Hi,
Snapdragon 820 has been officially announced with Adreno 530 which supports OpenCL 2.0..
one important feature (that is optional) is fine grained buffer SVM which allows addressing host data structures from GPU passing host pointer and using in GPU kernels like CPU code..
Also a OpenCL 2.0 optimization guide for Adreno 5xx series will be good as other vendors like AMD do..
Also info about supported optional extensions like msaa textures support, etc..
thanks..