Re: [PATCH 2/2] arm64: dts: imx8mp-ultra-mach-sbc: fix CBTU02043 USB Type-C orientation switch

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [High] The GPIO hog for the CBTU02043 XSD pin incorrectly drives the physical pin HIGH, placing the switch into shutdown mode instead of keeping it enabled.
--

--- Patch [2]: [PATCH 2/2] arm64: dts: imx8mp-ultra-mach-sbc: fix CBTU02043 USB Type-C orientation switch ---
commit 9b2cdf94fea52f7b5503f6d6e284f01ff2cf262b
Author: Peng Fan <peng.fan@nxp.com>

arm64: dts: imx8mp-ultra-mach-sbc: fix CBTU02043 USB Type-C orientation switch

This commit drops the gpio-sbu-mux node, replacing it with an
orientation-gpios property in the ptn5110 TCPC node. It also adds a gpio-hog
to keep the CBTU02043 switch's XSD (shutdown) pin held low, ensuring the
device remains enabled.

> diff --git a/arch/arm64/boot/dts/freescale/imx8mp-ultra-mach-sbc.dts b/arch/arm64/boot/dts/freescale/imx8mp-ultra-mach-sbc.dts
> index 3e6f9c88cc200..7e0550647751e 100644
> --- a/arch/arm64/boot/dts/freescale/imx8mp-ultra-mach-sbc.dts
> +++ b/arch/arm64/boot/dts/freescale/imx8mp-ultra-mach-sbc.dts

[ ... ]

> @@ -217,6 +202,15 @@ &gpio2 {
>  		"", "", "", "", "#SD2_CD", "", "", "",
>  		"", "", "", "", "#USB-C_EN", "", "", "",
>  		"", "", "", "", "", "", "", "";
> +
> +	cbtu02043-xsd-hog {
> +		gpio-hog;
> +		gpios = <20 GPIO_ACTIVE_LOW>;
> +		output-low;

[Severity: High]
Will this configuration inadvertently drive the XSD pin HIGH, placing the
switch into shutdown mode?

The commit message notes that the CBTU02043 XSD pin is active-low (LOW for
normal operation, HIGH for shutdown).

However, the gpio-hog node specifies both gpios = <20 GPIO_ACTIVE_LOW> and
output-low. The output-low property in the device tree binding requests a
logical 0 (inactive state). The GPIO subsystem evaluates this against the
GPIO_ACTIVE_LOW flag and inverts the logical 0 into a physical 1 (HIGH).

Could this be resolved by either using output-high (to request a logical 1 /
physical LOW) or by changing the polarity to GPIO_ACTIVE_HIGH while retaining
output-low, to ensure the physical pin is correctly driven LOW?

> +		line-name = "CBTU02043_XSD";
> +		pinctrl-names = "default";
> +		pinctrl-0 = <&pinctrl_cbtu02043_xsd>;
> +	};
>  };

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260819-imx8m-typec-v1-0-befc92ecb70a@nxp.com?part=2