How do I stop the home button from waking the device? I keep pressing the home button by accident in my pocket.

I have an S5, Cyanogen Marshmallow, rooted and xposed.

I can't find any way to stop wake on home with cm.  For Touchwiz there are xposed modules which stop this... How do I stop it on CM?
The setting was in Settings › Buttons – just toggle off Wake Device there. Duh!