Re: [PATCH 2/2] arm64: dts: freescale: add i.MX937 FRDM board support

[Joseph Guo (OSS)]

On 10/19/2026 7:10 PM, Joy Zou wrote:
> The i.MX937 is a derivative of the i.MX952 SoC, so it reuses the
> i.MX952 device tree as its base. Add imx937.dtsi based on imx952.dtsi
> and imx937-frdm.dts based on imx952-frdm.dtsi to support the NXP
> i.MX937 FRDM board.
> 
> Compared to the i.MX952, the i.MX937 drops the local dimming and ISP
> blocks and runs its Cortex-A55 cores at a lower maximum frequency.
> 
> The PCAL6416 GPIO expander is at I2C address 0x21 on i.MX937 FRDM,
> unlike 0x20 on i.MX952 FRDM, so disable the inherited node and add
> the expander at 0x21.
> 
> Signed-off-by: Joy Zou <joy.zou@xxxxxxxxxxx>
> ---
>  arch/arm64/boot/dts/freescale/Makefile        |   1 +
>  arch/arm64/boot/dts/freescale/imx937-frdm.dts | 111 ++++++++++++++++++++++++++
>  arch/arm64/boot/dts/freescale/imx937.dtsi     |  12 +++
>  3 files changed, 124 insertions(+)
> 
> diff --git a/arch/arm64/boot/dts/freescale/Makefile b/arch/arm64/boot/dts/freescale/Makefile
> index a80cccf34eb5..5945969ada9c 100644
> --- a/arch/arm64/boot/dts/freescale/Makefile
> +++ b/arch/arm64/boot/dts/freescale/Makefile
> @@ -944,6 +944,7 @@ dtb-$(CONFIG_ARCH_MXC) += imx93-tqma9352-mba93xxla-mini-ezurio-wlan.dtb
>  dtb-$(CONFIG_ARCH_MXC) += imx93-tqma9352-mba93xxla-mini-lvds-tm070jvhg33.dtb
>  dtb-$(CONFIG_ARCH_MXC) += imx93-var-dart-sonata.dtb
>  dtb-$(CONFIG_ARCH_MXC) += imx93-var-som-symphony.dtb
> +dtb-$(CONFIG_ARCH_MXC) += imx937-frdm.dtb
>  dtb-$(CONFIG_ARCH_MXC) += imx93w-evk.dtb
>  dtb-$(CONFIG_ARCH_MXC) += imx93w-frdm.dtb
>  dtb-$(CONFIG_ARCH_MXC) += imx943-evk.dtb
> diff --git a/arch/arm64/boot/dts/freescale/imx937-frdm.dts b/arch/arm64/boot/dts/freescale/imx937-frdm.dts
> new file mode 100644
> index 000000000000..d6be48c81057
> --- /dev/null
> +++ b/arch/arm64/boot/dts/freescale/imx937-frdm.dts
> @@ -0,0 +1,111 @@
> +// SPDX-License-Identifier: (GPL-2.0+ OR MIT)
> +/*
> + * Copyright 2026 NXP
> + */
> +
> +/dts-v1/;
> +
> +#include "imx937.dtsi"
> +#include "imx952-frdm.dtsi"
> +
> +/ {
> +	model = "NXP i.MX937 FRDM board";
> +	compatible = "fsl,imx937-frdm", "fsl,imx937", "fsl,imx952";
> +
> +	can_mux: mux-controller-0 {
> +		compatible = "gpio-mux";
> +		#mux-control-cells = <0>;
> +		#mux-state-cells = <1>;
> +		/*
> +		 * PCAL6416 (0x21) pin 4 selects the CAN/GPIO mux:
> +		 * low selects CAN, high selects GPIO. With GPIO_ACTIVE_HIGH,
> +		 * mux state 0 drives the pin low (CAN) and state 1 high (GPIO).
> +		 */
> +		mux-gpios = <&pcal6416_21 4 GPIO_ACTIVE_HIGH>;
> +	};
> +
> +	can_mux_pinctrl: pinctrl-gpiomux {
> +		compatible = "pinctrl-multiplexer";
> +
> +		can_fun: can-grp {
> +			mux-states = <&can_mux 0>;
> +		};
> +
> +		gpio_fun: gpio-grp {
> +			mux-states = <&can_mux 1>;
> +		};
> +	};
> +};

Hi Joy, 

This can mux is also compatible for i.MX952 FRDM. Can you please add it into imx952-frdm.dtsi instead?

