imx8M_Plus_SOM pin reassignments

[omordha]

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.

[omordha]

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.

[joanxie]

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-applicat...

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/...

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

[joanxie]

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.d..."

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