ASMC_KEY_RGEN
if (apple_smc_key_getinfo(dev, ASMC_KEY_RGEN, NULL, NULL) == 0)
error = apple_smc_mmio_key_read(dev, ASMC_KEY_RGEN, &rgen, 1);
if (apple_smc_key_read(dev, ASMC_KEY_RGEN, &gen, 1) != 0) {