ASoC: Add resource managed snd_soc_register_platform()

Simplify error handling and remove repetitive (and rarely executed) code
for unregistration by providing a devm_snd_soc_register_platform()
platform.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

include/sound/soc.h

@@ -377,6 +377,8 @@ int snd_soc_resume(struct device *dev);
 int snd_soc_poweroff(struct device *dev);
 int snd_soc_register_platform(struct device *dev,
 		const struct snd_soc_platform_driver *platform_drv);
+int devm_snd_soc_register_platform(struct device *dev,
+		const struct snd_soc_platform_driver *platform_drv);
 void snd_soc_unregister_platform(struct device *dev);
 int snd_soc_add_platform(struct device *dev, struct snd_soc_platform *platform,
 		const struct snd_soc_platform_driver *platform_drv);

sound/soc/soc-devres.c

@@ -52,6 +52,40 @@ int devm_snd_soc_register_component(struct device *dev,
 }
 EXPORT_SYMBOL_GPL(devm_snd_soc_register_component);
 
+static void devm_platform_release(struct device *dev, void *res)
+{
+	snd_soc_unregister_platform(*(struct device **)res);
+}
+
+/**
+ * devm_snd_soc_register_platform - resource managed platform registration
+ * @dev: Device used to manage platform
+ * @platform: platform to register
+ *
+ * Register a platform driver with automatic unregistration when the device is
+ * unregistered.
+ */
+int devm_snd_soc_register_platform(struct device *dev,
+			const struct snd_soc_platform_driver *platform_drv)
+{
+	struct device **ptr;
+	int ret;
+
+	ptr = devres_alloc(devm_platform_release, sizeof(*ptr), GFP_KERNEL);
+	if (!ptr)
+		return -ENOMEM;
+
+	ret = snd_soc_register_platform(dev, platform_drv);
+	if (ret == 0) {
+		*ptr = dev;
+		devres_add(dev, ptr);
+	} else {
+		devres_free(ptr);
+	}
+
+	return ret;
+}
+
 static void devm_card_release(struct device *dev, void *res)
 {
 	snd_soc_unregister_card(*(struct snd_soc_card **)res);