usb.c

linux-2.6.15.6

 * 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)
{
	struct usb_host_interface *intf;
	struct usb_device *dev;

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

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

	/* 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->bDeviceClass || id->bInterfaceClass ||
	       id->driver_info; id++) {

		if ((id->match_flags & USB_DEVICE_ID_MATCH_VENDOR) &&
		    id->idVendor != le16_to_cpu(dev->descriptor.idVendor))
			continue;

		if ((id->match_flags & USB_DEVICE_ID_MATCH_PRODUCT) &&
		    id->idProduct != le16_to_cpu(dev->descriptor.idProduct))
			continue;

		/* 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)))
			continue;

		if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_HI) &&
		    (id->bcdDevice_hi < le16_to_cpu(dev->descriptor.bcdDevice)))
			continue;

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

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

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

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

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

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

		return id;
	}

	return NULL;
}


static int __find_interface(struct device * dev, void * data)
{
	struct usb_interface ** ret = (struct usb_interface **)data;
	struct usb_interface * intf = *ret;
	int *minor = (int *)data;

	/* can't look at usb devices, only interfaces */
	if (dev->driver == &usb_generic_driver)
		return 0;

	intf = to_usb_interface(dev);
	if (intf->minor != -1 && intf->minor == *minor) {
		*ret = intf;
		return 1;
	}
	return 0;
}

/**
 * usb_find_interface - find usb_interface pointer for driver and device
 * @drv: the driver whose current configuration is considered
 * @minor: the minor number of the desired device
 *
 * This walks the driver device list and returns a pointer to the interface 
 * with the matching minor.  Note, this only works for devices that share the
 * USB major number.
 */
struct usb_interface *usb_find_interface(struct usb_driver *drv, int minor)
{
	struct usb_interface *intf = (struct usb_interface *)(long)minor;
	int ret;

	ret = driver_for_each_device(&drv->driver, NULL, &intf, __find_interface);

	return ret ? intf : NULL;
}

static int usb_device_match (struct device *dev, struct device_driver *drv)
{
	struct usb_interface *intf;
	struct usb_driver *usb_drv;
	const struct usb_device_id *id;

	/* check for generic driver, which we don't match any device with */
	if (drv == &usb_generic_driver)
		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;

	return 0;
}


#ifdef	CONFIG_HOTPLUG

/*
 * USB hotplugging invokes what /proc/sys/kernel/hotplug says
 * (normally /sbin/hotplug) when USB devices get added or removed.
 *
 * This invokes a user mode policy agent, typically helping to load driver
 * or other modules, configure the device, and more.  Drivers can provide
 * a MODULE_DEVICE_TABLE to help with module loading subtasks.
 *
 * We're called either from khubd (the typical case) or from root hub
 * (init, kapmd, modprobe, rmmod, etc), but the agents need to handle
 * delays in event delivery.  Use sysfs (and DEVPATH) to make sure the
 * device (and this configuration!) are still present.
 */
static int usb_hotplug (struct device *dev, char **envp, int num_envp,
			char *buffer, int buffer_size)
{
	struct usb_interface *intf;
	struct usb_device *usb_dev;
	struct usb_host_interface *alt;
	int i = 0;
	int length = 0;

	if (!dev)
		return -ENODEV;

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

	/* Must check driver_data here, as on remove driver is always NULL */
	if ((dev->driver == &usb_generic_driver) || 
	    (dev->driver_data == &usb_generic_driver_data))
		return 0;

	intf = to_usb_interface(dev);
	usb_dev = interface_to_usbdev (intf);
	alt = intf->cur_altsetting;

	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
	 * even act as usermode drivers.
	 *
	 * FIXME reduce hardwired intelligence here
	 */
	if (add_hotplug_env_var(envp, num_envp, &i,
				buffer, buffer_size, &length,
				"DEVICE=/proc/bus/usb/%03d/%03d",
				usb_dev->bus->busnum, usb_dev->devnum))
		return -ENOMEM;
#endif

	/* per-device configurations are common */
	if (add_hotplug_env_var(envp, num_envp, &i,
				buffer, buffer_size, &length,
				"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_hotplug_env_var(envp, num_envp, &i,
				buffer, buffer_size, &length,
				"TYPE=%d/%d/%d",
				usb_dev->descriptor.bDeviceClass,
				usb_dev->descriptor.bDeviceSubClass,
				usb_dev->descriptor.bDeviceProtocol))
		return -ENOMEM;

	if (add_hotplug_env_var(envp, num_envp, &i,
				buffer, buffer_size, &length,
				"INTERFACE=%d/%d/%d",
				alt->desc.bInterfaceClass,
				alt->desc.bInterfaceSubClass,
				alt->desc.bInterfaceProtocol))
		return -ENOMEM;

	if (add_hotplug_env_var(envp, num_envp, &i,
				buffer, buffer_size, &length,
				"MODALIAS=usb:v%04Xp%04Xd%04Xdc%02Xdsc%02Xdp%02Xic%02Xisc%02Xip%02X",
				le16_to_cpu(usb_dev->descriptor.idVendor),
				le16_to_cpu(usb_dev->descriptor.idProduct),
				le16_to_cpu(usb_dev->descriptor.bcdDevice),
				usb_dev->descriptor.bDeviceClass,
				usb_dev->descriptor.bDeviceSubClass,
				usb_dev->descriptor.bDeviceProtocol,
				alt->desc.bInterfaceClass,
				alt->desc.bInterfaceSubClass,
				alt->desc.bInterfaceProtocol))
		return -ENOMEM;

	envp[i] = NULL;

	return 0;
}

#else

static int usb_hotplug (struct device *dev, char **envp,
			int num_envp, char *buffer, int buffer_size)
{
	return -ENODEV;
}

