I was not able to get additional uarts to work using rsetup with the debian image.
I rebuilt the system using gentoo and was able to get it to boot, but the ethernet would not work. After updating uboot, it seemed to work, but the uarts still did not work.
I created my own overlay like this:
/dts-v1/;
/plugin/;
/ {
fragment@0 {
target = <&uart3>;
__overlay__ {
status = "okay";
};
};
fragment@1 {
target = <&uart4>;
__overlay__ {
status = "okay";
};
};
fragment@3 {
target = <&uart9>;
__overlay__ {
status = "okay";
};
};
};
and this portion works, but if I add a fragment for uart5, I get this when booting:
[ 2.040397] rockchip-pinctrl pinctrl: pin gpio2-2 already requested by fe690000.serial; cannot claim for fe2b0000.mmc
[ 2.041453] rockchip-pinctrl pinctrl: error -EINVAL: pin-66 (fe2b0000.mmc)
[ 2.042093] rockchip-pinctrl pinctrl: error -EINVAL: could not request pin 66 (gpio2-2) from group sdmmc0-clk on device rockchip-pinctrl
[ 2.042265] arm-scmi arm-scmi.8.auto: Using scmi_smc_transport
[ 2.043178] dwmmc_rockchip fe2b0000.mmc: Error applying setting, reverse things back
which makes teh system unbootable as it can’t read the SD card.
Is the dts defined incorrectly? I don’t think enabling the UART should do this. Is it actually on a different interface number?