Re: [PATCHv2 1/2] dt-bindings: xilinx-uartps: Add support for noctsrts

[Shubhrajyoti Datta <shubhrajyoti.datta@gmail.com>]

Hi Rob,
Thanks for  the review.

On Sat, Apr 6, 2019 at 11:36 AM Rob Herring <robh@kernel.org> wrote:
>
> On Tue, Apr 02, 2019 at 10:36:17AM +0530, shubhrajyoti.datta@gmail.com wrote:
> > From: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>
> >
> > Vivado has a configurationo for selecting the flow control.
>
> Vivado is ?
>
> > Add a dt binding to check for the same.
> >
> > Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>
> > ---
> >  Documentation/devicetree/bindings/serial/cdns,uart.txt | 4 ++++
> >  1 file changed, 4 insertions(+)
> >
> > diff --git a/Documentation/devicetree/bindings/serial/cdns,uart.txt b/Documentation/devicetree/bindings/serial/cdns,uart.txt
> > index 227bb77..5161a05 100644
> > --- a/Documentation/devicetree/bindings/serial/cdns,uart.txt
> > +++ b/Documentation/devicetree/bindings/serial/cdns,uart.txt
> > @@ -12,6 +12,10 @@ Required properties:
> >    See ../clocks/clock-bindings.txt for details.
> >
> >
> > +Optional properties:
> > +- xlnx,nortscts: The presence of this property indicates that the
> > +    UART does not support modem lines for RTS/CTS hardware flow control.
>
> We already have 'uart-has-rtscts'. Please use that. Maybe you need a new
> compatible as I'd guess current users assume RTS/CTS is present.

the setting in vivado (tool helps configure the board) which says no
flowcontrol.
this just keeps the lines in a unknown state.

this issue  with 'uart-has-rtscts'  is  backward compatibility
current code assumes rts / cts is
present. If not preset then it  will return false. So I  thought of
having a property with the inverse.
>
> > +
> >  Example:
> >       uart@e0000000 {
> >               compatible = "cdns,uart-r1p8";
> > --
> > 2.1.1
> >
>