MXC_W1_CONTROL
writeb(MXC_W1_CONTROL_RPP, dev->regs + MXC_W1_CONTROL);
u8 ctrl = readb(dev->regs + MXC_W1_CONTROL);
writeb(MXC_W1_CONTROL_WR(bit), dev->regs + MXC_W1_CONTROL);
u8 ctrl = readb(dev->regs + MXC_W1_CONTROL);