Re: [PATCH v1] arm64: dts: qcom: Enable CAN RX via GPIO expander

[Dmitry Baryshkov]

On Thu, Apr 02, 2026 at 04:22:53PM +0530, Anup Kulkarni wrote:
> Few CAN controllers, part of RTSS sub-system on LeMans, route
> their RX signal through a I2C GPIO expander at address 0x3b.
> RTSS subsystem is an MCU like sub-system on LeMans with independent
> booting capability through OSPI interface and supports peripherals like
> RGMII, CAN-FD, UART, I2C, SPI etc.
> 
> Describe this hardware wiring by configuring the expander GPIO 4 pin as
> hog with output-high, asserting the selected line during boot.

Missing platform name in the subject.

> 
> Signed-off-by: Anup Kulkarni <anup.kulkarni@xxxxxxxxxxxxxxxx>
> ---
>  arch/arm64/boot/dts/qcom/lemans-evk.dts | 7 +++++++
>  1 file changed, 7 insertions(+)
> 
> diff --git a/arch/arm64/boot/dts/qcom/lemans-evk.dts b/arch/arm64/boot/dts/qcom/lemans-evk.dts
> index a1ef4eba2a20..b8371bdf9933 100644
> --- a/arch/arm64/boot/dts/qcom/lemans-evk.dts
> +++ b/arch/arm64/boot/dts/qcom/lemans-evk.dts
> @@ -615,6 +615,13 @@ expander3: gpio@3b {
>  		interrupts-extended = <&tlmm 39 IRQ_TYPE_LEVEL_LOW>;
>  		pinctrl-0 = <&expander3_int>;
>  		pinctrl-names = "default";
> +
> +		rtss-can-sel-hog {

Why is it being described as a hog rather than a pinctrl used by the
CAN device?

> +			gpio-hog;
> +			gpios = <4 GPIO_ACTIVE_HIGH>;
> +			output-high;
> +			line-name = "rtss-can-sel";
> +		};
>  	};
>  
>  	eeprom@50 {
> -- 
> 2.34.1
> 

-- 
With best wishes
Dmitry