ASoC: SOF: hda: couple host and link DMA during FE hw_free

Host and link DMA are decoupled during FE hw_params. So,
they must be coupled in hw_free if the link DMA channel
is idle.

Signed-off-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>

Author: ranj063

sound/soc/sof/intel/apl.c

@@ -61,6 +61,7 @@ const struct snd_sof_dsp_ops sof_apl_ops = {
 	.pcm_open	= hda_dsp_pcm_open,
 	.pcm_close	= hda_dsp_pcm_close,
 	.pcm_hw_params	= hda_dsp_pcm_hw_params,
+	.pcm_hw_free	= hda_dsp_stream_hw_free,
 	.pcm_trigger	= hda_dsp_pcm_trigger,
 	.pcm_pointer	= hda_dsp_pcm_pointer,
 

sound/soc/sof/intel/cnl.c

@@ -217,6 +217,7 @@ const struct snd_sof_dsp_ops sof_cnl_ops = {
 	.pcm_open	= hda_dsp_pcm_open,
 	.pcm_close	= hda_dsp_pcm_close,
 	.pcm_hw_params	= hda_dsp_pcm_hw_params,
+	.pcm_hw_free	= hda_dsp_stream_hw_free,
 	.pcm_trigger	= hda_dsp_pcm_trigger,
 	.pcm_pointer	= hda_dsp_pcm_pointer,
 

sound/soc/sof/intel/hda-stream.c

@@ -438,6 +438,26 @@ int hda_dsp_stream_hw_params(struct snd_sof_dev *sdev,
 	return ret;
 }
 
+int hda_dsp_stream_hw_free(struct snd_sof_dev *sdev,
+			   struct snd_pcm_substream *substream)
+{
+	struct hdac_stream *stream = substream->runtime->private_data;
+	struct hdac_ext_stream *link_dev = container_of(stream,
+							struct hdac_ext_stream,
+							hstream);
+	struct hdac_bus *bus = sof_to_bus(sdev);
+	u32 mask = 0x1 << stream->index;
+
+	spin_lock(&bus->reg_lock);
+	/* couple host and link DMA if link DMA channel is idle */
+	if (!link_dev->link_locked)
+		snd_sof_dsp_update_bits(sdev, HDA_DSP_PP_BAR,
+					SOF_HDA_REG_PP_PPCTL, mask, 0);
+	spin_unlock(&bus->reg_lock);
+
+	return 0;
+}
+
 irqreturn_t hda_dsp_stream_interrupt(int irq, void *context)
 {
 	struct hdac_bus *bus = context;

sound/soc/sof/intel/hda.h

@@ -466,6 +466,8 @@ int hda_dsp_pcm_hw_params(struct snd_sof_dev *sdev,
 			  struct snd_pcm_substream *substream,
 			  struct snd_pcm_hw_params *params,
 			  struct sof_ipc_stream_params *ipc_params);
+int hda_dsp_stream_hw_free(struct snd_sof_dev *sdev,
+			   struct snd_pcm_substream *substream);
 int hda_dsp_pcm_trigger(struct snd_sof_dev *sdev,
 			struct snd_pcm_substream *substream, int cmd);
 snd_pcm_uframes_t hda_dsp_pcm_pointer(struct snd_sof_dev *sdev,

sound/soc/sof/ops.h

@@ -287,6 +287,17 @@ snd_sof_pcm_platform_hw_params(struct snd_sof_dev *sdev,
 	return 0;
 }
 
+/* host stream hw free */
+static inline int
+snd_sof_pcm_platform_hw_free(struct snd_sof_dev *sdev,
+			     struct snd_pcm_substream *substream)
+{
+	if (sof_ops(sdev) && sof_ops(sdev)->pcm_hw_free)
+		return sof_ops(sdev)->pcm_hw_free(sdev, substream);
+
+	return 0;
+}
+
 /* host stream trigger */
 static inline int
 snd_sof_pcm_platform_trigger(struct snd_sof_dev *sdev,

sound/soc/sof/pcm.c

@@ -251,6 +251,13 @@ static int sof_pcm_hw_free(struct snd_pcm_substream *substream)
 
 	cancel_work_sync(&spcm->stream[substream->stream].period_elapsed_work);
 
+	if (ret < 0)
+		return ret;
+
+	ret = snd_sof_pcm_platform_hw_free(sdev, substream);
+	if (ret < 0)
+		dev_err(sdev->dev, "error: platform hw free failed\n");
+
 	return ret;
 }
 

sound/soc/sof/sof-priv.h

@@ -143,6 +143,10 @@ struct snd_sof_dsp_ops {
 			     struct snd_pcm_hw_params *params,
 			     struct sof_ipc_stream_params *ipc_params); /* optional */
 
+	/* host stream hw_free */
+	int (*pcm_hw_free)(struct snd_sof_dev *sdev,
+			   struct snd_pcm_substream *substream); /* optional */
+
 	/* host stream trigger */
 	int (*pcm_trigger)(struct snd_sof_dev *sdev,
 			   struct snd_pcm_substream *substream,