[PATCH v3 2/2] arm64: dts: ti: Add audio overlay for k3-j721s2-evm

[Moteen Shah <m-shah@ti.com>]

From: Jayesh Choudhary <j-choudhary@ti.com>

Add device tree overlay to enable analog audio support on J721S2-EVM
using PCM3168A codec connected to McASP4 serializers.

- Add nodes for sound-card, audio codec, I2C3 and McASP4
- Add pinmux for I2C3, McASP4, AUDIO_EXT_REFCLK1 and WKUP_GPIO_0
- Add GPIO expander (TCA6408) for codec control
- Add GPIO hogs to route I2C3 lines and McASP serializers
- Set idle-state to 0 in mux0 and mux1 for McASP signal routing

Signed-off-by: Jayesh Choudhary <j-choudhary@ti.com>
Co-developed-by: Moteen Shah <m-shah@ti.com>
Signed-off-by: Moteen Shah <m-shah@ti.com>
---
 arch/arm64/boot/dts/ti/Makefile               |   4 +
 .../boot/dts/ti/k3-j721s2-evm-audio.dtso      | 161 ++++++++++++++++++
 2 files changed, 165 insertions(+)
 create mode 100644 arch/arm64/boot/dts/ti/k3-j721s2-evm-audio.dtso

diff --git a/arch/arm64/boot/dts/ti/Makefile b/arch/arm64/boot/dts/ti/Makefile
index ba01a929e06f..17048f2f5043 100644
--- a/arch/arm64/boot/dts/ti/Makefile
+++ b/arch/arm64/boot/dts/ti/Makefile
@@ -138,6 +138,7 @@ dtb-$(CONFIG_ARCH_K3) += k3-j721s2-common-proc-board.dtb
 dtb-$(CONFIG_ARCH_K3) += k3-j721s2-evm-gesi-exp-board.dtbo
 k3-j721s2-evm-dtbs := k3-j721s2-common-proc-board.dtb k3-j721s2-evm-gesi-exp-board.dtbo
 dtb-$(CONFIG_ARCH_K3) += k3-j721s2-evm.dtb
+dtb-$(CONFIG_ARCH_K3) += k3-j721s2-evm-audio.dtbo
 dtb-$(CONFIG_ARCH_K3) += k3-j721s2-evm-pcie1-ep.dtbo
 dtb-$(CONFIG_ARCH_K3) += k3-j721s2-evm-usb0-type-a.dtbo
 
