[PATCH 1/2] dt-bindings: display: bridge: Add TI DLPC3433 bindings

[Jagan Teki]

Hi Laurent,

On Thu, Nov 25, 2021 at 3:53 AM Laurent Pinchart
<laurent.pinchart at ideasonboard.com> wrote:
>
> Hi Jagan,
>
> Thank you for the patch.
>
> On Wed, Nov 24, 2021 at 10:55:52PM +0530, Jagan Teki wrote:
> > TI DLPC3433 is a MIPI DSI based display controller bridge
> > for processing high resolution DMD based projectors.
> >
> > It has a flexible configuration of MIPI DSI signal input
> > produces RGB565, RGB666, RGB888 output format with maximum
> > of 720p resolution in 60 and 120 Hz refresh rates.
> >
> > Add dt-bingings for it.
> >
> > Signed-off-by: Christopher Vollo <chris at renewoutreach.org>
> > Signed-off-by: Jagan Teki <jagan at amarulasolutions.com>
> > ---
> >  .../bindings/display/bridge/ti,dlpc3433.yaml  | 112 ++++++++++++++++++
> >  MAINTAINERS                                   |   6 +
> >  2 files changed, 118 insertions(+)
> >  create mode 100644 Documentation/devicetree/bindings/display/bridge/ti,dlpc3433.yaml
> >
> > diff --git a/Documentation/devicetree/bindings/display/bridge/ti,dlpc3433.yaml b/Documentation/devicetree/bindings/display/bridge/ti,dlpc3433.yaml
> > new file mode 100644
> > index 000000000000..3ade3a575c3e
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/display/bridge/ti,dlpc3433.yaml
> > @@ -0,0 +1,112 @@
> > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> > +%YAML 1.2
> > +---
> > +$id: http://devicetree.org/schemas/display/bridge/ti,dlpc3433.yaml#
> > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > +
> > +title: TI DLPC3433 Display Controller
> > +
> > +maintainers:
> > +  - Jagan Teki <jagan at amarulasolutions.com>
> > +  - Christopher Vollo <chris at renewoutreach.org>
> > +
> > +description: |
> > +  The DLPC3433 or DLPC3438 controllers provide a convenient,
> > +  multi-functional interface between system electronics and
> > +  the DMD, enabling small form factor, low power, and high
> > +  resolution HD displays.
>
> You may want to mention in the title and/or description that this is a
> DSI to DMD bridge. Actually, the device also supports a DPI input, which
> should be modelled in the DT bindings.

How can we model DPI since it is a DSI bridge bindings? Does it mean
we can add another node example to have DPI instead of DSI?

>
> > +
> > +properties:
> > +  compatible:
> > +    enum:
> > +      - ti,dlpc3433
>
> Or just
>
>   compatible:
>     const: ti,dlpc3433
>
> > +
> > +  reg:
> > +    maxItems: 1
> > +    description: virtual channel number of a DSI peripheral
>
> I don't think this is right, the reg is the I2C address. You can drop
> the description.
>
> > +
> > +  enable-gpios:
> > +    description: PROJ_EN pin, chip powers up PROJ_EN is high.
>
> It's called PROJ_ON, not PROJ_EN, in the datasheet.
>
> > +
> > +  vcc_intf-supply:
> > +    description: A 1.8V/3.3V supply that power the Host I/O.
> > +
> > +  vcc_flsh-supply:
> > +    description: A 1.8V/3.3V supply that power the Flash I/O.
> > +
> > +  ports:
> > +    $ref: /schemas/graph.yaml#/properties/ports
> > +
> > +    properties:
> > +      port at 0:
> > +        $ref: /schemas/graph.yaml#/$defs/port-base
> > +        unevaluatedProperties: false
> > +        description: Video port for MIPI DSI input.
> > +
> > +        properties:
> > +          endpoint:
> > +            $ref: /schemas/media/video-interfaces.yaml#
> > +            unevaluatedProperties: false
> > +
> > +            properties:
> > +              data-lanes:
> > +                description: array of physical DSI data lane indexes.
> > +                minItems: 1
> > +                items:
> > +                  - const: 1
> > +                  - const: 2
> > +                  - const: 3
> > +                  - const: 4
> > +
> > +      port at 1:
> > +        $ref: /schemas/graph.yaml#/properties/port
> > +        description: Video port for DPI output (DMD Projector).
>
> The output isn't DPI, but DMD.
>
> > +
> > +    required:
> > +      - port at 0
> > +      - port at 1
> > +
> > +required:
> > +  - compatible
> > +  - reg
> > +  - enable-gpios
>
> Can the chip be used with the PROJ_ON input hardwired to a high logic
> state, or does it need to be controlled ?

PROJ_ON require an explicit enablement via driver in order to have
device out-of-reset.

Thanks,
Jagan.