RE: [PATCH] ASoC: rt1320-sdw: kcontrol for brown-out feature switch

["Shuming [范書銘]" <shumingf@realtek.com>]

+static int rt1320_brown_out_put(struct snd_kcontrol *kcontrol,

+                                struct snd_ctl_elem_value *ucontrol)
+{
+       struct snd_soc_component *component = snd_kcontrol_chip(kcontrol);
+       struct rt1320_sdw_priv *rt1320 = snd_soc_component_get_drvdata(component);
+       struct device *dev = &rt1320->sdw_slave->dev;
+       int ret, tmp;
+
+       ret = pm_runtime_resume(component->dev);
+       if (ret < 0 && ret != -EACCES)
+               return ret;
+
+       rt1320->brown_out = ucontrol->value.integer.value[0];
+       regcache_cache_bypass(rt1320->regmap, true);
+
+       if (rt1320->brown_out == 1)
+               regmap_write(rt1320->regmap, 0xdb03, 0x00);
+       else
+               regmap_write(rt1320->regmap, 0xdb03, 0xf0);
+
+       regcache_cache_bypass(rt1320->regmap, false);
+
+       return 0;
+}
+
+static int rt1320_brown_out_get(struct snd_kcontrol *kcontrol,
+                                    struct snd_ctl_elem_value *ucontrol)
+{
+       struct snd_soc_component *component = snd_kcontrol_chip(kcontrol);
+       struct rt1320_sdw_priv *rt1320 = snd_soc_component_get_drvdata(component);
+
+       ucontrol->value.integer.value[0] = rt1320->brown_out;
+
+       return 0;
+}
+
 static int rt1320_r0_temperature_get(struct snd_kcontrol *kcontrol,
                                      struct snd_ctl_elem_value *ucontrol)
 {
@@ -2545,6 +2590,8 @@ static const struct snd_kcontrol_new rt1320_snd_controls[] = {
                 rt1320_r0_temperature_get, rt1320_r0_temperature_put),
         SOC_SINGLE_EXT("RAE Update", SND_SOC_NOPM, 0, 1, 0,
                 rt1320_rae_update_get, rt1320_rae_update_put),
+       SOC_ENUM_EXT("Brown Out Switch", rt1320_brown_out_enum,
+               rt1320_brown_out_get, rt1320_brown_out_put),
 };

 static const struct snd_kcontrol_new rt1320_spk_l_dac =
diff --git a/sound/soc/codecs/rt1320-sdw.h b/sound/soc/codecs/rt1320-sdw.h
index 5a9f496dd848..4a1d3fc4c8ee 100644
--- a/sound/soc/codecs/rt1320-sdw.h
+++ b/sound/soc/codecs/rt1320-sdw.h
@@ -159,6 +159,7 @@ struct rt1320_sdw_priv {
         bool hw_init;
         bool first_hw_init;
         int version_id;
+       int brown_out;
         unsigned int dev_id;

Could you set brown_out to 1 by default?
The blind write enables brown-out by default.