = -EPERM;
if (hcd->driver->set_usb2_hw_lpm) {
ret = hcd->driver->set_usb2_hw_lpm(hcd, udev, enable);
if (!ret)
udev->usb2_hw_lpm_enabled = enable;
}
return ret;
}
#endif /* CONFIG_PM_RUNTIME */
struct bus_type usb_bus_type = {
.name = "usb",
.match = usb_device_match,
.uevent = usb_uevent,
};