ASoC: Add snd_soc_kcontrol_platform() helper function

For platform controls snd_kcontrol_chip() currently returns a pointer to the
platform that registered the control. With the upcoming consolidation of
platform and CODEC controls this will change. Prepare for this by introducing
the snd_soc_kcontrol_platform() helper function that will hide the
implementation details of how the platform for a control can be obtained. This
will allow us to change this easily in the future.

The patch also updates all platforms to use this new helper function.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Mark Brown <broonie@linaro.org>

include/sound/soc.h

@@ -1242,6 +1242,20 @@ static inline struct snd_soc_codec *snd_soc_kcontrol_codec(
 	return snd_kcontrol_chip(kcontrol);
 }
 
+/**
+ * snd_soc_kcontrol_platform() - Returns the platform that registerd the control
+ * @kcontrol: The control for which to get the platform
+ *
+ * Note: This function will only work correctly if the control has been
+ * registered with snd_soc_add_platform_controls() or via table based setup of
+ * a snd_soc_platform_driver. Otherwise the behavior is undefined.
+ */
+static inline struct snd_soc_codec *snd_soc_kcontrol_platform(
+	struct snd_kcontrol *kcontrol)
+{
+	return snd_kcontrol_chip(kcontrol);
+}
+
 int snd_soc_util_init(void);
 void snd_soc_util_exit(void);
 

sound/soc/intel/sst-haswell-pcm.c

@@ -136,7 +136,7 @@ static inline unsigned int hsw_ipc_to_mixer(u32 value)
 static int hsw_stream_volume_put(struct snd_kcontrol *kcontrol,
 				struct snd_ctl_elem_value *ucontrol)
 {
-	struct snd_soc_platform *platform = snd_kcontrol_chip(kcontrol);
+	struct snd_soc_platform *platform = snd_soc_kcontrol_platform(kcontrol);
 	struct soc_mixer_control *mc =
 		(struct soc_mixer_control *)kcontrol->private_value;
 	struct hsw_priv_data *pdata =
@@ -174,7 +174,7 @@ static int hsw_stream_volume_put(struct snd_kcontrol *kcontrol,
 static int hsw_stream_volume_get(struct snd_kcontrol *kcontrol,
 				struct snd_ctl_elem_value *ucontrol)
 {
-	struct snd_soc_platform *platform = snd_kcontrol_chip(kcontrol);
+	struct snd_soc_platform *platform = snd_soc_kcontrol_platform(kcontrol);
 	struct soc_mixer_control *mc =
 		(struct soc_mixer_control *)kcontrol->private_value;
 	struct hsw_priv_data *pdata =
@@ -206,7 +206,7 @@ static int hsw_stream_volume_get(struct snd_kcontrol *kcontrol,
 static int hsw_volume_put(struct snd_kcontrol *kcontrol,
 				struct snd_ctl_elem_value *ucontrol)
 {
-	struct snd_soc_platform *platform = snd_kcontrol_chip(kcontrol);
+	struct snd_soc_platform *platform = snd_soc_kcontrol_platform(kcontrol);
 	struct hsw_priv_data *pdata = snd_soc_platform_get_drvdata(platform);
 	struct sst_hsw *hsw = pdata->hsw;
 	u32 volume;
@@ -231,7 +231,7 @@ static int hsw_volume_put(struct snd_kcontrol *kcontrol,
 static int hsw_volume_get(struct snd_kcontrol *kcontrol,
 				struct snd_ctl_elem_value *ucontrol)
 {
-	struct snd_soc_platform *platform = snd_kcontrol_chip(kcontrol);
+	struct snd_soc_platform *platform = snd_soc_kcontrol_platform(kcontrol);
 	struct hsw_priv_data *pdata = snd_soc_platform_get_drvdata(platform);
 	struct sst_hsw *hsw = pdata->hsw;
 	unsigned int volume = 0;