On Thu, Oct 12, 2023 at 08:35:59PM +0200, m.brock@xxxxxxxxxxxxx wrote: > 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. Ask them. We already have 'rts-gpios'. If that's what's always used, then perhaps we should use that in the RS485 case too? Rob
