From: Emil Svendsen <emas@bang-olufsen.dk>

Add control for channel summation.

3 modes are supported:

1. "Disabled": Normal operation

2. "2 Channel": Every two channels are summed and divided by 2

  Out 1 <- (CH1 + CH2) / 2
  Out 2 <- (CH1 + CH2) / 2
  Out 3 <- (CH3 + CH4) / 2
  Out 4 <- (CH3 + CH4) / 2

3. "4 Channel": Every four channels are summed and divided by 4

  Out 1 <- (CH1 + CH2 + CH3 + CH4) / 4
  Out 2 <- (CH1 + CH2 + CH3 + CH4) / 4
  Out 3 <- (CH1 + CH2 + CH3 + CH4) / 4
  Out 4 <- (CH1 + CH2 + CH3 + CH4) / 4

Signed-off-by: Emil Svendsen <emas@bang-olufsen.dk>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
---
 sound/soc/codecs/tlv320adcx140.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/sound/soc/codecs/tlv320adcx140.c b/sound/soc/codecs/tlv320adcx140.c
index e7c607af642f43b2b783597f3cba3a8cbb31de4a..ac6aab8d722409b2c47b4e1df2a23760bebe795b 100644
--- a/sound/soc/codecs/tlv320adcx140.c
+++ b/sound/soc/codecs/tlv320adcx140.c
@@ -222,6 +222,13 @@ static const struct snd_kcontrol_new decimation_filter_controls[] = {
 	SOC_DAPM_ENUM("Decimation Filter", decimation_filter_enum),
 };
 
+static const char * const channel_summation_text[] = {
+	"Disabled", "2 Channel", "4 Channel"
+};
+
+static SOC_ENUM_SINGLE_DECL(channel_summation_enum, ADCX140_DSP_CFG0, 2,
+			    channel_summation_text);
+
 static const char * const pdmclk_text[] = {
 	"2.8224 MHz", "1.4112 MHz", "705.6 kHz", "5.6448 MHz"
 };
@@ -711,6 +718,8 @@ static const struct snd_kcontrol_new adcx140_snd_controls[] = {
 	ADCX140_PHASE_CALIB_SWITCH("Phase Calibration Switch"),
 
 	SOC_SINGLE("Biquads Per Channel", ADCX140_DSP_CFG1, 5, 3, 0),
+
+	SOC_ENUM("Channel Summation", channel_summation_enum),
 };
 
 static int adcx140_reset(struct adcx140_priv *adcx140)

-- 
2.47.3