GPIO in the kernel: an introduction

GPIO in the kernel: an introduction

It sounds like your concern is accessing GPIOs from userspace, but I thought the primary intended consumer of this particular ABI was kernel drivers, and that accessing GPIOs via /sys was intended just for debugging, in lieu of a proper driver for the hardware you're playing with.

Then again, Documentation/gpio.txt does claim that "for some tasks, simple userspace GPIO drivers could be all that the system really needs", which at least suggests that it should be considered a production API. So complaints about API breakes are probably worth bringing up when they happen.