Re: [PATCH v4 1/2] serial: core: Add support for enabling RS485 mode via GPIO at boot time

[Greg Kroah-Hartman]

On Tue, Nov 21, 2023 at 09:28:10AM +0100, Tomas Paukrt wrote:
> Add an option to enable the RS485 mode at boot time based on
> the state of a GPIO pin (DIP switch or configuration jumper).
> The GPIO is defined by the device tree property "linux,rs485-mode-gpio".
> 
> Signed-off-by: Tomas Paukrt <tomaspaukrt@xxxxxxxx>
> ---
>  drivers/tty/serial/serial_core.c | 12 ++++++++++++
>  1 file changed, 12 insertions(+)
> 
> diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c
> index f1348a5..f1bf0b9 100644
> --- a/drivers/tty/serial/serial_core.c
> +++ b/drivers/tty/serial/serial_core.c
> @@ -3603,6 +3603,18 @@ int uart_get_rs485_mode(struct uart_port *port)
>  	}
> 
>  	/*
> +	 * Enable the RS485 mode based on the state of a GPIO pin.
> +	 */
> +	desc = devm_gpiod_get_optional(dev, "linux,rs485-mode", GPIOD_IN);
> +	if (IS_ERR(desc))
> +		return dev_err_probe(dev, PTR_ERR(desc), "Cannot get linux,rs485-mode-gpio\n");
> +	if (desc) {
> +		if (gpiod_get_value(desc))
> +			rs485conf->flags |= SER_RS485_ENABLED;
> +		devm_gpiod_put(dev, desc);
> +	}
> +
> +	/*
>  	 * Disabling termination by default is the safe choice:  Else if many
>  	 * bus participants enable it, no communication is possible at all.
>  	 * Works fine for short cables and users may enable for longer cables.
> --
> 2.7.4
> 
> 

Hi,

This is the friendly patch-bot of Greg Kroah-Hartman.  You have sent him
a patch that has triggered this response.  He used to manually respond
to these common problems, but in order to save his sanity (he kept
writing the same thing over and over, yet to different people), I was
created.  Hopefully you will not take offence and will fix the problem
in your patch and resubmit it so that it can be accepted into the Linux
kernel tree.

You are receiving this message because of the following common error(s)
as indicated below:

- This looks like a new version of a previously submitted patch, but you
  did not list below the --- line any changes from the previous version.
  Please read the section entitled "The canonical patch format" in the
  kernel file, Documentation/process/submitting-patches.rst for what
  needs to be done here to properly describe this.

If you wish to discuss this problem further, or you have questions about
how to resolve this issue, please feel free to respond to this email and
Greg will reply once he has dug out from the pending patches received
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thanks,

greg k-h's patch email bot