ASoC: soc-dai: add flag to mute and unmute stream during trigger

In some setups like Speaker amps which are very sensitive, ex: keeping them
unmute without actual data stream for very short duration results in a
static charge and results in pop and clicks. To minimize this, provide a way
to mute and unmute such codecs during trigger callbacks.
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Tested-by: Johan Hovold <johan+linaro@kernel.org>
Link: https://lore.kernel.org/r/20231027105747.32450-2-srinivas.kandagatla@linaro.orgSigned-off-by: Mark Brown <broonie@kernel.org>

include/sound/soc-dai.h

@@ -370,6 +370,7 @@ struct snd_soc_dai_ops {
 
 	/* bit field */
 	unsigned int no_capture_mute:1;
+	unsigned int mute_unmute_on_trigger:1;
 };
 
 struct snd_soc_cdai_ops {

sound/soc/soc-dai.c

@@ -658,6 +658,10 @@ int snd_soc_pcm_dai_trigger(struct snd_pcm_substream *substream,
 			ret = soc_dai_trigger(dai, substream, cmd);
 			if (ret < 0)
 				break;
+
+			if (dai->driver->ops && dai->driver->ops->mute_unmute_on_trigger)
+				snd_soc_dai_digital_mute(dai, 0, substream->stream);
+
 			soc_dai_mark_push(dai, substream, trigger);
 		}
 		break;
@@ -668,6 +672,9 @@ int snd_soc_pcm_dai_trigger(struct snd_pcm_substream *substream,
 			if (rollback && !soc_dai_mark_match(dai, substream, trigger))
 				continue;
 
+			if (dai->driver->ops && dai->driver->ops->mute_unmute_on_trigger)
+				snd_soc_dai_digital_mute(dai, 1, substream->stream);
+
 			r = soc_dai_trigger(dai, substream, cmd);
 			if (r < 0)
 				ret = r; /* use last ret */

sound/soc/soc-pcm.c

@@ -703,10 +703,12 @@ static int soc_pcm_clean(struct snd_soc_pcm_runtime *rtd,
 			if (snd_soc_dai_active(dai) == 0)
 				soc_pcm_set_dai_params(dai, NULL);
 
-			if (snd_soc_dai_stream_active(dai, substream->stream) == 0)
+			if (snd_soc_dai_stream_active(dai, substream->stream) ==  0) {
+				if (dai->driver->ops && !dai->driver->ops->mute_unmute_on_trigger)
 					snd_soc_dai_digital_mute(dai, 1, substream->stream);
 			}
 		}
+	}
 
 	for_each_rtd_dais(rtd, i, dai)
 		snd_soc_dai_shutdown(dai, substream, rollback);
@@ -898,8 +900,10 @@ static int __soc_pcm_prepare(struct snd_soc_pcm_runtime *rtd,
 	snd_soc_dapm_stream_event(rtd, substream->stream,
 			SND_SOC_DAPM_STREAM_START);
 
-	for_each_rtd_dais(rtd, i, dai)
+	for_each_rtd_dais(rtd, i, dai) {
+		if (dai->driver->ops && !dai->driver->ops->mute_unmute_on_trigger)
 			snd_soc_dai_digital_mute(dai, 0, substream->stream);
+	}
 
 out:
 	return soc_pcm_ret(rtd, ret);