Simple library for 128x64. Works fine with SH1106 1.3" OLED and OrangePi Zero (4.9 kernel). You just need to activate I2C interface by replacing "disabled" with "okay" in device tree file (or in the fex). Connect display and test with "sudo i2cdetect -y 0" (or 1). If your display has 3d address instead 3c, change OLED_I2C_ADDR parameter it in the oled.h. Enter "make" to compile and run demo with "sudo ./oled_demo /dev/i2c-0".
This library was written by Sonal Pinto for Arduino and ported to Linux by Vladimir Komendantskiy. I just wrote functions for text drawing and add three little fonts. This library only can draw text at X Y with specified font and draw custom pixel, but it is easy to write line, circle, rectangle drawing functions.