Re: [PATCH v6 5/8] dt-bindings: media: add TI DS90UB960 FPD-Link III Deserializer

[Tomi Valkeinen]

On 08/01/2023 05:23, Laurent Pinchart wrote:
> Hi Tomi,
>
> Thank you for the patch.
>
> On Thu, Jan 05, 2023 at 04:03:04PM +0200, Tomi Valkeinen wrote:
> > Add DT bindings for TI DS90UB960 FPD-Link III Deserializer.
> >
> > Signed-off-by: Tomi Valkeinen <tomi.valkeinen@xxxxxxxxxxxxxxxx>
> > Reviewed-by: Rob Herring <robh@xxxxxxxxxx>
> > ---
> >   .../bindings/media/i2c/ti,ds90ub960.yaml      | 402 ++++++++++++++++++
> >   1 file changed, 402 insertions(+)
> >   create mode 100644 Documentation/devicetree/bindings/media/i2c/ti,ds90ub960.yaml
> >
> > diff --git a/Documentation/devicetree/bindings/media/i2c/ti,ds90ub960.yaml b/Documentation/devicetree/bindings/media/i2c/ti,ds90ub960.yaml
> > new file mode 100644
> > index 000000000000..664799ae55be
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/media/i2c/ti,ds90ub960.yaml
> > @@ -0,0 +1,402 @@
> > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> > +%YAML 1.2
> > +---
> > +$id: http://devicetree.org/schemas/media/i2c/ti,ds90ub960.yaml#
> > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > +
> > +title: Texas Instruments DS90UB9XX Family FPD-Link Deserializer Hubs
> > +
> > +maintainers:
> > +  - Tomi Valkeinen <tomi.valkeinen@xxxxxxxxxxxxxxxx>
> > +
> > +description:
> > +  The TI DS90UB9XX devices are FPD-Link video deserializers with I2C and GPIO
> > +  forwarding.
> > +
> > +properties:
> > +  compatible:
> > +    enum:
> > +      - ti,ds90ub960-q1
> > +      - ti,ds90ub9702-q1
> > +
> > +  reg:
> > +    maxItems: 1
> > +
> > +  clocks:
> > +    maxItems: 1
> > +    description:
> > +      Reference clock connected to the REFCLK pin.
> > +
> > +  clock-names:
> > +    items:
> > +      - const: refclk
> > +
> > +  powerdown-gpios:
> > +    maxItems: 1
> > +    description:
> > +      Specifier for the GPIO connected to the PDB pin.
> > +
> > +  i2c-alias-pool:
> > +    $ref: /schemas/types.yaml#/definitions/uint16-array
> > +    description:
> > +      I2C alias pool is a pool of I2C addresses on the main I2C bus that can be
> > +      used to access the remote peripherals on the serializer's I2C bus. The
> > +      addresses must be available, not used by any other peripheral. Each
> > +      remote peripheral is assigned an alias from the pool, and transactions to
> > +      that address will be forwarded to the remote peripheral, with the address
> > +      translated to the remote peripheral's real address. This property is not
> > +      needed if there are no I2C addressable remote peripherals.
> > +
> > +  links:
> > +    type: object
> > +    additionalProperties: false
> > +
> > +    properties:
> > +      '#address-cells':
> > +        const: 1
> > +
> > +      '#size-cells':
> > +        const: 0
> > +
> > +      ti,manual-strobe:
> > +        type: boolean
> > +        description:
> > +          Enable manual strobe position and EQ level
> > +
> > +    patternProperties:
> > +      '^link@[0-3]$':
> > +        type: object
> > +        additionalProperties: false
> > +        properties:
> > +          reg:
> > +            description: The link number
> > +            maxItems: 1
> > +
> > +          i2c-alias:
> > +            description:
> > +              The I2C address used for the serializer. Transactions to this
> > +              address on the I2C bus where the deserializer resides are
> > +              forwarded to the serializer.
> > +
> > +          ti,rx-mode:
> > +            $ref: /schemas/types.yaml#/definitions/uint32
> > +            enum:
> > +              - 0 # RAW10
> > +              - 1 # RAW12 HF
> > +              - 2 # RAW12 LF
> > +              - 3 # CSI2 SYNC
> > +              - 4 # CSI2 NON-SYNC
> > +            description:
> > +              FPD-Link Input Mode. This should reflect the hardware and the
> > +              default mode of the connected camera module.
>
> As the remote device may not be a camera, I'd write "of the connected
> device" or "of the connected serializer".

