Re: [PATCH v5 4/8] dt-bindings: media: add bindings for TI DS90UB953

Tomi Valkeinen
2022-12-13T14:06:33Z

On 11/12/2022 19:34, Laurent Pinchart wrote:
> Hi Tomi,
>
> Thank you for the patch.
>
> On Thu, Dec 08, 2022 at 12:40:02PM +0200, Tomi Valkeinen wrote:
>> Add DT bindings for TI DS90UB953 FPDLink-3 Serializer.
>>
>> Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
>> ---
>> .../bindings/media/i2c/ti,ds90ub953.yaml | 112 ++++++++++++++++++
>> 1 file changed, 112 insertions(+)
>> create mode 100644 Documentation/devicetree/bindings/media/i2c/ti,ds90ub953.yaml
>>
>> diff --git a/Documentation/devicetree/bindings/media/i2c/ti,ds90ub953.yaml b/Documentation/devicetree/bindings/media/i2c/ti,ds90ub953.yaml
>> new file mode 100644
>> index 000000000000..fd7d25d93e2c
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/media/i2c/ti,ds90ub953.yaml
>> @@ -0,0 +1,112 @@
>> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
>> +%YAML 1.2
>> +---
>> +$id: http://devicetree.org/schemas/media/i2c/ti,ds90ub953.yaml#
>> +$schema: http://devicetree.org/meta-schemas/core.yaml#
>> +
>> +title: Texas Instruments DS90UB953 FPD-Link 3 Serializer
>> +
>> +maintainers:
>> + - Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
>> +
>> +description:
>> + The TI DS90UB953 is an FPD-Link 3 video serializer for MIPI CSI-2.
>> +
>> +properties:
>> + compatible:
>> + enum:
>> + - ti,ds90ub953-q1
>> + - ti,ds90ub971-q1
>> +
>> + '#gpio-cells':
>> + const: 2
>
> I would add a description here, to tell what the cells correspond to. In
> particular, the first cell selects the GPIO_* pin number, it would be
> nice to document that its value should be in the range [0, 3].
>
> Same comment for patch 3/8 (DS90UB913 bindings). There you could also
> mention that GPO2 and the output clock are mutually exclusive.

Yep. I have added this for ub913:
First cell is the GPO pin number, second cell is the flags. The
GPO pin
number must be in range of [0, 3]. Note that GPOs 2 and 3 are not
available in external oscillator mode.

and this for ub953:
First cell is the GPIO pin number, second cell is the flags. The
GPIO pin
number must be in range of [0, 3].

>> +
>> + gpio-controller: true
>> +
>
> No need for clocks and clock-names for the reference input clock ? Or is
> this because you support sync mode only for now ?

Right, I don't have the clock on my hw, but it's probably better to add
it to the binding already.

>> + '#clock-cells':
>> + const: 0
>> +
>> + ports:
>> + $ref: /schemas/graph.yaml#/properties/ports
>> +
>> + properties:
>> + port@0:
>> + $ref: /schemas/graph.yaml#/$defs/port-base
>> + unevaluatedProperties: false
>> + description: CSI-2 input port
>> +
>> + properties:
>> + endpoint:
>> + $ref: /schemas/media/video-interfaces.yaml#
>> + unevaluatedProperties: false
>
> Should the data-lanes property be required for the CSI-2 input ?

Yes.

>> +
>> + port@1:
>> + $ref: /schemas/graph.yaml#/properties/port
>> + unevaluatedProperties: false
>> + description: FPD-Link 3 output port
>> +
>> + i2c:
>> + $ref: /schemas/i2c/i2c-controller.yaml#
>> + unevaluatedProperties: false
>> +
>> +required:
>> + - compatible
>> + - '#gpio-cells'
>> + - gpio-controller
>> + - '#clock-cells'
>> + - ports
>> +
>> +additionalProperties: false
>> +
>> +examples:
>> + - |
>> + #include <dt-bindings/gpio/gpio.h>
>> +
>> + serializer {
>> + compatible = "ti,ds90ub953-q1";
>> +
>> + gpio-controller;
>> + #gpio-cells = <2>;
>> +
>> + #clock-cells = <0>;
>> +
>> + ports {
>> + #address-cells = <1>;
>> + #size-cells = <0>;
>> +
>> + port@0 {
>> + reg = <0>;
>> + ub953_in: endpoint {
>> + clock-lanes = <0>;
>> + data-lanes = <1 2 3 4>;
>> + remote-endpoint = <&sensor_out>;
>> + };
>> + };
>> +
>> + port@1 {
>> + reg = <1>;
>> + endpoint {
>> + remote-endpoint = <&deser_fpd_in>;
>> + };
>> + };
>> + };
>> +
>> + i2c {
>> + #address-cells = <1>;
>> + #size-cells = <0>;
>> +
>> + sensor@1a {
>> + compatible = "sony,imx274";
>> + reg = <0x1a>;
>> +
>> + reset-gpios = <&serializer 0 GPIO_ACTIVE_LOW>;
>
> Maybe add
>
> clocks = <&serializer>;
> clock-names = "inck";
>
> to showcase the clock connection ?

Yes, that's a good idea.

Tomi