GPIO_IN_POL
val = readl(GPIO_DATA_IN(ochip)) ^ readl(GPIO_IN_POL(ochip));
u = readl(GPIO_IN_POL(ochip));
writel(u, GPIO_IN_POL(ochip));
u = readl(GPIO_IN_POL(ochip));
writel(u, GPIO_IN_POL(ochip));
v = readl(GPIO_IN_POL(ochip)) ^ readl(GPIO_DATA_IN(ochip));
u = readl(GPIO_IN_POL(ochip));
writel(u, GPIO_IN_POL(ochip));
polarity = readl(GPIO_IN_POL(ochip));
writel(polarity, GPIO_IN_POL(ochip));
in_pol = readl_relaxed(GPIO_IN_POL(ochip));