On Thu, Oct 12, 2017 at 9:39 AM, Stephen Boyd [off-list ref] wrote:

For qcom platforms the driver will never be able to return the
direction for these certain pins because reading the register is
not allowed by the firmware. Doing so will cause the device to
crash with a security violation.

So I guess the driver needs to know what pin registers it can't
access so the user does not get a gun to shoot in the foot with.

If we augment gpiolib to just handle -EACCES or something
(-EIO?) from the driver .get_direction() callback for these lines,
things should be smooth?

Yours,
Linus Walleij