modlinkage Structure

static struct modlinkage xxmodlinkage = {
        MODREV_1,       /* ml_rev */
        &xxmodldrv,     /* ml_linkage[] */
        NULL            /* NULL termination */
};

The first field is the version number of the module loading subsystem and should be MODREV_1. The second field points to driver's modldrv structure defined next. The last element of the structure should always be NULL.