[PATCH v2 04/11] ARM: dts: imx6ul: Add Variscite audio codec files

Stefano Radaelli stefano.radaelli21 at gmail.com
Sat Sep 26 04:05:32 PDT 2026 

From: Stefano Radaelli <stefano.r at variscite.com>

Add shared WM8904 and WM8731 audio option DTSI files for
VAR-SOM-6UL and DART-6UL. Keep the codec, SAI2 setup and pinctrl
out of the module base so each board selects its fitted codec.

The DART-6UL WM8904 wrapper adds the microphone routes to IN2L,
IN2R and MICBIAS. Both modules use the same WM8731 description.

Signed-off-by: Stefano Radaelli <stefano.r at variscite.com>
---
v1->v2:
 - Share the WM8904 codec description between VAR-SOM-6UL and DART-6UL,
  keeping the DART-specific microphone routing in a small wrapper.
 - Consolidate the identical WM8731 descriptions into one shared DTSI
  and update the board includes.

 .../imx/imx6ul-imx6ull-var-dart-wm8904.dtsi   | 17 ++++
 .../nxp/imx/imx6ul-imx6ull-var-wm8731.dtsi    | 71 ++++++++++++++++
 .../nxp/imx/imx6ul-imx6ull-var-wm8904.dtsi    | 85 +++++++++++++++++++
 3 files changed, 173 insertions(+)
 create mode 100644 arch/arm/boot/dts/nxp/imx/imx6ul-imx6ull-var-dart-wm8904.dtsi
 create mode 100644 arch/arm/boot/dts/nxp/imx/imx6ul-imx6ull-var-wm8731.dtsi
 create mode 100644 arch/arm/boot/dts/nxp/imx/imx6ul-imx6ull-var-wm8904.dtsi

