• Mark Brown's avatar
    ASoC: Support turning off bias when the CODEC is idle · a96ca338
    Mark Brown authored
    Currently ASoC always maintains the bias of the CODEC while the system
    is active.  With older mobile CODECs this is required since the outputs
    are referenced to a non-zero voltage and enabling or disabling this
    voltage without audible pops or clicks in the output takes too long to
    do when starting or stopping audio.
    
    As a result of features such as ground referenced outputs and class D
    speaker drivers current generation devices are able to power on and off
    much more quickly without these system level issues so provide a new
    flag idle_bias_off in snd_soc_codec which will cause the core to turn
    off the CODEC bias.  The distinction between STANDBY and OFF is still
    maintained.  This is partly for consistency but also allows for
    potential future extensions such as per-machine overrides or deferring
    the bias removal.
    Signed-off-by: default avatarMark Brown <broonie@opensource.wolfsonmicro.com>
    Acked-by: default avatarLiam Girdwood <lrg@slimlogic.co.uk>
    a96ca338
soc.h 18.9 KB