driver.c 53.7 KB
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/*
 * 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
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 * matching, probing, releasing, suspending and resuming for
 * real drivers.
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 *
 */

#include <linux/device.h>
#include <linux/usb.h>
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#include <linux/usb/quirks.h>
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#include <linux/workqueue.h>
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#include "hcd.h"
#include "usb.h"

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#ifdef CONFIG_HOTPLUG

/*
 * Adds a new dynamic USBdevice ID to this driver,
 * and cause the driver to probe for all devices again.
 */
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ssize_t usb_store_new_id(struct usb_dynids *dynids,
			 struct device_driver *driver,
			 const char *buf, size_t count)
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{
	struct usb_dynid *dynid;
	u32 idVendor = 0;
	u32 idProduct = 0;
	int fields = 0;
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	int retval = 0;
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	fields = sscanf(buf, "%x %x", &idVendor, &idProduct);
	if (fields < 2)
		return -EINVAL;

	dynid = kzalloc(sizeof(*dynid), GFP_KERNEL);
	if (!dynid)
		return -ENOMEM;

	INIT_LIST_HEAD(&dynid->node);
	dynid->id.idVendor = idVendor;
	dynid->id.idProduct = idProduct;
	dynid->id.match_flags = USB_DEVICE_ID_MATCH_DEVICE;

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	spin_lock(&dynids->lock);
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	list_add_tail(&dynid->node, &dynids->list);
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	spin_unlock(&dynids->lock);
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	if (get_driver(driver)) {
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		retval = driver_attach(driver);
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		put_driver(driver);
	}

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	if (retval)
		return retval;
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	return count;
}
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EXPORT_SYMBOL_GPL(usb_store_new_id);

static ssize_t store_new_id(struct device_driver *driver,
			    const char *buf, size_t count)
{
	struct usb_driver *usb_drv = to_usb_driver(driver);

	return usb_store_new_id(&usb_drv->dynids, driver, buf, count);
}
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static DRIVER_ATTR(new_id, S_IWUSR, NULL, store_new_id);

static int usb_create_newid_file(struct usb_driver *usb_drv)
{
	int error = 0;

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	if (usb_drv->no_dynamic_id)
		goto exit;

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	if (usb_drv->probe != NULL)
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		error = driver_create_file(&usb_drv->drvwrap.driver,
					   &driver_attr_new_id);
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exit:
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	return error;
}

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static void usb_remove_newid_file(struct usb_driver *usb_drv)
{
	if (usb_drv->no_dynamic_id)
		return;

	if (usb_drv->probe != NULL)
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		driver_remove_file(&usb_drv->drvwrap.driver,
				   &driver_attr_new_id);
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}

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static void usb_free_dynids(struct usb_driver *usb_drv)
{
	struct usb_dynid *dynid, *n;

	spin_lock(&usb_drv->dynids.lock);
	list_for_each_entry_safe(dynid, n, &usb_drv->dynids.list, node) {
		list_del(&dynid->node);
		kfree(dynid);
	}
	spin_unlock(&usb_drv->dynids.lock);
}
#else
static inline int usb_create_newid_file(struct usb_driver *usb_drv)
{
	return 0;
}

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static void usb_remove_newid_file(struct usb_driver *usb_drv)
{
}

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static inline void usb_free_dynids(struct usb_driver *usb_drv)
{
}
#endif

static const struct usb_device_id *usb_match_dynamic_id(struct usb_interface *intf,
							struct usb_driver *drv)
{
	struct usb_dynid *dynid;

	spin_lock(&drv->dynids.lock);
	list_for_each_entry(dynid, &drv->dynids.list, node) {
		if (usb_match_one_id(intf, &dynid->id)) {
			spin_unlock(&drv->dynids.lock);
			return &dynid->id;
		}
	}
	spin_unlock(&drv->dynids.lock);
	return NULL;
}


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/* 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);
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	struct usb_device *udev = to_usb_device(dev);
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	int error = -ENODEV;

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	dev_dbg(dev, "%s\n", __func__);
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	/* TODO: Add real matching code */

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	/* The device should always appear to be in use
	 * unless the driver suports autosuspend.
	 */
	udev->pm_usage_cnt = !(udriver->supports_autosuspend);

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	error = udriver->probe(udev);
	return error;
}

/* called from driver core with dev locked */
static int usb_unbind_device(struct device *dev)
{
	struct usb_device_driver *udriver = to_usb_device_driver(dev->driver);

	udriver->disconnect(to_usb_device(dev));
	return 0;
}

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/*
 * 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);
}
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/* called from driver core with dev locked */
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static int usb_probe_interface(struct device *dev)
{
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	struct usb_driver *driver = to_usb_driver(dev->driver);
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	struct usb_interface *intf = to_usb_interface(dev);
	struct usb_device *udev = interface_to_usbdev(intf);
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	const struct usb_device_id *id;
	int error = -ENODEV;

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	dev_dbg(dev, "%s\n", __func__);
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	intf->needs_binding = 0;
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	if (usb_device_is_owned(udev))
		return -ENODEV;

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	if (udev->authorized == 0) {
		dev_err(&intf->dev, "Device is not authorized for usage\n");
		return -ENODEV;
	}
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	id = usb_match_id(intf, driver->id_table);
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	if (!id)
		id = usb_match_dynamic_id(intf, driver);
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	if (id) {
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		dev_dbg(dev, "%s - got id\n", __func__);
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		error = usb_autoresume_device(udev);
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		if (error)
			return error;

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		/* Interface "power state" doesn't correspond to any hardware
		 * state whatsoever.  We use it to record when it's bound to
		 * a driver that may start I/0:  it's not frozen/quiesced.
		 */
		mark_active(intf);
		intf->condition = USB_INTERFACE_BINDING;
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		/* The interface should always appear to be in use
		 * unless the driver suports autosuspend.
		 */
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		atomic_set(&intf->pm_usage_cnt, !driver->supports_autosuspend);
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		/* Carry out a deferred switch to altsetting 0 */
		if (intf->needs_altsetting0) {
			usb_set_interface(udev, intf->altsetting[0].
					desc.bInterfaceNumber, 0);
			intf->needs_altsetting0 = 0;
		}

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		error = driver->probe(intf, id);
		if (error) {
			mark_quiesced(intf);
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			intf->needs_remote_wakeup = 0;
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			intf->condition = USB_INTERFACE_UNBOUND;
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			usb_cancel_queued_reset(intf);
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		} else
			intf->condition = USB_INTERFACE_BOUND;
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		usb_autosuspend_device(udev);
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	}

	return error;
}

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/* called from driver core with dev locked */
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static int usb_unbind_interface(struct device *dev)
{
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	struct usb_driver *driver = to_usb_driver(dev->driver);
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	struct usb_interface *intf = to_usb_interface(dev);
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	struct usb_device *udev;
	int error;
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	intf->condition = USB_INTERFACE_UNBINDING;

