ASRS 2107205

Flight Crew was cleared for visual approach into ATL. Just inside of 4 miles, ATC told the flight crew "Low altitude alert. Check your altitude immediately" and was given a local altimeter setting. The aircraft was fully configured and one dot low on the PAPI lights. When notified from ATC, the crew leveled off and landed safely. Cause: Crossing over the FAF for the approach, the crew was 200ft above the prescribed altitude for the approach. The airplane was then set to a lower than normal descent path which caused the aircraft to dip below the PAPI light guidance for the visual approach. At this time, the PAPI were three red and one white dot. Suggestions: Despite the flight crew never seeing four red lights from the PAPI system, always correct altitude when the aircraft is seeing 3 red and 1 white PAPI light.