How to enable UART

[matthewoots]

Hi @avafinger wondering how do I enable UART on this guy, or is it enable already?

Am I able to use debug console for normal UART or can I use the UART4

[avafinger]

I know it is possible to use debug uart as normal uart by editing the kernel boot argument but i have never done it. I think there is some info about this on the net.

I think for the UART4 is just to enable it like this:

uart4: serial@ff370000 {
compatible = "rockchip,rk3399-uart", "snps,dw-apb-uart";
reg = <0x0 0xff370000 0x0 0x100>;
clocks = <&pmucru 6>, <&pmucru 34>;
clock-names = "baudclk", "apb_pclk";
interrupts = <0 102 4 0>;
reg-shift = <2>;
reg-io-width = <4>;
pinctrl-names = "default";
pinctrl-0 = <&uart4_xfer>;
status = "okay";
};

you have to decompile dtb, change it to:
status = "disabled";
and re-compile it.

Please, backup dtb before trying.