The original library has been modified to write to the I2C devices at /dev/i2c-X instead of driving the IO pins directly.
Device and address can be set in dev_io.h
Not implemented for SPI.

[04/2018] Tested on an Orange Pi Zero H2+ running Armbian (Armbian has something in the boot config called "overlays" which enable IO ports, in this case it was 'i2c0') with an "SSD1306" OLED display (128x64). Had to use type "OLED_SH1106_I2C_128x64" for the library init to get it to work.

Thanks to the original author, what follows is the original README:

Raspberry PI OLED Library Driver

This is the port of some of the most used OLED drivers such as the Adafruit, Seeedstudio, Tindie, Generic... to the Raspberry Pi. It can drive OLED with chipset such as SSD1306, SH1106, SSD1327 and SSD1308

This library replace the previous one named ArduiPi_SSD1306

This has been ported to work with the ArduiPi Project but it can work on almost any Raspberry PI.

Installation

Everything is documented on this dedicated post my blog