[PATCHv2 57/56] dt-bindings: display: panel-dsi-cm: convert to YAML
Laurent Pinchart
laurent.pinchart at ideasonboard.com
Thu Feb 27 22:08:55 UTC 2020
Hi Sebastian,
Thank you for the patch.
On Thu, Feb 27, 2020 at 09:35:21PM +0100, Sam Ravnborg wrote:
> On Tue, Feb 25, 2020 at 12:53:41PM +0100, Sebastian Reichel wrote:
> > Convert panel-dsi-cm bindings to YAML and add
> > missing properties while at it.
> >
> > Signed-off-by: Sebastian Reichel <sebastian.reichel at collabora.com>
>
> As saind in previous mail - I prefer to convert ann then patch.
> But end result is the same so OK.
I agree, splitting the patch would be better.
> > ---
> > .../bindings/display/panel/panel-dsi-cm.txt | 31 ------
> > .../bindings/display/panel/panel-dsi-cm.yaml | 97 +++++++++++++++++++
> > 2 files changed, 97 insertions(+), 31 deletions(-)
> > delete mode 100644 Documentation/devicetree/bindings/display/panel/panel-dsi-cm.txt
> > create mode 100644 Documentation/devicetree/bindings/display/panel/panel-dsi-cm.yaml
> >
> > diff --git a/Documentation/devicetree/bindings/display/panel/panel-dsi-cm.txt b/Documentation/devicetree/bindings/display/panel/panel-dsi-cm.txt
> > deleted file mode 100644
> > index f92d5c9adfc5..000000000000
> > --- a/Documentation/devicetree/bindings/display/panel/panel-dsi-cm.txt
> > +++ /dev/null
> > @@ -1,31 +0,0 @@
> > -Generic MIPI DSI Command Mode Panel
> > -===================================
> > -
> > -Required properties:
> > -- compatible: "panel-dsi-cm"
> > -- reg: DSI channel number
> > -
> > -Optional properties:
> > -- label: a symbolic name for the panel
> > -- reset-gpios: panel reset gpio
> > -- te-gpios: panel TE gpio
> > -
> > -Required nodes:
> > -- Video port for DSI input
> > -
> > -Example
> > --------
> > -
> > -lcd0: panel at 0 {
> > - compatible = "tpo,taal", "panel-dsi-cm";
> > - label = "lcd0";
> > - reg = <0>;
> > -
> > - reset-gpios = <&gpio4 6 GPIO_ACTIVE_HIGH>;
> > -
> > - port {
> > - lcd0_in: endpoint {
> > - remote-endpoint = <&dsi1_out_ep>;
> > - };
> > - };
> > -};
> > diff --git a/Documentation/devicetree/bindings/display/panel/panel-dsi-cm.yaml b/Documentation/devicetree/bindings/display/panel/panel-dsi-cm.yaml
> > new file mode 100644
> > index 000000000000..ca61171ae145
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/display/panel/panel-dsi-cm.yaml
> > @@ -0,0 +1,97 @@
> > +# SPDX-License-Identifier: (GPL-2.0-only or BSD-2-Clause)
> > +%YAML 1.2
> > +---
> > +$id: http://devicetree.org/schemas/display/panel/panel-dsi-cm.yaml#
> > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > +
> > +title: DSI command mode panels
> > +
> > +maintainers:
> > + - Tomi Valkeinen <tomi.valkeinen at ti.com>
> > + - Sebastian Reichel <sre at kernel.org>
> > +
> > +description: |
> > + This binding file is a collection of the DSI panels that
> > + are usually driven in command mode. If no backlight is
> > + referenced via the optional backlight property, the DSI
> > + panel is assumed to have native backlight support.
Maybe this sentence could be moved to the description of the backlight
property ? Or would it override the description from panel-common.yaml ?
If so, is there a way in the yaml bindings syntax to extend that
property ?
> > + The panel may use an OF graph binding for the association
> > + to the display, or it may be a direct child node of the
> > + display.
