check out the (new, not merged yet) #GlasgowInterfaceExplorer I²C controller documentation! https://whitequark.github.io/glasgow/refactor-i2c-initiator/applets/interface/i2c_controller.html
is there anything else you'd like to see, either in general in the docs, or as a part of this applet?
(there are no commands to read/write because usually you need to chain those and that's hard to express using a CLI)