Re: [PATCH v4 22/24] dt-bindings: display: tegra: document Tegra20 and Tegra30 CSI

Svyatoslav Ryhel
2025-10-09T05:35:35Z

чт, 9 жовт. 2025 р. о 00:22 Conor Dooley <conor@kernel.org> пише:
>
> On Wed, Oct 08, 2025 at 10:21:06PM +0100, Conor Dooley wrote:
> > On Wed, Oct 08, 2025 at 10:30:44AM +0300, Svyatoslav Ryhel wrote:
> > > Document CSI HW block found in Tegra20 and Tegra30 SoC.
> > >
> > > The #nvidia,mipi-calibrate-cells is not an introduction of property, such
> > > property already exists in nvidia,tegra114-mipi.yaml and is used in
> > > multiple device trees. In case of Tegra30 and Tegra20 CSI block combines
> > > mipi calibration function and CSI function, in Tegra114+ mipi calibration
> > > got a dedicated hardware block which is already supported. This property
> > > here is used to align with mipi-calibration logic used by Tegra114+.
> > >
> > > Signed-off-by: Svyatoslav Ryhel <clamor95@gmail.com>
> > > ---
> > > .../display/tegra/nvidia,tegra20-csi.yaml | 135 ++++++++++++++++++
> > > 1 file changed, 135 insertions(+)
> > > create mode 100644 Documentation/devicetree/bindings/display/tegra/nvidia,tegra20-csi.yaml
> > >
> > > diff --git a/Documentation/devicetree/bindings/display/tegra/nvidia,tegra20-csi.yaml b/Documentation/devicetree/bindings/display/tegra/nvidia,tegra20-csi.yaml
> > > new file mode 100644
> > > index 000000000000..817b3097846b
> > > --- /dev/null
> > > +++ b/Documentation/devicetree/bindings/display/tegra/nvidia,tegra20-csi.yaml
> > > @@ -0,0 +1,135 @@
> > > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> > > +%YAML 1.2
> > > +---
> > > +$id: http://devicetree.org/schemas/display/tegra/nvidia,tegra20-csi.yaml#
> > > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > > +
> > > +title: NVIDIA Tegra20 CSI controller
> > > +
> > > +maintainers:
> > > + - Svyatoslav Ryhel <clamor95@gmail.com>
> > > +
> > > +properties:
> > > + compatible:
> > > + enum:
> > > + - nvidia,tegra20-csi
> > > + - nvidia,tegra30-csi
> > > +
> > > + reg:
> > > + maxItems: 1
> > > +
> > > + clocks: true
> > > + clock-names: true
> > > +
> > > + avdd-dsi-csi-supply:
> > > + description: DSI/CSI power supply. Must supply 1.2 V.
> > > +
> > > + power-domains:
> > > + maxItems: 1
> > > +
> > > + "#nvidia,mipi-calibrate-cells":
> > > + description:
> > > + The number of cells in a MIPI calibration specifier. Should be 1.
> > > + The single cell specifies an id of the pad that need to be
> > > + calibrated for a given device. Valid pad ids for receiver would be
> > > + 0 for CSI-A; 1 for CSI-B; 2 for DSI-A and 3 for DSI-B.
> > > + $ref: /schemas/types.yaml#/definitions/uint32
> > > + const: 1
> > > +
> > > + "#address-cells":
> > > + const: 1
> > > +
> > > + "#size-cells":
> > > + const: 0
> > > +
> > > +patternProperties:
> > > + "^channel@[0-1]$":
> > > + type: object
> > > + description: channel 0 represents CSI-A and 1 represents CSI-B
> > > + additionalProperties: false
> > > +
> > > + properties:
> > > + reg:
> > > + maximum: 1
> > > +
> > > + nvidia,mipi-calibrate:
> > > + description: Should contain a phandle and a specifier specifying
> > > + which pad is used by this CSI channel and needs to be calibrated.
> > > + $ref: /schemas/types.yaml#/definitions/phandle-array
> > > +
> > > + "#address-cells":
> > > + const: 1
> > > +
> > > + "#size-cells":
