Re: [PATCH 2/5] dt-bindings: media: add i.MX parallel csi support

[Laurent Pinchart <laurent.pinchart@ideasonboard.com>]

Hi Frank, Alice,

Thank you for the patch.

On Mon, Jun 30, 2025 at 06:28:18PM -0400, Frank Li wrote:
> From: Alice Yuan <alice.yuan@nxp.com>
> 
> Document the binding for parallel CSI controller found in i.MX8QXP, i.MX93
> and i.MX91 SoCs.
> 
> Signed-off-by: Alice Yuan <alice.yuan@nxp.com>
> Signed-off-by: Frank Li <Frank.Li@nxp.com>
> ---
>  .../bindings/media/fsl,imx93-parallel-csi.yaml     | 108 +++++++++++++++++++++
>  MAINTAINERS                                        |   1 +
>  2 files changed, 109 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/media/fsl,imx93-parallel-csi.yaml b/Documentation/devicetree/bindings/media/fsl,imx93-parallel-csi.yaml
> new file mode 100644
> index 0000000000000..b4657c913adad
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/media/fsl,imx93-parallel-csi.yaml
> @@ -0,0 +1,108 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/media/fsl,imx93-parallel-csi.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: i.MX8/9 Parallel Camera Interface
> +
> +maintainers:
> +  - Frank Li <Frank.Li@nxp.com>
> +
> +description: |
> +  This is device node for the Parallel Camera Interface which enables the
> +  chip to connect directly to external Parallel CMOS image sensors.
> +  Supports up to 80MHz input clock from sensor.
> +  Supports the following input data formats
> +    - 8-bit/10-bit Camera Sensor Interface (CSI)
> +    - 8-bit data port for RGB, YCbCr, and YUV data input
> +    - 8-bit/10-bit data ports for Bayer data input
> +  Parallel Camera Interface is hooked to the Imaging subsystem via the
> +  Pixel Link.
> +
> +properties:
> +  compatible:
> +    oneOf:
> +      - const: fsl,imx8qxp-parallel-csi

Is there any chance we could avoid calling this "csi", given that the
whole block is called "Parallel Capture Interface" in the reference
manual ? "CSI" is horribly confusing as it usually refers to MIPI CSI-2.
I suppose calling it "PCI" for "Parallel Capture Interface" wouldn't
help :-/

> +      - items:
> +          - enum:
> +              - fsl,imx91-parallel-csi
> +          - const: fsl,imx93-parallel-csi
> +      - const: fsl,imx93-parallel-csi
> +
> +  reg:
> +    maxItems: 1
> +
> +  clocks:
> +    maxItems: 2
> +
> +  clock-names:
> +    items:
> +      - const: pixel
> +      - const: ipg
> +
> +  power-domains:
> +    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.
> +
> +      port@1:
> +        $ref: /schemas/graph.yaml#/$defs/port-base
> +        unevaluatedProperties: false
> +        description:
> +          Output port node.
> +
> +required:
> +  - compatible
> +  - reg
> +  - clocks
> +  - clock-names
> +  - ports

Patch 4/5 lists a power domain, and so does the example below for
i.MX93. Should the power-domains property be mandatory ?

> +
> +additionalProperties: false
> +
> +examples:
> +  - |
> +    #include <dt-bindings/clock/imx93-clock.h>
> +    #include <dt-bindings/power/fsl,imx93-power.h>
> +
> +    parallel-csi@4ac10070 {
> +        compatible = "fsl,imx93-parallel-csi";
> +        reg = <0x4ac10070 0x10>;

The i.MX93 reference manual doesn't document the register set for this
block, so I have a hard time reviewing this. Is there a plan to publish
a new version of the reference manual with the complete documentation
for the parallel interface ?

> +        clocks = <&clk IMX93_CLK_MIPI_CSI_GATE>,
> +                 <&clk IMX93_CLK_MEDIA_APB>;
> +        clock-names = "pixel", "ipg";
> +        assigned-clocks = <&clk IMX93_CLK_CAM_PIX>;
> +        assigned-clock-parents = <&clk IMX93_CLK_VIDEO_PLL>;
> +        assigned-clock-rates = <140000000>;
> +        power-domains = <&media_blk_ctrl IMX93_MEDIABLK_PD_MIPI_CSI>;
> +
> +        ports {
> +            #address-cells = <1>;
> +            #size-cells = <0>;
> +
> +            port@0 {
> +                reg = <0>;
> +
> +                endpoint {
> +                    remote-endpoint = <&mt9m114_ep>;
> +                };
> +            };
> +
> +            port@1 {
> +                reg = <1>;
> +                endpoint {
> +                    remote-endpoint = <&isi_in>;
> +                };
> +            };
> +        };
> +    };
> +...
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 8dc0f6609d1fe..3bd6772c11539 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -15107,6 +15107,7 @@ L:	linux-media@vger.kernel.org
>  S:	Maintained
>  T:	git git://linuxtv.org/media.git
>  F:	Documentation/admin-guide/media/imx7.rst
> +F:	Documentation/devicetree/bindings/media/fsl,imx93-parallel-csi.yaml
>  F:	Documentation/devicetree/bindings/media/nxp,imx-mipi-csi2.yaml
>  F:	Documentation/devicetree/bindings/media/nxp,imx7-csi.yaml
>  F:	Documentation/devicetree/bindings/media/nxp,imx8mq-mipi-csi2.yaml

-- 
Regards,

Laurent Pinchart