i.MX ProcessorsのトピックHow to ''disabled'' node UART3

How to ''disabled'' node UART3

ThinhNguyen_FE — Wed, 12 Jul 2023 09:59:52 GMT

Dear NXP Team,

We are developing in iMX8MP Eval Kit.

and now, if we want to "disabled" node UART3 of iMX8MP. Where will i find to access .dts and modify.

we are using Yocto to build.

After modifying, how to re- compile and re-build the image ?

How can I view the u-boot call to which .dtb ?

Regards,

Thinh

Re: How to ''disabled'' node UART3

Dhruvit — Fri, 14 Jul 2023 09:12:35 GMT

Hi @ThinhNguyen_FE,

I hope you are doing well.

One can disable uart3 in the device as below(at /arch/arm64/boot/dts/freescale
/imx8mp-evk.dts in linux-imx).

&uart3 {
pinctrl-names = "default";
pinctrl-0 = <&pinctrl_uart3>;
assigned-clocks = <&clk IMX8MP_CLK_UART3>;
assigned-clock-parents = <&clk IMX8MP_SYS_PLL1_80M>;
fsl,uart-has-rtscts;
- status = "okay";
+ status = "disabled";
};

Please create a patch after the above change & move that patch to /sources/meta-imx/meta-bsp/recipes-bsp/u-boot/u-boot-imx folder in yocto source.

and make below change in u-boot-imx_2022.04.bb

FILESEXTRAPATHS:prepend := "${THISDIR}/${PN}:"
SRC_URI += " file://<patch name>.patch "

after that, one can run bitbake command again to build the image.

How can I view the u-boot call to which .dtb?
[Ans]: one can use the below command.
=> printenv fdtfile

Thanks & Regards,
Dhruvit Vasavada

Re: How to ''disabled'' node UART3

ThinhNguyen_FE — Thu, 20 Jul 2023 09:39:52 GMT

Dear Dhruvit,

Thank so much.

Brgs,

Thinh

Re: How to ''disabled'' node UART3

Dhruvit — Thu, 20 Jul 2023 10:23:58 GMT

Hi @ThinhNguyen_FE,

I hope you are doing well.

If there are no further issues, can I mark this case as close ?

Thanks & Regards,
Dhruvit Vasavada