On Fri, Jan 26, 2024 at 06:27:44PM +0100, Farouk Bouabid wrote: > RS485 can have a receiver-enable gpio (rx-enable-gpios). When rs485 is s/gpio/GPIO/ > enabled, this gpio, if provided, must be driven active while receiving. > However when RS485 is disabled this gpio should not have an undefined > state. In that case, as DE and RE pins can be connected both to this gpio, > if its state is not properly defined, can cause unexpected transceiver > behavior. > This binding depend on rx-enable-gpios to be implemented. Sounds like a constraint: dependencies: rs485-rx-enable-inactive-when-rs485-disabled: [ rx-enable-gpios ] > > Signed-off-by: Farouk Bouabid <farouk.bouabid@xxxxxxxxxxxxxxxxxxxxx> > --- > Documentation/devicetree/bindings/serial/rs485.yaml | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/Documentation/devicetree/bindings/serial/rs485.yaml b/Documentation/devicetree/bindings/serial/rs485.yaml > index b64577036b5c..4c79dfaaf460 100644 > --- a/Documentation/devicetree/bindings/serial/rs485.yaml > +++ b/Documentation/devicetree/bindings/serial/rs485.yaml > @@ -55,6 +55,11 @@ properties: > description: GPIO to handle a separate RS485 receive enable signal > maxItems: 1 > > + rs485-rx-enable-inactive-when-rs485-disabled: For something a bit shorter, perhaps: rs485-rx-enable-inactive-on-disable > + description: rx-enable GPIO is not active when RS485 is disabled. If missing, active-state > + is assumed. > + $ref: /schemas/types.yaml#/definitions/flag > + > rs485-term-gpios: > description: GPIO pin to enable RS485 bus termination. > maxItems: 1 > > -- > 2.34.1 >
