Messages in this thread | | | Date | Thu, 9 May 2024 09:06:49 +0200 | Subject | Re: [PATCH v2 1/2] dt-bindings: hwmon: Document adt7475 PWM initial duty cycle | From | Krzysztof Kozlowski <> |
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On 08/05/2024 23:55, Chris Packham wrote: > Add documentation for the pwm-initial-duty-cycle and > pwm-initial-frequency properties. These allow the starting state of the > PWM outputs to be set to cater for hardware designs where undesirable > amounts of noise is created by the default hardware state. > > Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz> > --- > > Notes: > Changes in v2: > - Document 0 as a valid value (leaves hardware as-is) > > .../devicetree/bindings/hwmon/adt7475.yaml | 27 ++++++++++++++++++- > 1 file changed, 26 insertions(+), 1 deletion(-) > > diff --git a/Documentation/devicetree/bindings/hwmon/adt7475.yaml b/Documentation/devicetree/bindings/hwmon/adt7475.yaml > index 051c976ab711..97deda082b4a 100644 > --- a/Documentation/devicetree/bindings/hwmon/adt7475.yaml > +++ b/Documentation/devicetree/bindings/hwmon/adt7475.yaml > @@ -51,6 +51,30 @@ properties: > enum: [0, 1] > default: 1 > > + adi,pwm-initial-duty-cycle: > + description: | > + Configures the initial duty cycle for the PWM outputs. The hardware > + default is 100% but this may cause unwanted fan noise at startup. Set > + this to a value from 0 (0% duty cycle) to 255 (100% duty cycle). > + $ref: /schemas/types.yaml#/definitions/uint32-array > + minItems: 3 > + maxItems: 3 > + items: > + minimum: 0 > + maximum: 255 > + default: 255 > + > + adi,pwm-initial-frequency:
Frequency usually has some units, so use appropriate unit suffix and drop $ref. Maybe that's just target-rpm property?
But isn't this duplicating previous property? This is fan controller, not PWM provider (in any case you miss proper $refs to pwm.yaml or fan-common.yaml), so the only thing you initially want to configure is the fan rotation, not specific PWM waveform. If you you want to configure specific PWM waveform, then it's a PWM provider... but it is not... Confused.
Best regards, Krzysztof
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