Re: [PATCH v3 1/2] serial: core: Add option to enable RS485 mode via GPIO

Re: [PATCH v3 1/2] serial: core: Add option to enable RS485 mode via GPIO

[Tomas Paukrt]

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 "rs485-mode-gpio".

Signed-off-by: Tomas Paukrt <tomaspaukrt@email.cz>
---
 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, "rs485-mode", GPIOD_IN);
+	if (IS_ERR(desc))
+		return dev_err_probe(dev, PTR_ERR(desc), "Cannot get 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

Re: [PATCH v3 1/2] serial: core: Add option to enable RS485 mode via GPIO

[Krzysztof Kozlowski]

On 20/11/2023 22:45, 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 "rs485-mode-gpio".
> 
> Signed-off-by: Tomas Paukrt <tomaspaukrt@email.cz>
> ---
>  drivers/tty/serial/serial_core.c | 12 ++++++++++++

Why the subject is "Re:"? Please send each patchset as independent thread.

Best regards,
Krzysztof

Re: [PATCH v3 1/2] serial: core: Add option to enable RS485 mode via GPIO

[Greg Kroah-Hartman]

On Mon, Nov 20, 2023 at 10:45:20PM +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 "rs485-mode-gpio".
> 
> Signed-off-by: Tomas Paukrt <tomaspaukrt@email.cz>
> ---
>  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, "rs485-mode", GPIOD_IN);
> +	if (IS_ERR(desc))
> +		return dev_err_probe(dev, PTR_ERR(desc), "Cannot get 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
from other developers.

thanks,

greg k-h's patch email bot

Re: [PATCH v3 2/2] dt-bindings: serial: Add option to enable RS485 mode via GPIO

[Tomas Paukrt]

Add the device tree property "rs485-mode-gpio".

Signed-off-by: Tomas Paukrt <tomaspaukrt@email.cz>
---
 Documentation/devicetree/bindings/serial/rs485.yaml | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/Documentation/devicetree/bindings/serial/rs485.yaml b/Documentation/devicetree/bindings/serial/rs485.yaml
index 9418fd6..7a72f37 100644
--- a/Documentation/devicetree/bindings/serial/rs485.yaml
+++ b/Documentation/devicetree/bindings/serial/rs485.yaml
@@ -47,6 +47,10 @@ properties:
       later with proper ioctl.
     $ref: /schemas/types.yaml#/definitions/flag

+  rs485-mode-gpio:
+    description: GPIO pin to enable RS485 mode at boot time.
+    maxItems: 1
+
   rs485-rx-during-tx:
     description: enables the receiving of data even while sending data.
     $ref: /schemas/types.yaml#/definitions/flag
--
2.7.4

Re: [PATCH v3 2/2] dt-bindings: serial: Add option to enable RS485 mode via GPIO

[Krzysztof Kozlowski]

On 20/11/2023 22:45, Tomas Paukrt wrote:
> Add the device tree property "rs485-mode-gpio".
> 
> Signed-off-by: Tomas Paukrt <tomaspaukrt@email.cz>
> ---
>  Documentation/devicetree/bindings/serial/rs485.yaml | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/serial/rs485.yaml b/Documentation/devicetree/bindings/serial/rs485.yaml
> index 9418fd6..7a72f37 100644
> --- a/Documentation/devicetree/bindings/serial/rs485.yaml
> +++ b/Documentation/devicetree/bindings/serial/rs485.yaml
> @@ -47,6 +47,10 @@ properties:
>        later with proper ioctl.
>      $ref: /schemas/types.yaml#/definitions/flag
>  
> +  rs485-mode-gpio:
> +    description: GPIO pin to enable RS485 mode at boot time.
> +    maxItems: 1
> +

This does not look like generic RS485 property. Commit msg also does not
help to understand the context.

Best regards,
Krzysztof