Re: [PATCH v4 5/6] arm64: dts: imx8mm: imx8mp: Add FIO1 DTOs for Data Modul i.MX8M Mini and Plus eDM SBC

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [High] I2C node address collision corrupts LVDS configuration.
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commit 24245aa090bd2ca7fbe263d45e29abf9a13de9cf
Author: Marek Vasut <marex@nabladev.com>

arm64: dts: imx8mm: imx8mp: Add FIO1 DTOs for Data Modul i.MX8M Mini and Plus eDM SBC
    
Add DT overlay for feature connector expansion module eDM-MOD-iMX8Mm-FIO1
providing additional UARTs, CAN, PWM Beeper, I2C, SPI and GPIO breakout.
This adapter can be optionally populated onto the eDM SBC.

> diff --git a/arch/arm64/boot/dts/freescale/imx8mm-data-modul-edm-sbc-overlay-edm-mod-imx8mm-fio1.dtsi b/arch/arm64/boot/dts/freescale/imx8mm-data-modul-edm-sbc-overlay-edm-mod-imx8mm-fio1.dtsi
> new file mode 100644
> index 0000000000000..7851ca73ccd8e
> --- /dev/null
> +++ b/arch/arm64/boot/dts/freescale/imx8mm-data-modul-edm-sbc-overlay-edm-mod-imx8mm-fio1.dtsi
> @@ -0,0 +1,69 @@
[ ... ]
> +&i2c_feature {	/* Feature connector I2C */
> +	#address-cells = <1>;
> +	#size-cells = <0>;
> +
> +	gpio_feature: io-expander@20 {
> +		compatible = "nxp,pca9554";
> +		pinctrl-names = "default";
> +		pinctrl-0 = <&pinctrl_gpio_expander>;
> +		reg = <0x20>;

[Severity: High]
Does this node create an address collision on the i.MX8MP base board?

The i.MX8MP base board (imx8mp-data-modul-edm-sbc.dts) already defines an LVDS
PCA9554 GPIO expander at 0x20 on i2c2 (which is aliased to i2c_feature):

arch/arm64/boot/dts/freescale/imx8mp-data-modul-edm-sbc.dts:
i2c_feature: &i2c2 {
	...
	gpiolvds: io-expander@20 {
		compatible = "nxp,pca9554";
		reg = <0x20>;
	...
}

Loading the imx8mp-data-modul-edm-sbc-overlay-edm-mod-imx8mm-fio1.dtso overlay
would merge this io-expander@20 node into the existing gpiolvds node. Will
this overwrite the gpio-line-names and interrupts of the base board's LVDS
expander, and cause a physical I2C address conflict on the bus when the FIO1
module is populated?

> +		#gpio-cells = <2>;
> +		gpio-controller;
> +		#interrupt-cells = <2>;
> +		interrupt-controller;
> +		interrupt-parent = <&gpio4>;
> +		interrupts = <27 IRQ_TYPE_LEVEL_LOW>;
> +		gpio-line-names =
> +			"GPIO1_output", "GPIO1_input",
> +			"GPIO2_output", "GPIO2_input",
> +			"GPIO3_output", "GPIO3_input",
> +			"PCA9511A_READY", "";
> +	};

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260705200534.151803-1-marex@nabladev.com?part=5