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	/* Autoresume for set_interface call below */
	udev = interface_to_usbdev(intf);
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	error = usb_autoresume_device(udev);
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	/* Terminate all URBs for this interface unless the driver
	 * supports "soft" unbinding.
	 */
	if (!driver->soft_unbind)
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		usb_disable_interface(udev, intf, false);
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	driver->disconnect(intf);
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	usb_cancel_queued_reset(intf);
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	/* 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.
	 */
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	if (intf->cur_altsetting->desc.bAlternateSetting == 0) {
		/* Already in altsetting 0 so skip Set-Interface.
		 * Just re-enable it without affecting the endpoint toggles.
		 */
		usb_enable_interface(udev, intf, false);
	} else if (!error && intf->dev.power.status == DPM_ON)
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		usb_set_interface(udev, intf->altsetting[0].
				desc.bInterfaceNumber, 0);
	else
		intf->needs_altsetting0 = 1;
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	usb_set_intfdata(intf, NULL);
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	intf->condition = USB_INTERFACE_UNBOUND;
	mark_quiesced(intf);
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	intf->needs_remote_wakeup = 0;

	if (!error)
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		usb_autosuspend_device(udev);
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	return 0;
}

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/**
 * 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.
 *
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 * 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.
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 */
int usb_driver_claim_interface(struct usb_driver *driver,
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				struct usb_interface *iface, void *priv)
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{
	struct device *dev = &iface->dev;
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	struct usb_device *udev = interface_to_usbdev(iface);
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	int retval = 0;
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	if (dev->driver)
		return -EBUSY;

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	dev->driver = &driver->drvwrap.driver;
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	usb_set_intfdata(iface, priv);
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	iface->needs_binding = 0;
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	usb_pm_lock(udev);
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	iface->condition = USB_INTERFACE_BOUND;
	mark_active(iface);
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	atomic_set(&iface->pm_usage_cnt, !driver->supports_autosuspend);
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	usb_pm_unlock(udev);
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	/* if interface was already added, bind now; else let
	 * the future device_add() bind it, bypassing probe()
	 */
	if (device_is_registered(dev))
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		retval = device_bind_driver(dev);
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	return retval;
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}
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EXPORT_SYMBOL_GPL(usb_driver_claim_interface);
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/**
 * 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.
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 * 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.
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 */
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 */
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	if (!dev->driver || dev->driver != &driver->drvwrap.driver)
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		return;

	/* don't release from within disconnect() */
	if (iface->condition != USB_INTERFACE_BOUND)
		return;
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	iface->condition = USB_INTERFACE_UNBINDING;
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	/* Release via the driver core only if the interface
	 * has already been registered
	 */
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	if (device_is_registered(dev)) {
		device_release_driver(dev);
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	} else {
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		down(&dev->sem);
		usb_unbind_interface(dev);
		dev->driver = NULL;
		up(&dev->sem);
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	}
}
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EXPORT_SYMBOL_GPL(usb_driver_release_interface);
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/* returns 0 if no match, 1 if match */
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int usb_match_device(struct usb_device *dev, const struct usb_device_id *id)
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{
	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) &&
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	    (id->bDeviceSubClass != dev->descriptor.bDeviceSubClass))
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		return 0;

	if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_PROTOCOL) &&
	    (id->bDeviceProtocol != dev->descriptor.bDeviceProtocol))
		return 0;

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	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;

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	/* The interface class, subclass, and protocol should never be
	 * checked for a match if the device class is Vendor Specific,
	 * unless the match record specifies the Vendor ID. */
	if (dev->descriptor.bDeviceClass == USB_CLASS_VENDOR_SPEC &&
			!(id->match_flags & USB_DEVICE_ID_MATCH_VENDOR) &&
			(id->match_flags & (USB_DEVICE_ID_MATCH_INT_CLASS |
				USB_DEVICE_ID_MATCH_INT_SUBCLASS |
				USB_DEVICE_ID_MATCH_INT_PROTOCOL)))
		return 0;

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	if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_CLASS) &&
	    (id->bInterfaceClass != intf->desc.bInterfaceClass))
		return 0;

	if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_SUBCLASS) &&
	    (id->bInterfaceSubClass != intf->desc.bInterfaceSubClass))
		return 0;

	if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_PROTOCOL) &&
	    (id->bInterfaceProtocol != intf->desc.bInterfaceProtocol))
		return 0;

	return 1;
}
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EXPORT_SYMBOL_GPL(usb_match_one_id);

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/**
 * 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
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 * 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.)
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 *
 * 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. */
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	for (; id->idVendor || id->idProduct || id->bDeviceClass ||
	       id->bInterfaceClass || id->driver_info; id++) {
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		if (usb_match_one_id(interface, id))
			return id;
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	}

	return NULL;
}
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EXPORT_SYMBOL_GPL(usb_match_id);
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static int usb_device_match(struct device *dev, struct device_driver *drv)
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{
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	/* devices and interfaces are handled separately */
	if (is_usb_device(dev)) {
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		/* interface drivers never match devices */
		if (!is_usb_device_driver(drv))
			return 0;
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		/* TODO: Add real matching code */
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		return 1;

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	} else if (is_usb_interface(dev)) {
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		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;
	}

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	return 0;
}

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#ifdef	CONFIG_HOTPLUG
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static int usb_uevent(struct device *dev, struct kobj_uevent_env *env)
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{
	struct usb_device *usb_dev;

	/* driver is often null here; dev_dbg() would oops */
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	pr_debug("usb %s: uevent\n", dev_name(dev));
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	if (is_usb_device(dev)) {
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		usb_dev = to_usb_device(dev);
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	} else if (is_usb_interface(dev)) {
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		struct usb_interface *intf = to_usb_interface(dev);
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		usb_dev = interface_to_usbdev(intf);
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	} else {
		return 0;
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	}
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	if (usb_dev->devnum < 0) {
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		pr_debug("usb %s: already deleted?\n", dev_name(dev));
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		return -ENODEV;
	}
	if (!usb_dev->bus) {
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		pr_debug("usb %s: bus removed?\n", dev_name(dev));
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		return -ENODEV;
	}

#ifdef	CONFIG_USB_DEVICEFS
	/* If this is available, userspace programs can directly read
	 * all the device descriptors we don't tell them about.  Or
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	 * act as usermode drivers.
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	 */
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	if (add_uevent_var(env, "DEVICE=/proc/bus/usb/%03d/%03d",
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			   usb_dev->bus->busnum, usb_dev->devnum))
		return -ENOMEM;
#endif

	/* per-device configurations are common */
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	if (add_uevent_var(env, "PRODUCT=%x/%x/%x",
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			   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 */
658
	if (add_uevent_var(env, "TYPE=%d/%d/%d",
659 660 661 662 663 664 665 666 667 668
			   usb_dev->descriptor.bDeviceClass,
			   usb_dev->descriptor.bDeviceSubClass,
			   usb_dev->descriptor.bDeviceProtocol))
		return -ENOMEM;

	return 0;
}

#else

669
static int usb_uevent(struct device *dev, struct kobj_uevent_env *env)
670 671 672 673 674
{
	return -ENODEV;
}
#endif	/* CONFIG_HOTPLUG */

