nvmem_read_cell
error = nvmem_read_cell(sc->sc_rtc_node, "rtc_offset", &data,
error = nvmem_read_cell(sc->sc_node, "offset", &off, sizeof(off));
if (nvmem_read_cell(node, "calibration", &calib, size) == 0)
int nvmem_read_cell(int, const char *name, void *, bus_size_t);