[PATCH v3 3/7] ASoC: codec: pcm1681: Add TDM support

[Mohammad Rafi Shaik]

The PCM1681 selects the audio interface format using FMT[3:0] in the
format register. The driver currently supports only I2S, left-justified,
and right-justified formats, preventing a machine driver from selecting
TDM mode.
 
Add support for SND_SOC_DAIFMT_DSP_A and program the PCM1681 I2S TDM
format when it is selected. Also advertise DSP_A in the selectable DAI
formats.
 
While adding TDM support, correct the reset default for the format
register from 0x06 to 0x05. The current default does not match the
hardware reset value. Although this has no effect while regmap caching
is disabled, it could cause the TDM format write to be skipped if
regmap caching is enabled in the future.
 
The existing I2S, left-justified, and right-justified formats remain
unchanged.

Assisted-by: LLM
Signed-off-by: Mohammad Rafi Shaik <mohammad.rafi.shaik@xxxxxxxxxxxxxxxx>
---
 sound/soc/codecs/pcm1681.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/sound/soc/codecs/pcm1681.c b/sound/soc/codecs/pcm1681.c
index a1ccf1edf..3675b2236 100644
--- a/sound/soc/codecs/pcm1681.c
+++ b/sound/soc/codecs/pcm1681.c
@@ -53,7 +53,7 @@ static const struct reg_default pcm1681_reg_defaults[] = {
 	{ 0x06,	0xff },
 	{ 0x07,	0x00 },
 	{ 0x08,	0x00 },
-	{ 0x09,	0x06 },
+	{ 0x09,	0x05 },
 	{ 0x0A,	0x00 },
 	{ 0x0B,	0xff },
 	{ 0x0C,	0x0f },
@@ -217,6 +217,9 @@ static int pcm1681_hw_params(struct snd_pcm_substream *substream,
 	case SND_SOC_DAIFMT_LEFT_J:
 		val = 0x05;
 		break;
+	case SND_SOC_DAIFMT_DSP_A:
+		val = 0x06;
+		break;
 	default:
 		dev_err(component->dev, "Invalid DAI format\n");
 		return -EINVAL;
@@ -232,7 +235,8 @@ static int pcm1681_hw_params(struct snd_pcm_substream *substream,
 static const u64 pcm1681_selectable_formats =
 	SND_SOC_POSSIBLE_DAIFMT_I2S	|
 	SND_SOC_POSSIBLE_DAIFMT_RIGHT_J	|
-	SND_SOC_POSSIBLE_DAIFMT_LEFT_J;
+	SND_SOC_POSSIBLE_DAIFMT_LEFT_J |
+	SND_SOC_POSSIBLE_DAIFMT_DSP_A;
 
 static const struct snd_soc_dai_ops pcm1681_dai_ops = {
 	.set_fmt	= pcm1681_set_dai_fmt,

-- 
2.34.1