linux-stable/drivers/usb/core/driver.c
Martin Liu 8c97a46af0 driver core: hold dev's parent lock when needed
SoC have internal I/O buses that can't be proved for devices. The
devices on the buses can be accessed directly without additinal
configuration required. This type of bus is represented as
"simple-bus". In some platforms, we name "soc" with "simple-bus"
attribute and many devices are hooked under it described in DT
(device tree).

In commit bf74ad5bc4 ("Hold the device's parent's lock during
probe and remove") to solve USB subsystem lock sequence since
USB device's characteristic. Thus "soc" needs to be locked
whenever a device and driver's probing happen under "soc" bus.
During this period, an async driver tries to probe a device which
is under the "soc" bus would be blocked until previous driver
finish the probing and release "soc" lock. And the next probing
under the "soc" bus need to wait for async finish. Because of
that, driver's async probe for init time improvement will be
shadowed.

Since many devices don't have USB devices' characteristic, they
actually don't need parent's lock. Thus, we introduce a lock flag
in bus_type struct and driver core would lock the parent lock base
on the flag. For USB, we set this flag in usb_bus_type to keep
original lock behavior in driver core.

Async probe could have more benefit after this patch.

Signed-off-by: Martin Liu <liumartin@google.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-05-31 10:12:07 +02:00