@@ -264,6 +265,8 @@ k3-j721e-evm-pcie1-ep-dtbs := k3-j721e-common-proc-board.dtb \
 	k3-j721e-evm-pcie1-ep.dtbo
 k3-j721e-sk-csi2-dual-imx219-dtbs := k3-j721e-sk.dtb \
 	k3-j721e-sk-csi2-dual-imx219.dtbo
+k3-j721s2-evm-audio-dtbs := k3-j721s2-common-proc-board.dtb \
+	k3-j721s2-evm-audio.dtbo
 k3-j721s2-evm-pcie1-ep-dtbs := k3-j721s2-common-proc-board.dtb \
 	k3-j721s2-evm-pcie1-ep.dtbo
 k3-j721s2-evm-usb0-type-a-dtbs := k3-j721s2-common-proc-board.dtb \
@@ -328,6 +331,7 @@ dtb- += k3-am625-beagleplay-csi2-ov5640.dtb \
 	k3-j721e-evm-pcie0-ep.dtb \
 	k3-j721e-evm-pcie1-ep.dtb \
 	k3-j721e-sk-csi2-dual-imx219.dtb \
+	k3-j721s2-evm-audio.dtb \
 	k3-j721s2-evm-pcie1-ep.dtb \
 	k3-j721s2-evm-usb0-type-a.dtb \
 	k3-j722s-evm-csi2-quad-rpi-cam-imx219.dtb \
diff --git a/arch/arm64/boot/dts/ti/k3-j721s2-evm-audio.dtso b/arch/arm64/boot/dts/ti/k3-j721s2-evm-audio.dtso
new file mode 100644
index 000000000000..2a3ff1cfc650
--- /dev/null
+++ b/arch/arm64/boot/dts/ti/k3-j721s2-evm-audio.dtso
@@ -0,0 +1,161 @@
+// SPDX-License-Identifier: GPL-2.0-only OR MIT
+/*
+ * Device Tree Overlay for J721S2 Audio Support
+ *
+ * Copyright (C) 2026 Texas Instruments Incorporated - https://www.ti.com/
+ */
+
+/dts-v1/;
+/plugin/;
+
+#include <dt-bindings/gpio/gpio.h>
+
+#include "k3-pinctrl.h"
+
+&{/} {
+	codec_audio: sound {
+		compatible = "ti,j7200-cpb-audio";
+		model = "j721s2-cpb";
+
+		ti,cpb-mcasp = <&mcasp4>;
+		ti,cpb-codec = <&pcm3168a_1>;
+
+		clocks = <&k3_clks 213 0>, <&k3_clks 213 1>,
+			 <&k3_clks 157 299>, <&k3_clks 157 328>;
+		clock-names = "cpb-mcasp-auxclk", "cpb-mcasp-auxclk-48000",
+			      "cpb-codec-scki", "cpb-codec-scki-48000";
+	};
+
+	i2c_mux: mux-controller-2 {
+		compatible = "gpio-mux";
+		#mux-state-cells = <1>;
+		mux-gpios = <&wkup_gpio0 54 GPIO_ACTIVE_HIGH>;
+		idle-state = <1>;
+		pinctrl-names = "default";
+		pinctrl-0 = <&main_i2c3_mux_pins_default>;
+	};
+};
+
+&main_pmx0 {
+	mcasp4_pins_default: mcasp4-default-pins {
+		pinctrl-single,pins = <
+			J721S2_IOPAD(0x0c8, PIN_OUTPUT_PULLDOWN, 1) /* (AD28) MCASP4_ACLKX */
+			J721S2_IOPAD(0x06c, PIN_OUTPUT_PULLDOWN, 1) /* (V26) MCASP4_AFSX */
+			J721S2_IOPAD(0x068, PIN_INPUT_PULLDOWN, 1) /* (U28) MCASP4_AXR1 */
+			J721S2_IOPAD(0x0c4, PIN_OUTPUT_PULLDOWN, 1) /* (AB26) MCASP4_AXR2 */
+			J721S2_IOPAD(0x070, PIN_OUTPUT_PULLDOWN, 1) /* (R27) MCASP4_AXR3 */
+		>;
+	};
+
+	audio_ext_refclk1_pins_default: audio-ext-refclk1-default-pins {
+		pinctrl-single,pins = <
+			J721S2_IOPAD(0x078, PIN_OUTPUT, 1) /* (Y25) MCAN2_RX.AUDIO_EXT_REFCLK1 */
+		>;
+	};
+};
+
+&wkup_pmx2 {
+	main_i2c3_mux_pins_default: main-i2c3-mux-default-pins {
+		pinctrl-single,pins = <
+			J721S2_WKUP_IOPAD(0x038, PIN_OUTPUT, 7) /* (B27) WKUP_GPIO0_54 */
+		>;
+	};
+};
+
+&exp2 {
+	p09-hog {
+		/* P09 - MCASP/TRACE_MUX_S0 */
+		gpio-hog;
+		gpios = <9 GPIO_ACTIVE_HIGH>;
+		output-low;
+		line-name = "MCASP/TRACE_MUX_S0";
+	};
+
+	p10-hog {
+		/* P10 - MCASP/TRACE_MUX_S1 */
+		gpio-hog;
+		gpios = <10 GPIO_ACTIVE_HIGH>;
+		output-high;
+		line-name = "MCASP/TRACE_MUX_S1";
+	};
+};
+
+&mux0 {
+	idle-state = <0>;
+};
+
+&mux1 {
+	idle-state = <0>;
+};
+
+&scm_conf {
+	#address-cells = <1>;
+	#size-cells = <1>;
+
+	audio_refclk1: clock-controller@42e4 {
+		compatible = "ti,am62-audio-refclk";
+		reg = <0x42e4 0x4>;
+		clocks = <&k3_clks 157 299>;
+		assigned-clocks = <&k3_clks 157 299>;
+		assigned-clock-parents = <&k3_clks 157 328>;
+		#clock-cells = <0>;
+	};
+};
+
+&k3_clks {
+	/* Configure AUDIO_EXT_REFCLK1 pin as output */
+	pinctrl-names = "default";
+	pinctrl-0 = <&audio_ext_refclk1_pins_default>;
+};
+
+&main_i2c3 {
+	status = "okay";
+	pinctrl-names = "default";
+	pinctrl-0 = <&main_i2c3_pins_default>;
+	clock-frequency = <400000>;
+	mux-states = <&i2c_mux 1>;
+	#address-cells = <1>;
+	#size-cells = <0>;
+
+	exp3: gpio@20 {
+		compatible = "ti,tca6408";
+		reg = <0x20>;
+		gpio-controller;
+		#gpio-cells = <2>;
+		gpio-line-names = "CODEC_RSTZ", "CODEC_SPARE1",
+				  "UB926_RESETN", "UB926_LOCK",
+				  "UB926_PWR_SW_CNTRL", "UB926_TUNER_RESET",
+				  "UB926_GPIO_SPARE";
+	};
+
+	pcm3168a_1: audio-codec@44 {
+		compatible = "ti,pcm3168a";
+		reg = <0x44>;
+		#sound-dai-cells = <1>;
+		reset-gpios = <&exp3 0 GPIO_ACTIVE_LOW>;
+		clocks = <&audio_refclk1>;
+		clock-names = "scki";
+		VDD1-supply = <&vsys_3v3>;
+		VDD2-supply = <&vsys_3v3>;
+		VCCAD1-supply = <&vsys_5v0>;
+		VCCAD2-supply = <&vsys_5v0>;
+		VCCDA1-supply = <&vsys_5v0>;
+		VCCDA2-supply = <&vsys_5v0>;
+	};
+};
+
+&mcasp4 {
+	status = "okay";
+	#sound-dai-cells = <0>;
+	pinctrl-names = "default";
+	pinctrl-0 = <&mcasp4_pins_default>;
+	op-mode = <0>;          /* MCASP_IIS_MODE */
+	tdm-slots = <2>;
+	auxclk-fs-ratio = <256>;
+	serial-dir = <	/* 0: INACTIVE, 1: TX, 2: RX */
+		0 2 1 1
+		0 0 0 0
+		0 0 0 0
+		0 0 0 0
+	>;
+};
-- 
2.34.1