#endif	/* CONFIG_HOTPLUG */

/**
 * usb_release_dev - free a usb device structure when all users of it are finished.
 * @dev: device that's been disconnected
 *
 * Will be called only by the device core when all users of this usb device are
 * done.
 */
static void usb_release_dev(struct device *dev)
{
	struct usb_device *udev;

	udev = to_usb_device(dev);

	usb_destroy_configuration(udev);
	usb_bus_put(udev->bus);
	kfree(udev->product);
	kfree(udev->manufacturer);
	kfree(udev->serial);
	kfree(udev);
}

/**
 * usb_alloc_dev - usb device constructor (usbcore-internal)
 * @parent: hub to which device is connected; null to allocate a root hub
 * @bus: bus used to access the device
 * @port1: one-based index of port; ignored for root hubs
 * Context: !in_interrupt ()
 *
 * Only hub drivers (including virtual root hub drivers for host
 * controllers) should ever call this.
 *
 * This call may not be used in a non-sleeping context.
 */
struct usb_device *
usb_alloc_dev(struct usb_device *parent, struct usb_bus *bus, unsigned port1)
{
	struct usb_device *dev;

	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
	if (!dev)
		return NULL;

	bus = usb_bus_get(bus);
	if (!bus) {
		kfree(dev);
		return NULL;
	}

	device_initialize(&dev->dev);
	dev->dev.bus = &usb_bus_type;
	dev->dev.dma_mask = bus->controller->dma_mask;
	dev->dev.driver_data = &usb_generic_driver_data;
	dev->dev.driver = &usb_generic_driver;
	dev->dev.release = usb_release_dev;
	dev->state = USB_STATE_ATTACHED;

	INIT_LIST_HEAD(&dev->ep0.urb_list);
	dev->ep0.desc.bLength = USB_DT_ENDPOINT_SIZE;
	dev->ep0.desc.bDescriptorType = USB_DT_ENDPOINT;
	/* ep0 maxpacket comes later, from device descriptor */
	dev->ep_in[0] = dev->ep_out[0] = &dev->ep0;

	/* Save readable and stable topology id, distinguishing devices
	 * by location for diagnostics, tools, driver model, etc.  The
	 * string is a path along hub ports, from the root.  Each device's
	 * dev->devpath will be stable until USB is re-cabled, and hubs
	 * are often labeled with these port numbers.  The bus_id isn't
	 * as stable:  bus->busnum changes easily from modprobe order,
	 * cardbus or pci hotplugging, and so on.
	 */
	if (unlikely (!parent)) {
		dev->devpath [0] = '0';

		dev->dev.parent = bus->controller;
		sprintf (&dev->dev.bus_id[0], "usb%d", bus->busnum);
	} else {
		/* match any labeling on the hubs; it's one-based */
		if (parent->devpath [0] == '0')
			snprintf (dev->devpath, sizeof dev->devpath,
				"%d", port1);
		else
			snprintf (dev->devpath, sizeof dev->devpath,
				"%s.%d", parent->devpath, port1);

		dev->dev.parent = &parent->dev;
		sprintf (&dev->dev.bus_id[0], "%d-%s",
			bus->busnum, dev->devpath);

		/* hub driver sets up TT records */
	}

	dev->bus = bus;
	dev->parent = parent;
	INIT_LIST_HEAD(&dev->filelist);

	init_MUTEX(&dev->serialize);

	return dev;
}

/**
 * usb_get_dev - increments the reference count of the usb device structure
 * @dev: the device being referenced
 *
 * Each live reference to a device should be refcounted.
 *
 * Drivers for USB interfaces should normally record such references in
 * their probe() methods, when they bind to an interface, and release
 * them by calling usb_put_dev(), in their disconnect() methods.
 *
 * A pointer to the device with the incremented reference counter is returned.
 */
struct usb_device *usb_get_dev(struct usb_device *dev)
{
	if (dev)
		get_device(&dev->dev);
	return dev;
}

/**
 * usb_put_dev - release a use of the usb device structure
 * @dev: device that's been disconnected
 *
 * Must be called when a user of a device is finished with it.  When the last
 * user of the device calls this function, the memory of the device is freed.
 */
void usb_put_dev(struct usb_device *dev)
{
	if (dev)
		put_device(&dev->dev);
}

/**
 * usb_get_intf - increments the reference count of the usb interface structure
 * @intf: the interface being referenced
 *
 * Each live reference to a interface must be refcounted.
 *
 * Drivers for USB interfaces should normally record such references in
 * their probe() methods, when they bind to an interface, and release
 * them by calling usb_put_intf(), in their disconnect() methods.
 *
 * A pointer to the interface with the incremented reference counter is
 * returned.
 */
struct usb_interface *usb_get_intf(struct usb_interface *intf)
{
	if (intf)
		get_device(&intf->dev);
	return intf;
}

/**
 * usb_put_intf - release a use of the usb interface structure
 * @intf: interface that's been decremented
 *
 * Must be called when a user of an interface is finished with it.  When the
 * last user of the interface calls this function, the memory of the interface
 * is freed.
 */
void usb_put_intf(struct usb_interface *intf)
{
	if (intf)
		put_device(&intf->dev);
}