[PATCH v1 0/2] arm64: dts: imx8mm: Enable DMIC input on Variscite boards

[PATCH v1 0/2] arm64: dts: imx8mm: Enable DMIC input on Variscite boards

[Stefano Radaelli]

This series describes the digital microphone connection to the WM8904
codec on the Variscite DART-MX8M-MINI and VAR-SOM-MX8M-MINI platforms.

Configure IN1L as DMICDAT1 on both platforms to enable the digital
microphone capture path.

Stefano Radaelli (2):
  arm64: dts: imx8mm-var-dart: Enable WM8904 DMIC input
  arm64: dts: imx8mm-var-som: Enable WM8904 DMIC input

 arch/arm64/boot/dts/freescale/imx8mm-var-dart.dtsi | 2 ++
 arch/arm64/boot/dts/freescale/imx8mm-var-som.dtsi  | 2 ++
 2 files changed, 4 insertions(+)


base-commit: 31f9ec9f38735f42e1f0ba57347c420e56b99824
-- 
2.47.3

[PATCH v1 1/2] arm64: dts: imx8mm-var-dart: Enable WM8904 DMIC input

[Stefano Radaelli]

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

The digital microphone data line is connected to the WM8904 IN1L pin,
but this connection is not described in the device tree.

Configure IN1L as DMICDAT1 to enable the digital microphone capture
path.

Co-developed-by: Luan Rafael Carneiro <luan.r@variscite.com>
Signed-off-by: Luan Rafael Carneiro <luan.r@variscite.com>
Signed-off-by: Stefano Radaelli <stefano.r@variscite.com>
---
 arch/arm64/boot/dts/freescale/imx8mm-var-dart.dtsi | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/arm64/boot/dts/freescale/imx8mm-var-dart.dtsi b/arch/arm64/boot/dts/freescale/imx8mm-var-dart.dtsi
index c5f0e22f549b..183b4f7af009 100644
--- a/arch/arm64/boot/dts/freescale/imx8mm-var-dart.dtsi
+++ b/arch/arm64/boot/dts/freescale/imx8mm-var-dart.dtsi
@@ -300,6 +300,8 @@ wm8904: audio-codec@1a {
 				   /bits/ 16 <0x04af 0x324b 0x0010 0x050e>;
 		/* GPIO1 = DMIC_CLK, don't touch others */
 		wlf,gpio-cfg = <0x0018>, <0xffff>, <0xffff>, <0xffff>;
+		/* DMIC is connected to IN1L */
+		wlf,in1l-as-dmicdat1;
 	};
 };
 
-- 
2.47.3

Re: [PATCH v1 1/2] arm64: dts: imx8mm-var-dart: Enable WM8904 DMIC input

[sashiko-bot]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Medium] ASoC: dt: imx8mm: stale DMIC audio routing to Microphone Jack
--

commit 9bda3c8c55088e18eaa9e764f1a00912ea93534f
Author: Stefano Radaelli <stefano.r@variscite.com>

arm64: dts: imx8mm-var-dart: Enable WM8904 DMIC input

The digital microphone data line is connected to the WM8904 IN1L pin,
but this connection is not described in the device tree. Configure
IN1L as DMICDAT1 to enable the digital microphone capture path.

> diff --git a/arch/arm64/boot/dts/freescale/imx8mm-var-dart.dtsi b/arch/arm64/boot/dts/freescale/imx8mm-var-dart.dtsi
> index c5f0e22f549b4..183b4f7af009f 100644
> --- a/arch/arm64/boot/dts/freescale/imx8mm-var-dart.dtsi
> +++ b/arch/arm64/boot/dts/freescale/imx8mm-var-dart.dtsi
> @@ -300,6 +300,8 @@ wm8904: audio-codec@1a {
>  				   /bits/ 16 <0x04af 0x324b 0x0010 0x050e>;
>  		/* GPIO1 = DMIC_CLK, don't touch others */
>  		wlf,gpio-cfg = <0x0018>, <0xffff>, <0xffff>, <0xffff>;
> +		/* DMIC is connected to IN1L */
> +		wlf,in1l-as-dmicdat1;

[Severity: Medium]
Does this patch also need to update the simple-audio-card,routing array in
the sound-wm8904 node?

