imx93evk - Enable LPUART via IOMUX not working

[rti]

Hello all,

I am currently working with an imx93evk board.

I want to enable the LPUART3 via the GPIO Pins. Looking to the imx93evk Board Design in the IOMUX page I can see that for GPIO_IO14/15 we have as ALT1 the UART3 TX/RX.

Register

Piece of code:

    IOMUXC_SetPinMux(IOMUXC_PAD_GPIO_IO14__LPUART3_TX, 0U);

    IOMUXC_SetPinMux(IOMUXC_PAD_GPIO_IO15__LPUART3_RX, 0U);

    IOMUXC_SetPinConfig(IOMUXC_PAD_GPIO_IO15__LPUART3_RX,

                        IOMUXC_PAD_PD_MASK);

    IOMUXC_SetPinConfig(IOMUXC_PAD_GPIO_IO14__LPUART3_TX,

                        IOMUXC_PAD_DSE(15U));

I also enable the Clock of LPUART3.

Is there anything missing to enable the LPUART via the GPIO pins?

[danielchen]

Hi @rti 

If you just need to enable LPUART3 in Linux, you can refer to below link.

How to enable UART3 in FRDM-IMX93 board - NXP Community

Regards

Daniel

[rti]

Hello,

I made the same configuration but now for LPUART6 and everything works fine.

In addition I saw that in the imx93evk there is a reference that IW61X has GPIO12-15 mapped to SPI and UART2. Is this reserving completely the Pins or is there a TMUX where we can switch between M.2 Module and IOMUX ALTX pinout?

Thanks.

[manuelrodriguez]

Hi @rti ,

Are you using the SDK for this one? do you want to enable it on the M33?

Is Linux also running here? 

What EVK are you using?

There aren't many device trees where those pads are being used but just wanted to double check that:

https://github.com/nxp-imx/linux-imx/blob/lf-6.12.y/arch/arm64/boot/dts/freescale/imx93-9x9-qsb.dts#...

https://github.com/nxp-imx/linux-imx/blob/lf-6.12.y/arch/arm64/boot/dts/freescale/imx93-tqma9352-mba...

[rti]

Hello  @manuelrodriguez ,

Thanks for the reply.

I am using imx93evk 11x11 and SDK 24.12.

I want to enable the LPUART3 in the M33 core. I was able to do it for the LPUART6.

I am in doubt if this is blocked (since in the HW scheme, the pins are mentioned to be reserved for M2 module) or if it is already reserved by the kernel, or a third option if some TMUX is necessary to configure.

[manuelrodriguez]

Hi @rti ,

The code seems OK, and the default device tree is not using those pads (assuming you have an image with both Linux and M33 firmware running).

However where are you measuring the signals? I'm assuming you have a TTY2USB converter connected to J1001 pin 8 and 10?

The mention in the schematics I think refer to the IW61 pins not the i.MX93, if you are referencing this: