ASoC: dapm - Add DAPM stream completion event.

In preparation for Dynamic PCM (AKA DSP) support.

This adds a callback function to be called at the completion of a DAPM stream
event.

This can be used by DSP components to perform calculations based on DAPM graphs
after completion of stream events.

Signed-off-by: Liam Girdwood <lrg@ti.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

include/sound/soc-dapm.h

@@ -524,6 +524,8 @@ struct snd_soc_dapm_context {
 	enum snd_soc_bias_level target_bias_level;
 	struct list_head list;
 
+	int (*stream_event)(struct snd_soc_dapm_context *dapm, int event);
+
 #ifdef CONFIG_DEBUG_FS
 	struct dentry *debugfs_dapm;
 #endif

include/sound/soc.h

@@ -634,6 +634,9 @@ struct snd_soc_codec_driver {
 	void (*seq_notifier)(struct snd_soc_dapm_context *,
 			     enum snd_soc_dapm_type, int);
 
+	/* codec stream completion event */
+	int (*stream_event)(struct snd_soc_dapm_context *dapm, int event);
+
 	/* probe ordering - for components with runtime dependencies */
 	int probe_order;
 	int remove_order;
@@ -669,6 +672,9 @@ struct snd_soc_platform_driver {
 	/* platform stream ops */
 	struct snd_pcm_ops *ops;
 
+	/* platform stream completion event */
+	int (*stream_event)(struct snd_soc_dapm_context *dapm, int event);
+
 	/* probe ordering - for components with runtime dependencies */
 	int probe_order;
 	int remove_order;

sound/soc/soc-core.c

@@ -3141,6 +3141,7 @@ int snd_soc_register_platform(struct device *dev,
 	platform->driver = platform_drv;
 	platform->dapm.dev = dev;
 	platform->dapm.platform = platform;
+	platform->dapm.stream_event = platform_drv->stream_event;
 
 	mutex_lock(&client_mutex);
 	list_add(&platform->list, &platform_list);
@@ -3253,6 +3254,7 @@ int snd_soc_register_codec(struct device *dev,
 	codec->dapm.dev = dev;
 	codec->dapm.codec = codec;
 	codec->dapm.seq_notifier = codec_drv->seq_notifier;
+	codec->dapm.stream_event = codec_drv->stream_event;
 	codec->dev = dev;
 	codec->driver = codec_drv;
 	codec->num_dai = num_dai;

sound/soc/soc-dapm.c

@@ -2604,6 +2604,10 @@ static void soc_dapm_stream_event(struct snd_soc_dapm_context *dapm,
 	}
 
 	dapm_power_widgets(dapm, event);
+
+	/* do we need to notify any clients that DAPM stream is complete */
+	if (dapm->stream_event)
+		dapm->stream_event(dapm, event);
 }
 
 /**