How does this compare, if applicable, with protestant work ethic?
I regard "protestant" or "Calvinistic" as equivalent qualifiers of "work ethic". The many exponents of christian work ethic have included Benjamin Franklin (an agnostic who viewed Christian ethics favourably) and particularly the French theologian John Calvin 1509 - 1564 who based their thought on verses such as:
1 Timothy 5:18 For the scripture saith, Thou shalt not muzzle the ox that treadeth out the corn. And, The labourer is worthy of his reward. (KJ)
2 Thessalonians 3:10 The one who is unwilling to work shall not eat.
Calvin understood work as a means through which the believers expressed their gratitude to God for their redemption in Christ and as a service to their neighbours. Everybody was obliged to work; loafing and begging were rejected. The idea that economic success was a visible sign of God's grace played only a minor role in Calvin's thinking. It became more important in later, partly secularized forms of Calvinism and became the starting-point of Max Weber's theory about the rise of capitalism.