- * categories.
- *
- * If the 'may_create' flag is set then this is allowed to be the first time
- * the device is opened (i.e. the refcount will be 1 after this call). It
- * may be set to false if the device should have already been created.
- *
- * If the 'may_open' flag is set then the call will succeed even if another
- * caller has already opened it. It may be to false if the device should not
- * currently be open. */