[PATCH 4/4] ASoC: tas2770: Fix handling of mute/unmute

[Martin Povišer]

Because the PWR_CTRL field is modeled as the power state of the DAC
widget, and at the same time it is used to implement mute/unmute, we
need some additional book-keeping to have the right end result no matter
the sequence of calls. Without this fix, one can mute an ongoing stream
by toggling a speaker pin control.

Fixes: 1a476abc723e ("tas2770: add tas2770 smart PA kernel driver")
Signed-off-by: Martin Povišer <povik+lin at cutebit.org>
---
 sound/soc/codecs/tas2770.c | 57 ++++++++++++++++++++------------------
 sound/soc/codecs/tas2770.h |  2 ++
 2 files changed, 32 insertions(+), 27 deletions(-)

diff --git a/sound/soc/codecs/tas2770.c b/sound/soc/codecs/tas2770.c
index 10a79f8139be..9ea2aca65e89 100644
--- a/sound/soc/codecs/tas2770.c
+++ b/sound/soc/codecs/tas2770.c
@@ -46,6 +46,26 @@ static void tas2770_reset(struct tas2770_priv *tas2770)
 	usleep_range(1000, 2000);
 }
 
+static int tas2770_update_pwr_ctrl(struct tas2770_priv *tas2770)
+{
+	struct snd_soc_component *component = tas2770->component;
+	unsigned int val;
+	int ret;
+
+	if (tas2770->dac_powered)
+		val = tas2770->unmuted ?
+			TAS2770_PWR_CTRL_ACTIVE : TAS2770_PWR_CTRL_MUTE;
+	else
+		val = TAS2770_PWR_CTRL_SHUTDOWN;
+
+	ret = snd_soc_component_update_bits(component, TAS2770_PWR_CTRL,
+					    TAS2770_PWR_CTRL_MASK, val);
+	if (ret < 0)
+		return ret;
+
+	return 0;
+}
+
 #ifdef CONFIG_PM
 static int tas2770_codec_suspend(struct snd_soc_component *component)
 {
@@ -82,9 +102,7 @@ static int tas2770_codec_resume(struct snd_soc_component *component)
 		gpiod_set_value_cansleep(tas2770->sdz_gpio, 1);
 		usleep_range(1000, 2000);
 	} else {
-		ret = snd_soc_component_update_bits(component, TAS2770_PWR_CTRL,
-						    TAS2770_PWR_CTRL_MASK,
-						    TAS2770_PWR_CTRL_ACTIVE);
+		ret = tas2770_update_pwr_ctrl(tas2770);
 		if (ret < 0)
 			return ret;
 	}
@@ -120,24 +138,19 @@ static int tas2770_dac_event(struct snd_soc_dapm_widget *w,
 
 	switch (event) {
 	case SND_SOC_DAPM_POST_PMU:
-		ret = snd_soc_component_update_bits(component, TAS2770_PWR_CTRL,
-						    TAS2770_PWR_CTRL_MASK,
-						    TAS2770_PWR_CTRL_MUTE);
+		tas2770->dac_powered = 1;
+		ret = tas2770_update_pwr_ctrl(tas2770);
 		break;
 	case SND_SOC_DAPM_PRE_PMD:
-		ret = snd_soc_component_update_bits(component, TAS2770_PWR_CTRL,
-						    TAS2770_PWR_CTRL_MASK,
-						    TAS2770_PWR_CTRL_SHUTDOWN);
+		tas2770->dac_powered = 0;
+		ret = tas2770_update_pwr_ctrl(tas2770);
 		break;
 	default:
 		dev_err(tas2770->dev, "Not supported evevt\n");
 		return -EINVAL;
 	}
 
-	if (ret < 0)
-		return ret;
-
-	return 0;
+	return ret;
 }
 
 static const struct snd_kcontrol_new isense_switch =
@@ -171,21 +184,11 @@ static const struct snd_soc_dapm_route tas2770_audio_map[] = {
 static int tas2770_mute(struct snd_soc_dai *dai, int mute, int direction)
 {
 	struct snd_soc_component *component = dai->component;
-	int ret;
-
-	if (mute)
-		ret = snd_soc_component_update_bits(component, TAS2770_PWR_CTRL,
-						    TAS2770_PWR_CTRL_MASK,
-						    TAS2770_PWR_CTRL_MUTE);
-	else
-		ret = snd_soc_component_update_bits(component, TAS2770_PWR_CTRL,
-						    TAS2770_PWR_CTRL_MASK,
-						    TAS2770_PWR_CTRL_ACTIVE);
-
-	if (ret < 0)
-		return ret;
+	struct tas2770_priv *tas2770 =
+			snd_soc_component_get_drvdata(component);
 
-	return 0;
+	tas2770->unmuted = !mute;
+	return tas2770_update_pwr_ctrl(tas2770);
 }
 
 static int tas2770_set_bitwidth(struct tas2770_priv *tas2770, int bitwidth)
diff --git a/sound/soc/codecs/tas2770.h b/sound/soc/codecs/tas2770.h
index d51e88d8c338..f75f40781ab1 100644
--- a/sound/soc/codecs/tas2770.h
+++ b/sound/soc/codecs/tas2770.h
@@ -138,6 +138,8 @@ struct tas2770_priv {
 	struct device *dev;
 	int v_sense_slot;
 	int i_sense_slot;
+	bool dac_powered;
+	bool unmuted;
 };
 
 #endif /* __TAS2770__ */
-- 
2.33.0