A few days ago I was trying to use a battery backup board with the AML-S905X-CC, and I ran into a situation where I needed to recompile the driver because it was looking at i2c-1 (The RPi pin 3/5 i2c), and the kernel was assigning that set of pin to i2c-0. I decided to look into why, here’s what I found:
To use /alias entries in the device tree and to get predictable results, you must have all aliases used with real devices:
i2c0 <— The one I don’t care about
i2c1 <— The one I want
Enabling both I2C’s after this adjustment puts i2c-0 and i2c-1 where you want them, assuming you are a program written for a Raspberry Pi.
I’m looking at the other boards as well for the same adjustments