ASoC: SOF: add get_stream_position ops for pcm delay

PCM delay depends on stream position based on hardware
counter to calculate stream delay so add this ops to get
stream position according to hardware counter.
Signed-off-by: Rander Wang <rander.wang@intel.com>
Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Reviewed-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
Reviewed-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Signed-off-by: Peter Ujfalusi <peter.ujfalusi@linux.intel.com>
Link: https://lore.kernel.org/r/20230202132954.26773-8-peter.ujfalusi@linux.intel.comSigned-off-by: Mark Brown <broonie@kernel.org>

sound/soc/sof/ops.h

@@ -511,6 +511,16 @@ static inline int snd_sof_pcm_platform_ack(struct snd_sof_dev *sdev,
 	return 0;
 }
 
+static inline u64 snd_sof_pcm_get_stream_position(struct snd_sof_dev *sdev,
+						  struct snd_soc_component *component,
+						  struct snd_pcm_substream *substream)
+{
+	if (sof_ops(sdev) && sof_ops(sdev)->get_stream_position)
+		return sof_ops(sdev)->get_stream_position(sdev, component, substream);
+
+	return 0;
+}
+
 /* machine driver */
 static inline int
 snd_sof_machine_register(struct snd_sof_dev *sdev, void *pdata)

sound/soc/sof/sof-priv.h

@@ -248,6 +248,15 @@ struct snd_sof_dsp_ops {
 	/* pcm ack */
 	int (*pcm_ack)(struct snd_sof_dev *sdev, struct snd_pcm_substream *substream); /* optional */
 
+	/*
+	 * optional callback to retrieve the link DMA position for the substream
+	 * when the position is not reported in the shared SRAM windows but
+	 * instead from a host-accessible hardware counter.
+	 */
+	u64 (*get_stream_position)(struct snd_sof_dev *sdev,
+				   struct snd_soc_component *component,
+				   struct snd_pcm_substream *substream); /* optional */
+
 	/* host read DSP stream data */
 	int (*ipc_msg_data)(struct snd_sof_dev *sdev,
 			    struct snd_sof_pcm_stream *sps,