I'm building a kernel module in order to create a gamepad using raspberry pi GPIO. I'm using an ADC converter (MCP3008) to convert joystick analog entries in digital values. I've seen that the kernel mcp320x.c is already existing and I'd like to use it to read the values.

So my question is quite simple, how do I use mcp320x.c function to use it in my own kernel module ?

Multiple sources use EXPORT_SYMBOL, but to do this I have to modify the "official" driver (and may cause issues from updates).

Do you have any solution the may work ? Thank in advance :)