ASoC: tlv320adcx140: Add decimation filter support

Add decimation filter selection support.
Per Section 8.3.6.7 the Digital Decimation Filter is selectable between
a Linear Phase, Low Latency, and Ultra Low Latency filer.

Signed-off-by: Dan Murphy <dmurphy@ti.com>
Link: https://lore.kernel.org/r/20200221181358.22526-2-dmurphy@ti.com
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/sound/soc/codecs/tlv320adcx140.c b/sound/soc/codecs/tlv320adcx140.c
index 105e51be6fe68aed835aa494da2f51b40f5f5c51..93a0cb8e662ccfcb60fd7df3ab8aa6a0fd7bfc76 100644 (file)
--- a/sound/soc/codecs/tlv320adcx140.c
+++ b/sound/soc/codecs/tlv320adcx140.c
@@ -169,6 +169,17 @@ static DECLARE_TLV_DB_SCALE(agc_thresh_tlv, -3600, 200, 0);
 /* AGC Max Gain. From 3 dB to 42 dB in 3 dB steps */
 static DECLARE_TLV_DB_SCALE(agc_gain_tlv, 300, 300, 0);
 
+static const char * const decimation_filter_text[] = {
+       "Linear Phase", "Low Latency", "Ultra-low Latency"
+};
+
+static SOC_ENUM_SINGLE_DECL(decimation_filter_enum, ADCX140_DSP_CFG0, 4,
+                           decimation_filter_text);
+
+static const struct snd_kcontrol_new decimation_filter_controls[] = {
+       SOC_DAPM_ENUM("Decimation Filter", decimation_filter_enum),
+};
+
 static const char * const resistor_text[] = {
        "2.5 kOhm", "10 kOhm", "20 kOhm"
 };
@@ -404,6 +415,9 @@ static const struct snd_soc_dapm_widget adcx140_dapm_widgets[] = {
                        in3_resistor_controls),
        SND_SOC_DAPM_MUX("IN4 Analog Mic Resistor", SND_SOC_NOPM, 0, 0,
                        in4_resistor_controls),
+
+       SND_SOC_DAPM_MUX("Decimation Filter", SND_SOC_NOPM, 0, 0,
+                       decimation_filter_controls),
 };
 
 static const struct snd_soc_dapm_route adcx140_audio_map[] = {
@@ -418,6 +432,10 @@ static const struct snd_soc_dapm_route adcx140_audio_map[] = {
        {"CH3_ASI_EN", "Switch", "CH3_ADC"},
        {"CH4_ASI_EN", "Switch", "CH4_ADC"},
 
+       {"Decimation Filter", "Linear Phase", "DRE_ENABLE"},
+       {"Decimation Filter", "Low Latency", "DRE_ENABLE"},
+       {"Decimation Filter", "Ultra-low Latency", "DRE_ENABLE"},
+
        {"DRE_ENABLE", "Switch", "CH1_DRE_EN"},
        {"DRE_ENABLE", "Switch", "CH2_DRE_EN"},
        {"DRE_ENABLE", "Switch", "CH3_DRE_EN"},