IST7920 is used at run time in 1 crate (of which 1 optionally). It's used only as a dev dependency in 2 crates.

Depender (with downloads and own rev deps) IST7920 version
klaptik optional ^0.1.1
6.8K 44 stm32f4xx-hal dev ^0.1.1
n32g4xx-hal dev ^0.1.1