I was trying to include the sensor also in the "camera module", as the 
sensor's "normal" pixel cloud would affect RAW modes (HF/LF). Perhaps 
"connected device" covers this.

> > +
> > +          ti,cdr-mode:
> > +            $ref: /schemas/types.yaml#/definitions/uint32
> > +            enum:
> > +              - 0 # FPD-Link III
> > +              - 1 # FPD-Link IV
> > +            description:
> > +              FPD-Link CDR Mode. This should reflect the hardware and the
> > +              default mode of the connected camera module.
> > +
> > +          ti,strobe-pos:
> > +            $ref: /schemas/types.yaml#/definitions/int32
> > +            minimum: -13
> > +            maximum: 13
> > +            description: Manual strobe position
> > +
> > +          ti,eq-level:
> > +            $ref: /schemas/types.yaml#/definitions/uint32
> > +            maximum: 14
> > +            description: Manual EQ level
> > +
> > +          serializer:
> > +            type: object
> > +            description: FPD-Link Serializer node
> > +
> > +        required:
> > +          - reg
> > +          - i2c-alias
> > +          - ti,rx-mode
> > +          - serializer
> > +
> > +  ports:
> > +    $ref: /schemas/graph.yaml#/properties/ports
> > +
> > +    properties:
> > +      port@0:
> > +        $ref: /schemas/graph.yaml#/$defs/port-base
> > +        unevaluatedProperties: false
> > +        description: FPD-Link input 0
> > +
> > +        properties:
> > +          endpoint:
> > +            $ref: /schemas/media/video-interfaces.yaml#
> > +            unevaluatedProperties: false
> > +            description:
> > +              Endpoint for FPD-Link port. If the RX mode for this port is RAW,
> > +              hsync-active and vsync-active must be defined.
> > +
> > +      port@1:
> > +        $ref: /schemas/graph.yaml#/$defs/port-base
> > +        unevaluatedProperties: false
> > +        description: FPD-Link input 1
> > +
> > +        properties:
> > +          endpoint:
> > +            $ref: /schemas/media/video-interfaces.yaml#
> > +            unevaluatedProperties: false
> > +            description:
> > +              Endpoint for FPD-Link port. If the RX mode for this port is RAW,
> > +              hsync-active and vsync-active must be defined.
> > +
> > +      port@2:
> > +        $ref: /schemas/graph.yaml#/$defs/port-base
> > +        unevaluatedProperties: false
> > +        description: FPD-Link input 2
> > +
> > +        properties:
> > +          endpoint:
> > +            $ref: /schemas/media/video-interfaces.yaml#
> > +            unevaluatedProperties: false
> > +            description:
> > +              Endpoint for FPD-Link port. If the RX mode for this port is RAW,
> > +              hsync-active and vsync-active must be defined.
> > +
> > +      port@3:
> > +        $ref: /schemas/graph.yaml#/$defs/port-base
> > +        unevaluatedProperties: false
> > +        description: FPD-Link input 3
> > +
> > +        properties:
> > +          endpoint:
> > +            $ref: /schemas/media/video-interfaces.yaml#
> > +            unevaluatedProperties: false
> > +            description:
> > +              Endpoint for FPD-Link port. If the RX mode for this port is RAW,
> > +              hsync-active and vsync-active must be defined.
> > +
> > +      port@4:
> > +        $ref: /schemas/graph.yaml#/$defs/port-base
> > +        unevaluatedProperties: false
> > +        description: CSI-2 Output 0
> > +
> > +        properties:
> > +          endpoint:
> > +            $ref: /schemas/media/video-interfaces.yaml#
> > +            unevaluatedProperties: false
> > +
> > +            properties:
> > +              data-lanes:
> > +                minItems: 1
> > +                maxItems: 4
> > +
> > +            required:
> > +              - data-lanes
> > +
> > +      port@5:
> > +        $ref: /schemas/graph.yaml#/$defs/port-base
> > +        unevaluatedProperties: false
> > +        description: CSI-2 Output 1
> > +
> > +        properties:
> > +          endpoint:
> > +            $ref: /schemas/media/video-interfaces.yaml#
> > +            unevaluatedProperties: false
> > +
> > +            properties:
> > +              data-lanes:
> > +                minItems: 1
> > +                maxItems: 4
> > +
> > +            required:
> > +              - data-lanes
>
> I think you need
>
>      required:
>        - port@0
>        - port@1
>        - port@2
>        - port@3
>        - port@4
>        - port@5

Is that needed? I think often some of the ports are unused (e.g. the 
example in this yaml file). Is it customary to still require empty port 
nodes in the DT?

 Tomi