[PATCH v2 03/10] ASoC: tegra: Fix kcontrol put callback in DMIC

[Sameer Pujar]

The kcontrol put callback is expected to return 1 when there is change
in HW or when the update is acknowledged by driver. This would ensure
that change notifications are sent to subscribed applications. Update
the DMIC driver accordingly.

Fixes: 8c8ff982e9e2 ("ASoC: tegra: Add Tegra210 based DMIC driver")
Suggested-by: Jaroslav Kysela <perex at perex.cz>
Suggested-by: Mark Brown <broonie at kernel.org>
Signed-off-by: Sameer Pujar <spujar at nvidia.com>
---
 sound/soc/tegra/tegra210_dmic.c | 35 +++++++++++++++++++++++++++--------
 1 file changed, 27 insertions(+), 8 deletions(-)

diff --git a/sound/soc/tegra/tegra210_dmic.c b/sound/soc/tegra/tegra210_dmic.c
index b096478..39a63ed 100644
--- a/sound/soc/tegra/tegra210_dmic.c
+++ b/sound/soc/tegra/tegra210_dmic.c
@@ -185,20 +185,39 @@ static int tegra210_dmic_put_control(struct snd_kcontrol *kcontrol,
 	struct tegra210_dmic *dmic = snd_soc_component_get_drvdata(comp);
 	int value = ucontrol->value.integer.value[0];
 
-	if (strstr(kcontrol->id.name, "Boost Gain Volume"))
+	if (strstr(kcontrol->id.name, "Boost Gain Volume")) {
+		if (dmic->boost_gain == value)
+			return 0;
+
 		dmic->boost_gain = value;
-	else if (strstr(kcontrol->id.name, "Channel Select"))
-		dmic->ch_select = ucontrol->value.integer.value[0];
-	else if (strstr(kcontrol->id.name, "Mono To Stereo"))
+	} else if (strstr(kcontrol->id.name, "Channel Select")) {
+		if (dmic->ch_select == value)
+			return 0;
+
+		dmic->ch_select = value;
+	} else if (strstr(kcontrol->id.name, "Mono To Stereo")) {
+		if (dmic->mono_to_stereo == value)
+			return 0;
+
 		dmic->mono_to_stereo = value;
-	else if (strstr(kcontrol->id.name, "Stereo To Mono"))
+	} else if (strstr(kcontrol->id.name, "Stereo To Mono")) {
+		if (dmic->stereo_to_mono == value)
+			return 0;
+
 		dmic->stereo_to_mono = value;
-	else if (strstr(kcontrol->id.name, "OSR Value"))
+	} else if (strstr(kcontrol->id.name, "OSR Value")) {
+		if (dmic->osr_val == value)
+			return 0;
+
 		dmic->osr_val = value;
-	else if (strstr(kcontrol->id.name, "LR Polarity Select"))
+	} else if (strstr(kcontrol->id.name, "LR Polarity Select")) {
+		if (dmic->lrsel == value)
+			return 0;
+
 		dmic->lrsel = value;
+	}
 
-	return 0;
+	return 1;
 }
 
 static const struct snd_soc_dai_ops tegra210_dmic_dai_ops = {
-- 
2.7.4