Gpio button mapping

[pvstlife]

I’ve been searching for a few days and haven’t found a solid answer so I’m sorry if this question has been asked, and I just haven’t found it.

My set up:
-pi zero W
-Uniker 2.8” pi zero touch screen
-RetroPie 4.7
-2 way analog thumb stick
-McP3008 Converter

• 8 momentary switches

So I have the screen soldered on and working, and I have the buttons, mcp3008, and thumbstick all wired to the pi gpio.
I’m trying to map the thumbstick and buttons inside RetroPie to no avail. All of the button mapping things I’ve come across use gpio pins I’ve had to alter due to screen issues, so I haven’t been able to use other peoples mapping schemes.
Is there ANY way for me to set up my own gpio mapping to use the already soldered pins as buttons in RetroPie. All of the controls I’ve soldered are on open gpio pins.

Any help is greatly appreciated!! Sorry if this is worded strange, I can answer any questions about my set up/problems.

[mitu]

Try using GPIOnext to map your GPIO switches, it has a mapping utility to help. For the converter, I think you'll need to set-up a script to read the MCP data and translate them into a joystick input - but I don't think GPIOnext includes that.

[pvstlife]

@mitu
When I tried using gpionext I kept being met with error messages. I ended up just getting a few different parts to work with the super pi girl drivers. Still, thank you for the help.