ASoC: nau8821: Improve AMIC recording performance.

Since the hardware may be designed as a single-ended input, the headset mic
record only supports single-ended input on the left side. This patch
will enhance microphone recording performance for single-end.
Signed-off-by: Seven Lee <wtli@nuvoton.com>
Link: https://lore.kernel.org/r/20230823071244.1861487-2-wtli@nuvoton.comSigned-off-by: Mark Brown <broonie@kernel.org>

sound/soc/codecs/nau8821.c

@@ -624,6 +624,36 @@ static int system_clock_control(struct snd_soc_dapm_widget *w,
 	return 0;
 }
 
+static int nau8821_left_fepga_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);
+	struct nau8821 *nau8821 = snd_soc_component_get_drvdata(component);
+
+	if (!nau8821->left_input_single_end)
+		return 0;
+
+	switch (event) {
+	case SND_SOC_DAPM_POST_PMU:
+		regmap_update_bits(nau8821->regmap, NAU8821_R77_FEPGA,
+			NAU8821_ACDC_CTRL_MASK | NAU8821_FEPGA_MODEL_MASK,
+			NAU8821_ACDC_VREF_MICN | NAU8821_FEPGA_MODEL_AAF);
+		regmap_update_bits(nau8821->regmap, NAU8821_R76_BOOST,
+			NAU8821_HP_BOOST_DISCHRG_EN, NAU8821_HP_BOOST_DISCHRG_EN);
+		break;
+	case SND_SOC_DAPM_POST_PMD:
+		regmap_update_bits(nau8821->regmap, NAU8821_R77_FEPGA,
+			NAU8821_ACDC_CTRL_MASK | NAU8821_FEPGA_MODEL_MASK, 0);
+		regmap_update_bits(nau8821->regmap, NAU8821_R76_BOOST,
+			NAU8821_HP_BOOST_DISCHRG_EN, 0);
+		break;
+	default:
+		break;
+	}
+
+	return 0;
+}
+
 static const struct snd_soc_dapm_widget nau8821_dapm_widgets[] = {
 	SND_SOC_DAPM_SUPPLY("System Clock", SND_SOC_NOPM, 0, 0,
 		system_clock_control, SND_SOC_DAPM_POST_PMD),
@@ -635,8 +665,10 @@ static const struct snd_soc_dapm_widget nau8821_dapm_widgets[] = {
 		NAU8821_POWERUP_ADCL_SFT, 0),
 	SND_SOC_DAPM_ADC("ADCR Power", NULL, NAU8821_R72_ANALOG_ADC_2,
 		NAU8821_POWERUP_ADCR_SFT, 0),
+	/* single-ended design only on the left */
 	SND_SOC_DAPM_PGA_S("Frontend PGA L", 1, NAU8821_R7F_POWER_UP_CONTROL,
-		NAU8821_PUP_PGA_L_SFT, 0, NULL, 0),
+		NAU8821_PUP_PGA_L_SFT, 0, nau8821_left_fepga_event,
+		SND_SOC_DAPM_POST_PMU | SND_SOC_DAPM_POST_PMD),
 	SND_SOC_DAPM_PGA_S("Frontend PGA R", 1, NAU8821_R7F_POWER_UP_CONTROL,
 		NAU8821_PUP_PGA_R_SFT, 0, NULL, 0),
 	SND_SOC_DAPM_PGA_S("ADCL Digital path", 0, NAU8821_R01_ENA_CTRL,
@@ -1677,6 +1709,8 @@ static int nau8821_read_device_properties(struct device *dev,
 		"nuvoton,jkdet-pull-up");
 	nau8821->key_enable = device_property_read_bool(dev,
 		"nuvoton,key-enable");
+	nau8821->left_input_single_end = device_property_read_bool(dev,
+		"nuvoton,left-input-single-end");
 	ret = device_property_read_u32(dev, "nuvoton,jkdet-polarity",
 		&nau8821->jkdet_polarity);
 	if (ret)
@@ -1760,6 +1794,12 @@ static void nau8821_init_regs(struct nau8821 *nau8821)
 		NAU8821_ADC_SYNC_DOWN_MASK, NAU8821_ADC_SYNC_DOWN_64);
 	regmap_update_bits(regmap, NAU8821_R2C_DAC_CTRL1,
 		NAU8821_DAC_OVERSAMPLE_MASK, NAU8821_DAC_OVERSAMPLE_64);
+	if (nau8821->left_input_single_end) {
+		regmap_update_bits(regmap, NAU8821_R6B_PGA_MUTE,
+			NAU8821_MUTE_MICNL_EN, NAU8821_MUTE_MICNL_EN);
+		regmap_update_bits(regmap, NAU8821_R74_MIC_BIAS,
+			NAU8821_MICBIAS_LOWNOISE_EN, NAU8821_MICBIAS_LOWNOISE_EN);
+	}
 }
 
 static int nau8821_setup_irq(struct nau8821 *nau8821)

sound/soc/codecs/nau8821.h

@@ -433,6 +433,14 @@
 #define NAU8821_DAC_CAPACITOR_MSB		(0x1 << 1)
 #define NAU8821_DAC_CAPACITOR_LSB		0x1
 
