maxrtc_read
if (maxrtc_read(sc, &cmd, sizeof(cmd), &data_r, sizeof(data_r))) {
if (maxrtc_read(sc, &cmd, sizeof(cmd), &data_r, sizeof(data_r))) {
if (maxrtc_read(sc, &cmd, sizeof(cmd), data, sizeof(data))) {
int maxrtc_read(struct maxrtc_softc *, uint8_t *, uint8_t,