Re: [PATCH 07/10] ARM: dts: imx6ulz: Add BSH SMM-M2B board support

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Medium] ARM: dts: imx6ulz: orphaned usdhc2_pwrseq claims GPIO2_IO21 on SMM-M2B
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commit c962f6331220298bd138ac7db3207348f699e289
Author: Qiu Guochang <guochang.qiu@cn.bosch.com>

ARM: dts: imx6ulz: Add BSH SMM-M2B board support

This commit adds device tree support for the BSH SMM-M2B SystemMaster board by
including the common imx6ulz-bsh-smm-m2-common.dtsi definitions and setting
the board model and compatible strings.

> diff --git a/arch/arm/boot/dts/nxp/imx/imx6ulz-bsh-smm-m2b.dts b/arch/arm/boot/dts/nxp/imx/imx6ulz-bsh-smm-m2b.dts
> new file mode 100644
> index 0000000000000..9dc92da6ace97
> --- /dev/null
> +++ b/arch/arm/boot/dts/nxp/imx/imx6ulz-bsh-smm-m2b.dts
> @@ -0,0 +1,13 @@
> +// SPDX-License-Identifier: (GPL-2.0 OR MIT)
> +/*
> + * Copyright (C) 2021 BSH Hausgeraete GmbH
> + */
> +
> +/dts-v1/;
> +
> +#include "imx6ulz-bsh-smm-m2-common.dtsi"
> +
> +/ {
> +	model = "BSH SMM M2B";
> +	compatible = "bsh,imx6ulz-bsh-smm-m2b", "fsl,imx6ull", "fsl,imx6ulz";
> +};

[Severity: Medium]
Does including imx6ulz-bsh-smm-m2-common.dtsi leave an active usdhc2_pwrseq
platform device on the BSH SMM-M2B that claims and drives GPIO2_IO21 even
though usdhc2 and its pinmux are not present on this variant?

In arch/arm/boot/dts/nxp/imx/imx6ulz-bsh-smm-m2-common.dtsi, the root node
unconditionally defines:

	usdhc2_pwrseq: usdhc2-pwrseq {
		compatible = "mmc-pwrseq-simple";
		reset-gpios = <&gpio2 21 GPIO_ACTIVE_LOW>;
	};

However, the consumer &usdhc2 node and the pinctrl_wlan group that muxes
MX6UL_PAD_SD1_DATA3__GPIO2_IO21 only exist in
arch/arm/boot/dts/nxp/imx/imx6ulz-bsh-smm-m2.dts:

	pinctrl_wlan: wlangrp {
		fsl,pins = <
			...
			/* WL_REG_ON */
			MX6UL_PAD_SD1_DATA3__GPIO2_IO21		0x3029

When booting with imx6ulz-bsh-smm-m2b.dtb, the platform bus still populates
/usdhc2-pwrseq and drivers/mmc/core/pwrseq_simple.c:mmc_pwrseq_simple_probe()
executes:

	pwrseq->reset_gpios = devm_gpiod_get_array(dev, "reset",
						   GPIOD_OUT_HIGH);

This requests GPIO2_IO21 and drives it low as an active-low reset output
without its pad being muxed to GPIO2_IO21 and with no enabled usdhc2 consumer.

Should usdhc2_pwrseq be moved into imx6ulz-bsh-smm-m2.dts alongside &usdhc2
and pinctrl_wlan, or disabled/deleted in imx6ulz-bsh-smm-m2b.dts?

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20261104-add-bsh-smm-m2-v1-0-369f0a77e021@cn.bosch.com?part=7