wait_until_mux_stable
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);
wait_until_mux_stable(base + regs->mux, 16, 1, 0);
wait_until_mux_stable(base + regs->mux, 16, 1, 0);