675
/**
676 677
 * usb_register_device_driver - register a USB device (not interface) driver
 * @new_udriver: USB operations for the device driver
678
 * @owner: module owner of this driver.
679
 *
680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736
 * Registers a USB device driver with the USB core.  The list of
 * unattached devices will be rescanned whenever a new driver is
 * added, allowing the new driver to attach to any recognized devices.
 * Returns a negative error code on failure and 0 on success.
 */
int usb_register_device_driver(struct usb_device_driver *new_udriver,
		struct module *owner)
{
	int retval = 0;

	if (usb_disabled())
		return -ENODEV;

	new_udriver->drvwrap.for_devices = 1;
	new_udriver->drvwrap.driver.name = (char *) new_udriver->name;
	new_udriver->drvwrap.driver.bus = &usb_bus_type;
	new_udriver->drvwrap.driver.probe = usb_probe_device;
	new_udriver->drvwrap.driver.remove = usb_unbind_device;
	new_udriver->drvwrap.driver.owner = owner;

	retval = driver_register(&new_udriver->drvwrap.driver);

	if (!retval) {
		pr_info("%s: registered new device driver %s\n",
			usbcore_name, new_udriver->name);
		usbfs_update_special();
	} else {
		printk(KERN_ERR "%s: error %d registering device "
			"	driver %s\n",
			usbcore_name, retval, new_udriver->name);
	}

	return retval;
}
EXPORT_SYMBOL_GPL(usb_register_device_driver);

/**
 * usb_deregister_device_driver - unregister a USB device (not interface) driver
 * @udriver: USB operations of the device driver to unregister
 * Context: must be able to sleep
 *
 * Unlinks the specified driver from the internal USB driver list.
 */
void usb_deregister_device_driver(struct usb_device_driver *udriver)
{
	pr_info("%s: deregistering device driver %s\n",
			usbcore_name, udriver->name);

	driver_unregister(&udriver->drvwrap.driver);
	usbfs_update_special();
}
EXPORT_SYMBOL_GPL(usb_deregister_device_driver);

/**
 * usb_register_driver - register a USB interface driver
 * @new_driver: USB operations for the interface driver
 * @owner: module owner of this driver.
R
Randy Dunlap 已提交
737
 * @mod_name: module name string
738 739 740 741
 *
 * 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.
742 743 744 745 746 747
 * 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.
 */
748 749
int usb_register_driver(struct usb_driver *new_driver, struct module *owner,
			const char *mod_name)
750 751 752 753 754 755
{
	int retval = 0;

	if (usb_disabled())
		return -ENODEV;

756 757 758 759 760 761
	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;
762
	new_driver->drvwrap.driver.mod_name = mod_name;
763 764
	spin_lock_init(&new_driver->dynids.lock);
	INIT_LIST_HEAD(&new_driver->dynids.list);
765

766
	retval = driver_register(&new_driver->drvwrap.driver);
767 768

	if (!retval) {
769
		pr_info("%s: registered new interface driver %s\n",
770 771
			usbcore_name, new_driver->name);
		usbfs_update_special();
772
		usb_create_newid_file(new_driver);
773
	} else {
774 775
		printk(KERN_ERR "%s: error %d registering interface "
			"	driver %s\n",
776 777 778 779 780
			usbcore_name, retval, new_driver->name);
	}

	return retval;
}
781
EXPORT_SYMBOL_GPL(usb_register_driver);
782 783

/**
784 785
 * usb_deregister - unregister a USB interface driver
 * @driver: USB operations of the interface driver to unregister
786 787 788 789 790 791 792 793 794 795
 * 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)
{
796 797
	pr_info("%s: deregistering interface driver %s\n",
			usbcore_name, driver->name);
798

799
	usb_remove_newid_file(driver);
800
	usb_free_dynids(driver);
801
	driver_unregister(&driver->drvwrap.driver);
802 803 804

	usbfs_update_special();
}
805
EXPORT_SYMBOL_GPL(usb_deregister);
806

807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830
/* 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.
 *
831 832
 * Note: Rebinds will be skipped if a system sleep transition is in
 * progress and the PM "complete" callback hasn't occurred yet.
833 834 835 836 837 838 839 840 841 842 843 844 845 846 847
 */
void usb_rebind_intf(struct usb_interface *intf)
{
	int rc;

	/* Delayed unbind of an existing driver */
	if (intf->dev.driver) {
		struct usb_driver *driver =
				to_usb_driver(intf->dev.driver);

		dev_dbg(&intf->dev, "forced unbind\n");
		usb_driver_release_interface(driver, intf);
	}

	/* Try to rebind the interface */
848 849 850 851 852 853
	if (intf->dev.power.status == DPM_ON) {
		intf->needs_binding = 0;
		rc = device_attach(&intf->dev);
		if (rc < 0)
			dev_warn(&intf->dev, "rebind failed: %d\n", rc);
	}
854 855
}

A
Alan Stern 已提交
856 857
#ifdef CONFIG_PM

858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885
#define DO_UNBIND	0
#define DO_REBIND	1

/* Unbind drivers for @udev's interfaces that don't support suspend/resume,
 * or rebind interfaces that have been unbound, according to @action.
 *
 * The caller must hold @udev's device lock.
 */
static void do_unbind_rebind(struct usb_device *udev, int action)
{
	struct usb_host_config	*config;
	int			i;
	struct usb_interface	*intf;
	struct usb_driver	*drv;

	config = udev->actconfig;
	if (config) {
		for (i = 0; i < config->desc.bNumInterfaces; ++i) {
			intf = config->interface[i];
			switch (action) {
			case DO_UNBIND:
				if (intf->dev.driver) {
					drv = to_usb_driver(intf->dev.driver);
					if (!drv->suspend || !drv->resume)
						usb_forced_unbind_intf(intf);
				}
				break;
			case DO_REBIND:
886
				if (intf->needs_binding)
887 888 889 890 891 892 893
					usb_rebind_intf(intf);
				break;
			}
		}
	}
}

894
/* Caller has locked udev's pm_mutex */
895
static int usb_suspend_device(struct usb_device *udev, pm_message_t msg)
896
{
897
	struct usb_device_driver	*udriver;
898
	int				status = 0;
899

900 901 902 903
	if (udev->state == USB_STATE_NOTATTACHED ||
			udev->state == USB_STATE_SUSPENDED)
		goto done;

904 905 906 907
	/* 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 {
908
		udev->do_remote_wakeup = 0;
909
		udriver = &usb_generic_driver;
910
	}
911 912
	status = udriver->suspend(udev, msg);

A
Alan Stern 已提交
913
 done:
914
	dev_vdbg(&udev->dev, "%s: status %d\n", __func__, status);
915
	return status;
916 917
}

918
/* Caller has locked udev's pm_mutex */
A
Alan Stern 已提交
919
static int usb_resume_device(struct usb_device *udev, pm_message_t msg)
920 921
{
	struct usb_device_driver	*udriver;
922
	int				status = 0;
923

A
Alan Stern 已提交
924 925
	if (udev->state == USB_STATE_NOTATTACHED)
		goto done;
926

927 928 929
	/* Can't resume it if it doesn't have a driver. */
	if (udev->dev.driver == NULL) {
		status = -ENOTCONN;
930
		goto done;
931 932
	}

A
Alan Stern 已提交
933 934 935
	if (udev->quirks & USB_QUIRK_RESET_RESUME)
		udev->reset_resume = 1;

936
	udriver = to_usb_device_driver(udev->dev.driver);
A
Alan Stern 已提交
937
	status = udriver->resume(udev, msg);
938

