topic imx8M_Plus_SOM pin reassignments in i.MX Processors

imx8M_Plus_SOM pin reassignments

omordha — Mon, 27 Feb 2023 18:13:02 GMT

I need to reassign some pins to create more GPIO. I'm looking at the SA1 group. I've never done this before; never seen a device tree, etc. I need help to accomplish this. Thanks.

Re: imx8M_Plus_SOM pin reassignments

joanxie — Tue, 28 Feb 2023 04:03:22 GMT

firstly you need check if current bsp uses SAI1 for gpio already, for example, you can find

"https://source.codeaurora.org/external/imx/linux-imx/tree/arch/arm64/boot/dts/freescale/imx8mp-evk.dts?h=lf-5.15.y"

MX8MP_IOMUXC_SAI1_RXD0__GPIO4_IO02 0x19, you can set other SAI1 pins according to reference manual, for example, for MX8MP_IOMUXC_SAI1_RXD0__GPIO4_IO02, you can check the 8.2.4.232 SW_PAD_CTL_PAD_SAI1_RXD0 SW PAD Control Register (IOMUXC_SW_PAD_CTL_PAD_SAI1_RXD0) of reference manual

Re: imx8M_Plus_SOM pin reassignments

omordha — Tue, 28 Feb 2023 15:29:44 GMT

Thanks for the reply. I'm going to have to start from scratch. What is a BSP? I looked at the file in your link. I'm guessing that it's device tree file. I've never seen one before, so I don't know what any of it means. I looked at the i.MX 8M Plus Applications Processor
Reference Manual (8.2.4.232). I don't see anything in the register that refers to GPIO.

Re: imx8M_Plus_SOM pin reassignments

joanxie — Wed, 01 Mar 2023 04:45:56 GMT

bsp is board support packages, did you use I.MX before? you also can find bsp documents from

"https://source.codeaurora.org/external/imx/linux-imx/tree/Documentation?h=imx_5.4.70_2.3.0"

the documents and images for linux, pls find

"https://www.nxp.com/design/software/embedded-software/i-mx-software/embedded-linux-for-i-mx-applications-processors:IMXLINUX"

for example, if you use SAI1_RXD0 as GPIO, you can refer to the 8.2.4.232 to set it

"https://source.codeaurora.org/external/imx/linux-imx/tree/Documentation/devicetree/bindings/pinctrl/fsl,imx8mq-pinctrl.txt?h=imx_4.19.35_1.1.0"

if you first use imx processors, pls refer to these documents and source code firstly