[D18] add TLV320AIC32X4 audio support

* audio over SAI2 interface
* output needs to be enabled: /usr/bin/amixer sset -q 'LO Driver Gain' 100%
* sound works only at 48000Hz: this derives from SAI2 assigned clock rate.
  * Filesystem support for pulseaudio:
    /etc/pulse/daemon.conf --> default-sample-rate = 48000
                               alternate-sample-rate = 48000
* on CSB79REVB: I2S0 to audio jack CN41 (switch SW16 2-4 position OFF,
  jumper CN82 position 2-3)

arch/arm64/boot/dts/seco/seco-imx8mp-d18.dts

@@ -90,12 +90,38 @@ reg_wifi_ac_en: regulator-wifi-ac-en {
 		status = "okay";
 	};
 
+	reg_audio: regulator-soc-audio {
+		compatible = "regulator-fixed";
+		regulator-name = "tlv320aic32x4_supply";
+		regulator-min-microvolt = <1800000>;
+		regulator-max-microvolt = <1800000>;
+		regulator-always-on;
+	};
+
 	bt_sco_codec: bt_sco_codec {
 	};
 
 	sound-bt-sco {
 	};
 
+	sound {
+		status                            = "okay";
+		compatible                        = "simple-audio-card";
+		simple-audio-card,format          = "i2s";
+		simple-audio-card,name            = "tlv-audio";
+		simple-audio-card,frame-master    = <&cpudai>;
+		simple-audio-card,bitclock-master = <&cpudai>;
+
+		cpudai: simple-audio-card,cpu {
+			sound-dai          = <&sai2>;
+			dai-tdm-slot-num   = <2>;
+			dai-tdm-slot-width = <16>;
+		};
+		simple-audio-card,codec {
+			sound-dai = <&tlvcodec 0>;
+		};
+	};
+
 	sound-hdmi {
 		compatible = "fsl,imx-audio-cdnhdmi";
 		model = "audio-hdmi";
@@ -402,6 +428,31 @@ wifi_disable {
 			gpios = <11 GPIO_ACTIVE_HIGH>;
 			output-low;
 		};
+
+		tlv320_reset {
+			gpio-hog;
+			gpios = <8 GPIO_ACTIVE_HIGH>;
+			output-high;
+		};
+	};
+};
+
+&i2c5 {
+	clock-frequency = <100000>;
+	pinctrl-names = "default";
+	pinctrl-0 = <&pinctrl_i2c5>;
+	status = "okay";
+
+	tlvcodec: tlv320aic32x4@18 {
+		#sound-dai-cells = <0>;
+		status = "okay";
+		compatible = "ti,tlv320aic32x4";
+		reg = <0x18>;
+		ldoin-supply = <&reg_audio>;
+		iov-supply = <&reg_audio>;
+		clocks = <&clk IMX8MP_CLK_SAI2_ROOT>;
+		clock-names = "mclk";
+		route-on-lineout;
 	};
 };
 
@@ -515,9 +566,9 @@ &sai2 {
 	pinctrl-names = "default";
 	pinctrl-0 = <&pinctrl_sai2>;
 	assigned-clocks = <&clk IMX8MP_CLK_SAI2>;
-	assigned-clock-parents = <&clk IMX8MP_AUDIO_PLL1_OUT>;
-	assigned-clock-rates = <12288000>;
-	status = "disabled";
+	assigned-clock-parents = <&clk IMX8MP_AUDIO_PLL2_OUT>;
+	assigned-clock-rates = <1536000>;
+	status = "okay";
 };
 
 &sai3 {
@@ -797,6 +848,13 @@ MX8MP_IOMUXC_I2C3_SDA__I2C3_SDA		0x400001c3
 		>;
 	};
 
+	pinctrl_i2c5: i2c5grp {
+		fsl,pins = <
+			MX8MP_IOMUXC_SPDIF_RX__I2C5_SDA		0x400001c3
+			MX8MP_IOMUXC_SPDIF_TX__I2C5_SCL		0x400001c3
+		>;
+	};
+
 	pinctrl_mipi_dsi_en: mipi_dsi_en {
 		fsl,pins = <
 			MX8MP_IOMUXC_GPIO1_IO08__GPIO1_IO08	0x16
@@ -824,8 +882,9 @@ MX8MP_IOMUXC_GPIO1_IO10__USB1_ID	0x0
 
 	pinctrl_sai2: sai2grp {
 		fsl,pins = <
-			MX8MP_IOMUXC_SAI2_TXC__AUDIOMIX_SAI2_TX_BCLK	0xd6
+			MX8MP_IOMUXC_SAI2_MCLK__AUDIOMIX_SAI2_MCLK	0xd6
 			MX8MP_IOMUXC_SAI2_TXFS__AUDIOMIX_SAI2_TX_SYNC	0xd6
+			MX8MP_IOMUXC_SAI2_TXC__AUDIOMIX_SAI2_TX_BCLK	0xd6
 			MX8MP_IOMUXC_SAI2_TXD0__AUDIOMIX_SAI2_TX_DATA00	0xd6
 			MX8MP_IOMUXC_SAI2_RXD0__AUDIOMIX_SAI2_RX_DATA00	0xd6
 		>;