driver.c

linux 内核源代码

	    (id->bcdDevice_hi < le16_to_cpu(dev->descriptor.bcdDevice)))
		return 0;

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

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

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

	return 1;
}

/* returns 0 if no match, 1 if match */
int usb_match_one_id(struct usb_interface *interface,
		     const struct usb_device_id *id)
{
	struct usb_host_interface *intf;
	struct usb_device *dev;

	/* proc_connectinfo in devio.c may call us with id == NULL. */
	if (id == NULL)
		return 0;

	intf = interface->cur_altsetting;
	dev = interface_to_usbdev(interface);

	if (!usb_match_device(dev, id))
		return 0;

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

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

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

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

	return 1;
}
EXPORT_SYMBOL_GPL(usb_match_one_id);

/**
 * usb_match_id - find first usb_device_id matching device or interface
 * @interface: the interface of interest
 * @id: array of usb_device_id structures, terminated by zero entry
 *
 * usb_match_id searches an array of usb_device_id's and returns
 * the first one matching the device or interface, or null.
 * This is used when binding (or rebinding) a driver to an interface.
 * Most USB device drivers will use this indirectly, through the usb core,
 * but some layered driver frameworks use it directly.
 * These device tables are exported with MODULE_DEVICE_TABLE, through
 * modutils, to support the driver loading functionality of USB hotplugging.
 *
 * What Matches:
 *
 * The "match_flags" element in a usb_device_id controls which
 * members are used.  If the corresponding bit is set, the
 * value in the device_id must match its corresponding member
 * in the device or interface descriptor, or else the device_id
 * does not match.
 *
 * "driver_info" is normally used only by device drivers,
 * but you can create a wildcard "matches anything" usb_device_id
 * as a driver's "modules.usbmap" entry if you provide an id with
 * only a nonzero "driver_info" field.  If you do this, the USB device
 * driver's probe() routine should use additional intelligence to
 * decide whether to bind to the specified interface.
 *
 * What Makes Good usb_device_id Tables:
 *
 * The match algorithm is very simple, so that intelligence in
 * driver selection must come from smart driver id records.
 * Unless you have good reasons to use another selection policy,
 * provide match elements only in related groups, and order match
 * specifiers from specific to general.  Use the macros provided
 * for that purpose if you can.
 *
 * The most specific match specifiers use device descriptor
 * data.  These are commonly used with product-specific matches;
 * the USB_DEVICE macro lets you provide vendor and product IDs,
 * and you can also match against ranges of product revisions.
 * These are widely used for devices with application or vendor
 * specific bDeviceClass values.
 *
 * Matches based on device class/subclass/protocol specifications
 * are slightly more general; use the USB_DEVICE_INFO macro, or
 * its siblings.  These are used with single-function devices
 * where bDeviceClass doesn't specify that each interface has
 * its own class.
 *
 * Matches based on interface class/subclass/protocol are the
 * most general; they let drivers bind to any interface on a
 * multiple-function device.  Use the USB_INTERFACE_INFO
 * macro, or its siblings, to match class-per-interface style
 * devices (as recorded in bInterfaceClass).
 *
 * Note that an entry created by USB_INTERFACE_INFO won't match
 * any interface if the device class is set to Vendor-Specific.
 * This is deliberate; according to the USB spec the meanings of
 * the interface class/subclass/protocol for these devices are also
 * vendor-specific, and hence matching against a standard product
 * class wouldn't work anyway.  If you really want to use an
 * interface-based match for such a device, create a match record
 * that also specifies the vendor ID.  (Unforunately there isn't a
 * standard macro for creating records like this.)
 *
 * Within those groups, remember that not all combinations are
 * meaningful.  For example, don't give a product version range
 * without vendor and product IDs; or specify a protocol without
 * its associated class and subclass.
 */
const struct usb_device_id *usb_match_id(struct usb_interface *interface,
					 const struct usb_device_id *id)
{
	/* proc_connectinfo in devio.c may call us with id == NULL. */
	if (id == NULL)
		return NULL;

	/* It is important to check that id->driver_info is nonzero,
	   since an entry that is all zeroes except for a nonzero
	   id->driver_info is the way to create an entry that
	   indicates that the driver want to examine every
	   device and interface. */
	for (; id->idVendor || id->idProduct || id->bDeviceClass ||
	       id->bInterfaceClass || id->driver_info; id++) {
		if (usb_match_one_id(interface, id))
			return id;
	}

	return NULL;
}
EXPORT_SYMBOL_GPL_FUTURE(usb_match_id);

static int usb_device_match(struct device *dev, struct device_driver *drv)
{
	/* devices and interfaces are handled separately */
	if (is_usb_device(dev)) {

		/* interface drivers never match devices */
		if (!is_usb_device_driver(drv))
			return 0;

		/* TODO: Add real matching code */
		return 1;

	} else {
		struct usb_interface *intf;
		struct usb_driver *usb_drv;
		const struct usb_device_id *id;

