MAX31790_FAN_CFG_RPM_MODE
else if (fan_config & MAX31790_FAN_CFG_RPM_MODE)
fan_config &= ~MAX31790_FAN_CFG_RPM_MODE;
fan_config &= ~(MAX31790_FAN_CFG_CTRL_MON | MAX31790_FAN_CFG_RPM_MODE);
fan_config |= (MAX31790_FAN_CFG_RPM_MODE | MAX31790_FAN_CFG_TACH_INPUT_EN);