ASoC: nau8821: Add delay control for ADC

Merge series from Seven Lee <wtli@nuvoton.com>:

Change the original fixed delay to the assignment from the property. It
will make it more flexible to different platforms to avoid pop noise at
the beginning of recording.

Documentation/devicetree/bindings/sound/nuvoton,nau8821.yaml

@@ -103,6 +103,12 @@ properties:
         just limited to the left adc for design demand.
     type: boolean
 
+  nuvoton,adc-delay-ms:
+    description: Delay (in ms) to make input path stable and avoid pop noise.
+    minimum: 125
+    maximum: 500
+    default: 125
+
   '#sound-dai-cells':
     const: 0
 
@@ -136,6 +142,7 @@ examples:
             nuvoton,jack-eject-debounce = <0>;
             nuvoton,dmic-clk-threshold = <3072000>;
             nuvoton,dmic-slew-rate = <0>;
+            nuvoton,adc-delay-ms = <125>;
             #sound-dai-cells = <0>;
         };
     };

sound/soc/codecs/nau8821.c

@@ -511,13 +511,9 @@ static int nau8821_left_adc_event(struct snd_soc_dapm_widget *w,
 
 	switch (event) {
 	case SND_SOC_DAPM_POST_PMU:
-		msleep(125);
-		regmap_update_bits(nau8821->regmap, NAU8821_R01_ENA_CTRL,
-			NAU8821_EN_ADCL, NAU8821_EN_ADCL);
+		msleep(nau8821->adc_delay);
 		break;
 	case SND_SOC_DAPM_POST_PMD:
-		regmap_update_bits(nau8821->regmap,
-			NAU8821_R01_ENA_CTRL, NAU8821_EN_ADCL, 0);
 		break;
 	default:
 		return -EINVAL;
@@ -535,13 +531,9 @@ static int nau8821_right_adc_event(struct snd_soc_dapm_widget *w,
 
 	switch (event) {
 	case SND_SOC_DAPM_POST_PMU:
-		msleep(125);
-		regmap_update_bits(nau8821->regmap, NAU8821_R01_ENA_CTRL,
-			NAU8821_EN_ADCR, NAU8821_EN_ADCR);
+		msleep(nau8821->adc_delay);
 		break;
 	case SND_SOC_DAPM_POST_PMD:
-		regmap_update_bits(nau8821->regmap,
-			NAU8821_R01_ENA_CTRL, NAU8821_EN_ADCR, 0);
 		break;
 	default:
 		return -EINVAL;
@@ -1697,6 +1689,7 @@ static void nau8821_print_device_properties(struct nau8821 *nau8821)
 	dev_dbg(dev, "dmic-clk-threshold:       %d\n",
 		nau8821->dmic_clk_threshold);
 	dev_dbg(dev, "key_enable:       %d\n", nau8821->key_enable);
+	dev_dbg(dev, "adc-delay-ms:		%d\n", nau8821->adc_delay);
 }
 
 static int nau8821_read_device_properties(struct device *dev,
@@ -1742,6 +1735,12 @@ static int nau8821_read_device_properties(struct device *dev,
 		&nau8821->dmic_slew_rate);
 	if (ret)
 		nau8821->dmic_slew_rate = 0;
+	ret = device_property_read_u32(dev, "nuvoton,adc-delay-ms",
+		&nau8821->adc_delay);
+	if (ret)
+		nau8821->adc_delay = 125;
+	if (nau8821->adc_delay < 125 || nau8821->adc_delay > 500)
+		dev_warn(dev, "Please set the suitable delay time!\n");
 
 	return 0;
 }

sound/soc/codecs/nau8821.h

@@ -577,6 +577,7 @@ struct nau8821 {
 	int dmic_clk_threshold;
 	int dmic_slew_rate;
 	int key_enable;
+	int adc_delay;
 };
 
 int nau8821_enable_jack_detect(struct snd_soc_component *component,