i.MX ProcessorsのトピックRe: i.MX8 ADC_IN0 pin can't set as GPIO function

i.MX8 ADC_IN0 pin can't set as GPIO function

zoro — Thu, 22 Aug 2019 11:05:07 GMT

Hi all:

1. i.MX8 ADC_IN0 pin can't config to GPIO function, here is my dts pin config:

SC_P_ADC_IN0_LSIO_GPIO3_IO18 0x1E000000

2. when as output function, pin value always 0;

3. when as input function, gpio value always 0 no matter what level at the pin connected.

Re: i.MX8 ADC_IN0 pin can't set as GPIO function

igorpadykov — Thu, 22 Aug 2019 23:51:47 GMT

Hi zeng

this pad is dual voltage pad and needs special configuartion, one can try to add in dts:

pinctrl_hog*:
SC_P_COMP_CTL_GPIO_1V8_3V3_GPIORHT 0x000514a0

Best regards
igor
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Re: i.MX8 ADC_IN0 pin can't set as GPIO function

zoro — Fri, 23 Aug 2019 03:14:36 GMT

igorpadykov‌, Thanks for your reply at first.

1. Here is my current config in dts:

pinctrl_hog: hoggrp {
fsl,pins = <
[...]
SC_P_COMP_CTL_GPIO_1V8_3V3_GPIORHT 0x000514a0
SC_P_ADC_IN0_LSIO_GPIO3_IO18 0x1E000000 //irq
>;
};

2. It can not work well.

Re: i.MX8 ADC_IN0 pin can't set as GPIO function

zoro — Fri, 23 Aug 2019 08:06:04 GMT

1. when i change SC_P_COMP_CTL_GPIO_1V8_3V3_GPIORHT to SC_P_COMP_CTL_GPIO_1V8_3V3_GPIORHT_PAD, it can work now, but i don't know why. :smileyhappy:

pinctrl_hog: hoggrp {
fsl,pins = <
SC_P_COMP_CTL_GPIO_1V8_3V3_GPIORHT_PAD 0x000514a0
SC_P_ADC_IN0_LSIO_GPIO3_IO18 0x1E000000 //irq
>;
};

2. Is 1V8_3V3 in SC_P_COMP_CTL_GPIO_1V8_3V3_GPIORHT_PAD means the pin compatible 1.8V and 3.3V External voltage？

3. What is the mean RH in GPIORHT?

Re: i.MX8 ADC_IN0 pin can't set as GPIO function

igorpadykov — Fri, 23 Aug 2019 10:40:39 GMT

>>SC_P_COMP_CTL_GPIO_1V8_3V3_GPIORHT_PAD, it can work now,
>but i don't know why

right, seems correct usage with *_PAD, similar example can be found for

"SC_P_COMP_CTL_GPIO_1V8_3V3_GPIORHB_PAD" in

fsl-imx8qxp-mek-lcdif.dts\freescale\dts\boot\arm64\arch - linux-imx - i.MX Linux kernel

That specific "dual voltage" pad setting is needed for i.MX8QM/QXP processors,

details can be found in IOMUX Chapter of Reference Manual.

Best regards
igor

Re: i.MX8 ADC_IN0 pin can't set as GPIO function

zoro — Sat, 24 Aug 2019 03:57:54 GMT

1. We can control ADC_IN0 as GPIO input/output at /sys/class/gpio/ in filesystem now;

2. but when i try to use ADC_IN0 as interrupt pin, it still can't work.

2.1 I have use this tool to test interrupt: GitHub - OnionIoT/gpioIrq: Example of using sysfs for edge detection interrupts on the Omega's GPIOs

2.2 I have try this tool at Raspberry Pi 0, it is ok:

Re: i.MX8 ADC_IN0 pin can't set as GPIO function

igorpadykov — Sat, 24 Aug 2019 10:07:57 GMT

may be helpful to look:

https://community.nxp.com/thread/510246

Re: i.MX8 ADC_IN0 pin can't set as GPIO function

zoro — Wed, 28 Aug 2019 06:30:42 GMT

I read the post, but i still don't know how to enable the irq for ADC_IN0, still can't work. :smileysad:

Re: i.MX8 ADC_IN0 pin can't set as GPIO function

igorpadykov — Wed, 28 Aug 2019 10:43:00 GMT

also one can look at example pinctrl_gpio_leds: SC_P_SPDIF0_TX_LSIO_GPIO2_IO15

fsl-imx8qm-ddr4-arm2.dts\freescale\dts\boot\arm64\arch - linux-imx - i.MX Linux kernel

Best regards
igor

Re: i.MX8 ADC_IN0 pin can't set as GPIO function

zoro — Thu, 29 Aug 2019 02:27:25 GMT

1. I always try the both edge type interrupt at ADC_IN0 before and it can't work;

2. when i try rising/falling edge type interrupt at ADC_IN0 today and it works for me;

3. i.MX8 GPIO driver do not support both edge type interrupt;

Thanks.

Re: i.MX8 ADC_IN0 pin can't set as GPIO function

nolan_zinn — Mon, 23 Mar 2020 21:12:12 GMT

igorpadykov‌ Do you know how to change this

SC_P_COMP_CTL_GPIO_1V8_3V3_GPIORHB_PAD 0x000514a0

to use the 3.3V level instead of 1.8V? I assume it has to do with the hex value at the end, but I couldn't find any references on how to set this in the devicetree.

Thanks,

Nolan Z