Re: [PATCH v4 1/3] dt-bindings: hwmon: fan: Add fan binding to schema

From: Naresh Solanki
Date: Tue Oct 25 2022 - 05:22:22 EST




On 24-10-2022 09:48 pm, Rob Herring wrote:
So if we unload and reload the driver module, it should go back to the
default?
This is RPM to be set during probe if desired.

I think it is really, 'target RPM if not already configured' which could
be keep the setting from a register (e.g. what the bootloader set) or
perhaps you already have temperature information to use...
Yes. missed it. It should be target-rpm will correct this. in next version.

+ $ref: /schemas/types.yaml#/definitions/uint32
+ pwm-frequency:
+ description:
+ PWM frequency for fan in Hertz(Hz).
+ $ref: /schemas/types.yaml#/definitions/uint32
+
+ pwm-polarity-inverse:
+ description:
+ Inverse PWM polarity for fan.
+ type: boolean
As I said before, the PWM binding handles these 2 settings. Use it. Yes,
it's a bit of an overkill when the child is the consumer of the parent.
Until some 'clever' h/w engineer decides to use one of the PWMs for
something else like a backlight.
I would like you to consider this as something recommended by fan datasheet for the given fan instance.
This info can be used by fan controller driver to configure PWM source/provider accordingly.

If you still feel that may not make sense then I'll remove this property.


Thanks,
Naresh