Re: [PATCH v5 1/3] dt-bindings: hwmon: Add Microchip emc2305 support

[Daniel Baluta <daniel.baluta@xxxxxxxxx>]

On Tue, Mar 18, 2025 at 5:22 PM Guenter Roeck <linux@xxxxxxxxxxxx> wrote:
>
> On 3/18/25 01:54, florin.leotescu@xxxxxxxxxxx wrote:
> > From: Florin Leotescu <florin.leotescu@xxxxxxx>
> >
> > Introduce yaml schema for Microchip emc2305 pwm fan controller.
> >
> > Signed-off-by: Florin Leotescu <florin.leotescu@xxxxxxx>
> > Reviewed-by: Frank Li <Frank.Li@xxxxxxx>
> > ---
> >   .../bindings/hwmon/microchip,emc2305.yaml     | 113 ++++++++++++++++++
> >   1 file changed, 113 insertions(+)
> >   create mode 100644 Documentation/devicetree/bindings/hwmon/microchip,emc2305.yaml
> >
> > diff --git a/Documentation/devicetree/bindings/hwmon/microchip,emc2305.yaml b/Documentation/devicetree/bindings/hwmon/microchip,emc2305.yaml
> > new file mode 100644
> > index 000000000000..e61ef97e63af
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/hwmon/microchip,emc2305.yaml
> > @@ -0,0 +1,113 @@
> > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> > +%YAML 1.2
> > +---
> > +
> > +$id: http://devicetree.org/schemas/hwmon/microchip,emc2305.yaml#
> > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > +
> > +title: Microchip EMC2305 SMBus compliant PWM fan controller
> > +
> > +maintainers:
> > +  - Michael Shych <michaelsh@xxxxxxxxxx>
> > +
> > +description:
> > +  Microchip EMC2301/2/3/5 pwm controller which supports
> > +  up to five programmable fan control circuits.
> > +
> > +properties:
> > +  compatible:
> > +    oneOf:
> > +      - enum:
> > +          - microchip,emc2305
> > +      - items:
> > +          - enum:
> > +              - microchip,emc2303
> > +              - microchip,emc2302
> > +              - microchip,emc2301
> > +          - const: microchip,emc2305
> > +
> > +  reg:
> > +    maxItems: 1
> > +
> > +  '#address-cells':
> > +    const: 1
> > +
> > +  '#size-cells':
> > +    const: 0
> > +
> > +  '#pwm-cells':
> > +    const: 3
> > +    description: |
> > +      Number of cells in a PWM specifier.
> > +      - cell 0: The PWM frequency
> > +      - cell 1: The PWM polarity: 0 or PWM_POLARITY_INVERTED
> > +      - cell 2: The PWM output config:
> > +           - 0 (Open-Drain)
> > +           - 1 (Push-Pull)
> > +
> > +
> > +patternProperties:
> > +  '^fan@[0-4]$':
> > +    $ref: fan-common.yaml#
> > +    unevaluatedProperties: false
> > +    properties:
> > +      reg:
> > +        description:
> > +          The fan number used to determine the associated PWM channel.
> > +
> > +    required:
> > +      - reg
> > +      - pwms
>
> Is it necessary to make 'pwms' mandatory ? The current code works
> just fine with defaults.

The code adding OF support is added just in the next patch, so the
current code isn't event
probed when trying to use dts.

Or am I missing something?

+static const struct of_device_id of_emc2305_match_table[] = {
+       { .compatible = "microchip,emc2305", },
+       {},
+};
+MODULE_DEVICE_TABLE(of, of_emc2305_match_table);

I have no strong opinion on this we could make pwms optional.