[PATCH 1/6] dt-bindings: hwmon: sparx5: add LAN969x fan controller

[Robert Marko]

On Tue, Oct 13, 2026 at 6:30 PM Conor Dooley <conor at kernel.org> wrote:
>
> On Tue, Oct 13, 2026 at 02:56:25PM +0200, Robert Marko wrote:
> > LAN969x integrates a PWM fan controller with a tachometer input in
> > addition to the Sparx5-compatible temperature sensor. Add a LAN969x
> > hardware-monitor compatible and describe the second register region.
> >
> > Describe the fan as a child node using a two-cell PWM specifier for the
> > period and standard polarity flags. The child also carries the optional
> > tachometer pulses-per-revolution and thermal cooling properties.
> >
> > Keep the existing microchip,lan9691-temp compatible for device tree ABI
> > compatibility.
> >
> > Signed-off-by: Robert Marko <robert.marko at sartura.hr>
> > ---
> >  .../bindings/hwmon/microchip,sparx5-temp.yaml | 90 ++++++++++++++++++-
> >  1 file changed, 87 insertions(+), 3 deletions(-)
> >
> > diff --git a/Documentation/devicetree/bindings/hwmon/microchip,sparx5-temp.yaml b/Documentation/devicetree/bindings/hwmon/microchip,sparx5-temp.yaml
> > index 611fcadb1e771..e91c2a3ccd3c9 100644
> > --- a/Documentation/devicetree/bindings/hwmon/microchip,sparx5-temp.yaml
> > +++ b/Documentation/devicetree/bindings/hwmon/microchip,sparx5-temp.yaml
> > @@ -4,13 +4,15 @@
> >  $id: http://devicetree.org/schemas/hwmon/microchip,sparx5-temp.yaml#
> >  $schema: http://devicetree.org/meta-schemas/core.yaml#
> >
> > -title: Microchip Sparx5 Temperature Monitor
> > +title: Microchip Sparx5 Hardware Monitor
> >
> >  maintainers:
> >    - Lars Povlsen <lars.povlsen at microchip.com>
> >
> >  description: |
> > -  Microchip Sparx5 embedded temperature monitor
> > +  Microchip Sparx5 temperature monitor with a fan controller on LAN969x.
> > +  The fan child's pwms property references this node to specify the
> > +  PWM period and polarity.
> >
> >  properties:
> >    compatible:
> > @@ -18,11 +20,19 @@ properties:
> >        - const: microchip,sparx5-temp
> >        - items:
> >            - enum:
> > +              - microchip,lan9691-hwmon
> >                - microchip,lan9691-temp
> >            - const: microchip,sparx5-temp
> >
> >    reg:
> > -    maxItems: 1
> > +    minItems: 1
> > +    maxItems: 2
> > +
> > +  reg-names:
> > +    minItems: 1
> > +    items:
> > +      - const: temp
> > +      - const: fan
> >
> >    clocks:
> >      items:
> > @@ -31,11 +41,67 @@ properties:
> >    '#thermal-sensor-cells':
> >      const: 0
> >
> > +  '#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
> > +        default: 2
> > +
> > +    required:
> > +      - pwms
> > +
> > +    dependencies:
> > +      '#cooling-cells':
> > +        - cooling-levels
> > +      cooling-levels:
> > +        - '#cooling-cells'
> > +
> >  required:
> >    - compatible
> >    - reg
> >    - clocks
> >
> > +allOf:
> > +  - if:
> > +      properties:
> > +        compatible:
> > +          contains:
> > +            const: microchip,lan9691-hwmon
> > +    then:
> > +      properties:
> > +        reg:
> > +          minItems: 2
> > +        reg-names:
> > +          minItems: 2
> > +      required:
> > +        - '#pwm-cells'
> > +        - reg-names
> > +    else:
> > +      properties:
> > +        '#pwm-cells': false
> > +        fan: false
> > +        reg:
> > +          maxItems: 1
> > +        reg-names:
> > +          maxItems: 1
> > +
> >  additionalProperties: false
> >
> >  examples:
> > @@ -46,3 +112,21 @@ examples:
> >          #thermal-sensor-cells = <0>;
> >          clocks = <&sys_clk>;
> >      };
> > +
> > +  - |
> > +    #include <dt-bindings/pwm/pwm.h>
> > +
> > +    hwmon: hwmon at e2020100 {
> > +        compatible = "microchip,lan9691-hwmon", "microchip,sparx5-temp";
> > +        reg = <0xe2020100 0xc>, <0xe2010348 0xc>;
>
> Are these actually the same device? These are somewhat disparate
> register regions - and the second is at a very odd offset.

Not really, they can be separately configured and have their own register space.

I did not see a point in separate drivers, but we could model these as
separate DT
nodes with their individual bindings if that is more appropriate.

Regards,
Robert

>
> Thanks,
> Conor.
>
> > +        reg-names = "temp", "fan";
> > +        #pwm-cells = <2>;
> > +        #thermal-sensor-cells = <0>;
> > +        clocks = <&sys_clk>;
> > +
> > +        fan {
> > +            pwms = <&hwmon 40000 PWM_POLARITY_INVERTED>;
> > +            cooling-levels = <0 128 192 255>;
> > +            #cooling-cells = <2>;
> > +        };
> > +    };
> > --
> > 2.56.0
> >



-- 
Robert Marko
Staff Embedded Linux Engineer
Sartura d.d.
Lendavska ulica 16a
10000 Zagreb, Croatia
Email: robert.marko at sartura.hr
Web: www.sartura.hr