topic Re: imx287 gpio in i.MX Processors

imx287 gpio

adityapatil — Wed, 13 Dec 2017 04:44:54 GMT

I am working on imx287 CPU with linux-2.6.35.3.

I have configured the PIN 3_10 to be output and low in the kernel.

But, when I restart the pin remains high value till the kernel has initialized gpmi (mx28 pins) in file mx28evk_pins.c and then becomes low.

How can I avoid this and keep the pin low even after restart.

-Thanks

Re: imx287 gpio

igorpadykov — Wed, 13 Dec 2017 06:45:14 GMT

Hi Aditya

one can add gpio initialization in bootlet sources.
For obtaining bootlets sources:

1. ./ltib -m prep -p imx-bootlets
This command will put imx-bootlets source codes in the folder --
ltib/rpm/build/

2. modify sources
3. ./ltib -m scbuild -p imx-bootlets

This command will build new images.

Best regards
igor
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Re: imx287 gpio

adityapatil — Thu, 28 Dec 2017 02:05:57 GMT

1.I have the bootlet sources

2. Can I add the gpio initialization in bootlet source without using ltib?

-Thanks

Re: imx287 gpio

igorpadykov — Thu, 28 Dec 2017 05:27:46 GMT

in general one can use yocto with uboot, please look at

https://community.nxp.com/thread/306491

~igor

Re: imx287 gpio

adityapatil — Fri, 29 Dec 2017 04:58:58 GMT

hi igor,

I did some modification in the file init-mx28.c in boot_prep of bootlet source code

//Pin_1_28 as out and low

HW_PINCTRL_MUXSEL3_SET(3 << 24);

HW_PINCTRL_DOE1_SET(1 << 24);

HW_PINCTRL_DOUT1_CLR(1 << 24);

But still the pin fails to be low on startup.

Thanks,

-Aditya