In normal operation, the left and right channel digital audio data is converted to analogue in two separate DACs. There is a mono-mix mode where the two audio channels are mixed together digitally and then converted to analogue using only one DAC, while the other DAC is switched off. The mono-mix signal can be selected to appear on both analogue output channels. The mono mix is automatically attenuated by 6dB to prevent clipping.
Signed-off-by: Zidan Wang zidan.wang@freescale.com --- sound/soc/codecs/wm8960.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/sound/soc/codecs/wm8960.c b/sound/soc/codecs/wm8960.c index 162def8..029031b 100644 --- a/sound/soc/codecs/wm8960.c +++ b/sound/soc/codecs/wm8960.c @@ -153,6 +153,7 @@ static const char *wm8960_adc_data_output_sel[] = { "Left Data = Right ADC; Right Data = Right ADC", "Left Data = Right ADC; Right Data = Left ADC", }; +static const char *wm8960_dmonomix[] = {"Stereo", "Mono"};
static const struct soc_enum wm8960_enum[] = { SOC_ENUM_SINGLE(WM8960_DACCTL1, 5, 4, wm8960_polarity), @@ -162,6 +163,7 @@ static const struct soc_enum wm8960_enum[] = { SOC_ENUM_SINGLE(WM8960_ALC1, 7, 4, wm8960_alcfunc), SOC_ENUM_SINGLE(WM8960_ALC3, 8, 2, wm8960_alcmode), SOC_ENUM_SINGLE(WM8960_ADDCTL1, 2, 4, wm8960_adc_data_output_sel), + SOC_ENUM_SINGLE(WM8960_ADDCTL1, 4, 2, wm8960_dmonomix), };
static const int deemph_settings[] = { 0, 32000, 44100, 48000 }; @@ -304,6 +306,7 @@ SOC_SINGLE_TLV("Right Output Mixer RINPUT3 Volume", WM8960_ROUTMIX, 4, 7, 1, bypass_tlv),
SOC_ENUM("ADC Data Output Select", wm8960_enum[6]), +SOC_ENUM("DAC Mono Mix", wm8960_enum[7]), };
static const struct snd_kcontrol_new wm8960_lin_boost[] = {