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

From: Stefano Radaelli

Date: Sat Sep 26 2026 - 07:06:29 EST

From: Stefano Radaelli <stefano.r@xxxxxxxxxxxxx>

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@xxxxxxxxxxxxx>
---
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@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@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