[PATCH 4/4] ASoC: codecs: wsa881x: mute/unmute PA in correct sequence

[Srinivas Kandagatla <srinivas.kandagatla@linaro.org>]

In the current setup the PA is left unmuted even when the
Soundwire ports are not started streaming. This can lead to click
and pop sounds during start.
There is a same issue in the reverse order where in the PA is
left unmute even after the data stream is stopped, the time
between data stream stopping and port closing is long enough
to accumulate DC on the line resulting in Click/Pop noise
during end of stream.

Moving the mute/unmute to trigger stop/start respectively seems to
help a lot with this Click/Pop issues reported on this Codec.

Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
---
 sound/soc/codecs/wsa881x.c | 30 +++++++++++++++++++++++++++++-
 1 file changed, 29 insertions(+), 1 deletion(-)

diff --git a/sound/soc/codecs/wsa881x.c b/sound/soc/codecs/wsa881x.c
index f709231b1277..4ce72a7f01b6 100644
--- a/sound/soc/codecs/wsa881x.c
+++ b/sound/soc/codecs/wsa881x.c
@@ -1033,11 +1033,39 @@ static int wsa881x_digital_mute(struct snd_soc_dai *dai, int mute, int stream)
 	return 0;
 }
 
+static int wsa881x_trigger(struct snd_pcm_substream *s, int cmd,
+			   struct snd_soc_dai *dai)
+{
+	switch (cmd) {
+	case SNDRV_PCM_TRIGGER_START:
+	case SNDRV_PCM_TRIGGER_RESUME:
+	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
+		wsa881x_digital_mute(dai, false, 0);
+		break;
+	case SNDRV_PCM_TRIGGER_STOP:
+	case SNDRV_PCM_TRIGGER_SUSPEND:
+	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
+		wsa881x_digital_mute(dai, true, 0);
+		break;
+	default:
+		break;
+	}
+
+	return 0;
+}
+
+static int wsa881x_startup(struct snd_pcm_substream *stream,
+			   struct snd_soc_dai *dai)
+{
+	return wsa881x_digital_mute(dai, true, 0);
+}
+
 static const struct snd_soc_dai_ops wsa881x_dai_ops = {
+	.startup = wsa881x_startup,
 	.hw_params = wsa881x_hw_params,
 	.hw_free = wsa881x_hw_free,
-	.mute_stream = wsa881x_digital_mute,
 	.set_stream = wsa881x_set_sdw_stream,
+	.trigger = wsa881x_trigger,
 };
 
 static struct snd_soc_dai_driver wsa881x_dais[] = {
-- 
2.21.0