ASoC: SOF: topology: add helper for setting up IPC component

Add helper to allocate buffer for IPC component, configure the basic
settings, and set up the extended data for the subsequent IPC sending.

Signed-off-by: Keyon Jie <yang.jie@linux.intel.com>
Reviewed-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
Signed-off-by: Kai Vehmanen <kai.vehmanen@linux.intel.com>
Link: https://lore.kernel.org/r/20200904132744.1699575-7-kai.vehmanen@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/soc/sof/topology.c

@@ -1453,6 +1453,51 @@ static int sof_connect_dai_widget(struct snd_soc_component *scomp,
 	return 0;
 }
 
+/**
+ * sof_comp_alloc - allocate and initialize buffer for a new component
+ * @swidget: pointer to struct snd_sof_widget containing extended data
+ * @ipc_size: IPC payload size that will be updated depending on valid
+ *  extended data.
+ * @index: ID of the pipeline the component belongs to
+ * @core: index of the DSP core that the component should run on
+ *
+ * Return: The pointer to the new allocated component, NULL if failed.
+ */
+static struct sof_ipc_comp *sof_comp_alloc(struct snd_sof_widget *swidget,
+					   size_t *ipc_size, int index,
+					   int core)
+{
+	u8 nil_uuid[SOF_UUID_SIZE] = {0};
+	struct sof_ipc_comp *comp;
+	size_t total_size = *ipc_size;
+
+	/* only non-zero UUID is valid */
+	if (memcmp(&swidget->comp_ext, nil_uuid, SOF_UUID_SIZE))
+		total_size += sizeof(swidget->comp_ext);
+
+	comp = kzalloc(total_size, GFP_KERNEL);
+	if (!comp)
+		return NULL;
+
+	/* configure comp new IPC message */
+	comp->hdr.size = total_size;
+	comp->hdr.cmd = SOF_IPC_GLB_TPLG_MSG | SOF_IPC_TPLG_COMP_NEW;
+	comp->id = swidget->comp_id;
+	comp->pipeline_id = index;
+	comp->core = core;
+
+	/* handle the extended data if needed */
+	if (total_size > *ipc_size) {
+		/* append extended data to the end of the component */
+		memcpy((u8 *)comp + *ipc_size, &swidget->comp_ext, sizeof(swidget->comp_ext));
+		comp->ext_data_length = sizeof(swidget->comp_ext);
+	}
+
+	/* update ipc_size and return */
+	*ipc_size = total_size;
+	return comp;
+}
+
 static int sof_widget_load_dai(struct snd_soc_component *scomp, int index,
 			       struct snd_sof_widget *swidget, int core,
 			       struct snd_soc_tplg_dapm_widget *tw,