ASoC: tas5086: fix Mid-Z implementation

It turns out that the TAS5086 doesn't like channel start parts to be
empty, and if all channels are configured to Mid-Z, part 1 has to be
used.

Signed-off-by: Daniel Mack <zonque@gmail.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

1 files changed, 9 insertions, 6 deletions

diff --git a/sound/soc/codecs/tas5086.c b/sound/soc/codecs/tas5086.c
index 8bbdf25530ca..6d31d88f7204 100644
--- a/sound/soc/codecs/tas5086.c
+++ b/sound/soc/codecs/tas5086.c
@@ -721,7 +721,7 @@ static int tas5086_probe(struct snd_soc_codec *codec)
 {
         struct tas5086_private *priv = snd_soc_codec_get_drvdata(codec);
         int charge_period = 1300000; /* hardware default is 1300 ms */
-        u8 pwm_start = TAS5086_PWM_START_CHANNEL_MASK;
+        u8 pwm_start_mid_z = 0;
         int i, ret;
 
         if (of_match_device(of_match_ptr(tas5086_dt_ids), codec->dev)) {
@@ -735,16 +735,19 @@ static int tas5086_probe(struct snd_soc_codec *codec)
                                  "ti,mid-z-channel-%d", i + 1);
 
                         if (of_get_property(of_node, name, NULL) != NULL)
-                                pwm_start &= ~(1 << i);
+                                pwm_start_mid_z |= 1 << i;
                 }
         }
 
         /*
-         * Configure 'part 2' of the PWM starts to always use MID-Z, and tell
-         * all configured mid-z channels to start start under 'part 2'.
+         * If any of the channels is configured to start in Mid-Z mode,
+         * configure 'part 1' of the PWM starts to use Mid-Z, and tell
+         * all configured mid-z channels to start start under 'part 1'.
          */
-        regmap_write(priv->regmap, TAS5086_PWM_START,
-                     TAS5086_PWM_START_MIDZ_FOR_START_2 | pwm_start);
+        if (pwm_start_mid_z)
+                regmap_write(priv->regmap, TAS5086_PWM_START,
+                             TAS5086_PWM_START_MIDZ_FOR_START_1 |
+                                pwm_start_mid_z);
 
         /* lookup and set split-capacitor charge period */
         if (charge_period == 0) {