> > > + const: 0
> > > +
> > > + port@0:
> > > + $ref: /schemas/graph.yaml#/$defs/port-base
> > > + unevaluatedProperties: false
> > > + description: port receiving the video stream from the sensor
> > > +
> > > + properties:
> > > + endpoint:
> > > + $ref: /schemas/media/video-interfaces.yaml#
> > > + unevaluatedProperties: false
> > > +
> > > + required:
> > > + - data-lanes
> > > +
> > > + port@1:
> > > + $ref: /schemas/graph.yaml#/properties/port
> > > + description: port sending the video stream to the VI
> > > +
> > > + required:
> > > + - reg
> > > + - "#address-cells"
> > > + - "#size-cells"
> > > + - port@0
> > > + - port@1
> > > +
> > > +allOf:
> > > + - if:
> > > + properties:
> > > + compatible:
> > > + contains:
> > > + enum:
> > > + - nvidia,tegra20-csi
> > > + then:
> > > + properties:
> > > + clocks:
> > > + items:
> > > + - description: module clock
> > > +
> > > + clock-names: false
> > > +
> > > + - if:
> > > + properties:
> > > + compatible:
> > > + contains:
> > > + enum:
> > > + - nvidia,tegra30-csi
> > > + then:
> > > + properties:
> > > + clocks:
> > > + items:
> > > + - description: module clock
> > > + - description: PAD A clock
> > > + - description: PAD B clock
> > > +
> > > + clock-names:
> > > + items:
> > > + - const: csi
> > > + - const: csia-pad
> > > + - const: csib-pad
> >
> > This clocks section seems like it could get simpler. Since the clock
> > descriptions are shared, and tegra20 has no clock-names, you could just
> > move the detail of the properties out to where you have the ": true"
> > stuff (we prefer that properties are defined outside of if/then/else
> > blocks) and just restrict them here. For tegra20 that'd be
> >
> > if:
> > properties:
> > compatible:
> > contains:
> > enum:
> > - nvidia,tegra20-csi
> > then:
> > properties:
> > clocks:
> > maxItems: 1
> >
> > clock-names: false
> >
> > (although it could easily be maxItems: 1 ?)
> > and for tegra30
> >
> > if:
> > properties:
> > compatible:
> > contains:
> > enum:
> > - nvidia,tegra30-csi
> > then:
> > properties:
> > clocks:
> > minItems: 3
> >
> > clock-names:
> > maxItems: 3
> >
> > Of course you'd then have to add minItems: 1 and maxItems: 3 to the
> > extracted definitions.

What do you mean by your last statement? Add minItems: 1 and maxItems:
3 like this?

This does to common properties
clocks:
minItems: 1
maxItems: 3
items:
- description: module clock
- description: PAD A clock
- description: PAD B clock

clock-names:
minItems: 1
maxItems: 3
items:
- const: csi
- const: csia-pad
- const: csib-pad

This goes to conditional
if:
properties:
compatible:
contains:
enum:
- nvidia,tegra20-csi
then:
properties:
clocks:
maxItems: 1

clock-names: false

if:
properties:
compatible:
contains:
enum:
- nvidia,tegra30-csi
then:
properties:
clocks:
minItems: 3

clock-names:
maxItems: 3

>
> Oh, also: if you want clock-names to ever actually be usable, you have
> to require it. Otherwise a driver must be written to handle it not being
> there.
>

Yes, driver takes this into account and handles it.

> > > +additionalProperties: false
> > > +
> > > +required:
> > > + - compatible
> > > + - reg
> > > + - clocks
> > > + - power-domains
> > > + - "#address-cells"
> > > + - "#size-cells"
> > > +
> > > +# see nvidia,tegra20-vi.yaml for an example
> > > --
> > > 2.48.1
> > >
>
>