1926 lines
55 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* 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
*
* Released under the GPLv2 only.
*
* 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,
const struct usb_device_id *id_table,
struct device_driver *driver,
const char *buf, size_t count)
{
struct usb_dynid *dynid;
u32 idVendor = 0;
u32 idProduct = 0;
unsigned int bInterfaceClass = 0;
u32 refVendor, refProduct;
int fields = 0;
int retval = 0;
fields = sscanf(buf, "%x %x %x %x %x", &idVendor, &idProduct,
&bInterfaceClass, &refVendor, &refProduct);
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 > 2 && bInterfaceClass) {
if (bInterfaceClass > 255) {
retval = -EINVAL;
goto fail;
}
dynid->id.bInterfaceClass = (u8)bInterfaceClass;
dynid->id.match_flags |= USB_DEVICE_ID_MATCH_INT_CLASS;
}
if (fields > 4) {
const struct usb_device_id *id = id_table;
if (!id) {
retval = -ENODEV;
goto fail;
}
for (; id->match_flags; id++)
if (id->idVendor == refVendor && id->idProduct == refProduct)
break;
if (id->match_flags) {
dynid->id.driver_info = id->driver_info;
} else {
retval = -ENODEV;
goto fail;
}
}
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;
fail:
kfree(dynid);
return retval;
}
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 new_id_show(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 new_id_store(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, usb_drv->id_table, driver, buf, count);
}
static DRIVER_ATTR_RW(new_id);
/*
* Remove a USB device ID from this driver
*/
static ssize_t remove_id_store(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 ssize_t remove_id_show(struct device_driver *driver, char *buf)
{
return new_id_show(driver, buf);
}
static DRIVER_ATTR_RW(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;
}
/* 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 = -ENODEV;
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;
} else if (intf->authorized == 0) {
dev_err(&intf->dev, "Interface %d is not authorized for usage\n",
intf->altsetting->desc.bInterfaceNumber);
return error;
}
id = usb_match_dynamic_id(intf, driver);
if (!id)
id = usb_match_id(intf, driver->id_table);
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.
*/
if (driver->disable_hub_initiated_lpm) {
lpm_disable_error = usb_unlocked_disable_lpm(udev);
if (lpm_disable_error) {
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;
/* 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_host_endpoint *ep, **eps = NULL;
struct usb_device *udev;
int i, j, error, r;
int lpm_disable_error = -ENODEV;
intf->condition = USB_INTERFACE_UNBINDING;
/* Autoresume for set_interface call below */
udev = interface_to_usbdev(intf);
error = usb_autoresume_device(udev);
/* If hub-initiated LPM policy may change, 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.
*/
if (driver->disable_hub_initiated_lpm)
lpm_disable_error = usb_unlocked_disable_lpm(udev);
/*
* Terminate all URBs for this interface unless the driver
* supports "soft" unbinding and the device is still present.
*/
if (!driver->soft_unbind || udev->state == USB_STATE_NOTATTACHED)
usb_disable_interface(udev, intf, false);
driver->disconnect(intf);
/* Free streams */
for (i = 0, j = 0; i < intf->cur_altsetting->desc.bNumEndpoints; i++) {
ep = &intf->cur_altsetting->endpoint[i];
if (ep->streams == 0)
continue;
if (j == 0) {
eps = kmalloc_array(USB_MAXENDPOINTS, sizeof(void *),
GFP_KERNEL);
if (!eps)
break;
}
eps[j++] = ep;
}
if (j) {
usb_free_streams(intf, eps, j, GFP_KERNEL);
kfree(eps);
}
/* 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.
*
* Return: 0 on success.
*/
int usb_driver_claim_interface(struct usb_driver *driver,
struct usb_interface *iface, void *priv)
{
struct device *dev;
struct usb_device *udev;
int retval = 0;
int lpm_disable_error = -ENODEV;
if (!iface)
return -ENODEV;
dev = &iface->dev;
if (dev->driver)
return -EBUSY;
/* reject claim if interface is not authorized */
if (!iface->authorized)
return -ENODEV;
udev = interface_to_usbdev(iface);
dev->driver = &driver->drvwrap.driver;
usb_set_intfdata(iface, priv);
iface->needs_binding = 0;
iface->condition = USB_INTERFACE_BOUND;
/* See the comment about disabling LPM in usb_probe_interface(). */
if (driver->disable_hub_initiated_lpm) {
lpm_disable_error = usb_unlocked_disable_lpm(udev);
if (lpm_disable_error) {
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.
*
* Return: The first matching usb_device_id, or %NULL.
*
* 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.
*
* Return: 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 = 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.
*
* Return: 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 = 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 @intf's lock.
*/
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;
}
/*
* Unbind drivers for @udev's marked interfaces. These interfaces have
* the needs_binding flag set, for example by usb_resume_interface().
*
* The caller must hold @udev's device lock.
*/
static void unbind_marked_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);
}
}
}
/* Delayed forced unbinding of a USB interface driver and scan
* for rebinding.
*
* The caller must hold @intf's device's lock, but not @intf's lock.
*
* Note: Rebinds will be skipped if a system sleep transition is in
* progress and the PM "complete" callback hasn't occurred yet.
*/
static 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 && rc != -EPROBE_DEFER)
dev_warn(&intf->dev, "rebind failed: %d\n", rc);
}
}
/*
* Rebind drivers to @udev's marked interfaces. These interfaces have
* the needs_binding flag set.
*
* The caller must hold @udev's device lock.
*/
static void rebind_marked_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);
}
}
}
/*
* Unbind all of @udev's marked interfaces and then rebind all of them.
* This ordering is necessary because some drivers claim several interfaces
* when they are first probed.
*
* The caller must hold @udev's device lock.
*/
void usb_unbind_and_rebind_marked_interfaces(struct usb_device *udev)
{
unbind_marked_interfaces(udev);
rebind_marked_interfaces(udev);
}
#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);
}
}
}
}
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_dbg(&intf->dev, "no reset_resume for driver %s?\n",
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.
*
* Return: 0 if the suspend succeeded.
*/
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 device is inaccessible, don't try to resume
* suspended interfaces and just return the error.
*/
if (status && status != -EBUSY) {
int err;
u16 devstat;
err = usb_get_std_status(udev, USB_RECIP_DEVICE, 0,
&devstat);
if (err) {
dev_err(&udev->dev,
"Failed to suspend device, error %d\n",
status);
goto done;
}
}
}
/* 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.
*
* Return: 0 on success.
*/
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);
int r;
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);
r = usb_suspend_both(udev, msg);
if (r)
return r;
if (udev->quirks & USB_QUIRK_DISCONNECT_SUSPEND)
usb_port_disable(udev);
return 0;
}
/* 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)
rebind_marked_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_marked_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;
}
/**
* 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.
*
* Return: 0 on success. A negative error code otherwise.
*/
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.
*
* Return: 0 on success.
*/
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.
*
* Return: 0 on success. A negative error code otherwise.
*/
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;
if (udev->state == USB_STATE_NOTATTACHED)
return -ENODEV;
/* 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;
}
/*
* If the device is a direct child of the root hub and the HCD
* doesn't handle wakeup requests, don't allow autosuspend when
* wakeup is needed.
*/
if (w && udev->parent == udev->bus->root_hub &&
bus_to_hcd(udev->bus)->cant_recv_wakeups) {
dev_dbg(&udev->dev, "HCD doesn't handle wakeup requests\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
* (except for root hubs, because they don't suspend through
* an upstream port like other USB devices).
*/
if (status != 0 && udev->parent)
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);
/* Tell the core not to suspend it, though. */
return -EBUSY;
}
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 (enable && !udev->usb2_hw_lpm_allowed)
return 0;
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 */
struct bus_type usb_bus_type = {
.name = "usb",
.match = usb_device_match,
.uevent = usb_uevent,
.need_parent_lock = true,
};