WM8991_DAC_MUTE
val = snd_soc_component_read(component, WM8991_DAC_CTRL) & ~WM8991_DAC_MUTE;
snd_soc_component_write(component, WM8991_DAC_CTRL, val | WM8991_DAC_MUTE);
snd_soc_component_write(component, WM8991_DAC_CTRL, val | WM8991_DAC_MUTE);