Re: [PATCH v2 6/7] serial: 8250: Support separate rs485 rx-enable GPIO

From: Lukas Wunner
Date: Sat May 16 2020 - 16:17:56 EST


On Thu, Mar 26, 2020 at 12:14:21AM +0100, Heiko Stuebner wrote:
> --- a/drivers/tty/serial/serial_core.c
> +++ b/drivers/tty/serial/serial_core.c
> @@ -3356,6 +3356,18 @@ int uart_get_rs485_mode(struct uart_port *port)
> rs485conf->flags |= SER_RS485_TERMINATE_BUS;
> }
>
> + port->rs485_re_gpio = devm_gpiod_get(dev, "rs485-rx-enable",
> + GPIOD_FLAGS_BIT_DIR_OUT);

I think you want to use GPIOD_OUT_HIGH here so that rs485 reception
is enabled by default and only disabled at runtime when sending
(if half-duplex mode is used).

Thanks,

Lukas