ASoC: soc-core: add debugfs_prefix member to snd_soc_component_driver

Allow the component debugfs_prefix to be set from
snd_soc_component_driver. First use case is avoiding a duplicate
debugfs entry error in case a device has multiple components
which have the same name therefore.

Note that we don't set component->debugfs_prefix if it's set already.
That's needed because partially component->debugfs_prefix is set
before calling snd_soc_component_initialize().
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Link: https://lore.kernel.org/r/d18bff6a-1df1-5f95-0cf8-10dbaa62d7be@gmail.comSigned-off-by: Mark Brown <broonie@kernel.org>

include/sound/soc-component.h

@@ -179,6 +179,10 @@ struct snd_soc_component_driver {
 				  struct snd_pcm_hw_params *params);
 	bool use_dai_pcm_id;	/* use DAI link PCM ID as PCM device number */
 	int be_pcm_base;	/* base device ID for all BE PCMs */
+
+#ifdef CONFIG_DEBUG_FS
+	const char *debugfs_prefix;
+#endif
 };
 
 struct snd_soc_component {

sound/soc/soc-core.c

@@ -2587,6 +2587,11 @@ int snd_soc_component_initialize(struct snd_soc_component *component,
 	component->dev		= dev;
 	component->driver	= driver;
 
+#ifdef CONFIG_DEBUG_FS
+	if (!component->debugfs_prefix)
+		component->debugfs_prefix = driver->debugfs_prefix;
+#endif
+
 	return 0;
 }
 EXPORT_SYMBOL_GPL(snd_soc_component_initialize);