Help with .dts files (imx6)

[charlieschultz]

I am using an imx6ulevk (no LCD connected). I'm trying to use a few of the LCD lines to toggle some LEDs that I've added to the board (specifically DATA00 - DATA02, aka GPIO3.5 - GPIO3.7).

I've modified the imx6ul-14x14-evk.dts file (attached as imxtul-oib.dts) and compiled it. Then I copy it to my NFS folder and run netboot on the evk to load the kernel, dtb file, etc.

I then go to /sys/class/gpio. I can export the GPIO pins (e.g. echo 70 > export) I'm using and write the direction and value settings, but the GPIO lines (LEDs) do not toggle.

Is there something else that I'm not doing, and is my .dts file ok?

Thanks in advance,

Charlie

Original Attachment has been moved to: imx6ul-oib.dts.zip

[charlieschultz]

Thanks all. Memtool showed me that the mux pins were not getting set for gpio. Adding them to the "hog" list in the .dts file fixed that and I can now toggle the LEDs. I'm still a bit unclear as to why the pinctrl_gpio3 definition didn't do the same thing.

[piyushashtikar]

Please consider to mark the answer as "correct" .

It will help other users who face similar problem.

Thanks.

[piyushashtikar]

I suggest first of all using memtool utility check if IOMUX register for specific pad is set correctly. (refer iMX Reference Manual for addresses od register)

ie. if that pin is really configured as a GPIO.

Secondly refer this url: GPIO (Linux) 

Regards,

Piyush Ashtikar

[igorpadykov]

Hi Charlie

please check

Simple GPIO Example - quandry | NXP Community 

also may be useful to remove lcd configs from uboot.

Best regards
igor
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