		/* device drivers never match interfaces */
		if (is_usb_device_driver(drv))
			return 0;

		intf = to_usb_interface(dev);
		usb_drv = to_usb_driver(drv);

		id = usb_match_id(intf, usb_drv->id_table);
		if (id)
			return 1;

		id = usb_match_dynamic_id(intf, usb_drv);
		if (id)
			return 1;
	}

	return 0;
}

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

	/* driver is often null here; dev_dbg() would oops */
	pr_debug ("usb %s: uevent\n", dev->bus_id);

	if (is_usb_device(dev))
		usb_dev = to_usb_device(dev);
	else {
		struct usb_interface *intf = to_usb_interface(dev);
		usb_dev = interface_to_usbdev(intf);
	}

	if (usb_dev->devnum < 0) {
		pr_debug ("usb %s: already deleted?\n", dev->bus_id);
		return -ENODEV;
	}
	if (!usb_dev->bus) {
		pr_debug ("usb %s: bus removed?\n", dev->bus_id);
		return -ENODEV;
	}

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

	/* per-device configurations are common */
	if (add_uevent_var(env, "PRODUCT=%x/%x/%x",
			   le16_to_cpu(usb_dev->descriptor.idVendor),
			   le16_to_cpu(usb_dev->descriptor.idProduct),
			   le16_to_cpu(usb_dev->descriptor.bcdDevice)))
		return -ENOMEM;

	/* class-based driver binding models */
	if (add_uevent_var(env, "TYPE=%d/%d/%d",
			   usb_dev->descriptor.bDeviceClass,
			   usb_dev->descriptor.bDeviceSubClass,
			   usb_dev->descriptor.bDeviceProtocol))
		return -ENOMEM;

	return 0;
}

#else

static int usb_uevent(struct device *dev, struct kobj_uevent_env *env)
{
	return -ENODEV;
}
#endif	/* CONFIG_HOTPLUG */

/**
 * usb_register_device_driver - register a USB device (not interface) driver
 * @new_udriver: USB operations for the device driver
 * @owner: module owner of this driver.
 *
 * Registers a USB device driver with the USB core.  The list of
 * unattached devices will be rescanned whenever a new driver is
 * added, allowing the new driver to attach to any recognized devices.
 * Returns a negative error code on failure and 0 on success.
 */
int usb_register_device_driver(struct usb_device_driver *new_udriver,
		struct module *owner)
{
	int retval = 0;

	if (usb_disabled())
		return -ENODEV;

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

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

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

	return retval;
}
EXPORT_SYMBOL_GPL(usb_register_device_driver);

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

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

/**
 * usb_register_driver - register a USB interface driver
 * @new_driver: USB operations for the interface driver
 * @owner: module owner of this driver.
 * @mod_name: module name string
 *
 * Registers a USB interface driver with the USB core.  The list of
 * unattached interfaces will be rescanned whenever a new driver is
 * added, allowing the new driver to attach to any recognized interfaces.
 * Returns a negative error code on failure and 0 on success.
 *
 * NOTE: if you want your driver to use the USB major number, you must call
 * usb_register_dev() to enable that functionality.  This function no longer
 * takes care of that.
 */
int usb_register_driver(struct usb_driver *new_driver, struct module *owner,
			const char *mod_name)
{
	int retval = 0;

	if (usb_disabled())
		return -ENODEV;

	new_driver->drvwrap.for_devices = 0;
	new_driver->drvwrap.driver.name = (char *) new_driver->name;
	new_driver->drvwrap.driver.bus = &usb_bus_type;
	new_driver->drvwrap.driver.probe = usb_probe_interface;
	new_driver->drvwrap.driver.remove = usb_unbind_interface;
	new_driver->drvwrap.driver.owner = owner;
	new_driver->drvwrap.driver.mod_name = mod_name;
	spin_lock_init(&new_driver->dynids.lock);
	INIT_LIST_HEAD(&new_driver->dynids.list);

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

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

	return retval;
}
EXPORT_SYMBOL_GPL_FUTURE(usb_register_driver);

/**
 * usb_deregister - unregister a USB interface driver
 * @driver: USB operations of the interface driver to unregister
 * Context: must be able to sleep
 *
 * Unlinks the specified driver from the internal USB driver list.
 *
 * NOTE: If you called usb_register_dev(), you still need to call
 * usb_deregister_dev() to clean up your driver's allocated minor numbers,
 * this * call will no longer do it for you.
 */
void usb_deregister(struct usb_driver *driver)
{
	pr_info("%s: deregistering interface driver %s\n",
			usbcore_name, driver->name);

	usb_remove_newid_file(driver);
	usb_free_dynids(driver);
	driver_unregister(&driver->drvwrap.driver);

	usbfs_update_special();
}
EXPORT_SYMBOL_GPL_FUTURE(usb_deregister);

#ifdef CONFIG_PM

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

	if (udev->state == USB_STATE_NOTATTACHED ||
			udev->state == USB_STATE_SUSPENDED)
		goto done;