Enable two UARTs for VoCore, one UART lite, one UART full.
Just need to change DTS a little:(VOCORE.dts under openwrt source code)
First, enable uart@500
uart@500 { status = "okay"; };
Then, remove uartf from ralink,group:gpio.
pinctrl { state_default: pinctrl0 { gpio { ralink,group = "jtag", "led"; -> remove "uartf" ralink,function = "gpio"; }; }; };
Finally, delete the code that export uartf as gpio:
in gpio-export section, remove gpio7, gpio8, gpio9, gpio10, gpio11, gpio12, gpio13, gpio14. If we keep them will get some error in log, but no effect to system boot.
PS: find a possible bug here, gpio10 and gpio11 are missed 🙂
Now good news is the two UARTs work same time, bad news is we lose eight gpio. 😉
Hope one day a hero will make a new rt5350-uart driver, so that allows ralink-function=”uartf,gpio”, then we can save 4 gpios. It is a good chance to practise Linux driver code. 😀