ASoC: Let snd_soc_platform subclass snd_soc_component

There is an increasing amount of code that is very similar between platforms,
CODECS and other components. Making platforms a component will allow us to
share this code. For now the patch just adds component and component_driver
fields to the platform and platform_driver structs and registers the platform as
a component. Followup patches will be used to consolidate code between the
different types of components.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Mark Brown <broonie@linaro.org>

include/sound/soc.h

@@ -778,6 +778,7 @@ struct snd_soc_platform_driver {
 	int (*remove)(struct snd_soc_platform *);
 	int (*suspend)(struct snd_soc_dai *dai);
 	int (*resume)(struct snd_soc_dai *dai);
+	struct snd_soc_component_driver component_driver;
 
 	/* pcm creation and destruction */
 	int (*pcm_new)(struct snd_soc_pcm_runtime *);
@@ -831,6 +832,8 @@ struct snd_soc_platform {
 	struct list_head list;
 	struct list_head card_list;
 
+	struct snd_soc_component component;
+
 	struct snd_soc_dapm_context dapm;
 
 #ifdef CONFIG_DEBUG_FS
@@ -1107,6 +1110,19 @@ static inline struct snd_soc_codec *snd_soc_component_to_codec(
 	return container_of(component, struct snd_soc_codec, component);
 }
 
+/**
+ * snd_soc_component_to_platform() - Casts a component to the platform it is embedded in
+ * @component: The component to cast to a platform
+ *
+ * This function must only be used on components that are known to be platforms.
+ * Otherwise the behavior is undefined.
+ */
+static inline struct snd_soc_platform *snd_soc_component_to_platform(
+	struct snd_soc_component *component)
+{
+	return container_of(component, struct snd_soc_platform, component);
+}
+
 /* codec IO */
 unsigned int snd_soc_read(struct snd_soc_codec *codec, unsigned int reg);
 unsigned int snd_soc_write(struct snd_soc_codec *codec,

sound/soc/soc-core.c

@@ -3921,6 +3921,8 @@ EXPORT_SYMBOL_GPL(snd_soc_unregister_component);
 int snd_soc_add_platform(struct device *dev, struct snd_soc_platform *platform,
 		const struct snd_soc_platform_driver *platform_drv)
 {
+	int ret;
+
 	/* create platform component name */
 	platform->name = fmt_single_name(dev, &platform->id);
 	if (platform->name == NULL)
@@ -3933,6 +3935,16 @@ int snd_soc_add_platform(struct device *dev, struct snd_soc_platform *platform,
 	platform->dapm.stream_event = platform_drv->stream_event;
 	mutex_init(&platform->mutex);
 
+	/* register component */
+	ret = __snd_soc_register_component(dev, &platform->component,
+					   &platform_drv->component_driver,
+					   NULL, NULL, 0, false);
+	if (ret < 0) {
+		dev_err(platform->component.dev,
+			"ASoC: Failed to register component: %d\n", ret);
+		return ret;
+	}
+
 	mutex_lock(&client_mutex);
 	list_add(&platform->list, &platform_list);
 	mutex_unlock(&client_mutex);
@@ -3974,6 +3986,8 @@ EXPORT_SYMBOL_GPL(snd_soc_register_platform);
  */
 void snd_soc_remove_platform(struct snd_soc_platform *platform)
 {
+	snd_soc_unregister_component(platform->dev);
+
 	mutex_lock(&client_mutex);
 	list_del(&platform->list);
 	mutex_unlock(&client_mutex);