ASoC: twl6040: Workaround for headset DC offset caused pop noise

Both Headset DAC need to be turned on/off at the same time before
any of the output drivers are enabled (HS Left/Right, Earpiece).
Move the HS DAC enable code to sequenced DAPM_SUPPLY, and attach
it to the DACs.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

1 files changed, 28 insertions, 8 deletions

diff --git a/sound/soc/codecs/twl6040.c b/sound/soc/codecs/twl6040.c
index 864849838f4d..636923051ad3 100644
--- a/sound/soc/codecs/twl6040.c
+++ b/sound/soc/codecs/twl6040.c
@@ -654,6 +654,26 @@ static int headset_power_mode(struct snd_soc_codec *codec, int high_perf)
 static int twl6040_hs_dac_event(struct snd_soc_dapm_widget *w,
                         struct snd_kcontrol *kcontrol, int event)
 {
+        struct snd_soc_codec *codec = w->codec;
+        u8 hslctl, hsrctl;
+
+        /*
+         * Workaround for Headset DC offset caused pop noise:
+         * Both HS DAC need to be turned on (before the HS driver) and off at
+         * the same time.
+         */
+        hslctl = twl6040_read_reg_cache(codec, TWL6040_REG_HSLCTL);
+        hsrctl = twl6040_read_reg_cache(codec, TWL6040_REG_HSRCTL);
+        if (SND_SOC_DAPM_EVENT_ON(event)) {
+                hslctl |= TWL6040_HSDACENA;
+                hsrctl |= TWL6040_HSDACENA;
+        } else {
+                hslctl &= ~TWL6040_HSDACENA;
+                hsrctl &= ~TWL6040_HSDACENA;
+        }
+        twl6040_write(codec, TWL6040_REG_HSLCTL, hslctl);
+        twl6040_write(codec, TWL6040_REG_HSRCTL, hsrctl);
+
         msleep(1);
         return 0;
 }
@@ -1103,14 +1123,8 @@ static const struct snd_soc_dapm_widget twl6040_dapm_widgets[] = {
                         TWL6040_REG_DMICBCTL, 4, 0),
 
         /* DACs */
-        SND_SOC_DAPM_DAC_E("HSDAC Left", "Headset Playback",
-                        TWL6040_REG_HSLCTL, 0, 0,
-                        twl6040_hs_dac_event,
-                        SND_SOC_DAPM_POST_PMU | SND_SOC_DAPM_POST_PMD),
-        SND_SOC_DAPM_DAC_E("HSDAC Right", "Headset Playback",
-                        TWL6040_REG_HSRCTL, 0, 0,
-                        twl6040_hs_dac_event,
-                        SND_SOC_DAPM_POST_PMU | SND_SOC_DAPM_POST_PMD),
+        SND_SOC_DAPM_DAC("HSDAC Left", "Headset Playback", SND_SOC_NOPM, 0, 0),
+        SND_SOC_DAPM_DAC("HSDAC Right", "Headset Playback", SND_SOC_NOPM, 0, 0),
         SND_SOC_DAPM_DAC_E("HFDAC Left", "Handsfree Playback",
                         TWL6040_REG_HFLCTL, 0, 0,
                         twl6040_power_mode_event,
@@ -1175,6 +1189,9 @@ static const struct snd_soc_dapm_widget twl6040_dapm_widgets[] = {
                             NULL, 0),
         SND_SOC_DAPM_SUPPLY("Vibra Right Control", TWL6040_REG_VIBCTLR, 2, 0,
                             NULL, 0),
+        SND_SOC_DAPM_SUPPLY_S("HSDAC Power", 1, SND_SOC_NOPM, 0, 0,
+                              twl6040_hs_dac_event,
+                              SND_SOC_DAPM_POST_PMU | SND_SOC_DAPM_POST_PMD),
 
         /* Analog playback PGAs */
         SND_SOC_DAPM_PGA("HF Left PGA",
@@ -1204,6 +1221,9 @@ static const struct snd_soc_dapm_route intercon[] = {
         {"AFMAmpL", NULL, "AFML"},
         {"AFMAmpR", NULL, "AFMR"},
 
+        {"HSDAC Left", NULL, "HSDAC Power"},
+        {"HSDAC Right", NULL, "HSDAC Power"},
+
         {"Headset Left Playback", "HS DAC", "HSDAC Left"},
         {"Headset Left Playback", "Line-In amp", "AFMAmpL"},