diff -ura linux-2.6.9-rc2-mm1/include/linux/i2c.h b/include/linux/i2c.h
--- linux-2.6.9-rc2-mm1/include/linux/i2c.h	2004-09-20 12:38:24.000000000 +0200
+++ b/include/linux/i2c.h	2004-09-20 18:53:32.000000000 +0200
@@ -231,6 +231,11 @@
 	struct i2c_algorithm *algo;/* the algorithm to access the bus	*/
 	void *algo_data;
 
+	/* a ioctl like command that can be used to perform specific functions
+	 * with the adapter.
+	 */
+	int (*command)(struct i2c_adapter *adapter, unsigned int cmd, void *arg);
+
 	/* --- administration stuff. */
 	int (*client_register)(struct i2c_client *);
 	int (*client_unregister)(struct i2c_client *);