On Thu, Feb 02, 2017 at 02:38:55AM +0000, Bard Liao wrote:

It is a codec GPIO, indeed. But we don't register it to gpiolib. So there is no other way to touch the GPIO. We are using it to do headset ground control and we should control its level according to if headset is using. That's why we control it by a DAPM event.

So one option here would be to register it with gpiolib...