[PATCH 1/3 v2] drm/panel: Add generic DSI panel YAML bindings

[Rob Herring]

On Tue, Oct 15, 2019 at 3:28 AM Linus Walleij <linus.walleij at linaro.org> wrote:
>
> This adds a starting point for processing and defining generic
> bindings used by DSI panels. We just define one single bool
> property to force the panel into video mode for now.
>
> Cc: devicetree at vger.kernel.org
> Suggested-by: Rob Herring <robh at kernel.org>
> Signed-off-by: Linus Walleij <linus.walleij at linaro.org>
> ---
> ChangeLog v1->v2:
> - New patch after feedback.
> ---
>  .../display/panel/panel-dsi-common.yaml       | 31 +++++++++++++++++++
>  1 file changed, 31 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/display/panel/panel-dsi-common.yaml
>
> diff --git a/Documentation/devicetree/bindings/display/panel/panel-dsi-common.yaml b/Documentation/devicetree/bindings/display/panel/panel-dsi-common.yaml
> new file mode 100644
> index 000000000000..4242dc25c917
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/display/panel/panel-dsi-common.yaml
> @@ -0,0 +1,31 @@
> +# SPDX-License-Identifier: GPL-2.0

(GPL-2.0-only OR BSD-2-Clause) for new bindings.

> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/display/panel/panel-dsi-common.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Common Properties for DSI Display Panels
> +
> +maintainers:
> +  - Linus Walleij <linus.walleij at linaro.org>
> +
> +description: |
> +  This document defines device tree properties common to DSI, Display
> +  Serial Interface panels. It doesn't constitue a device tree binding

constitute

> +  specification by itself but is meant to be referenced by device tree
> +  bindings.
> +
> +  When referenced from panel device tree bindings the properties defined in
> +  this document are defined as follows. The panel device tree bindings are
> +  responsible for defining whether each property is required or optional.
> +
> +properties:
> +
> +  enforce-video-mode:

As all DSI panels are a child of DSI controllers (unless perhaps if
they are video mode only), I think this schema needs to define the DSI
controller and panel (i.e. the bus) structure. Then this property can
be under the child node schema.

So something like this:

properties:
  $nodename:
    pattern: "^dsi-controller@"
  "#address-cells":
    const: 1
  "#size-cells":
    const: 1
patternProperties:
  "^panel@[0-9]$": # not sure what's the range of addresses...
    type: object
    properties:
      reg:
        maxItems: 1
        items:
          - maximum: ??
      enforce-video-mode:
        ...


> +    type: boolean
> +    description:
> +      The best option is usually to run a panel in command mode, as this
> +      gives better control over the panel hardware. However for different
> +      reasons like broken hardware, missing features or testing, it may be
> +      useful to be able to force a command mode-capable panel into video
> +      mode.
> --
> 2.21.0
>