[PATCH v3 7/9] ASoC: SOF: add get_stream_position ops for pcm delay

[Peter Ujfalusi]

From: Rander Wang <rander.wang at intel.com>

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 at intel.com>
Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart at linux.intel.com>
Reviewed-by: Ranjani Sridharan <ranjani.sridharan at linux.intel.com>
Reviewed-by: Bard Liao <yung-chuan.liao at linux.intel.com>
Signed-off-by: Peter Ujfalusi <peter.ujfalusi at linux.intel.com>
---
 sound/soc/sof/ops.h      | 10 ++++++++++
 sound/soc/sof/sof-priv.h |  9 +++++++++
 2 files changed, 19 insertions(+)

diff --git a/sound/soc/sof/ops.h b/sound/soc/sof/ops.h
index febe318b9427..03752c8405ca 100644
--- a/sound/soc/sof/ops.h
+++ b/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)
diff --git a/sound/soc/sof/sof-priv.h b/sound/soc/sof/sof-priv.h
index fd1c3b17a396..14f7adb2dc12 100644
--- a/sound/soc/sof/sof-priv.h
+++ b/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,
-- 
2.39.1