ASoC: SOF: sof-audio: Add helpers to set up and destroy a pipeline

Add helpers to set up and destroy a pipeline along with its widgets
and connections. Also, add a ref_count field to struct snd_sof_widget
that will be used to track the widget's usage across pipelines.

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

sound/soc/sof/sof-audio.c

@@ -21,6 +21,12 @@ static int sof_widget_setup(struct snd_sof_dev *sdev, struct snd_sof_widget *swi
 	size_t ipc_size;
 	int ret;
 
+	/* widget set up already? */
+	if (swidget->ref_count)
+		return 0;
+
+	swidget->ref_count++;
+
 	/* skip if there is no private data */
 	if (!swidget->private)
 		return 0;
@@ -66,12 +72,84 @@ static int sof_widget_setup(struct snd_sof_dev *sdev, struct snd_sof_widget *swi
 	return ret;
 }
 
+static int sof_route_set_up(struct snd_sof_dev *sdev, struct snd_sof_widget *wsource,
+			    struct snd_sof_widget *wsink)
+{
+	struct sof_ipc_pipe_comp_connect connect;
+	struct sof_ipc_reply reply;
+	int ret;
+
+	connect.hdr.size = sizeof(connect);
+	connect.hdr.cmd = SOF_IPC_GLB_TPLG_MSG | SOF_IPC_TPLG_COMP_CONNECT;
+	connect.source_id = wsource->comp_id;
+	connect.sink_id = wsink->comp_id;
+
+	/* send ipc */
+	ret = sof_ipc_tx_message(sdev->ipc, connect.hdr.cmd, &connect, sizeof(connect),
+				 &reply, sizeof(reply));
+	if (ret < 0)
+		dev_err(sdev->dev, "error: failed to load route sink %s <- %s source\n",
+			wsink->widget->name, wsource->widget->name);
+
+	return ret;
+}
+
+int sof_pcm_pipeline_set_up(struct snd_sof_dev *sdev, struct snd_sof_pcm *spcm, int dir)
+{
+	struct snd_sof_route_list *route_list = spcm->stream[dir].route_list;
+	struct snd_sof_widget *pipeline_widget = route_list->pipeline_widget;
+	int ret, i;
+
+	if (!route_list)
+		return -ENOENT;
+
+	/* set up pipeline widget */
+	ret = sof_widget_setup(sdev, pipeline_widget);
+	if (ret < 0)
+		return ret;
+
+	/* set up widgets and routes as we walk the list */
+	for (i = 0; i < route_list->num_widgets; i++) {
+		struct snd_sof_widget *swidget = route_list->widgets[i];
+
+		ret = sof_widget_setup(sdev, swidget);
+		if (ret < 0)
+			return ret;
+
+		/* set up the route with the previous widget */
+		if (i > 0) {
+			struct snd_sof_widget *wsink, *wsource;
+
+			if (dir == SNDRV_PCM_STREAM_PLAYBACK) {
+				wsink = swidget;
+				wsource = route_list->widgets[i - 1];
+			} else {
+				wsource = swidget;
+				wsink = route_list->widgets[i - 1];
+			}
+
+			ret = sof_route_set_up(sdev, wsource, wsink);
+			if (ret < 0)
+				return ret;
+		}
+	}
+
+	/* complete pipeline */
+	pipeline_widget->complete = snd_sof_complete_pipeline(sdev->dev, pipeline_widget);
+}
+
 static int sof_widget_free(struct snd_sof_dev *sdev, struct snd_sof_widget *swidget)
 {
 	struct sof_ipc_free ipc_free;
 	struct sof_ipc_reply reply;
 	int ret;
 
+	/* free the widget only when the last pipeline it is part of has been stopped */
+	if (swidget->ref_count > 1)
+		return 0;
+
+	swidget->ref_count--;
+
 	/* skip if there is no private data */
 	if (!swidget->private)
 		return 0;
@@ -103,6 +181,30 @@ static int sof_widget_free(struct snd_sof_dev *sdev, struct snd_sof_widget *swid
 	return ret;
 }
 
+int sof_pcm_pipeline_destroy(struct snd_sof_dev *sdev, struct snd_sof_pcm *spcm, int dir)
+{
+	struct snd_sof_route_list *route_list = spcm->stream[dir].route_list;
+	struct snd_sof_widget *pipeline_widget = route_list->pipeline_widget;
+	int ret, i;
+
+	if (!route_list)
+		return -ENOENT;
+
+	/* remove pipeline widget */
+	ret = sof_widget_free(sdev, pipeline_widget);
+	if (ret < 0)
+		return ret;
+
+	/* remove all widgets in the route */
+	for (i = 0; i < route_list->num_widgets; i++) {
+		struct snd_sof_widget *swidget = route_list->widgets[i];
+
+		ret = sof_widget_free(sdev, swidget);
+		if (ret < 0)
+			return ret;
+	}
+}
+
 /*
  * Free all widgets and pipelines. This should be called after topology parsing is complete
  * to facilitate dynamic pipeline loading/unloading during PCM open/close.

sound/soc/sof/sof-audio.h

@@ -93,6 +93,11 @@ struct snd_sof_widget {
 	int complete;
 	int core;
 	int id;
+	/*
+	 * Widgets could be part of multiple pipeilnes. ref_count would be incremented when
+	 * each pipeline is started
+	 */
+	int ref_count;
 
 	struct snd_soc_dapm_widget *widget;
 	struct list_head list;	/* list in sdev widget list */
@@ -231,5 +236,7 @@ void sof_machine_unregister(struct snd_sof_dev *sdev, void *pdata);
 
 /* PCM */
 int sof_pcm_route_set_up_all(struct snd_sof_dev *sdev);
+int sof_pcm_pipeline_set_up(struct snd_sof_dev *sdev, struct snd_sof_pcm *spcm, int dir);
+int sof_pcm_pipeline_destroy(struct snd_sof_dev *sdev, struct snd_sof_pcm *spcm, int dir);
 
 #endif