A
Alan Stern 已提交
939
 done:
940
	dev_vdbg(&udev->dev, "%s: status %d\n", __func__, status);
A
Alan Stern 已提交
941
	if (status == 0)
942
		udev->autoresume_disabled = 0;
943
	return status;
944 945
}

946
/* Caller has locked intf's usb_device's pm mutex */
947 948
static int usb_suspend_interface(struct usb_device *udev,
		struct usb_interface *intf, pm_message_t msg)
949 950
{
	struct usb_driver	*driver;
951
	int			status = 0;
952

953
	/* with no hardware, USB interfaces only use FREEZE and ON states */
954
	if (udev->state == USB_STATE_NOTATTACHED || !is_active(intf))
955
		goto done;
956

957 958
	/* This can happen; see usb_driver_release_interface() */
	if (intf->condition == USB_INTERFACE_UNBOUND)
959
		goto done;
960
	driver = to_usb_driver(intf->dev.driver);
961

962
	if (driver->suspend) {
963
		status = driver->suspend(intf, msg);
964 965
		if (status == 0)
			mark_quiesced(intf);
A
Alan Stern 已提交
966
		else if (!(msg.event & PM_EVENT_AUTO))
967 968
			dev_err(&intf->dev, "%s error %d\n",
					"suspend", status);
969
	} else {
970 971 972 973
		/* Later we will unbind the driver and reprobe */
		intf->needs_binding = 1;
		dev_warn(&intf->dev, "no %s for driver %s?\n",
				"suspend", driver->name);
974 975
		mark_quiesced(intf);
	}
976

A
Alan Stern 已提交
977
 done:
978
	dev_vdbg(&intf->dev, "%s: status %d\n", __func__, status);
979 980 981
	return status;
}

982
/* Caller has locked intf's usb_device's pm_mutex */
983
static int usb_resume_interface(struct usb_device *udev,
A
Alan Stern 已提交
984
		struct usb_interface *intf, pm_message_t msg, int reset_resume)
985
{
986
	struct usb_driver	*driver;
987
	int			status = 0;
988

989
	if (udev->state == USB_STATE_NOTATTACHED || is_active(intf))
990
		goto done;
991

992 993 994 995
	/* Don't let autoresume interfere with unbinding */
	if (intf->condition == USB_INTERFACE_UNBINDING)
		goto done;

996
	/* Can't resume it if it doesn't have a driver. */
997 998 999 1000 1001 1002 1003 1004 1005
	if (intf->condition == USB_INTERFACE_UNBOUND) {

		/* Carry out a deferred switch to altsetting 0 */
		if (intf->needs_altsetting0 &&
				intf->dev.power.status == DPM_ON) {
			usb_set_interface(udev, intf->altsetting[0].
					desc.bInterfaceNumber, 0);
			intf->needs_altsetting0 = 0;
		}
1006
		goto done;
1007
	}
1008 1009 1010

	/* Don't resume if the interface is marked for rebinding */
	if (intf->needs_binding)
1011
		goto done;
1012
	driver = to_usb_driver(intf->dev.driver);
1013

A
Alan Stern 已提交
1014 1015 1016 1017 1018 1019 1020
	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 {
1021
			intf->needs_binding = 1;
A
Alan Stern 已提交
1022 1023 1024 1025 1026 1027 1028 1029 1030 1031
			dev_warn(&intf->dev, "no %s for driver %s?\n",
					"reset_resume", driver->name);
		}
	} else {
		if (driver->resume) {
			status = driver->resume(intf);
			if (status)
				dev_err(&intf->dev, "%s error %d\n",
						"resume", status);
		} else {
1032
			intf->needs_binding = 1;
A
Alan Stern 已提交
1033 1034 1035 1036
			dev_warn(&intf->dev, "no %s for driver %s?\n",
					"resume", driver->name);
		}
	}
1037 1038

done:
1039
	dev_vdbg(&intf->dev, "%s: status %d\n", __func__, status);
1040
	if (status == 0 && intf->condition == USB_INTERFACE_BOUND)
A
Alan Stern 已提交
1041
		mark_active(intf);
A
Alan Stern 已提交
1042

1043
	/* Later we will unbind the driver and/or reprobe, if necessary */
1044
	return status;
1045 1046
}

1047 1048
#ifdef	CONFIG_USB_SUSPEND

A
Alan Stern 已提交
1049
/* Internal routine to check whether we may autosuspend a device. */
1050
static int autosuspend_check(struct usb_device *udev, int reschedule)
A
Alan Stern 已提交
1051 1052 1053
{
	int			i;
	struct usb_interface	*intf;
1054
	unsigned long		suspend_time, j;
A
Alan Stern 已提交
1055

1056 1057 1058 1059
	/* For autosuspend, fail fast if anything is in use or autosuspend
	 * is disabled.  Also fail if any interfaces require remote wakeup
	 * but it isn't available.
	 */
A
Alan Stern 已提交
1060 1061
	if (udev->pm_usage_cnt > 0)
		return -EBUSY;
1062
	if (udev->autosuspend_delay < 0 || udev->autosuspend_disabled)
1063 1064
		return -EPERM;

1065
	suspend_time = udev->last_busy + udev->autosuspend_delay;
A
Alan Stern 已提交
1066 1067 1068 1069 1070
	if (udev->actconfig) {
		for (i = 0; i < udev->actconfig->desc.bNumInterfaces; i++) {
			intf = udev->actconfig->interface[i];
			if (!is_active(intf))
				continue;
A
Alan Stern 已提交
1071
			if (atomic_read(&intf->pm_usage_cnt) > 0)
A
Alan Stern 已提交
1072 1073 1074 1075 1076 1077 1078
				return -EBUSY;
			if (intf->needs_remote_wakeup &&
					!udev->do_remote_wakeup) {
				dev_dbg(&udev->dev, "remote wakeup needed "
						"for autosuspend\n");
				return -EOPNOTSUPP;
			}
A
Alan Stern 已提交
1079 1080 1081 1082 1083 1084 1085 1086 1087

			/* Don't allow autosuspend if the device will need
			 * a reset-resume and any of its interface drivers
			 * doesn't include support.
			 */
			if (udev->quirks & USB_QUIRK_RESET_RESUME) {
				struct usb_driver *driver;

				driver = to_usb_driver(intf->dev.driver);
1088 1089
				if (!driver->reset_resume ||
				    intf->needs_remote_wakeup)
A
Alan Stern 已提交
1090 1091
					return -EOPNOTSUPP;
			}
A
Alan Stern 已提交
1092 1093
		}
	}
1094 1095

	/* If everything is okay but the device hasn't been idle for long
1096 1097 1098
	 * enough, queue a delayed autosuspend request.  If the device
	 * _has_ been idle for long enough and the reschedule flag is set,
	 * likewise queue a delayed (1 second) autosuspend request.
1099
	 */
1100 1101 1102 1103 1104 1105
	j = jiffies;
	if (time_before(j, suspend_time))
		reschedule = 1;
	else
		suspend_time = j + HZ;
	if (reschedule) {
1106
		if (!timer_pending(&udev->autosuspend.timer)) {
1107
			queue_delayed_work(ksuspend_usb_wq, &udev->autosuspend,
1108
				round_jiffies_up_relative(suspend_time - j));
1109
		}
1110 1111
		return -EAGAIN;
	}
A
Alan Stern 已提交
1112 1113 1114
	return 0;
}

