ASoC: core - Add platform widget IO

Allow platform driver widgets to perform any IO required for DAPM.
Signed-off-by: Liam Girdwood <lrg@ti.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

include/sound/soc-dapm.h

@@ -447,6 +447,7 @@ struct snd_soc_dapm_widget {
 	char *name;		/* widget name */
 	char *sname;	/* stream name */
 	struct snd_soc_codec *codec;
+	struct snd_soc_platform *platform;
 	struct list_head list;
 	struct snd_soc_dapm_context *dapm;
 
@@ -510,6 +511,7 @@ struct snd_soc_dapm_context {
 
 	struct device *dev; /* from parent - for debug */
 	struct snd_soc_codec *codec; /* parent codec */
+	struct snd_soc_platform *platform; /* parent platform */
 	struct snd_soc_card *card; /* parent card */
 
 	/* used during DAPM updates */

include/sound/soc.h

@@ -682,6 +682,8 @@ struct snd_soc_platform {
 	struct snd_soc_card *card;
 	struct list_head list;
 	struct list_head card_list;
+
+	struct snd_soc_dapm_context dapm;
 };
 
 struct snd_soc_dai_link {

sound/soc/soc-core.c

@@ -993,6 +993,7 @@ static int soc_probe_platform(struct snd_soc_card *card,
 	const struct snd_soc_platform_driver *driver = platform->driver;
 
 	platform->card = card;
+	platform->dapm.card = card;
 
 	if (!try_module_get(platform->dev->driver->owner))
 		return -ENODEV;
@@ -1010,6 +1011,7 @@ static int soc_probe_platform(struct snd_soc_card *card,
 	/* mark platform as probed and add to card platform list */
 	platform->probed = 1;
 	list_add(&platform->card_list, &card->platform_dev_list);
+	list_add(&platform->dapm.list, &card->dapm_list);
 
 	return 0;
 
@@ -3122,6 +3124,8 @@ int snd_soc_register_platform(struct device *dev,
 
 	platform->dev = dev;
 	platform->driver = platform_drv;
+	platform->dapm.dev = dev;
+	platform->dapm.platform = platform;
 
 	mutex_lock(&client_mutex);
 	list_add(&platform->list, &platform_list);

sound/soc/soc-dapm.c

@@ -128,14 +128,22 @@ static int soc_widget_read(struct snd_soc_dapm_widget *w, int reg)
 {
 	if (w->codec)
 		return snd_soc_read(w->codec, reg);
-	return 0;
+	else if (w->platform)
+		return snd_soc_platform_read(w->platform, reg);
+
+	dev_err(w->dapm->dev, "no valid widget read method\n");
+	return -1;
 }
 
 static int soc_widget_write(struct snd_soc_dapm_widget *w, int reg, int val)
 {
 	if (w->codec)
 		return snd_soc_write(w->codec, reg, val);
-	return 0;
+	else if (w->platform)
+		return snd_soc_platform_write(w->platform, reg, val);
+
+	dev_err(w->dapm->dev, "no valid widget write method\n");
+	return -1;
 }
 
 static int soc_widget_update_bits(struct snd_soc_dapm_widget *w,
@@ -2495,6 +2503,7 @@ int snd_soc_dapm_new_control(struct snd_soc_dapm_context *dapm,
 	dapm->n_widgets++;
 	w->dapm = dapm;
 	w->codec = dapm->codec;
+	w->platform = dapm->platform;
 	INIT_LIST_HEAD(&w->sources);
 	INIT_LIST_HEAD(&w->sinks);
 	INIT_LIST_HEAD(&w->list);