MUX_MASK
wait_until_mux_stable(base + regs->mux_stat, 16, MUX_MASK, 2);
wait_until_mux_stable(base + regs->mux_stat, 16, MUX_MASK, 1);
wait_until_mux_stable(base + regs->mux_stat, 0, MUX_MASK, 2);
wait_until_mux_stable(base + regs->mux_stat, 0, MUX_MASK, 1);
#define get_mux_field(val) (((val) & MUX_MASK) >> MUX_SHIFT)
val &= ~MUX_MASK;