diff --git a/arch/arm/boot/dts/nxp/imx/imx6ul-imx6ull-var-dart-wm8904.dtsi b/arch/arm/boot/dts/nxp/imx/imx6ul-imx6ull-var-dart-wm8904.dtsi
new file mode 100644
index 000000000000..236022f3da10
--- /dev/null
+++ b/arch/arm/boot/dts/nxp/imx/imx6ul-imx6ull-var-dart-wm8904.dtsi
@@ -0,0 +1,17 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2026 Variscite Ltd. - https://www.variscite.com
+ */
+
+#include "imx6ul-imx6ull-var-wm8904.dtsi"
+
+&sound_wm8904 {
+	simple-audio-card,routing =
+		"Headphone Jack", "HPOUTL",
+		"Headphone Jack", "HPOUTR",
+		"IN1L", "Line In Jack",
+		"IN1R", "Line In Jack",
+		"IN2L", "Microphone Jack",
+		"IN2R", "Microphone Jack",
+		"Microphone Jack", "MICBIAS";
+};
diff --git a/arch/arm/boot/dts/nxp/imx/imx6ul-imx6ull-var-wm8731.dtsi b/arch/arm/boot/dts/nxp/imx/imx6ul-imx6ull-var-wm8731.dtsi
new file mode 100644
index 000000000000..7d74fc3b7014
--- /dev/null
+++ b/arch/arm/boot/dts/nxp/imx/imx6ul-imx6ull-var-wm8731.dtsi
@@ -0,0 +1,71 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2026 Variscite Ltd. - https://www.variscite.com
+ */
+
+/ {
+	sound {
+		compatible = "simple-audio-card";
+		simple-audio-card,bitclock-master = <&sound_master>;
+		simple-audio-card,format = "i2s";
+		simple-audio-card,frame-master = <&sound_master>;
+		simple-audio-card,name = "wm8731audio";
+		simple-audio-card,routing =
+			"Headphone Jack", "RHPOUT",
+			"Headphone Jack", "LHPOUT",
+			"LLINEIN", "Line Jack",
+			"RLINEIN", "Line Jack",
+			"MICIN", "Mic Bias",
+			"Mic Bias", "Mic Jack";
+		simple-audio-card,widgets =
+			"Headphone", "Headphone Jack",
+			"Line", "Line Jack",
+			"Microphone", "Mic Jack";
+
+		sound_master: simple-audio-card,cpu {
+			sound-dai = <&sai2>;
+		};
+
+		simple-audio-card,codec {
+			sound-dai = <&codec>;
+			system-clock-frequency = <12288000>;
+		};
+	};
+};
+
+&i2c2 {
+	codec: audio-codec at 1a {
+		compatible = "wlf,wm8731";
+		reg = <0x1a>;
+		#sound-dai-cells = <0>;
+		clocks = <&clks IMX6UL_CLK_SAI2>;
+		clock-names = "mclk";
+		AVDD-supply = <&reg_3p3v>;
+		DBVDD-supply = <&reg_3p3v>;
+		DCVDD-supply = <&reg_3p3v>;
+		HPVDD-supply = <&reg_3p3v>;
+	};
+};
+
+&sai2 {
+	pinctrl-names = "default";
+	pinctrl-0 = <&pinctrl_sai2>;
+	assigned-clocks = <&clks IMX6UL_CLK_SAI2_SEL>,
+			  <&clks IMX6UL_CLK_SAI2>;
+	assigned-clock-parents = <&clks IMX6UL_CLK_PLL4_AUDIO_DIV>;
+	assigned-clock-rates = <0>, <12288000>;
+	fsl,sai-mclk-direction-output;
+	status = "okay";
+};
+
+&iomuxc {
+	pinctrl_sai2: sai2-grp {
+		fsl,pins = <
+			MX6UL_PAD_JTAG_TDI__SAI2_TX_BCLK	0x17088
+			MX6UL_PAD_JTAG_TDO__SAI2_TX_SYNC	0x17088
+			MX6UL_PAD_JTAG_TRST_B__SAI2_TX_DATA	0x11088
+			MX6UL_PAD_JTAG_TCK__SAI2_RX_DATA	0x11088
+			MX6UL_PAD_JTAG_TMS__SAI2_MCLK		0x17088
+		>;
+	};
+};
diff --git a/arch/arm/boot/dts/nxp/imx/imx6ul-imx6ull-var-wm8904.dtsi b/arch/arm/boot/dts/nxp/imx/imx6ul-imx6ull-var-wm8904.dtsi
new file mode 100644
index 000000000000..dd5f6e4edad5
--- /dev/null
+++ b/arch/arm/boot/dts/nxp/imx/imx6ul-imx6ull-var-wm8904.dtsi
@@ -0,0 +1,85 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2026 Variscite Ltd. - https://www.variscite.com
+ */
+
+/ {
+	sound_wm8904: sound {
+		compatible = "simple-audio-card";
+		simple-audio-card,bitclock-master = <&sound_master>;
+		simple-audio-card,format = "i2s";
+		simple-audio-card,frame-master = <&sound_master>;
+		simple-audio-card,name = "wm8904audio";
+		simple-audio-card,routing =
+			"Headphone Jack", "HPOUTL",
+			"Headphone Jack", "HPOUTR",
+			"IN1L", "Line In Jack",
+			"IN1R", "Line In Jack";
+		simple-audio-card,widgets =
+			"Microphone", "Microphone Jack",
+			"Headphone", "Headphone Jack",
+			"Line", "Line In Jack";
+		simple-audio-card,mclk-fs = <256>;
+
+		simple-audio-card,cpu {
+			sound-dai = <&sai2>;
+		};
+
+		sound_master: simple-audio-card,codec {
+			sound-dai = <&codec>;
+		};
+	};
+};
+
+&i2c2 {
+	codec: audio-codec at 1a {
+		compatible = "wlf,wm8904";
+		reg = <0x1a>;
+		#sound-dai-cells = <0>;
+		clocks = <&clks IMX6UL_CLK_SAI2>;
+		clock-names = "mclk";
+		AVDD-supply = <&reg_3p3v>;
+		CPVDD-supply = <&reg_3p3v>;
+		DBVDD-supply = <&reg_3p3v>;
+		DCVDD-supply = <&reg_3p3v>;
+		MICVDD-supply = <&reg_3p3v>;
+		wlf,drc-cfg-names = "default", "peaklimiter", "tradition",
+				    "soft", "music";
+		/*
+		 * Config registers per name, respectively:
+		 * KNEE_IP = 0,   KNEE_OP = 0,     HI_COMP = 1,   LO_COMP = 1
+		 * KNEE_IP = -24, KNEE_OP = -6,    HI_COMP = 1/4, LO_COMP = 1
+		 * KNEE_IP = -42, KNEE_OP = -3,    HI_COMP = 0,   LO_COMP = 1
+		 * KNEE_IP = -45, KNEE_OP = -9,    HI_COMP = 1/8, LO_COMP = 1
+		 * KNEE_IP = -30, KNEE_OP = -10.5, HI_COMP = 1/4, LO_COMP = 1
+		 */
+		wlf,drc-cfg-regs = /bits/ 16 <0x01af 0x3248 0x0000 0x0000>,
+				   /bits/ 16 <0x04af 0x324b 0x0010 0x0408>,
+				   /bits/ 16 <0x04af 0x324b 0x0028 0x0704>,
+				   /bits/ 16 <0x04af 0x324b 0x0018 0x078c>,
+				   /bits/ 16 <0x04af 0x324b 0x0010 0x050e>;
+	};
+};
+
+&sai2 {
+	pinctrl-names = "default";
+	pinctrl-0 = <&pinctrl_sai2>;
+	assigned-clocks = <&clks IMX6UL_CLK_SAI2_SEL>,
+			  <&clks IMX6UL_CLK_SAI2>;
+	assigned-clock-parents = <&clks IMX6UL_CLK_PLL4_AUDIO_DIV>;
+	assigned-clock-rates = <0>, <11565177>;
+	fsl,sai-mclk-direction-output;
+	status = "okay";
+};
+
+&iomuxc {
+	pinctrl_sai2: sai2-grp {
+		fsl,pins = <
+			MX6UL_PAD_JTAG_TDI__SAI2_TX_BCLK	0x17088
+			MX6UL_PAD_JTAG_TDO__SAI2_TX_SYNC	0x17088
+			MX6UL_PAD_JTAG_TRST_B__SAI2_TX_DATA	0x11088
+			MX6UL_PAD_JTAG_TCK__SAI2_RX_DATA	0x11088
+			MX6UL_PAD_JTAG_TMS__SAI2_MCLK		0x17088
+		>;
+	};
+};
-- 
2.47.3

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