The impression i get from the auraslate is that yes they have source code. But said code is not freely redistributable. Note how one need to pay for a CD with the source on it. Basically, they have managed to negotiate a deal where the source for the drivers are licensed on a individual basis. You can't take the source on the CD and make a working firmware image that you can put online as far as i can tell. So there is no way for a community to put up a git server and cooperate on improving the driver quality. At best one can pass patches around, but i am not even sure if that is allowed. Hell it may even be that if anyone that has looked at the source goes on to make a free version for inclusion into the kernel proper, one risk the kind of lawsuit we observed when SCO claimed IBM had used UNIX code in Linux. Looking at the source may well taint the person from ever working on a related area of the kernel ever again, for fear of unconsciously using something seen and so getting sued. As such, the reverse engineered Mali driver, or no driver at all, may be better than the Auraslate drivers. I am not a lawyer tho.