Re: [PATCH v2 1/6] dt-bindings: hwmon: add Microchip LAN969x fan controller

[Rob Herring <robh@kernel.org>]

On Mon, Nov 09, 2026 at 02:35:05PM +0100, Robert Marko wrote:
> The LAN969x fan controller has a PWM output and tachometer input in a
> register block separate from the Sparx5-compatible temperature sensor.
> Describe it with its own compatible and binding.
> 
> The optional fan child specifies PWM period and polarity, tachometer
> pulses per revolution, and thermal cooling levels.
> 
> Signed-off-by: Robert Marko <robert.marko@sartura.hr>
> ---
> Changes in v2:
> - Describe the fan controller in a separate binding and compatible.
> - Keep the existing temperature-sensor binding unchanged.
> 
>  .../bindings/hwmon/microchip,lan9691-fan.yaml | 83 +++++++++++++++++++
>  1 file changed, 83 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/hwmon/microchip,lan9691-fan.yaml
> 
> diff --git a/Documentation/devicetree/bindings/hwmon/microchip,lan9691-fan.yaml b/Documentation/devicetree/bindings/hwmon/microchip,lan9691-fan.yaml
> new file mode 100644
> index 0000000000000..0b7d38a6d20ae
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/hwmon/microchip,lan9691-fan.yaml
> @@ -0,0 +1,83 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/hwmon/microchip,lan9691-fan.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Microchip LAN969x Fan Controller
> +
> +maintainers:
> +  - Robert Marko <robert.marko@sartura.hr>
> +
> +description: |

Don't need '|'

> +  LAN969x fan controller with a PWM output and tachometer input. The fan
> +  child's pwms property references this node to specify the PWM period and
> +  polarity.
> +
> +properties:
> +  compatible:
> +    const: microchip,lan9691-fan
> +
> +  reg:
> +    maxItems: 1
> +
> +  clocks:
> +    items:
> +      - description: System reference clock
> +
> +  '#pwm-cells':
> +    const: 2
> +    description: |
> +      Number of cells in a PWM specifier.
> +      - cell 0: PWM period in nanoseconds
> +      - cell 1: PWM polarity: 0 or PWM_POLARITY_INVERTED
> +
> +  fan:
> +    $ref: fan-common.yaml#
> +    unevaluatedProperties: false
> +
> +    properties:
> +      cooling-levels:
> +        description:
> +          PWM duty-cycle values corresponding to thermal cooling states.
> +        items:
> +          maximum: 255
> +
> +      pulses-per-revolution:
> +        minimum: 1
> +        maximum: 4

Drop. That's already the max in fan-common.yaml. minimum should be added 
there too as 0 would never make sense.

> +        default: 2
> +
> +    required:
> +      - pwms
> +
> +    dependencies:
> +      '#cooling-cells':
> +        - cooling-levels
> +      cooling-levels:
> +        - '#cooling-cells'

The dependencies should also go in fan-common.yaml. Perhaps 
cooling-levels without #cooling-cells might make sense sometimes?

Rob