ASoC: core: Implement devm_snd_soc_register_component()

Since with the wider use of devres many drivers are now only calling
snd_soc_unregister_component() in their remove functions providing a
managed version will save a reasonable amount of code.
Signed-off-by: Mark Brown <broonie@linaro.org>

include/sound/soc.h

@@ -386,6 +386,9 @@ void snd_soc_unregister_codec(struct device *dev);
 int snd_soc_register_component(struct device *dev,
 			 const struct snd_soc_component_driver *cmpnt_drv,
 			 struct snd_soc_dai_driver *dai_drv, int num_dai);
+int devm_snd_soc_register_component(struct device *dev,
+			 const struct snd_soc_component_driver *cmpnt_drv,
+			 struct snd_soc_dai_driver *dai_drv, int num_dai);
 void snd_soc_unregister_component(struct device *dev);
 int snd_soc_codec_volatile_register(struct snd_soc_codec *codec,
 				    unsigned int reg);

sound/soc/Makefile

 snd-soc-core-objs := soc-core.o soc-dapm.o soc-jack.o soc-cache.o soc-utils.o
-snd-soc-core-objs += soc-pcm.o soc-compress.o soc-io.o
+snd-soc-core-objs += soc-pcm.o soc-compress.o soc-io.o soc-devres.o
 
 ifneq ($(CONFIG_SND_SOC_GENERIC_DMAENGINE_PCM),)
 snd-soc-core-objs += soc-generic-dmaengine-pcm.o

sound/soc/soc-devres.c

+/*
+ * soc-devres.c  --  ALSA SoC Audio Layer devres functions
+ *
+ * Copyright (C) 2013 Linaro Ltd
+ *
+ *  This program is free software; you can redistribute  it and/or modify it
+ *  under  the terms of  the GNU General  Public License as published by the
+ *  Free Software Foundation;  either version 2 of the  License, or (at your
+ *  option) any later version.
+ */
+
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <sound/soc.h>
+
+static void devm_component_release(struct device *dev, void *res)
+{
+	snd_soc_unregister_component(*(struct device **)res);
+}
+
+/**
+ * devm_snd_soc_register_component - resource managed component registration
+ * @dev: Device used to manage component
+ * @cmpnt_drv: Component driver
+ * @dai_drv: DAI driver
+ * @num_dai: Number of DAIs to register
+ *
+ * Register a component with automatic unregistration when the device is
+ * unregistered.
+ */
+int devm_snd_soc_register_component(struct device *dev,
+			 const struct snd_soc_component_driver *cmpnt_drv,
+			 struct snd_soc_dai_driver *dai_drv, int num_dai)
+{
+	struct device **ptr;
+	int ret;
+
+	ptr = devres_alloc(devm_component_release, sizeof(*ptr), GFP_KERNEL);
+	if (!ptr)
+		return -ENOMEM;
+
+	ret = snd_soc_register_component(dev, cmpnt_drv, dai_drv, num_dai);
+	if (ret == 0) {
+		*ptr = dev;
+		devres_add(dev, ptr);
+	} else {
+		devres_free(ptr);
+	}
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(devm_snd_soc_register_component);