We're using nanopi neo plus2 for some projects. Many of them need to communicate via RS-485.
Nanopi neo2 and neo plus2 has both 2 8250 UART (with TX-RX-RTS-CTS).
We tried to set SER_RS485_ENABLED to make ttyS1 to work as rs-485 but we've got "Inappropriate ioctl for device" when run the test program.
Is these UART compatible with RS-485 ?
Is there any patch to build Linux kernel with serial driver compatible RS-485 for AllWinner H5 SoC (I mean to use RTS as TxEn) ?