Re: [PATCH 1/2] dt-bindings: hwmon: pwm-fan: Document start from dead stop properties

[Conor Dooley <conor@kernel.org>]

[-- Attachment #1: Type: text/plain, Size: 2250 bytes --]

On Tue, Nov 05, 2024 at 02:52:15PM +0100, Marek Vasut wrote:
> Delta AFC0612DB-F00 fan has to be set to at least 30% PWM duty cycle
> to spin up from a dead stop, and can be afterward throttled down to
> lower PWM duty cycle. Introduce support for operating such fans which
> need to start at higher PWM duty cycle first and can slow down next.
> 
> Document two new DT properties, "fan-dead-stop-start-percent" and
> "fan-dead-stop-start-usec". The former describes the minimum percent
> of fan RPM at which it will surely spin up from dead stop. This value
> can be found in the fan datasheet and can be converted to PWM duty
> cycle easily. The "fan-dead-stop-start-usec" describes the minimum
> time in microseconds for which the fan has to be set to dead stop
> start RPM for the fan to surely spin up.
> 
> Signed-off-by: Marek Vasut <marex@denx.de>
> ---
> Cc: Conor Dooley <conor+dt@kernel.org>
> Cc: Guenter Roeck <linux@roeck-us.net>
> Cc: Jean Delvare <jdelvare@suse.com>
> Cc: Krzysztof Kozlowski <krzk+dt@kernel.org>
> Cc: Rob Herring <robh@kernel.org>
> Cc: devicetree@vger.kernel.org
> Cc: linux-hwmon@vger.kernel.org
> ---
>  Documentation/devicetree/bindings/hwmon/pwm-fan.yaml | 11 +++++++++++
>  1 file changed, 11 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/hwmon/pwm-fan.yaml b/Documentation/devicetree/bindings/hwmon/pwm-fan.yaml
> index 4e5abf7580cc6..f1042471b5176 100644
> --- a/Documentation/devicetree/bindings/hwmon/pwm-fan.yaml
> +++ b/Documentation/devicetree/bindings/hwmon/pwm-fan.yaml
> @@ -31,6 +31,17 @@ properties:
>        it must be self resetting edge interrupts.
>      maxItems: 1
>  
> +  fan-dead-stop-start-percent:
> +    description:
> +      Minimum fan RPM in percent to start from dead stop.
> +    minimum: 0
> +    maximum: 100
> +
> +  fan-dead-stop-start-usec:

s/usec/us/ and you get the type from property-units.yaml automagically.

> +    description:
> +      Time to wait in microseconds after start from dead stop.
> +    $ref: /schemas/types.yaml#/definitions/uint32
> +
>    pulses-per-revolution:
>      description:
>        Define the number of pulses per fan revolution for each tachometer
> -- 
> 2.45.2
> 

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 228 bytes --]