Re: [PATCH v2 3/4] dt-bindings: drm/bridge: ti-sn65dsi83: Add vcc supply bindings

[Laurent Pinchart <laurent.pinchart@ideasonboard.com>]

Hi Maxime,

On Wed, Oct 13, 2021 at 09:47:22AM +0200, Maxime Ripard wrote:
> On Tue, Oct 12, 2021 at 08:48:42AM +0200, Alexander Stein wrote:
> > Add a VCC regulator which needs to be enabled before the EN pin is
> > released.
> > 
> > Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
> > Signed-off-by: Alexander Stein <alexander.stein@ew.tq-group.com>
> > ---
> >  .../devicetree/bindings/display/bridge/ti,sn65dsi83.yaml     | 5 +++++
> >  1 file changed, 5 insertions(+)
> > 
> > diff --git a/Documentation/devicetree/bindings/display/bridge/ti,sn65dsi83.yaml b/Documentation/devicetree/bindings/display/bridge/ti,sn65dsi83.yaml
> > index a5779bf17849..49ace6f312d5 100644
> > --- a/Documentation/devicetree/bindings/display/bridge/ti,sn65dsi83.yaml
> > +++ b/Documentation/devicetree/bindings/display/bridge/ti,sn65dsi83.yaml
> > @@ -32,6 +32,9 @@ properties:
> >      maxItems: 1
> >      description: GPIO specifier for bridge_en pin (active high).
> >  
> > +  vcc-supply:
> > +    description: A 1.8V power supply (see regulator/regulator.yaml).
> > +
> >    ports:
> >      $ref: /schemas/graph.yaml#/properties/ports
> >  
> > @@ -93,6 +96,7 @@ properties:
> >  required:
> >    - compatible
> >    - reg
> > +  - vcc-supply
> 
> This isn't a backward-compatible change. All the previous users of that
> binding will now require a vcc-supply property even though it was
> working fine for them before.
> 
> You handle that nicely in the code, but you can't make that new property
> required.

We can't make it required in the driver, but can't we make it required
in the bindings ? This indicates that all new DTs need to set the
property. We also need to mass-patch the in-tree DTs to avoid validation
failures, but apart from that, I don't see any issue.

-- 
Regards,

Laurent Pinchart