We made a board based on 1046ardb and used 485. How can I modify rcw and device tree to use it?
According to your schematic, you are using processor GPIO lines to manage DE and RE inputs of your 485 transmitter. This means DE and RE lines are expected to be managed in your software, by using GPIO (General Purpose I/O) lines. So, modifying only RCW and device tree is not enough to utilize this connection, a custom Linux driver will be required.