ASoC: SOF: mediatek: add pcm_pointer callback for mt8186

add pcm_pointer callback for mt8186 to support read
host position from DSP
Signed-off-by: Chunxu Li <chunxu.li@mediatek.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Link: https://lore.kernel.org/r/20220921120239.31934-1-chunxu.li@mediatek.comSigned-off-by: Mark Brown <broonie@kernel.org>

sound/soc/sof/mediatek/mt8186/mt8186.c

@@ -470,6 +470,38 @@ static int mt8186_pcm_hw_params(struct snd_sof_dev *sdev,
 	return 0;
 }
 
+static snd_pcm_uframes_t mt8186_pcm_pointer(struct snd_sof_dev *sdev,
+					    struct snd_pcm_substream *substream)
+{
+	int ret;
+	snd_pcm_uframes_t pos;
+	struct snd_sof_pcm *spcm;
+	struct sof_ipc_stream_posn posn;
+	struct snd_sof_pcm_stream *stream;
+	struct snd_soc_component *scomp = sdev->component;
+	struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
+
+	spcm = snd_sof_find_spcm_dai(scomp, rtd);
+	if (!spcm) {
+		dev_warn_ratelimited(sdev->dev, "warn: can't find PCM with DAI ID %d\n",
+				     rtd->dai_link->id);
+		return 0;
+	}
+
+	stream = &spcm->stream[substream->stream];
+	ret = snd_sof_ipc_msg_data(sdev, stream->substream, &posn, sizeof(posn));
+	if (ret < 0) {
+		dev_warn(sdev->dev, "failed to read stream position: %d\n", ret);
+		return 0;
+	}
+
+	memcpy(&stream->posn, &posn, sizeof(posn));
+	pos = spcm->stream[substream->stream].posn.host_posn;
+	pos = bytes_to_frames(substream->runtime, pos);
+
+	return pos;
+}
+
 static struct snd_soc_dai_driver mt8186_dai[] = {
 {
 	.name = "SOF_DL1",
@@ -537,6 +569,7 @@ static struct snd_sof_dsp_ops sof_mt8186_ops = {
 	/* stream callbacks */
 	.pcm_open	= sof_stream_pcm_open,
 	.pcm_hw_params	= mt8186_pcm_hw_params,
+	.pcm_pointer	= mt8186_pcm_pointer,
 	.pcm_close	= sof_stream_pcm_close,
 
 	/* firmware loading */