ARM PL061 GPIO controller Required properties: - compatible : "arm,pl061", "arm,primecell" - #gpio-cells : Should be two. The first cell is the pin number and the second cell is used to specify optional parameters: - bit 0 specifies polarity (0 for normal, 1 for inverted) - gpio-controller : Marks the device node as a GPIO controller. - interrupts : Interrupt mapping for GPIO IRQ. - gpio-ranges : Interaction with the PINCTRL subsystem.