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Registered: ‎09-30-2011

Set a default ZYNQ MIO/GPIO value in the Device Tree

This is very frustrating.  I am using the standard linux gpio access for Zynq and have an issue where I need a specific IO to come up as a logic 1. The implicit default is a zero - which is bad for me. It must be a 1.

My device tree entry is

gpio0: gpio@e000a000 {
compatible = "xlnx,zynq-gpio-1.0";
#gpio-cells = <2>;
clocks = <&clkc 42>;
gpio-controller;
interrupt-controller;
#interrupt-cells = <2>;
interrupt-parent = <&intc>;
interrupts = <0 20 4>;
reg = <0xe000a000 0x1000>;
};

The Xilinx Wiki device tree documentation doesn't explain how to modify this to do what I want and I am getting the feeling that I can't do what I want but I hope I can. I don't want to change my GPIO model to gpio-leds or gpio-keys but if I reaaly have to, I suppose I will.

I am hoping that these entries might help me

gpio-mask-high = <0x0>;
gpio-mask-low = <0x5600>;

but I can't find anything that explains what their function is.

Any ideas out there?

Much appreciated

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Registered: ‎09-30-2011

It sure would be cool if either of these worked:

xlnx,dout-default = <0x00C000>;

-- or --

gpio_default: default {
    gpio-output-high = <14 15>;
};

Do they? Does anyone know?

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