ASoC: q6asm-dai: add next track metadata support

This patch adds support to metadata required to do a gapless playback.
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Tested-by: Vinod Koul <vkoul@kernel.org>
Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Reviewed-by: Vinod Koul <vkoul@kernel.org>
Link: https://lore.kernel.org/r/20200727093806.17089-8-srinivas.kandagatla@linaro.orgSigned-off-by: Mark Brown <broonie@kernel.org>

sound/soc/qcom/qdsp6/q6asm-dai.c

@@ -67,6 +67,8 @@ struct q6asm_dai_rtd {
 	uint32_t stream_id;
 	uint16_t session_id;
 	enum stream_state state;
+	uint32_t initial_samples_drop;
+	uint32_t trailing_samples_drop;
 };
 
 struct q6asm_dai_data {
@@ -865,6 +867,29 @@ static int q6asm_dai_compr_set_params(struct snd_soc_component *component,
 	return 0;
 }
 
+static int q6asm_dai_compr_set_metadata(struct snd_soc_component *component,
+					struct snd_compr_stream *stream,
+					struct snd_compr_metadata *metadata)
+{
+	struct snd_compr_runtime *runtime = stream->runtime;
+	struct q6asm_dai_rtd *prtd = runtime->private_data;
+	int ret = 0;
+
+	switch (metadata->key) {
+	case SNDRV_COMPRESS_ENCODER_PADDING:
+		prtd->trailing_samples_drop = metadata->value[0];
+		break;
+	case SNDRV_COMPRESS_ENCODER_DELAY:
+		prtd->initial_samples_drop = metadata->value[0];
+		break;
+	default:
+		ret = -EINVAL;
+		break;
+	}
+
+	return ret;
+}
+
 static int q6asm_dai_compr_trigger(struct snd_soc_component *component,
 				   struct snd_compr_stream *stream, int cmd)
 {
@@ -981,6 +1006,7 @@ static struct snd_compress_ops q6asm_dai_compress_ops = {
 	.open		= q6asm_dai_compr_open,
 	.free		= q6asm_dai_compr_free,
 	.set_params	= q6asm_dai_compr_set_params,
+	.set_metadata	= q6asm_dai_compr_set_metadata,
 	.pointer	= q6asm_dai_compr_pointer,
 	.trigger	= q6asm_dai_compr_trigger,
 	.get_caps	= q6asm_dai_compr_get_caps,