PS2DATA
writel_relaxed(ps2if->buf[ps2if->tail], ps2if->base + PS2DATA);
writel_relaxed(val, ps2if->base + PS2DATA);
if ((readl_relaxed(ps2if->base + PS2DATA) & 0xff) == 0xff)
scancode = readl_relaxed(ps2if->base + PS2DATA) & 0xff;