2024-01-26 17:28:58

by Farouk Bouabid

Subject: [PATCH v5 1/6] dt-bindings: serial: Add binding for rs485 receiver enable GPIO

From: Heiko Stuebner <[email protected]>

RS485 has two signals to control transmissions "driver enable" (DE) and
"receiver enable" (RE). DE is already handled via the uarts RTS signal
while the 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 <[email protected]>
Signed-off-by: Farouk Bouabid <[email protected]>
---
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 9418fd66a8e9..b64577036b5c 100644
--- a/Documentation/devicetree/bindings/serial/rs485.yaml
+++ b/Documentation/devicetree/bindings/serial/rs485.yaml
@@ -51,6 +51,10 @@ 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
+ maxItems: 1
+
rs485-term-gpios:
description: GPIO pin to enable RS485 bus termination.
maxItems: 1

--
2.34.1

2024-01-30 22:57:07

by Rob Herring

Subject: Re: [PATCH v5 1/6] dt-bindings: serial: Add binding for rs485 receiver enable GPIO

On Fri, 26 Jan 2024 18:27:42 +0100, Farouk Bouabid wrote:
> From: Heiko Stuebner <[email protected]>
>
> RS485 has two signals to control transmissions "driver enable" (DE) and
> "receiver enable" (RE). DE is already handled via the uarts RTS signal
> while the 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 <[email protected]>
> Signed-off-by: Farouk Bouabid <[email protected]>
> ---
> Documentation/devicetree/bindings/serial/rs485.yaml | 4 ++++
> 1 file changed, 4 insertions(+)
>

Reviewed-by: Rob Herring <[email protected]>