1115 1116
#else

1117
static inline int autosuspend_check(struct usb_device *udev, int reschedule)
A
Alan Stern 已提交
1118 1119 1120
{
	return 0;
}
1121

1122
#endif	/* CONFIG_USB_SUSPEND */
1123

1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134
/**
 * usb_suspend_both - suspend a USB device and its interfaces
 * @udev: the usb_device to suspend
 * @msg: Power Management message describing this state transition
 *
 * This is the central routine for suspending USB devices.  It calls the
 * suspend methods for all the interface drivers in @udev and then calls
 * the suspend method for @udev itself.  If an error occurs at any stage,
 * all the interfaces which were suspended are resumed so that they remain
 * in the same state as the device.
 *
A
Alan Stern 已提交
1135 1136 1137
 * If an autosuspend is in progress the routine checks first to make sure
 * that neither the device itself or any of its active interfaces is in use
 * (pm_usage_cnt is greater than 0).  If they are, the autosuspend fails.
1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158
 *
 * If the suspend succeeds, the routine recursively queues an autosuspend
 * request for @udev's parent device, thereby propagating the change up
 * the device tree.  If all of the parent's children are now suspended,
 * the parent will autosuspend in turn.
 *
 * The suspend method calls are subject to mutual exclusion under control
 * of @udev's pm_mutex.  Many of these calls are also under the protection
 * of @udev's device lock (including all requests originating outside the
 * USB subsystem), but autosuspend requests generated by a child device or
 * interface driver may not be.  Usbcore will insure that the method calls
 * do not arrive during bind, unbind, or reset operations.  However, drivers
 * must be prepared to handle suspend calls arriving at unpredictable times.
 * The only way to block such calls is to do an autoresume (preventing
 * autosuspends) while holding @udev's device lock (preventing outside
 * suspends).
 *
 * The caller must hold @udev->pm_mutex.
 *
 * This routine can run only in process context.
 */
A
Alan Stern 已提交
1159
static int usb_suspend_both(struct usb_device *udev, pm_message_t msg)
1160 1161 1162 1163
{
	int			status = 0;
	int			i = 0;
	struct usb_interface	*intf;
1164 1165
	struct usb_device	*parent = udev->parent;

1166 1167 1168
	if (udev->state == USB_STATE_NOTATTACHED ||
			udev->state == USB_STATE_SUSPENDED)
		goto done;
1169

1170 1171
	udev->do_remote_wakeup = device_may_wakeup(&udev->dev);

A
Alan Stern 已提交
1172
	if (msg.event & PM_EVENT_AUTO) {
1173
		status = autosuspend_check(udev, 0);
A
Alan Stern 已提交
1174
		if (status < 0)
1175
			goto done;
1176 1177 1178
	}

	/* Suspend all the interfaces and then udev itself */
1179 1180 1181
	if (udev->actconfig) {
		for (; i < udev->actconfig->desc.bNumInterfaces; i++) {
			intf = udev->actconfig->interface[i];
1182
			status = usb_suspend_interface(udev, intf, msg);
1183 1184 1185 1186
			if (status != 0)
				break;
		}
	}
1187
	if (status == 0)
1188
		status = usb_suspend_device(udev, msg);
1189 1190 1191

	/* If the suspend failed, resume interfaces that did get suspended */
	if (status != 0) {
A
Alan Stern 已提交
1192 1193 1194
		pm_message_t msg2;

		msg2.event = msg.event ^ (PM_EVENT_SUSPEND | PM_EVENT_RESUME);
1195 1196
		while (--i >= 0) {
			intf = udev->actconfig->interface[i];
A
Alan Stern 已提交
1197
			usb_resume_interface(udev, intf, msg2, 0);
1198
		}
1199

A
Alan Stern 已提交
1200
		/* Try another autosuspend when the interfaces aren't busy */
A
Alan Stern 已提交
1201
		if (msg.event & PM_EVENT_AUTO)
1202
			autosuspend_check(udev, status == -EBUSY);
A
Alan Stern 已提交
1203

1204 1205 1206
	/* If the suspend succeeded then prevent any more URB submissions,
	 * flush any outstanding URBs, and propagate the suspend up the tree.
	 */
A
Alan Stern 已提交
1207 1208
	} else {
		cancel_delayed_work(&udev->autosuspend);
1209 1210 1211 1212 1213
		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]);
		}
1214 1215 1216 1217 1218 1219

		/* If this is just a FREEZE or a PRETHAW, udev might
		 * not really be suspended.  Only true suspends get
		 * propagated up the device tree.
		 */
		if (parent && udev->state == USB_STATE_SUSPENDED)
A
Alan Stern 已提交
1220 1221
			usb_autosuspend_device(parent);
	}
1222

1223
 done:
1224
	dev_vdbg(&udev->dev, "%s: status %d\n", __func__, status);
1225 1226 1227
	return status;
}

1228 1229 1230
/**
 * usb_resume_both - resume a USB device and its interfaces
 * @udev: the usb_device to resume
A
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1231
 * @msg: Power Management message describing this state transition
1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256
 *
 * This is the central routine for resuming USB devices.  It calls the
 * the resume method for @udev and then calls the resume methods for all
 * the interface drivers in @udev.
 *
 * Before starting the resume, the routine calls itself recursively for
 * the parent device of @udev, thereby propagating the change up the device
 * tree and assuring that @udev will be able to resume.  If the parent is
 * unable to resume successfully, the routine fails.
 *
 * The resume method calls are subject to mutual exclusion under control
 * of @udev's pm_mutex.  Many of these calls are also under the protection
 * of @udev's device lock (including all requests originating outside the
 * USB subsystem), but autoresume requests generated by a child device or
 * interface driver may not be.  Usbcore will insure that the method calls
 * do not arrive during bind, unbind, or reset operations.  However, drivers
 * must be prepared to handle resume calls arriving at unpredictable times.
 * The only way to block such calls is to do an autoresume (preventing
 * other autoresumes) while holding @udev's device lock (preventing outside
 * resumes).
 *
 * The caller must hold @udev->pm_mutex.
 *
 * This routine can run only in process context.
 */
A
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1257
static int usb_resume_both(struct usb_device *udev, pm_message_t msg)
1258
{
1259
	int			status = 0;
1260 1261
	int			i;
	struct usb_interface	*intf;
1262 1263 1264
	struct usb_device	*parent = udev->parent;

	cancel_delayed_work(&udev->autosuspend);
1265 1266 1267 1268
	if (udev->state == USB_STATE_NOTATTACHED) {
		status = -ENODEV;
		goto done;
	}
1269
	udev->can_submit = 1;
1270

1271 1272
	/* Propagate the resume up the tree, if necessary */
	if (udev->state == USB_STATE_SUSPENDED) {
A
Alan Stern 已提交
1273 1274
		if ((msg.event & PM_EVENT_AUTO) &&
				udev->autoresume_disabled) {
1275 1276 1277
			status = -EPERM;
			goto done;
		}
1278
		if (parent) {
1279
			status = usb_autoresume_device(parent);
1280
			if (status == 0) {
A
Alan Stern 已提交
1281
				status = usb_resume_device(udev, msg);
A
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1282 1283
				if (status || udev->state ==
						USB_STATE_NOTATTACHED) {
1284
					usb_autosuspend_device(parent);
1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298