Currently, the routing in arch/arm64/boot/dts/freescale/imx8mm-var-dart.dtsi
still maps IN1L to "Microphone Jack":

	sound-wm8904 {
		...
		simple-audio-card,routing =
			...
			"IN1L", "Microphone Jack",
			"IN1R", "Microphone Jack";
		...
	}

Exposing an onboard digital microphone (DMIC) as a "Microphone Jack" causes
semantic confusion in ALSA userspace. Audio routing daemons like PulseAudio
and PipeWire use widget names to distinguish between built-in microphones and
external pluggable headsets.

Leaving the newly configured digital IN1L input tied to an external analog
jack breaks userspace jack detection logic and presents incorrect routing
options.

>  	};
>  };

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/cover.1792139809.git.stefano.r@variscite.com?part=1

Re: [PATCH v1 1/2] arm64: dts: imx8mm-var-dart: Enable WM8904 DMIC input

[Stefano Radaelli]

On Fri, Oct 16, 2026 at 08:49:52AM +0000, sashiko-bot@kernel.org wrote:
> 
> [Severity: Medium]
> Does this patch also need to update the simple-audio-card,routing array in
> the sound-wm8904 node?
> 
> Currently, the routing in arch/arm64/boot/dts/freescale/imx8mm-var-dart.dtsi
> still maps IN1L to "Microphone Jack":
> 
> 	sound-wm8904 {
> 		...
> 		simple-audio-card,routing =
> 			...
> 			"IN1L", "Microphone Jack",
> 			"IN1R", "Microphone Jack";
> 		...
> 	}
> 
> Exposing an onboard digital microphone (DMIC) as a "Microphone Jack" causes
> semantic confusion in ALSA userspace. Audio routing daemons like PulseAudio
> and PipeWire use widget names to distinguish between built-in microphones and
> external pluggable headsets.
> 
> Leaving the newly configured digital IN1L input tied to an external analog
> jack breaks userspace jack detection logic and presents incorrect routing
> options.
> 

“Microphone Jack” is the existing DAPM widget name; it does not select
analog operation or enable jack detection.
This board does not configure microphone jack detection through
simple-audio-card, so I do not see how retaining this name would cause
the reported userspace jack detection failure.

This patch adds the missing IN1L DMIC configuration.
The same configuration, including the existing widget name and routing,
is also used on the Variscite DART-MX91, DART-MX93 and DART-MX95.

A more descriptive widget name could be considered separately.
I would prefer to keep this patch focused on the missing DMIC property.

Stefano

[PATCH v1 2/2] arm64: dts: imx8mm-var-som: Enable WM8904 DMIC input

[Stefano Radaelli]

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

The digital microphone data line is connected to the WM8904 IN1L pin,
but this connection is not described in the device tree.

Configure IN1L as DMICDAT1 to enable the digital microphone capture
path.

Co-developed-by: Luan Rafael Carneiro <luan.r@variscite.com>
Signed-off-by: Luan Rafael Carneiro <luan.r@variscite.com>
Signed-off-by: Stefano Radaelli <stefano.r@variscite.com>
---
 arch/arm64/boot/dts/freescale/imx8mm-var-som.dtsi | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/arm64/boot/dts/freescale/imx8mm-var-som.dtsi b/arch/arm64/boot/dts/freescale/imx8mm-var-som.dtsi
index d05b1ab17fed..514cc568fb71 100644
--- a/arch/arm64/boot/dts/freescale/imx8mm-var-som.dtsi
+++ b/arch/arm64/boot/dts/freescale/imx8mm-var-som.dtsi
@@ -348,6 +348,8 @@ wm8904: codec@1a {
 				   /bits/ 16 <0x04af 0x324b 0x0010 0x050e>;
 		/* GPIO1 = DMIC_CLK, don't touch others */
 		wlf,gpio-cfg = <0x0018>, <0xffff>, <0xffff>, <0xffff>;
+		/* DMIC is connected to IN1L */
+		wlf,in1l-as-dmicdat1;
 	};
 };
 
-- 
2.47.3