_SMC_KEY
return _SMC_KEY("gP\0\0") | hex_asc_hi(offset) << 8 | hex_asc_lo(offset);
ret = apple_smc_get_key_info(smc, _SMC_KEY(key), &sensor->info);
sensor->macsmc_key = _SMC_KEY(key);
#define SMC_KEY(s) (smc_key)(_SMC_KEY(#s))