[1/2] media: dt-bindings: alvium: add document YAML binding

Add documentation of device tree in YAML schema for the ALVIUM
Camera from Allied Vision Inc.

References:
 - https://www.alliedvision.com/en/products/embedded-vision-solutions

Signed-off-by: Tommaso Merciai <tomm.merciai@gmail.com>
---
 .../media/i2c/alliedvision,alvium.yaml        | 117 ++++++++++++++++++
 1 file changed, 117 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/media/i2c/alliedvision,alvium.yaml

Hello Krzysztof,

On Tue, May 30, 2023 at 05:52:17PM +0200, Krzysztof Kozlowski wrote:
> On 26/05/2023 12:34, Tommaso Merciai wrote:
> > Add documentation of device tree in YAML schema for the ALVIUM
> > Camera from Allied Vision Inc.
> > 
> 
> Thank you for your patch. There is something to discuss/improve.
> 
> 
> > References:
> >  - https://www.alliedvision.com/en/products/embedded-vision-solutions
> > 
> > Signed-off-by: Tommaso Merciai <tomm.merciai@gmail.com>
> > ---
> >  .../media/i2c/alliedvision,alvium.yaml        | 117 ++++++++++++++++++
> >  1 file changed, 117 insertions(+)
> >  create mode 100644 Documentation/devicetree/bindings/media/i2c/alliedvision,alvium.yaml
> > 
> > diff --git a/Documentation/devicetree/bindings/media/i2c/alliedvision,alvium.yaml b/Documentation/devicetree/bindings/media/i2c/alliedvision,alvium.yaml
> > new file mode 100644
> > index 000000000000..5385fe849ffd
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/media/i2c/alliedvision,alvium.yaml
> > @@ -0,0 +1,117 @@
> > +# SPDX-License-Identifier: GPL-2.0
> 
> Dual license please.
> 
> Please run scripts/checkpatch.pl and fix reported warnings. Some
> warnings can be ignored, but the code here looks like it needs a fix.
> Feel free to get in touch if the warning is not clear.
> 
> It does not look like you tested the bindings, at least after quick
> look. Please run `make dt_binding_check` (see
> Documentation/devicetree/bindings/writing-schema.rst for instructions).
> Maybe you need to update your dtschema and yamllint.
> 
> > +%YAML 1.2
> > +---
> > +$id: http://devicetree.org/schemas/media/i2c/alliedvision,alvium.yaml#
> > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > +
> > +title: Alliedvision Alvium Camera
> > +
> > +maintainers:
> > +  - Tommaso Merciai <tomm.merciai@gmail.com>
> > +  - Martin Hecht <martin.hecht@avnet.eu>
> > +
> > +allOf:
> > +  - $ref: /schemas/media/video-interface-devices.yaml#
> > +
> > +properties:
> > +  compatible:
> > +    const: alliedvision,alvium
> 
> Missing vendor prefix in vendor-prefixes.yaml
> 
> > +
> > +  reg:
> > +    maxItems: 1
> > +
> > +  clocks:
> > +    description: XCLK Input Clock
> 
> maxItems: 1
> 
> > +
> > +  clock-names:
> > +    const: xclk
> 
> Drop names, useless for one entry with generic name.
> 
> > +
> > +  powerdown-gpios:
> > +    maxItems: 1
> > +    description: >
> > +      Reference to the GPIO connected to the powerdown pin, if any.
> 
> Drop description, it's obvious.
> 
> > +
> > +  reset-gpios:
> > +    maxItems: 1
> > +    description: >
> > +      Reference to the GPIO connected to the reset pin, if any.
> 
> Drop description, it's obvious.
> 
> 
> > +
> > +  streamon-delay:
> > +    maxItems: 1
> > +    description: >
> > +      Delay before camera start capturing frames in us.
> 
> Missing vendor prefix (unless it is a common property), missing units
> suffix in property name (-us). It's not a list. Why this should be a
> hardware property?
> 
> > +
> > +  rotation:
> > +    enum:
> > +      - 0
> > +      - 180
> > +
> > +  port:
> > +    description: Digital Output Port
> > +    $ref: /schemas/graph.yaml#/$defs/port-base
> > +    additionalProperties: false
> > +
> > +    properties:
> > +      endpoint:
> > +        $ref: /schemas/media/video-interfaces.yaml#
> > +        unevaluatedProperties: false
> > +
> > +        properties:
> > +          clock-lanes:
> > +            const: 0
> 
> Blank line
> 
> > +          data-lanes:
> > +            minItems: 1
> > +            maxItems: 4
> 
> Four items and each 1 or 4? so <4>, <1>, and what else? Please provide
> example for this.
> 
> > +            items:
> > +              enum: [1, 4]
> > +          link-frequencies: true
> 
> Drop this one, should not be needed.
> 
> > +
> > +        required:
> > +          - data-lanes
> > +          - link-frequencies
> > +
> > +required:
> > +  - compatible
> > +  - reg
> > +  - clocks
> > +  - clock-names
> > +  - port
> > +
> > +additionalProperties: false
> > +
> > +examples:
> > +  - |
> > +      #include <dt-bindings/clock/imx6qdl-clock.h>
> > +      #include <dt-bindings/gpio/gpio.h>
> 
> Use 4 spaces for example indentation. Not 6.
> 
> > +
> > +      i2c {
> > +          #address-cells = <1>;
> > +          #size-cells = <0>;
> > +
> > +          camera: alvium@3c {
> 
> Node names should be generic. See also explanation and list of examples
> in DT specification:
> https://devicetree-specification.readthedocs.io/en/latest/chapter2-devicetree-basics.html#generic-names-recommendation
> 
> > +              compatible = "alliedvision,alvium";
> > +              reg = <0x3c>;
> > +              pinctrl-names = "default";
> > +              pinctrl-0 = <&pinctrl_csi0_pwn>, <&pinctrl_csi0_rst>, <&pinctrl_csi_mclk>;
> > +              clocks = <&clk IMX8MP_CLK_IPP_DO_CLKO2>;
> > +              clock-names = "xclk";
> > +              assigned-clocks = <&clk IMX8MP_CLK_IPP_DO_CLKO2>;
> > +              assigned-clock-parents = <&clk IMX8MP_CLK_24M>;
> > +              assigned-clock-rates = <24000000>;
> > +              streamon-delay = <20>;
> > +              powerdown-gpios = <&gpio2 11 GPIO_ACTIVE_HIGH>;
> > +              reset-gpios = <&gpio1 6 GPIO_ACTIVE_LOW>;
> > +              status = "okay";
> 
> Drop status
> 
> > +
> > +              port {
> > +                  alvium_out: endpoint {
> > +                      remote-endpoint = <&mipi_csi_0_in>;
> > +                      data-lanes = <1 2 3 4>;
> 
> OK, here is the example. You did not test it.

Thanks for your review.
I miss this on v2, mb.
I'll apply your hints on v3.

Regards,
Tommaso


> 
> 
> 
> Best regards,
> Krzysztof
>