ASoC: add Component level .read/.write

In current ALSA SoC, Codec only has .read/.write callback.
Codec will be merged into Component in next generation ALSA SoC,
thus current Codec specific feature need to be merged into it.
This is glue patch for it.
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

include/sound/soc.h

@@ -802,6 +802,9 @@ struct snd_soc_component_driver {
 	int (*suspend)(struct snd_soc_component *);
 	int (*resume)(struct snd_soc_component *);
 
+	unsigned int (*read)(struct snd_soc_component *, unsigned int);
+	int (*write)(struct snd_soc_component *, unsigned int, unsigned int);
+
 	/* pcm creation and destruction */
 	int (*pcm_new)(struct snd_soc_pcm_runtime *);
 	void (*pcm_free)(struct snd_pcm *);

sound/soc/soc-io.c

@@ -34,6 +34,10 @@ int snd_soc_component_read(struct snd_soc_component *component,
 		ret = regmap_read(component->regmap, reg, val);
 	else if (component->read)
 		ret = component->read(component, reg, val);
+	else if (component->driver->read) {
+		*val = component->driver->read(component, reg);
+		ret = 0;
+	}
 	else
 		ret = -EIO;
 
@@ -70,6 +74,8 @@ int snd_soc_component_write(struct snd_soc_component *component,
 		return regmap_write(component->regmap, reg, val);
 	else if (component->write)
 		return component->write(component, reg, val);
+	else if (component->driver->write)
+		return component->driver->write(component, reg, val);
 	else
 		return -EIO;
 }