Re: [PATCH v2 5/7] dt-bindings: serial: Add binding for rs485 receiver enable GPIO
From: Andy Shevchenko
Date: Mon Mar 30 2020 - 10:54:17 EST
On Thu, Mar 26, 2020 at 12:14:20AM +0100, Heiko Stuebner wrote:
> From: Heiko Stuebner <heiko.stuebner@xxxxxxxxxxxxxxxxxxxxx>
>
> RS485 has two signals to control transmissions "drivee enable" (RE) and
drivee -> driver ?
> "receiver enable" (DE). RE is already handled via the uarts RTS signal
Typo in abbreviations in parentheses, you probably need to swap them.
> while RE signal on most implementations doesn't get handled separately
> at all.
>
> As there still will be cases where this is needed though add a gpio
> property for declaring this signal pin.
>
> Signed-off-by: Heiko Stuebner <heiko.stuebner@xxxxxxxxxxxxxxxxxxxxx>
> ---
> 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 a9ad17864889..e55730de796d 100644
> --- a/Documentation/devicetree/bindings/serial/rs485.yaml
> +++ b/Documentation/devicetree/bindings/serial/rs485.yaml
> @@ -44,6 +44,10 @@ properties:
> description: enables the receiving of data even while sending data.
> $ref: /schemas/types.yaml#/definitions/flag
>
> + rs485-rx-enable-gpios:
> + description: GPIO to handle a separate RS485 receive enable signal
> + $ref: /schemas/types.yaml#/definitions/flag
> +
> rs485-term-gpios:
> description: GPIO pin to enable RS485 bus termination.
> maxItems: 1
> --
> 2.24.1
>
--
With Best Regards,
Andy Shevchenko