> > +
> > +allOf:
> > + - $ref: panel-common.yaml#
> > +
> > +properties:
> > +
> > + compatible:
> > + enum:
> > + # compatible must be listed in alphabetical order, ordered by compatible.
> > + # The description in the comment is mandatory for each compatible.
> > + - motorola,droid4-panel, panel-dsi-cm
> > + - nokia,himalaya, panel-dsi-cm
> > + - tpo,taal, panel-dsi-cm
>
> Please consider to use the following syntax (from memory - may require
> an enum:):
>
> compatible:
> description:
> Shall contain a panel specific compatible and "panel-dsi-cm"
> in that order.
> items:
> - oneOf:
> # Maybe add a short description of this panel
> - motorola,droid4-panel
> # Maybe add a short description of this panel
> - nokia,himalaya
> # Maybe add a short description of this panel
> - tpo,taal
>
> - const: panel-dsi-cm
>
> Then panel-dsi-cm is always specified as a second mandatory compatible.
This is not only nicer, but it's actually correct, while the original
version isn't. The original version would require, for instance,
compatible = "motorola,droid4-panel, panel-dsi-cm";
and not
compatible = "motorola,droid4-panel", "panel-dsi-cm";
> > +
> > + reg:
> > + maxItems: 1
> > + description: DSI virtual channel
> > +
> > + te-gpios:
> > + maxItems: 1
> > + description:
> > + Specifier for a GPIO connected to the panel TE (tearing event) signal.
> > + The GPIO informs the system, that data should be sent to the display
> > + on rising edges of the GPIO to avoid (or reduce) tearing effects.
> > + Falling edge can be supported by inverting the GPIO specifier polarity
> > + flag.
>
> te-gpios is used by several panels.
> Please add it to panel-common with your nice description.
Possible too late to change this, but shouldn't we really have used
interrupts = <...>;
interrupt-names = "te";
?
The TE signal may be connected to an interrupt pin that is not a GPIO.
> With the above addressed:
> Reviewed-by: Sam Ravnborg <sam at ravnborg.org>
>
> > +
> > + vddi-supply:
> > + description:
> > + Display panels require power to be supplied. While several panels need
> > + more than one power supply with panel-specific constraints governing the
> > + order and timings of the power supplies, in many cases a single power
> > + supply is sufficient, either because the panel has a single power rail, or
> > + because all its power rails can be driven by the same supply. In that case
> > + the vddi-supply property specifies the supply powering the panel as a
> > + phandle to a regulator.
> > +
> > + vpnl-supply:
> > + description:
> > + When the display panel needs a second power supply, this property can be
> > + used in addition to vddi-supply. Both supplies will be enabled at the
> > + same time before the panel is being accessed.
Too late for this too, but I wonder if the best practice for this kind
of cases wouldn't be to specify a single supply that would be modelled
by a regulator with multiple inputs.
> > + width-mm: true
> > + height-mm: true
> > + label: true
> > + rotation: true
> > + panel-timing: true
> > + port: true
> > + reset-gpios: true
> > + backlight: true
> > +
> > +additionalProperties: false
> > +
> > +required:
> > + - compatible
> > + - port
You wrote in the overall description that the panel may have a port node
or may be a child of the DSI controller. Doesn't that make port optional
?
Should we require width-mm and height-mm ?
> > + - reg
> > +
> > +examples:
> > + - |
> > + dsi1 at 12345678 {
> > + #address-cells = <1>;
> > + #size-cells = <0>;
> > + panel at 0 {
> > + compatible = "tpo,taal", "panel-dsi-cm";
> > + label = "lcd0";
> > + reg = <0>;
> > + reset-gpios = <&gpio4 6 GPIO_ACTIVE_HIGH>;
> > +
> > + port {
> > + panel: endpoint {
> > + remote-endpoint = <&dsi1_out_ep>;
> > + };
> > + };
> > + };
> > + };
--
Regards,
Laurent Pinchart
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