Re: [PATCH v1 1/8] dt-bindings: display: panel: properly document LG LD070WX3 panel

[Svyatoslav Ryhel <clamor95@gmail.com>]

вт, 30 вер. 2025 р. о 06:12 Doug Anderson <dianders@chromium.org> пише:
>
> Hi,
>
> On Mon, Sep 29, 2025 at 7:25 AM Svyatoslav Ryhel <clamor95@gmail.com> wrote:
> >
> > LG LD070WX3-SL01 was mistakenly documented as a simple DSI panel, which it
> > clearly is not. Address this by adding the proper schema for this panel.
> >
> > Signed-off-by: Svyatoslav Ryhel <clamor95@gmail.com>
> > ---
> >  .../bindings/display/panel/lg,ld070wx3.yaml   | 60 +++++++++++++++++++
> >  .../display/panel/panel-simple-dsi.yaml       |  2 -
> >  2 files changed, 60 insertions(+), 2 deletions(-)
> >  create mode 100644 Documentation/devicetree/bindings/display/panel/lg,ld070wx3.yaml
> >
> > diff --git a/Documentation/devicetree/bindings/display/panel/lg,ld070wx3.yaml b/Documentation/devicetree/bindings/display/panel/lg,ld070wx3.yaml
> > new file mode 100644
> > index 000000000000..0a82cf311452
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/display/panel/lg,ld070wx3.yaml
> > @@ -0,0 +1,60 @@
> > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> > +%YAML 1.2
> > +---
> > +$id: http://devicetree.org/schemas/display/panel/lg,ld070wx3.yaml#
> > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > +
> > +title: LG Corporation 7" WXGA TFT LCD panel
> > +
> > +maintainers:
> > +  - Svyatoslav Ryhel <clamor95@gmail.com>
> > +
> > +allOf:
> > +  - $ref: panel-common.yaml#
> > +
> > +properties:
> > +  compatible:
> > +    items:
> > +      - const: lg,ld070wx3-sl01
> > +
> > +  reg:
> > +    maxItems: 1
> > +
> > +  vdd-supply: true
> > +  vcc-supply: true
> > +
> > +  backlight: true
> > +  port: true
> > +
> > +required:
> > +  - compatible
> > +  - vdd-supply
> > +  - vcc-supply
>
> I suspect you'll get a NAK here because you're not preserving backward
> compatibility for existing device trees. While there can sometimes be
> reasons to do that, you'd need to provide a very strong justification.
>
>
> It seems like instead of breaking compatibility you could just have
> two supplies:
>
> * power-supply - The name for the "dvdd" supply.
> * avdd-supply - The name for the "avdd" supply.
>
> ...and then you make both of them not "required". Maybe you'd add some
> documentation saying that things might not work 100% correctly if they
> weren't provided but that old device trees didn't specify them?

Schema describes hardware. If it does not (and in this case it clearly
DOES NOT), then such schema should be adjusted according to hardware.
If there are any users of such binding, they should be adjusted too
(third commit of this patchset does exactly that). Panel datasheet is
explicit, panel has ONLY vdd supply and vcc supply, names are taken
from there too.