Then new pinctrl for flexcan2/3 can dropped here too.

Regards,
Joseph
> +
> +/* Select CAN on the shared CAN/GPIO mux when FlexCAN is enabled. */
> +&flexcan2 {
> +	pinctrl-0 = <&pinctrl_flexcan2>, <&can_fun>;
> +};
> +
> +/*
> + * The CAN transceiver silent-mode line is on the 0x21 PCAL6416 on
> + * i.MX937 FRDM (the inherited 0x20 expander is disabled below).
> + */
> +&flexcan2_phy {
> +	silent-gpios = <&pcal6416_21 6 GPIO_ACTIVE_HIGH>;
> +};
> +
> +&flexcan3 {
> +	pinctrl-0 = <&pinctrl_flexcan3>, <&can_fun>;
> +};
> +
> +&flexcan3_phy {
> +	silent-gpios = <&pcal6416_21 6 GPIO_ACTIVE_HIGH>;
> +};
> +
> +&lpi2c2 {
> +	pcal6416_21: gpio@21 {
> +		compatible = "nxp,pcal6416";
> +		reg = <0x21>;
> +		#interrupt-cells = <2>;
> +		interrupt-controller;
> +		interrupt-parent = <&gpio5>;
> +		interrupts = <14 IRQ_TYPE_LEVEL_LOW>;
> +		#gpio-cells = <2>;
> +		gpio-controller;
> +		pinctrl-0 = <&pinctrl_pcal6416>;
> +		pinctrl-names = "default";
> +		vcc-supply = <&reg_3p3v>;
> +	};
> +};
> +
> +/*
> + * The PCAL6416 GPIO expander is at address 0x21 on i.MX937 FRDM,
> + * unlike 0x20 on i.MX952 FRDM. Disable the inherited node.
> + */
> +&pcal6416 {
> +	status = "disabled";
> +};
> +
> +/*
> + * The 0x20 PCAL6416 inherited from imx952-frdm.dtsi is disabled above;
> + * re-point every consumer to the 0x21 expander (pcal6416_21).
> + */
> +&reg_ext_3v3 {
> +	gpio = <&pcal6416_21 13 GPIO_ACTIVE_HIGH>;
> +};
> +
> +&reg_ext_5v {
> +	gpio = <&pcal6416_21 12 GPIO_ACTIVE_HIGH>;
> +};
> +
> +&reg_m2_pwr {
> +	gpio = <&pcal6416_21 11 GPIO_ACTIVE_HIGH>;
> +};
> +
> +&reg_usb_vbus {
> +	gpio = <&pcal6416_21 15 GPIO_ACTIVE_HIGH>;
> +};
> +
> +&reg_usdhc3_vmmc {
> +	gpio = <&pcal6416_21 9 GPIO_ACTIVE_HIGH>;
> +};
> +
> +&usdhc3_pwrseq {
> +	reset-gpios = <&pcal6416_21 8 GPIO_ACTIVE_LOW>;
> +};
> diff --git a/arch/arm64/boot/dts/freescale/imx937.dtsi b/arch/arm64/boot/dts/freescale/imx937.dtsi
> new file mode 100644
> index 000000000000..7912a9c282d8
> --- /dev/null
> +++ b/arch/arm64/boot/dts/freescale/imx937.dtsi
> @@ -0,0 +1,12 @@
> +// SPDX-License-Identifier: (GPL-2.0-only OR MIT)
> +/*
> + * Copyright 2026 NXP
> + */
> +
> +#include "imx952.dtsi"
> +
> +&gpu_opp_table {
> +	opp-1000000000 {
> +		status = "disabled";
> +	};
> +};
>