+/* MUTE_MIC_L_N (0x6b) */
+#define NAU8821_MUTE_MICNL_SFT		5
+#define NAU8821_MUTE_MICNL_EN           (0x1 << NAU8821_MUTE_MICNL_SFT)
+#define NAU8821_MUTE_MICNR_SFT          4
+#define NAU8821_MUTE_MICNR_EN           (0x1 << NAU8821_MUTE_MICNR_SFT)
+#define NAU8821_MUTE_MICRP_SFT          2
+#define NAU8821_MUTE_MICRP_EN           (0x1 << NAU8821_MUTE_MICRP_SFT)
+
 /* ANALOG_ADC_1 (0x71) */
 #define NAU8821_MICDET_EN_SFT		0
 #define NAU8821_MICDET_MASK		0x1
@@ -463,23 +471,39 @@
 
 /* MIC_BIAS (0x74) */
 #define NAU8821_MICBIAS_JKR2		(0x1 << 12)
+#define NAU8821_MICBIAS_LOWNOISE_SFT	10
+#define NAU8821_MICBIAS_LOWNOISE_EN	(0x1 << NAU8821_MICBIAS_LOWNOISE_SFT)
 #define NAU8821_MICBIAS_POWERUP_SFT	8
+#define NAU8821_MICBIAS_POWERUP_EN	(0x1 << NAU8821_MICBIAS_POWERUP_SFT)
 #define NAU8821_MICBIAS_VOLTAGE_SFT	0
 #define NAU8821_MICBIAS_VOLTAGE_MASK	0x7
 
 /* BOOST (0x76) */
 #define NAU8821_PRECHARGE_DIS		(0x1 << 13)
 #define NAU8821_GLOBAL_BIAS_EN		(0x1 << 12)
+#define NAU8821_HP_BOOST_DISCHRG_SFT	11
+#define NAU8821_HP_BOOST_DISCHRG_EN	(0x1 << NAU8821_HP_BOOST_DISCHRG_SFT)
 #define NAU8821_HP_BOOST_DIS_SFT	9
 #define NAU8821_HP_BOOST_DIS		(0x1 << NAU8821_HP_BOOST_DIS_SFT)
 #define NAU8821_HP_BOOST_G_DIS		(0x1 << 8)
 #define NAU8821_SHORT_SHUTDOWN_EN	(0x1 << 6)
 
 /* FEPGA (0x77) */
+#define NAU8821_ACDC_CTRL_SFT		14
+#define NAU8821_ACDC_CTRL_MASK		(0x3 << NAU8821_ACDC_CTRL_SFT)
+#define NAU8821_ACDC_VREF_MICP		(0x1 << NAU8821_ACDC_CTRL_SFT)
+#define NAU8821_ACDC_VREF_MICN		(0x2 << NAU8821_ACDC_CTRL_SFT)
 #define NAU8821_FEPGA_MODEL_SFT		4
 #define NAU8821_FEPGA_MODEL_MASK	(0xf << NAU8821_FEPGA_MODEL_SFT)
+#define NAU8821_FEPGA_MODEL_AAF		(0x1 << NAU8821_FEPGA_MODEL_SFT)
+#define NAU8821_FEPGA_MODEL_DIS		(0x2 << NAU8821_FEPGA_MODEL_SFT)
+#define NAU8821_FEPGA_MODEL_IMP12K	(0x8 << NAU8821_FEPGA_MODEL_SFT)
 #define NAU8821_FEPGA_MODER_SFT		0
 #define NAU8821_FEPGA_MODER_MASK	0xf
+#define NAU8821_FEPGA_MODER_AAF		0x1
+#define NAU8821_FEPGA_MODER_DIS		0x2
+#define NAU8821_FEPGA_MODER_IMP12K	0x8
+
 
 /* PGA_GAIN (0x7e) */
 #define NAU8821_PGA_GAIN_L_SFT	        8
@@ -543,6 +567,7 @@ struct nau8821 {
 	bool jkdet_enable;
 	bool jkdet_pull_enable;
 	bool jkdet_pull_up;
+	bool left_input_single_end;
 	int jkdet_polarity;
 	int jack_insert_debounce;
 	int jack_eject_debounce;