sgtl5000: improve switch on vag power for line_in -> output

Commit '3e3ea9ba80e8 sgtl5000: switch on vag power for line_in -> output'
switched on VAG power when using a direct connection from line_in ->
headphone output, but it did not switch it off when switching back
to DAC -> HP.

Additionally with commit 'abff9e8b0ddf ASoC: sgtl5000: fix VAG power
up timing' the combination of the two commits introduced a pop on the
headphone when using DAC -> HP.

Detect the HP muxing state differently and thus address both issues.

Signed-off-by: Max Krummenacher <max.krummenacher@toradex.com>
Acked-by: Stefan Agner <stefan.agner@toradex.com>
(cherry picked from commit a2130af576ac29935b8062574f45ca6999852ba4)

1 files changed, 34 insertions, 29 deletions

diff --git a/sound/soc/codecs/sgtl5000.c b/sound/soc/codecs/sgtl5000.c
index a8952ed4185f..73a7aeaed6ed 100644
--- a/sound/soc/codecs/sgtl5000.c
+++ b/sound/soc/codecs/sgtl5000.c
@@ -323,6 +323,13 @@ static int vag_and_mute_control(struct snd_soc_component *component,
 		break;
 	case SND_SOC_DAPM_PRE_PMD:
 		/*
+		 * Don't clear VAG_POWERUP when there is a local loop
+		 * from LINE_IN to the HP.
+		 */
+		if (snd_soc_read(codec, SGTL5000_CHIP_ANA_CTRL) &
+		    SGTL5000_HP_SEL_MASK)
+			break;
+		/*
 		 * Don't clear VAG_POWERUP, when both DAC and ADC are
 		 * operational to prevent inadvertently starving the
 		 * other one of them.
@@ -342,38 +349,36 @@ static int vag_and_mute_control(struct snd_soc_component *component,
 }
 
 /*
- * Mute Headphone when power it up/down.
- * Control VAG power on HP power path.
+ * If we mux a direct path from LINE_IN to HP, VAG must be powered up.
+ * With the SND_SOC_DAPM_POST_REG event the new state of the headphone mux is
+ * available.
  */
-static int headphone_pga_event(struct snd_soc_dapm_widget *w,
+static int headphone_mux_event(struct snd_soc_dapm_widget *w,
 	struct snd_kcontrol *kcontrol, int event)
 {
-	struct snd_soc_component *component =
-		snd_soc_dapm_to_component(w->dapm);
-
-	return vag_and_mute_control(component, event, HP_POWER_EVENT);
-}
-
-/* As manual describes, ADC/DAC powering up/down requires
- * to mute outputs to avoid pops.
- * Control VAG power on ADC/DAC power path.
- */
-static int adc_updown_depop(struct snd_soc_dapm_widget *w,
-	struct snd_kcontrol *kcontrol, int event)
-{
-	struct snd_soc_component *component =
-		snd_soc_dapm_to_component(w->dapm);
-
-	return vag_and_mute_control(component, event, ADC_POWER_EVENT);
-}
+	struct snd_soc_codec *codec = snd_soc_dapm_to_codec(w->dapm);
 
-static int dac_updown_depop(struct snd_soc_dapm_widget *w,
-	struct snd_kcontrol *kcontrol, int event)
-{
-	struct snd_soc_component *component =
-		snd_soc_dapm_to_component(w->dapm);
+	/*
+	 * switch on VAG unconditionally on any change of the headphone muxer
+	 * early to lessen pop.
+	 */
+	switch (event) {
+	case SND_SOC_DAPM_PRE_REG:
+		snd_soc_update_bits(codec, SGTL5000_CHIP_ANA_POWER,
+				SGTL5000_VAG_POWERUP, SGTL5000_VAG_POWERUP);
+		break;
+	/*
+	 * The call to power_vag_event() switches VAG off again, if VAG need
+	 * not be switched on.
+	 */
+	case SND_SOC_DAPM_POST_REG:
+		power_vag_event(w, kcontrol, SND_SOC_DAPM_PRE_PMD);
+		break;
+	default:
+		break;
+	}
 
-	return vag_and_mute_control(component, event, DAC_POWER_EVENT);
+	return 0;
 }
 
 /* input sources for ADC */
@@ -419,8 +424,8 @@ static const struct snd_soc_dapm_widget sgtl5000_dapm_widgets[] = {
 
 	SND_SOC_DAPM_MUX("Capture Mux", SND_SOC_NOPM, 0, 0, &adc_mux),
 	SND_SOC_DAPM_MUX_E("Headphone Mux", SND_SOC_NOPM, 0, 0, &dac_mux,
-			   power_vag_event,
-			   SND_SOC_DAPM_POST_PMU | SND_SOC_DAPM_PRE_POST_PMD),
+			   headphone_mux_event,
+			   SND_SOC_DAPM_PRE_REG | SND_SOC_DAPM_POST_REG),
 
 	/* aif for i2s input */
 	SND_SOC_DAPM_AIF_IN("AIFIN", "Playback",