imx8mm - Pin bank and offset mapping

[raman_thapar]

Hello,

I was trying to setup some pins in uBoot and was trying to find the IO bank and offset mapping so I could make use of 

IMX_GPIO_NR(bank, nr) to control the pin.

I didnt see anything in the reference manual and the imx dts files on the kernel side use this format

* The pin function ID is a tuple of

* <mux_reg conf_reg input_reg mux_mode input_val>

Also in the kernel is there a recommended place for board initialization or is it best to keep that in uboot?

Thanks!

[igorpadykov]

Hi Raman

for IMX_GPIO_NR one can look at

gpio.h\arch-imx8\asm\include\arm\arch - uboot-imx - i.MX U-Boot 

spl.c\imx8mq_evk\freescale\board - uboot-imx - i.MX U-Boot 

>Also in the kernel is there a recommended place for board initialization or is it best to keep that in uboot?

it depends on kernel, in latest for example clock initialization is performed in

imx\clk\drivers - linux-imx - i.MX Linux kernel 

Best regards
igor
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[raman_thapar]

Thanks Igor

In this example

#define USDHC2_CD_GPIO IMX_GPIO_NR(2, 12)

I wanted to know how I could find that bank 2 and offset 12 corresponds to a specific pin. 

So for example where can I find the mapping from SAI5_RXC or AC15 to a bank and offset number.

Thanks!

[igorpadykov]

Hi Raman

from gpio.h\arch-imx8\asm\include\arm\arch - uboot-imx - i.MX U-Boot

/* IMX8 the GPIO index is from 0 not 1 */#define IMX_GPIO_NR(port, index)  (((port)*32)+((index)&31))
port number can be found in IOMUX Chapter of i.MX8M Mini Reference Manual
i.MX 8M Mini Applications Processor Reference Manual

Best regards
igor

[raman_thapar]

Thanks Igor I found this in uboot and understand how to use the #define.

What I need is a way to map from a named pin for example SAI5_RXC or AC15 to a bank/port and offset number. 

Do you know where I can find that? 

Thanks,

Raman

[igorpadykov]

Hi Raman

from p.1395 RM : GPIO3_IO20 (port3, index 20)

Best regards
igor