Re: [PATCH 1/3] arm64: dts: imx8mm: Correct WDOG_B pin configuration

From: Krzysztof Kozlowski
Date: Mon Oct 12 2020 - 02:53:17 EST


On Fri, 9 Oct 2020 at 09:52, Anson Huang <Anson.Huang@xxxxxxx> wrote:
>
> Different revision of i.MX8MM EVK boards may have different external
> pull up registor design, some are enabled while some are NOT, to make
> sure the WDOG_B pin works properly, better to enable internal pull up
> resistor. Since enabling internal pull up resistor is NOT harmful and
> having benefit of flexibility on different board design, just enable
> it for all i.MX8MM boards.
>
> Signed-off-by: Anson Huang <Anson.Huang@xxxxxxx>
> ---
> arch/arm64/boot/dts/freescale/imx8mm-beacon-som.dtsi | 2 +-
> arch/arm64/boot/dts/freescale/imx8mm-evk.dtsi | 2 +-
> arch/arm64/boot/dts/freescale/imx8mm-var-som.dtsi | 2 +-
> 3 files changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/arch/arm64/boot/dts/freescale/imx8mm-beacon-som.dtsi b/arch/arm64/boot/dts/freescale/imx8mm-beacon-som.dtsi
> index 6de86a4..a941301 100644
> --- a/arch/arm64/boot/dts/freescale/imx8mm-beacon-som.dtsi
> +++ b/arch/arm64/boot/dts/freescale/imx8mm-beacon-som.dtsi
> @@ -398,7 +398,7 @@
>
> pinctrl_wdog: wdoggrp {
> fsl,pins = <
> - MX8MM_IOMUXC_GPIO1_IO02_WDOG1_WDOG_B 0xc6
> + MX8MM_IOMUXC_GPIO1_IO02_WDOG1_WDOG_B 0x166

Enabling pull up makes sense but you change other bits - disable
Schmitt input and enable open drain. This change is not documented /
explained in commit msg.

Best regards,
Krzysztof