Re: [PATCH v5 1/4] dt-bindings: media: Document bindings for DW MIPI CSI-2 Host

From: Rob Herring
Date: Fri Dec 16 2022 - 18:36:50 EST


On Fri, Dec 16, 2022 at 04:37:14PM +0200, Eugen Hristev wrote:
> Add bindings for Synopsys DesignWare MIPI CSI-2 host.
>
> Signed-off-by: Luis Oliveira <lolivei@xxxxxxxxxxxx>
> [eugen.hristev@xxxxxxxxxxxxx: reworked binding, converted to yaml]
> Signed-off-by: Eugen Hristev <eugen.hristev@xxxxxxxxxxxxx>
> ---
> .../bindings/media/snps,dw-csi.yaml | 149 ++++++++++++++++++
> 1 file changed, 149 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/media/snps,dw-csi.yaml
>
> diff --git a/Documentation/devicetree/bindings/media/snps,dw-csi.yaml b/Documentation/devicetree/bindings/media/snps,dw-csi.yaml
> new file mode 100644
> index 000000000000..439eadc8e517
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/media/snps,dw-csi.yaml
> @@ -0,0 +1,149 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/media/snps,dw-csi.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Synopsys DesignWare CSI-2 Host controller (csi2host)
> +
> +maintainers:
> + - Eugen Hristev <eugen.hristev@xxxxxxxxxxxxx>
> +
> +description:
> + CSI2HOST is used to receive image coming from an MIPI CSI-2 compatible
> + camera. It will convert the incoming CSI-2 stream into a dedicated
> + interface called the Synopsys IDI (Image Data Interface).
> + This interface is a 32-bit SoC internal only, and can be assimilated
> + with a CSI-2 interface.
> +
> +properties:
> + compatible:
> + const: snps,dw-csi

This needs an SoC specific compatible.

> +
> + reg:
> + maxItems: 1
> +
> + clocks:
> + maxItems: 2
> +
> + clock-names:
> + description:
> + CSI2HOST can have two clocks connected. One clock is the
> + peripheral clock for the inside functionality of the hardware block.
> + This is named 'perclk'. The second clock can be the phy clock,
> + which is used to clock the phy via an internal link.
> + This clock is named 'phyclk', phy clock.

The schema says most of this, don't repeat it in freeform text. If you
want a description of each clock, that goes 'clocks' like this:

items:
- description: ...
- description: ...

> + items:
> + - const: perclk
> + - const: phyclk
> +
> + phys:
> + maxItems: 1
> + description: MIPI D-PHY
> +
> + phy-names:
> + items:
> + - const: dphy
> +
> + resets:
> + maxItems: 1
> +
> + interrupts:
> + maxItems: 1
> +
> + ports:
> + $ref: /schemas/graph.yaml#/properties/ports
> +
> + properties:
> + port@0:
> + $ref: /schemas/graph.yaml#/$defs/port-base
> + unevaluatedProperties: false
> + description:
> + Input port node, single endpoint describing the input port.
> +
> + properties:
> + endpoint:
> + $ref: video-interfaces.yaml#
> + unevaluatedProperties: false
> + description: Endpoint connected to input device

Don't need generic descriptions. Only the port nodes need to define what
they are.

> +
> + properties:
> + bus-type:
> + const: 4
> +
> + data-lanes:
> + minItems: 1
> + maxItems: 4
> + items:
> + maximum: 4
> +
> + clock-lanes:
> + maxItems: 1
> +
> + remote-endpoint: true

Don't need to list this.

> +
> + port@1:
> + $ref: /schemas/graph.yaml#/$defs/port-base
> + unevaluatedProperties: false
> + description:
> + Output port node, single endpoint describing the output port.
> +
> + properties:
> + endpoint:
> + unevaluatedProperties: false
> + $ref: video-interfaces.yaml#
> + description: Endpoint connected to output device
> +
> + properties:
> + bus-type:
> + const: 4
> +
> + remote-endpoint: true

Ditto.

> +
> + required:
> + - port@0
> + - port@1
> +
> +additionalProperties: false
> +
> +required:
> + - compatible
> + - ports
> +
> +examples:
> + - |
> + csi2: csi2@3000 {
> + compatible = "snps,dw-csi";
> + reg = <0x03000 0x7FF>;
> + phys = <&mipi_dphy_rx>;
> + phy-names = "dphy";
> + resets = <&dw_rst 1>;
> + interrupts = <2>;
> +
> + ports {
> + #address-cells = <1>;
> + #size-cells = <0>;
> +
> + port@0 {
> + reg = <0>;
> +
> + csi_ep1: endpoint {
> + bus-type = <4>; /* MIPI CSI2 D-PHY */
> + remote-endpoint = <&camera_1>;
> + data-lanes = <1 2>;
> + clock-lanes = <0>;
> + };
> + };
> +
> + port@1 {
> + reg = <1>;
> +
> + csi_ep2: endpoint {
> + remote-endpoint = <&idi_receiver>;
> + bus-type = <4>;
> + };
> + };
> + };
> + };
> +
> +...
> --
> 2.25.1
>
>