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 <CAMty3ZAQPEnCgj9r+tsuqiOzRzHPnKSEXcDqE7LKHH16Zu2Wvw@mail.gmail.com> <ZCWkdc+x0LXDSohj@francesco-nb.int.toradex.com>
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From:   Jagan Teki <jagan@amarulasolutions.com>
Date:   Thu, 30 Mar 2023 23:07:47 +0530
Message-ID: <CAMty3ZDwj5OuBzTBHrBitS0qD8QEv8=80YR2zZLDnL_nrmd3fg@mail.gmail.com>
Subject: Re: [PATCH v1 1/2] dt-bindings: display: bridge: sn65dsi83: Add DSI
 video mode
To:     Francesco Dolcini <francesco@dolcini.it>
Cc:     Andrzej Hajda <andrzej.hajda@intel.com>,
        Neil Armstrong <neil.armstrong@linaro.org>,
        Robert Foss <rfoss@kernel.org>,
        Laurent Pinchart <Laurent.pinchart@ideasonboard.com>,
        Jonas Karlman <jonas@kwiboo.se>,
        Jernej Skrabec <jernej.skrabec@gmail.com>,
        dri-devel@lists.freedesktop.org, Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Marek Vasut <marex@denx.de>, devicetree@vger.kernel.org,
        Francesco Dolcini <francesco.dolcini@toradex.com>,
        linux-kernel@vger.kernel.org
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On Thu, Mar 30, 2023 at 8:32=E2=80=AFPM Francesco Dolcini <francesco@dolcin=
i.it> wrote:
>
> On Thu, Mar 30, 2023 at 07:56:26PM +0530, Jagan Teki wrote:
> > On Thu, Mar 30, 2023 at 3:48=E2=80=AFPM Francesco Dolcini <francesco@do=
lcini.it> wrote:
> > >
> > > From: Francesco Dolcini <francesco.dolcini@toradex.com>
> > >
> > > SN65DSI8[34] device supports burst video mode and non-burst video mod=
e
> > > with sync events or with sync pulses packet transmission as described=
 in
> > > the DSI specification.
> > >
> > > Add property to select the expected mode, this allows for example to
> > > select a mode that is compatible with the DSI host interface.
> > >
> > > Signed-off-by: Francesco Dolcini <francesco.dolcini@toradex.com>
> > > ---
> > >  .../devicetree/bindings/display/bridge/ti,sn65dsi83.yaml  | 8 ++++++=
++
> > >  1 file changed, 8 insertions(+)
> > >
> > > diff --git a/Documentation/devicetree/bindings/display/bridge/ti,sn65=
dsi83.yaml b/Documentation/devicetree/bindings/display/bridge/ti,sn65dsi83.=
yaml
> > > index 48a97bb3e2e0..ebee16726b02 100644
> > > --- a/Documentation/devicetree/bindings/display/bridge/ti,sn65dsi83.y=
aml
> > > +++ b/Documentation/devicetree/bindings/display/bridge/ti,sn65dsi83.y=
aml
> > > @@ -35,6 +35,14 @@ properties:
> > >    vcc-supply:
> > >      description: A 1.8V power supply (see regulator/regulator.yaml).
> > >
> > > +  dsi-video-mode:
> > > +    description: |
> > > +      0 - burst-mode
> > > +      1 - non-burst with sync event
> > > +      2 - non-burst with sync pulse
> > > +    $ref: /schemas/types.yaml#/definitions/uint32
> > > +    enum: [0, 1, 2]
> >
> > I'm thinking this can go to dsi common code since the video modes are
> > common across all controllers and make the core initialize the default
> > and update if any sink devices are willing to change the modes. Sound
> > like a big move but worth useful.
>
> Not sure I understood where do you want to move this.

Yes, it can be new may be
Documentation/devicetree/bindings/display/dsi-device.yaml

>
> In any case this is something about the display side of the DSI video
> connection, with the bridge as a special case, not about the controller.
> To my understanding the controller is supposed to support all the modes.

Yes, that is what I'm saying. DSI sink will send this mode via
mode_flags and the controller act accordingly.  The point here is
these modes are generic across all DSI sink devices so having common
bindings can make it easy for all devices to use. As I said it can be
new, but worth trying - anyway let's see how others are commenting on
this.

Thanks,
Jagan.