					/* It's possible usb_resume_device()
					 * failed after the port was
					 * unsuspended, causing udev to be
					 * logically disconnected.  We don't
					 * want usb_disconnect() to autosuspend
					 * the parent again, so tell it that
					 * udev disconnected while still
					 * suspended. */
					if (udev->state ==
							USB_STATE_NOTATTACHED)
						udev->discon_suspended = 1;
				}
			}
1299 1300 1301 1302 1303
		} else {

			/* We can't progagate beyond the USB subsystem,
			 * so if a root hub's controller is suspended
			 * then we're stuck. */
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1304
			status = usb_resume_device(udev, msg);
1305
		}
A
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1306
	} else if (udev->reset_resume)
A
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		status = usb_resume_device(udev, msg);
1308

1309 1310 1311
	if (status == 0 && udev->actconfig) {
		for (i = 0; i < udev->actconfig->desc.bNumInterfaces; i++) {
			intf = udev->actconfig->interface[i];
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1312 1313
			usb_resume_interface(udev, intf, msg,
					udev->reset_resume);
1314 1315
		}
	}
1316

1317
 done:
1318
	dev_vdbg(&udev->dev, "%s: status %d\n", __func__, status);
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1319 1320
	if (!status)
		udev->reset_resume = 0;
1321 1322 1323 1324 1325
	return status;
}

#ifdef CONFIG_USB_SUSPEND

1326 1327 1328 1329 1330 1331 1332 1333
/* Internal routine to adjust a device's usage counter and change
 * its autosuspend state.
 */
static int usb_autopm_do_device(struct usb_device *udev, int inc_usage_cnt)
{
	int	status = 0;

	usb_pm_lock(udev);
1334
	udev->auto_pm = 1;
1335 1336
	udev->pm_usage_cnt += inc_usage_cnt;
	WARN_ON(udev->pm_usage_cnt < 0);
1337 1338
	if (inc_usage_cnt)
		udev->last_busy = jiffies;
1339
	if (inc_usage_cnt >= 0 && udev->pm_usage_cnt > 0) {
1340
		if (udev->state == USB_STATE_SUSPENDED)
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1341
			status = usb_resume_both(udev, PMSG_AUTO_RESUME);
1342 1343
		if (status != 0)
			udev->pm_usage_cnt -= inc_usage_cnt;
1344 1345 1346
		else if (inc_usage_cnt)
			udev->last_busy = jiffies;
	} else if (inc_usage_cnt <= 0 && udev->pm_usage_cnt <= 0) {
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1347
		status = usb_suspend_both(udev, PMSG_AUTO_SUSPEND);
1348
	}
1349 1350 1351 1352
	usb_pm_unlock(udev);
	return status;
}

1353 1354 1355 1356 1357 1358 1359 1360 1361
/* usb_autosuspend_work - callback routine to autosuspend a USB device */
void usb_autosuspend_work(struct work_struct *work)
{
	struct usb_device *udev =
		container_of(work, struct usb_device, autosuspend.work);

	usb_autopm_do_device(udev, 0);
}

1362 1363 1364 1365 1366 1367 1368 1369 1370 1371 1372 1373 1374
/* usb_autoresume_work - callback routine to autoresume a USB device */
void usb_autoresume_work(struct work_struct *work)
{
	struct usb_device *udev =
		container_of(work, struct usb_device, autoresume);

	/* Wake it up, let the drivers do their thing, and then put it
	 * back to sleep.
	 */
	if (usb_autopm_do_device(udev, 1) == 0)
		usb_autopm_do_device(udev, -1);
}

1375 1376
/**
 * usb_autosuspend_device - delayed autosuspend of a USB device and its interfaces
1377
 * @udev: the usb_device to autosuspend
1378 1379 1380 1381 1382
 *
 * 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.
 *
1383 1384 1385 1386 1387 1388
 * @udev's usage counter is decremented.  If it or any of the usage counters
 * for an active interface is greater than 0, no autosuspend request will be
 * queued.  (If an interface driver does not support autosuspend then its
 * usage counter is permanently positive.)  Furthermore, if an interface
 * driver requires remote-wakeup capability during autosuspend but remote
 * wakeup is disabled, the autosuspend will fail.
1389 1390 1391 1392 1393 1394
 *
 * Often the caller will hold @udev's device lock, but this is not
 * necessary.
 *
 * This routine can run only in process context.
 */
1395
void usb_autosuspend_device(struct usb_device *udev)
1396
{
1397 1398 1399
	int	status;

	status = usb_autopm_do_device(udev, -1);
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	dev_vdbg(&udev->dev, "%s: cnt %d\n",
1401
			__func__, udev->pm_usage_cnt);
1402 1403 1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419
}

/**
 * usb_try_autosuspend_device - attempt an autosuspend of a USB device and its interfaces
 * @udev: the usb_device to autosuspend
 *
 * This routine should be called when a core subsystem thinks @udev may
 * be ready to autosuspend.
 *
 * @udev's usage counter left unchanged.  If it or any of the usage counters
 * for an active interface is greater than 0, or autosuspend is not allowed
 * for any other reason, no autosuspend request will be queued.
 *
 * This routine can run only in process context.
 */
void usb_try_autosuspend_device(struct usb_device *udev)
{
	usb_autopm_do_device(udev, 0);
A
Alan Stern 已提交
1420
	dev_vdbg(&udev->dev, "%s: cnt %d\n",
1421
			__func__, udev->pm_usage_cnt);
1422 1423 1424 1425
}

/**
 * usb_autoresume_device - immediately autoresume a USB device and its interfaces
1426
 * @udev: the usb_device to autoresume
1427 1428
 *
 * This routine should be called when a core subsystem wants to use @udev
1429 1430 1431 1432 1433
 * 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.
1434
 *
1435 1436
 * @udev's usage counter is incremented to prevent subsequent autosuspends.
 * However if the autoresume fails then the usage counter is re-decremented.
1437 1438 1439 1440 1441 1442
 *
 * Often the caller will hold @udev's device lock, but this is not
 * necessary (and attempting it might cause deadlock).
 *
 * This routine can run only in process context.
 */
1443
int usb_autoresume_device(struct usb_device *udev)
1444 1445 1446
{
	int	status;

1447
	status = usb_autopm_do_device(udev, 1);
A
Alan Stern 已提交
1448
	dev_vdbg(&udev->dev, "%s: status %d cnt %d\n",
1449
			__func__, status, udev->pm_usage_cnt);
1450 1451 1452
	return status;
}

