driver.c

linux 内核源代码

/*
 * drivers/usb/driver.c - most of the driver model stuff for usb
 *
 * (C) Copyright 2005 Greg Kroah-Hartman <[e-mail]>
 *
 * based on drivers/usb/usb.c which had the following copyrights:
 *	(C) Copyright Linus Torvalds 1999
 *	(C) Copyright Johannes Erdfelt 1999-2001
 *	(C) Copyright Andreas Gal 1999
 *	(C) Copyright Gregory P. Smith 1999
 *	(C) Copyright Deti Fliegl 1999 (new USB architecture)
 *	(C) Copyright Randy Dunlap 2000
 *	(C) Copyright David Brownell 2000-2004
 *	(C) Copyright Yggdrasil Computing, Inc. 2000
 *		(usb_device_id matching changes by Adam J. Richter)
 *	(C) Copyright Greg Kroah-Hartman 2002-2003
 *
 * NOTE! This is not actually a driver at all, rather this is
 * just a collection of helper routines that implement the
 * matching, probing, releasing, suspending and resuming for
 * real drivers.
 *
 */

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


#ifdef CONFIG_HOTPLUG

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

	fields = sscanf(buf, "%x %x", &idVendor, &idProduct);
	if (fields < 2)
		return -EINVAL;

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

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

	spin_lock(&dynids->lock);
	list_add_tail(&dynid->node, &dynids->list);
	spin_unlock(&dynids->lock);

	if (get_driver(driver)) {
		retval = driver_attach(driver);
		put_driver(driver);
	}

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

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

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

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

	if (usb_drv->no_dynamic_id)
		goto exit;

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

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

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

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

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

static void usb_remove_newid_file(struct usb_driver *usb_drv)
{
}

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

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

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


/* called from driver core with dev locked */
static int usb_probe_device(struct device *dev)
{
	struct usb_device_driver *udriver = to_usb_device_driver(dev->driver);
	struct usb_device *udev;
	int error = -ENODEV;

	dev_dbg(dev, "%s\n", __FUNCTION__);

	if (!is_usb_device(dev))	/* Sanity check */
		return error;

	udev = to_usb_device(dev);

	/* TODO: Add real matching code */

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

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

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

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


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

	dev_dbg(dev, "%s\n", __FUNCTION__);

	if (is_usb_device(dev))		/* Sanity check */
		return error;

	intf = to_usb_interface(dev);
	udev = interface_to_usbdev(intf);

 	if (udev->authorized == 0) {
 		dev_err(&intf->dev, "Device is not authorized for usage\n");
 		return -ENODEV;
 	}

	id = usb_match_id(intf, driver->id_table);
	if (!id)
		id = usb_match_dynamic_id(intf, driver);
	if (id) {
		dev_dbg(dev, "%s - got id\n", __FUNCTION__);

		error = usb_autoresume_device(udev);
		if (error)
			return error;

		/* Interface "power state" doesn't correspond to any hardware
		 * state whatsoever.  We use it to record when it's bound to
		 * a driver that may start I/0:  it's not frozen/quiesced.
		 */
		mark_active(intf);
		intf->condition = USB_INTERFACE_BINDING;

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

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

		usb_autosuspend_device(udev);
	}

	return error;
}

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

	intf->condition = USB_INTERFACE_UNBINDING;

	/* Autoresume for set_interface call below */
	udev = interface_to_usbdev(intf);
	error = usb_autoresume_device(udev);

	/* release all urbs for this interface */
	usb_disable_interface(interface_to_usbdev(intf), intf);

	driver->disconnect(intf);

	/* reset other interface state */
	usb_set_interface(interface_to_usbdev(intf),
			intf->altsetting[0].desc.bInterfaceNumber,
			0);
	usb_set_intfdata(intf, NULL);

	intf->condition = USB_INTERFACE_UNBOUND;
	mark_quiesced(intf);
	intf->needs_remote_wakeup = 0;

	if (!error)
		usb_autosuspend_device(udev);

	return 0;
}

/**
 * usb_driver_claim_interface - bind a driver to an interface
 * @driver: the driver to be bound
 * @iface: the interface to which it will be bound; must be in the
 *	usb device's active configuration
 * @priv: driver data associated with that interface
 *
 * This is used by usb device drivers that need to claim more than one
 * interface on a device when probing (audio and acm are current examples).
 * No device driver should directly modify internal usb_interface or
 * usb_device structure members.
 *
 * Few drivers should need to use this routine, since the most natural
 * way to bind to an interface is to return the private data from
 * the driver's probe() method.
 *
 * Callers must own the device lock, so driver probe() entries don't need
 * extra locking, but other call contexts may need to explicitly claim that
 * lock.
 */
int usb_driver_claim_interface(struct usb_driver *driver,
				struct usb_interface *iface, void* priv)
{
	struct device *dev = &iface->dev;
	struct usb_device *udev = interface_to_usbdev(iface);
	int retval = 0;

	if (dev->driver)
		return -EBUSY;

	dev->driver = &driver->drvwrap.driver;
	usb_set_intfdata(iface, priv);

	usb_pm_lock(udev);
	iface->condition = USB_INTERFACE_BOUND;
	mark_active(iface);
	iface->pm_usage_cnt = !(driver->supports_autosuspend);
	usb_pm_unlock(udev);

	/* if interface was already added, bind now; else let
	 * the future device_add() bind it, bypassing probe()
	 */
	if (device_is_registered(dev))
		retval = device_bind_driver(dev);

	return retval;
}
EXPORT_SYMBOL(usb_driver_claim_interface);

/**
 * usb_driver_release_interface - unbind a driver from an interface
 * @driver: the driver to be unbound
 * @iface: the interface from which it will be unbound
 *
 * This can be used by drivers to release an interface without waiting
 * for their disconnect() methods to be called.  In typical cases this
 * also causes the driver disconnect() method to be called.
 *
 * This call is synchronous, and may not be used in an interrupt context.
 * Callers must own the device lock, so driver disconnect() entries don't
 * need extra locking, but other call contexts may need to explicitly claim
 * that lock.
 */
void usb_driver_release_interface(struct usb_driver *driver,
					struct usb_interface *iface)
{
	struct device *dev = &iface->dev;
	struct usb_device *udev = interface_to_usbdev(iface);

	/* this should never happen, don't release something that's not ours */
	if (!dev->driver || dev->driver != &driver->drvwrap.driver)
		return;

	/* don't release from within disconnect() */
	if (iface->condition != USB_INTERFACE_BOUND)
		return;

	/* don't release if the interface hasn't been added yet */
	if (device_is_registered(dev)) {
		iface->condition = USB_INTERFACE_UNBINDING;
		device_release_driver(dev);
	}

	dev->driver = NULL;
	usb_set_intfdata(iface, NULL);

	usb_pm_lock(udev);
	iface->condition = USB_INTERFACE_UNBOUND;
	mark_quiesced(iface);
	iface->needs_remote_wakeup = 0;
	usb_pm_unlock(udev);
}
EXPORT_SYMBOL(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) &&