Manikanta Guntupalli wrote on 2023-10-11 16:56:
Add optional gpio property to uartps node and reference to rs485.yaml On Xilinx/AMD Kria SOM KD240 board rs485 connects via TI ISOW1432 Transceiver device, where one GPIO is used for driving DE/RE signals. With rs485 half duplex configuration, DE and RE shorts to each other,
s/shorts/are connected
and at a time, any node acts as either a driver or a receiver. Here, DE - Driver enable. If pin is floating, driver is disabled. RE - Receiver enable. If pin is floating, receiver buffer is disabled.
Please use DE and /RE to indicate DE is active high and /RE is active low.
xlnx,phy-ctrl-gpios is optional property, because it is not required for uart console node.
How about introducing an rs485 generic gpios property instead of xlnx private one? See also rs485-term-gpios and rs485-rx-during-tx-gpios. Also note that every kernel driver expects to use RTS for this purpose. So why not give this driver the option to choose a gpio instead of its native RTS? And from there on use the rts route? What if someone wants to use normal (non-rs485) RTS on a GPIO instead of the native pin? @Rob Herring I am curious to know how the rs485 maintainers look at this. Maarten