A
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1453 1454 1455 1456 1457 1458 1459 1460 1461 1462 1463 1464 1465
/* Internal routine to adjust an interface's usage counter and change
 * its device's autosuspend state.
 */
static int usb_autopm_do_interface(struct usb_interface *intf,
		int inc_usage_cnt)
{
	struct usb_device	*udev = interface_to_usbdev(intf);
	int			status = 0;

	usb_pm_lock(udev);
	if (intf->condition == USB_INTERFACE_UNBOUND)
		status = -ENODEV;
	else {
1466
		udev->auto_pm = 1;
A
Alan Stern 已提交
1467
		atomic_add(inc_usage_cnt, &intf->pm_usage_cnt);
1468
		udev->last_busy = jiffies;
A
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1469 1470
		if (inc_usage_cnt >= 0 &&
				atomic_read(&intf->pm_usage_cnt) > 0) {
1471
			if (udev->state == USB_STATE_SUSPENDED)
A
Alan Stern 已提交
1472 1473
				status = usb_resume_both(udev,
						PMSG_AUTO_RESUME);
A
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1474
			if (status != 0)
A
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1475
				atomic_sub(inc_usage_cnt, &intf->pm_usage_cnt);
1476
			else
1477
				udev->last_busy = jiffies;
A
Alan Stern 已提交
1478 1479
		} else if (inc_usage_cnt <= 0 &&
				atomic_read(&intf->pm_usage_cnt) <= 0) {
A
Alan Stern 已提交
1480
			status = usb_suspend_both(udev, PMSG_AUTO_SUSPEND);
1481
		}
A
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1482 1483 1484 1485 1486
	}
	usb_pm_unlock(udev);
	return status;
}

1487 1488
/**
 * usb_autopm_put_interface - decrement a USB interface's PM-usage counter
1489
 * @intf: the usb_interface whose counter should be decremented
1490 1491 1492 1493 1494 1495 1496 1497 1498 1499 1500 1501 1502 1503 1504 1505 1506 1507 1508 1509 1510 1511 1512 1513 1514 1515 1516 1517 1518 1519
 *
 * This routine should be called by an interface driver when it is
 * finished using @intf and wants to allow it to autosuspend.  A typical
 * example would be a character-device driver when its device file is
 * closed.
 *
 * The routine decrements @intf's usage counter.  When the counter reaches
 * 0, a delayed autosuspend request for @intf's device is queued.  When
 * the delay expires, if @intf->pm_usage_cnt is still <= 0 along with all
 * the other usage counters for the sibling interfaces and @intf's
 * usb_device, the device and all its interfaces will be autosuspended.
 *
 * Note that @intf->pm_usage_cnt is owned by the interface driver.  The
 * core will not change its value other than the increment and decrement
 * in usb_autopm_get_interface and usb_autopm_put_interface.  The driver
 * may use this simple counter-oriented discipline or may set the value
 * any way it likes.
 *
 * If the driver has set @intf->needs_remote_wakeup then autosuspend will
 * take place only if the device's remote-wakeup facility is enabled.
 *
 * Suspend method calls queued by this routine can arrive at any time
 * while @intf is resumed and its usage counter is equal to 0.  They are
 * not protected by the usb_device's lock but only by its pm_mutex.
 * Drivers must provide their own synchronization.
 *
 * This routine can run only in process context.
 */
void usb_autopm_put_interface(struct usb_interface *intf)
{
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Alan Stern 已提交
1520
	int	status;
1521

A
Alan Stern 已提交
1522
	status = usb_autopm_do_interface(intf, -1);
A
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1523
	dev_vdbg(&intf->dev, "%s: status %d cnt %d\n",
A
Alan Stern 已提交
1524
			__func__, status, atomic_read(&intf->pm_usage_cnt));
1525 1526 1527
}
EXPORT_SYMBOL_GPL(usb_autopm_put_interface);

1528 1529 1530 1531 1532 1533 1534 1535 1536 1537 1538 1539 1540 1541 1542 1543 1544 1545 1546 1547 1548 1549 1550 1551
/**
 * usb_autopm_put_interface_async - decrement a USB interface's PM-usage counter
 * @intf: the usb_interface whose counter should be decremented
 *
 * This routine does essentially the same thing as
 * usb_autopm_put_interface(): it decrements @intf's usage counter and
 * queues a delayed autosuspend request if the counter is <= 0.  The
 * difference is that it does not acquire the device's pm_mutex;
 * callers must handle all synchronization issues themselves.
 *
 * Typically a driver would call this routine during an URB's completion
 * handler, if no more URBs were pending.
 *
 * This routine can run in atomic context.
 */
void usb_autopm_put_interface_async(struct usb_interface *intf)
{
	struct usb_device	*udev = interface_to_usbdev(intf);
	int			status = 0;

	if (intf->condition == USB_INTERFACE_UNBOUND) {
		status = -ENODEV;
	} else {
		udev->last_busy = jiffies;
A
Alan Stern 已提交
1552
		atomic_dec(&intf->pm_usage_cnt);
1553 1554
		if (udev->autosuspend_disabled || udev->autosuspend_delay < 0)
			status = -EPERM;
A
Alan Stern 已提交
1555
		else if (atomic_read(&intf->pm_usage_cnt) <= 0 &&
1556 1557
				!timer_pending(&udev->autosuspend.timer)) {
			queue_delayed_work(ksuspend_usb_wq, &udev->autosuspend,
1558
					round_jiffies_up_relative(
1559 1560 1561 1562
						udev->autosuspend_delay));
		}
	}
	dev_vdbg(&intf->dev, "%s: status %d cnt %d\n",
A
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1563
			__func__, status, atomic_read(&intf->pm_usage_cnt));
1564 1565 1566
}
EXPORT_SYMBOL_GPL(usb_autopm_put_interface_async);

1567 1568
/**
 * usb_autopm_get_interface - increment a USB interface's PM-usage counter
1569
 * @intf: the usb_interface whose counter should be incremented
1570 1571 1572 1573 1574 1575 1576 1577 1578
 *
 * 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.
 *
1579 1580 1581 1582 1583 1584 1585 1586
 *
 * The routine increments @intf's usage counter.  (However if the
 * autoresume fails then the counter is re-decremented.)  So long as the
 * counter is greater than 0, autosuspend will not be allowed for @intf
 * or its usb_device.  When the driver is finished using @intf it should
 * call usb_autopm_put_interface() to decrement the usage counter and
 * queue a delayed autosuspend request (if the counter is <= 0).
 *
1587 1588 1589 1590 1591 1592 1593 1594 1595 1596 1597 1598 1599 1600 1601 1602
 *
 * Note that @intf->pm_usage_cnt is owned by the interface driver.  The
 * core will not change its value other than the increment and decrement
 * in usb_autopm_get_interface and usb_autopm_put_interface.  The driver
 * may use this simple counter-oriented discipline or may set the value
 * any way it likes.
 *
 * Resume method calls generated by this routine can arrive at any time
 * while @intf is suspended.  They are not protected by the usb_device's
 * lock but only by its pm_mutex.  Drivers must provide their own
 * synchronization.
 *
 * This routine can run only in process context.
 */
int usb_autopm_get_interface(struct usb_interface *intf)
{
A
Alan Stern 已提交
1603
	int	status;
1604

A
Alan Stern 已提交
1605
	status = usb_autopm_do_interface(intf, 1);
A
Alan Stern 已提交
1606
	dev_vdbg(&intf->dev, "%s: status %d cnt %d\n",
A
Alan Stern 已提交
1607
			__func__, status, atomic_read(&intf->pm_usage_cnt));
1608 1609
	return status;
}
1610 1611
EXPORT_SYMBOL_GPL(usb_autopm_get_interface);

