topic Re: How to enable UART2 in Linux on LX2160A? in Layerscape

How to enable UART2 in Linux on LX2160A?

ZhaoZheng1 — Fri, 10 Oct 2025 08:21:31 GMT

Hi,

I'd like to enable both UART1 and UARAT2 in Linux on LX2160A.
kernel version: 5.15.71

configuration in dts, it seems ok.

Check UART control register, UART2 has not been enabled.
root@localhost:~# devmem2 0x21d0030 32
0x00000300
root@localhost:~# devmem2 0x21c0030 32
0x00000B01

May i have your comments?
Many thanks!

Zhao

Re: How to enable UART2 in Linux on LX2160A?

ZhaoZheng1 — Sat, 11 Oct 2025 08:46:53 GMT

BTW, I have a trial to modify the register of UARTCR to enable UART2, still not working..

Re: How to enable UART2 in Linux on LX2160A?

yipingwang — Mon, 13 Oct 2025 02:12:22 GMT

Please try below patch

https://patchwork.ozlabs.org/project/uboot/cover/1607490724-6447-1-git-send-email-vabhav.sharma@oss.nxp.com/

Then enable CONFIG_SERIAL_PROBE_ALL=y in lx2160ardb_tfa_defconfig after applying this patch.

Re: How to enable UART2 in Linux on LX2160A?

ZhaoZheng1 — Mon, 13 Oct 2025 02:25:49 GMT

Hi Yiping,

Thanks for your great help.

I checked the patch, it's about u-boot.
Does it mean enable UART2 in Linux should probe all UARTs in u-boot?

Thanks,

Zhao

Re: How to enable UART2 in Linux on LX2160A?

yipingwang — Mon, 13 Oct 2025 02:31:05 GMT

Yes, you need to apply this patch in u-boot. Then check UART1 and UART2 in Linux.

Re: How to enable UART2 in Linux on LX2160A?

ZhaoZheng1 — Mon, 13 Oct 2025 02:33:10 GMT

That's make sense.

I just checked the patch already integrated into u-boot mainline at least in LF-5.15.y.

Re: How to enable UART2 in Linux on LX2160A?

yipingwang — Mon, 13 Oct 2025 02:41:42 GMT

Please enable CONFIG_SERIAL_PROBE_ALL=y in lx2160ardb_tfa_defconfig after applying this patch.

We have verified this method in LSDK 21.08.

Re: How to enable UART2 in Linux on LX2160A?

ZhaoZheng1 — Mon, 13 Oct 2025 07:38:02 GMT

Thanks a lot, Yiping.

Regards,

Zhao

Re: How to enable UART2 in Linux on LX2160A?

kenli — Thu, 13 Nov 2025 18:32:47 GMT

Dear Zhaozhao,
The fsl-lx2160a.dtsi was added through an out-of-tree patch from my customer in 2023 and was merged into our branch in 2024; it is now fully supported.
Commit reference: git show 8b4a8708d37c1174f6a8ee0b8c78ad78c89df8e4

Re: How to enable UART2 in Linux on LX2160A?

ZhaoZheng1 — Fri, 14 Nov 2025 03:17:50 GMT

Hi Ken,

Thanks for your kindly support.

Regards,

Zhao