[PATCH 2/6] ASoC: tlv320adcx140: Fix BCLK inversion for DSP modes

[Dan Murphy]

Fix the BCLK inversion for DSP modes
This is how it is defined by ASoC:
 * BCLK:
 * - "normal" polarity means signal is available at rising edge of BCLK
 * - "inverted" polarity means signal is available at falling edge of BCLK

The adcx140 defines the BCLK edge based on coding type.
The PCM (DSP_A/B) should drive on rising and sample on falling edge, so
from ASoC pov, it is IB_NF. But from the codec pov if it is configured in
DSP mode, then the BCLK should not be inverted, defaults to the coding
standard.

For i2s, it is NB_NF from ASoC pov (drive on falling, sample on rising).
>From the codec's pov BCLK should not invert either, as this is the default
for the coding.

So, inversion must take the format into account:
IB_NF + DSP_A/B == the codec bclk inversion should be disabled
NB_NF + DSP_A/B == the codec bclk inversion should be enabled
NB_NF + I2S == the codec bclk inversion should be disabled

Signed-off-by: Dan Murphy <dmurphy@xxxxxx>
---
 sound/soc/codecs/tlv320adcx140.c | 44 +++++++++++++++++---------------
 1 file changed, 23 insertions(+), 21 deletions(-)

diff --git a/sound/soc/codecs/tlv320adcx140.c b/sound/soc/codecs/tlv320adcx140.c
index 3909c1cf52be..73d18e8002e4 100644
--- a/sound/soc/codecs/tlv320adcx140.c
+++ b/sound/soc/codecs/tlv320adcx140.c
@@ -673,7 +673,7 @@ static int adcx140_set_dai_fmt(struct snd_soc_dai *codec_dai,
 	u8 iface_reg1 = 0;
 	u8 iface_reg2 = 0;
 	int offset = 0;
-	int width = adcx140->slot_width;
+	bool inverted_bclk = false;
 
 	/* set master/slave audio interface */
 	switch (fmt & SND_SOC_DAIFMT_MASTER_MASK) {
@@ -689,24 +689,6 @@ static int adcx140_set_dai_fmt(struct snd_soc_dai *codec_dai,
 		return -EINVAL;
 	}
 
-	/* signal polarity */
-	switch (fmt & SND_SOC_DAIFMT_INV_MASK) {
-	case SND_SOC_DAIFMT_NB_IF:
-		iface_reg1 |= ADCX140_FSYNCINV_BIT;
-		break;
-	case SND_SOC_DAIFMT_IB_IF:
-		iface_reg1 |= ADCX140_BCLKINV_BIT | ADCX140_FSYNCINV_BIT;
-		break;
-	case SND_SOC_DAIFMT_IB_NF:
-		iface_reg1 |= ADCX140_BCLKINV_BIT;
-		break;
-	case SND_SOC_DAIFMT_NB_NF:
-		break;
-	default:
-		dev_err(component->dev, "Invalid DAI clock signal polarity\n");
-		return -EINVAL;
-	}
-
 	/* interface format */
 	switch (fmt & SND_SOC_DAIFMT_FORMAT_MASK) {
 	case SND_SOC_DAIFMT_I2S:
@@ -716,16 +698,36 @@ static int adcx140_set_dai_fmt(struct snd_soc_dai *codec_dai,
 		iface_reg1 |= ADCX140_LEFT_JUST_BIT;
 		break;
 	case SND_SOC_DAIFMT_DSP_A:
-		offset += (adcx140->tdm_delay * width + 1);
+		offset = 1;
+		inverted_bclk = true;
 		break;
 	case SND_SOC_DAIFMT_DSP_B:
-		offset += adcx140->tdm_delay * width;
+		inverted_bclk = true;
 		break;
 	default:
 		dev_err(component->dev, "Invalid DAI interface format\n");
 		return -EINVAL;
 	}
 
+	/* signal polarity */
+	switch (fmt & SND_SOC_DAIFMT_INV_MASK) {
+	case SND_SOC_DAIFMT_IB_NF:
+	case SND_SOC_DAIFMT_IB_IF:
+		inverted_bclk = !inverted_bclk;
+		break;
+	case SND_SOC_DAIFMT_NB_IF:
+		iface_reg1 |= ADCX140_FSYNCINV_BIT;
+		break;
+	case SND_SOC_DAIFMT_NB_NF:
+		break;
+	default:
+		dev_err(component->dev, "Invalid DAI clock signal polarity\n");
+		return -EINVAL;
+	}
+
+	if (inverted_bclk)
+		iface_reg1 |= ADCX140_BCLKINV_BIT;
+
 	adcx140->dai_fmt = fmt & SND_SOC_DAIFMT_FORMAT_MASK;
 
 	adcx140_pwr_ctrl(adcx140, false);
-- 
2.28.0