1612 1613 1614 1615 1616 1617 1618 1619 1620 1621 1622 1623 1624 1625 1626 1627 1628 1629 1630 1631 1632 1633 1634
/**
 * usb_autopm_get_interface_async - increment a USB interface's PM-usage counter
 * @intf: the usb_interface whose counter should be incremented
 *
 * This routine does much the same thing as
 * usb_autopm_get_interface(): it increments @intf's usage counter and
 * queues an autoresume request if the result is > 0.  The differences
 * are that it does not acquire the device's pm_mutex (callers must
 * handle all synchronization issues themselves), and it does not
 * autoresume the device directly (it only queues a request).  After a
 * successful call, the device will generally not yet be resumed.
 *
 * This routine can run in atomic context.
 */
int usb_autopm_get_interface_async(struct usb_interface *intf)
{
	struct usb_device	*udev = interface_to_usbdev(intf);
	int			status = 0;

	if (intf->condition == USB_INTERFACE_UNBOUND)
		status = -ENODEV;
	else if (udev->autoresume_disabled)
		status = -EPERM;
A
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1635 1636 1637 1638 1639 1640
	else {
		atomic_inc(&intf->pm_usage_cnt);
		if (atomic_read(&intf->pm_usage_cnt) > 0 &&
				udev->state == USB_STATE_SUSPENDED)
			queue_work(ksuspend_usb_wq, &udev->autoresume);
	}
1641
	dev_vdbg(&intf->dev, "%s: status %d cnt %d\n",
A
Alan Stern 已提交
1642
			__func__, status, atomic_read(&intf->pm_usage_cnt));
1643 1644 1645 1646
	return status;
}
EXPORT_SYMBOL_GPL(usb_autopm_get_interface_async);

1647 1648 1649 1650 1651 1652 1653 1654 1655 1656 1657 1658 1659 1660 1661 1662
/**
 * usb_autopm_set_interface - set a USB interface's autosuspend state
 * @intf: the usb_interface whose state should be set
 *
 * This routine sets the autosuspend state of @intf's device according
 * to @intf's usage counter, which the caller must have set previously.
 * If the counter is <= 0, the device is autosuspended (if it isn't
 * already suspended and if nothing else prevents the autosuspend).  If
 * the counter is > 0, the device is autoresumed (if it isn't already
 * awake).
 */
int usb_autopm_set_interface(struct usb_interface *intf)
{
	int	status;

	status = usb_autopm_do_interface(intf, 0);
A
Alan Stern 已提交
1663
	dev_vdbg(&intf->dev, "%s: status %d cnt %d\n",
A
Alan Stern 已提交
1664
			__func__, status, atomic_read(&intf->pm_usage_cnt));
1665 1666 1667 1668
	return status;
}
EXPORT_SYMBOL_GPL(usb_autopm_set_interface);

A
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1669 1670 1671 1672 1673
#else

void usb_autosuspend_work(struct work_struct *work)
{}

1674 1675 1676
void usb_autoresume_work(struct work_struct *work)
{}

1677
#endif /* CONFIG_USB_SUSPEND */
1678

1679 1680 1681 1682 1683 1684 1685 1686 1687 1688 1689 1690 1691 1692 1693 1694
/**
 * usb_external_suspend_device - external suspend of a USB device and its interfaces
 * @udev: the usb_device to suspend
 * @msg: Power Management message describing this state transition
 *
 * This routine handles external suspend requests: ones not generated
 * internally by a USB driver (autosuspend) but rather coming from the user
 * (via sysfs) or the PM core (system sleep).  The suspend will be carried
 * out regardless of @udev's usage counter or those of its interfaces,
 * and regardless of whether or not remote wakeup is enabled.  Of course,
 * interface drivers still have the option of failing the suspend (if
 * there are unsuspended children, for example).
 *
 * The caller must hold @udev's device lock.
 */
int usb_external_suspend_device(struct usb_device *udev, pm_message_t msg)
1695 1696 1697
{
	int	status;

1698
	do_unbind_rebind(udev, DO_UNBIND);
1699 1700 1701 1702
	usb_pm_lock(udev);
	udev->auto_pm = 0;
	status = usb_suspend_both(udev, msg);
	usb_pm_unlock(udev);
1703 1704 1705
	return status;
}

1706 1707 1708
/**
 * usb_external_resume_device - external resume of a USB device and its interfaces
 * @udev: the usb_device to resume
A
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 * @msg: Power Management message describing this state transition
1710 1711 1712 1713 1714 1715 1716 1717
 *
 * This routine handles external resume requests: ones not generated
 * internally by a USB driver (autoresume) but rather coming from the user
 * (via sysfs), the PM core (system resume), or the device itself (remote
 * wakeup).  @udev's usage counter is unaffected.
 *
 * The caller must hold @udev's device lock.
 */
A
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1718
int usb_external_resume_device(struct usb_device *udev, pm_message_t msg)
1719 1720 1721
{
	int	status;

1722 1723
	usb_pm_lock(udev);
	udev->auto_pm = 0;
A
Alan Stern 已提交
1724
	status = usb_resume_both(udev, msg);
A
Alan Stern 已提交
1725
	udev->last_busy = jiffies;
1726
	usb_pm_unlock(udev);
1727 1728
	if (status == 0)
		do_unbind_rebind(udev, DO_REBIND);
1729

1730 1731 1732 1733
	/* Now that the device is awake, we can start trying to autosuspend
	 * it again. */
	if (status == 0)
		usb_try_autosuspend_device(udev);
1734 1735 1736
	return status;
}

A
Alan Stern 已提交
1737
int usb_suspend(struct device *dev, pm_message_t msg)
1738
{
1739 1740 1741 1742 1743
	struct usb_device	*udev;

	udev = to_usb_device(dev);

	/* If udev is already suspended, we can skip this suspend and
1744 1745 1746 1747 1748
	 * we should also skip the upcoming system resume.  High-speed
	 * root hubs are an exception; they need to resume whenever the
	 * system wakes up in order for USB-PERSIST port handover to work
	 * properly.
	 */
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	if (udev->state == USB_STATE_SUSPENDED) {
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		if (udev->parent || udev->speed != USB_SPEED_HIGH)
			udev->skip_sys_resume = 1;
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		return 0;
	}

	udev->skip_sys_resume = 0;
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	return usb_external_suspend_device(udev, msg);
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}

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int usb_resume(struct device *dev, pm_message_t msg)
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{
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	struct usb_device	*udev;
1762
	int			status;
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	udev = to_usb_device(dev);
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	/* If udev->skip_sys_resume is set then udev was already suspended
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	 * when the system sleep started, so we don't want to resume it
	 * during this system wakeup.
	 */
	if (udev->skip_sys_resume)
		return 0;
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	status = usb_external_resume_device(udev, msg);

	/* Avoid PM error messages for devices disconnected while suspended
	 * as we'll display regular disconnect messages just a bit later.
	 */
	if (status == -ENODEV)
		return 0;
	return status;
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}

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#endif /* CONFIG_PM */

struct bus_type usb_bus_type = {
	.name =		"usb",
	.match =	usb_device_match,
	.uevent =	usb_uevent,
};