I have assumed that these dates from the RI Cemetery Database belong to this Ezekiel, because they are in the right time frame and the grave is in the right area.
Some genealogies show that Ezekiel married Elizabeth's sister, Abigail. It is a confusing puzzle that needs more research.
The will of Ezekiel Johnson, of Coventry, was dated 18 Apr 1789 and proved 7 Nov 1791. In it he mentions his wife Elizabeth, four sons, and four daughters, the last of which - at least - is under 18.
I have wondered if he had another son named Philip who died in 1785. There was a Philip Johnson who is noted in the Maple Root records as having died 13 July 1785. This might explain why Ezekiel Jr. had a son named Philip. Based on his age at death and place of burial (information from Linda Mathew), I am including him in this family group.
From Linda Mathew: "Ezekiel . . . when he made his [will] in 1789 left all of his real estate, undivided, to his sons Ezekiel, Edmund, and Daniel. Ezekiel, Sr., died in 1791 and the following year the brothers divided the land. Daniel received 50 acres in West Greenwich. Ezekiel and Edmund got the Coventry portions of their father's land, but Edmund sold his to Ezekiel a few years later when he moved to upstate New York."
Abt 1731 - 1791 (60 years)