Re: [PATCH v5 2/3] ARM: dts: imx7d: add Variscite VAR-SOM-MX7 support

[Stefano Radaelli <stefano.radaelli21@gmail.com>]

On Wed, Aug 26, 2026 at 08:31:32AM +0000, sashiko-bot@kernel.org wrote:
> > diff --git a/arch/arm/boot/dts/nxp/imx/imx7d-var-som-mx7customboard.dtsi b/arch/arm/boot/dts/nxp/imx/imx7d-var-som-mx7customboard.dtsi
> > index 0000000000000..aecc8c747f041
> > --- /dev/null
> > +++ b/arch/arm/boot/dts/nxp/imx/imx7d-var-som-mx7customboard.dtsi
> [ ... ]
> > +&usdhc1 {
> > +	pinctrl-names = "default", "state_100mhz", "state_200mhz";
> > +	pinctrl-0 = <&pinctrl_usdhc1>, <&pinctrl_usdhc1_gpio>;
> > +	pinctrl-1 = <&pinctrl_usdhc1_100mhz>, <&pinctrl_usdhc1_gpio>;
> > +	pinctrl-2 = <&pinctrl_usdhc1_200mhz>, <&pinctrl_usdhc1_gpio>;
> > +	cd-gpios = <&gpio5 0 GPIO_ACTIVE_LOW>;
> > +	no-1-8-v;
> 
> [Severity: Medium]
> Does including the no-1-8-v property here needlessly cap SD card performance
> by explicitly disabling all 1.8V capabilities and preventing UHS-I
> negotiation?
> 
> The pinctrl configurations below for SD1_VSELECT prove the hardware supports
> 1.8V switching:
> 
> > +	pinctrl_usdhc1_gpio: usdhc1-gpiogrp {
> > +		fsl,pins = <
> > +			MX7D_PAD_SD1_CD_B__GPIO5_IO0		0x59
> > +			MX7D_PAD_GPIO1_IO08__SD1_VSELECT	0x59
> > +		>;
> > +	};
> 
> With no-1-8-v present, the MMC subsystem will never switch to 1.8V, rendering
> the UHS-I pinctrl states dead code and capping speeds at 50MHz.

This is intentional. The board does not support reliable 1.8V signaling
on this SD interface, so no-1-8-v is required despite the presence of
the VSELECT pinmux.

> 
> > diff --git a/arch/arm/boot/dts/nxp/imx/imx7d-var-som.dtsi b/arch/arm/boot/dts/nxp/imx/imx7d-var-som.dtsi
> > index 0000000000000..158158afc3391
> > --- /dev/null
> > +++ b/arch/arm/boot/dts/nxp/imx/imx7d-var-som.dtsi
> [ ... ]
> > +	codec_wm8904: sound {
> > +		compatible = "simple-audio-card";
> > +		simple-audio-card,bitclock-master = <&dailink_master>;
> > +		simple-audio-card,format = "i2s";
> > +		simple-audio-card,frame-master = <&dailink_master>;
> > +		simple-audio-card,name = "wm8904-audio";
> > +		simple-audio-card,routing =
> > +			"Headphone Jack", "HPOUTL",
> > +			"Headphone Jack", "HPOUTR",
> > +			"IN2L", "Line In Jack",
> > +			"IN2R", "Line In Jack",
> > +			"IN1L", "Microphone Jack",
> > +			"IN1R", "Microphone Jack",
> > +			"Microphone Jack", "MICBIAS";
> 
> [Severity: Medium]
> Does this routing contradict the configuration of IN1L as a digital input?
> 
> The routing maps the analog Microphone Jack to IN1L. However, the wm8904
> node configures IN1L as a digital microphone input via wlf,in1l-as-dmicdat1:
> 
> > +	wm8904: audio-codec@1a {
> > +		compatible = "wlf,wm8904";
> > +		reg = <0x1a>;
> [ ... ]
> > +		/* DMIC is connected to IN1L */
> > +		wlf,in1l-as-dmicdat1;
> > +	};
> 
> Because IN1L is placed in digital mode, does this cause the analog signal
> from the Microphone Jack to be ignored and break analog audio capture?


This is intentional. IN1L is used as DMICDAT1, while the analog
microphone path is handled through the remaining codec input routing.
The current routing matches the board hardware configuration.

Stefano