HW_AUDIOOUT_CTRL_CLKGATE
AO_WR(sc, HW_AUDIOOUT_CTRL_CLR, HW_AUDIOOUT_CTRL_CLKGATE);
while (!(AO_RD(sc, HW_AUDIOOUT_CTRL) & HW_AUDIOOUT_CTRL_CLKGATE))
AO_WR(sc, HW_AUDIOOUT_CTRL_CLR, HW_AUDIOOUT_CTRL_CLKGATE);
while (AO_RD(sc, HW_AUDIOOUT_CTRL) & HW_AUDIOOUT_CTRL_CLKGATE)