i.MX Processors中的主题 Re: setting GPIO

setting GPIO

ddeyo1 — Fri, 11 Mar 2022 20:41:30 GMT

I am using an iMX8mm SOM from Boundary that initially had gpio2 configured for usdhc1 emmc interface and usdhc2 for the sdcard. We are using emmc but not sdcard.

I have been able to reconfigure all of my other gpio ports and pins and all of them work except for all of the usdhc2 pins. I've removed the usdhc2 node from my device tree and I no longer get a clock on SD2_CLK.

However when I export gpio 45 (gpio2 13), change the direction to output and set the value to 1, my pin stays low.

Is there anything that would prevent a pin mux change for usdhc?

I should add that I have also added gpio14 and gpio15 and my pinctrl settings are the same as my working pins. None of the usdhc2 pins can be changed.

Re: setting GPIO

josephzhou1 — Sat, 12 Mar 2022 13:04:44 GMT

Re: setting GPIO

ddeyo1 — Sat, 12 Mar 2022 15:25:33 GMT

Did you have a question or answer?

-dwd

Re: setting GPIO

disheng — Mon, 14 Mar 2022 06:52:38 GMT

Probably the pins are also configured in the uboot, there is a .c file for your board initialization, you can take a look there.

Re: setting GPIO

Kecy — Wed, 06 Jul 2022 09:22:05 GMT

ddeyo1

I have the same problem, have you solved it

Re: setting GPIO

ddeyo1 — Wed, 06 Jul 2022 15:02:58 GMT

Yes, I solved it. I think it was in uboot. I think I had to enable hog on the CONFIG for uboot.

file: configs/nitrogen8mm_4g_defconfig b/configs/nitrogen8mm_4g_defconfig

change: CONFIG_GPIO_HOG=y

I was told this was off by default.

Then, of course, I had to include the pinctrl settings for my pins in a hog node in my uboot dts file.

Re: setting GPIO

ddeyo1 — Wed, 06 Jul 2022 15:08:19 GMT

This is my added node that goes under &iomuxc:

pinctrl_hog: hoggrp {
fsl,pins = <
MX8MMN(IOMUXC_SD2_CD_B_GPIO2_IO12, 0x16)
MX8MMN(IOMUXC_SD2_CLK_GPIO2_IO13, 0x16)
MX8MMN(IOMUXC_SD2_CMD_GPIO2_IO14, 0x16)
MX8MMN(IOMUXC_SD2_DATA0_GPIO2_IO15, 0x16)
MX8MMN(IOMUXC_SD2_RESET_B_GPIO2_IO19, 0x16)
MX8MMN(IOMUXC_NAND_ALE_GPIO3_IO0, 0x16)
MX8MMN(IOMUXC_ECSPI2_SS0_GPIO5_IO13, 0x16)
>;
};