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shaddow501

Armbian overly toggle GPIO at BOOT

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Hello

 

Does anyone know how to toggle GPIO output at boot / power up as an overlay or similar?

I have seen only examples that show GPIO in function and I didnt find much information how to toggle GPIO out function.

 

Basically I would like to be able to turn LCD back light on when the board is booting and than to be able to control the brightness. (That I can do after the Linux is up and running)

but before the Linux is up I still want to be able to control the LCD back light.

 

 

Can anyone help with that matter?

 

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On 6/13/2019 at 10:17 AM, nradulovic said:

Hello,

 

Did you have a look at this? https://www.kernel.org/doc/Documentation/devicetree/bindings/gpio/gpio.txt

 

There are some attributes that can set initial value during initialization. See for example: output-low and output-high properties.

 

Is that what you need?

Actually I need to see a working example of the dts file...

Because I do not know how to build it correctly.

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