[PATCH linux dev-4.10 1/6] dt-bindings: max31785: Add mark-fan-installed property

[Joel Stanley]

On Sat, Jul 29, 2017 at 1:52 AM, Andrew Jeffery <andrew at aj.id.au> wrote:
> It's a system design decision with regards to managing the default
> values of registers such as FAN_CONFIG_1_2. Do not assume the hardware
> is configured such as the fans are marked as installed, rather expose a
> devicetree option to inform the driver of whether it should mark the
> fan as installed itself.

I think we would be better served by making this a property of the
device (instead of each fan).

The property presence indicates "check the register to enable/disable
specific fans". For systems that have this bit configured, we have the
existing behaviour of the driver.

Otherwise we just set the register based on the fan child nodes that
are present in the device tree, which is your proposed behaviour.

Cheers,

Joel


>
> Signed-off-by: Andrew Jeffery <andrew at aj.id.au>
> ---
>  Documentation/devicetree/bindings/hwmon/pmbus/max31785.txt | 2 ++
>  1 file changed, 2 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/hwmon/pmbus/max31785.txt b/Documentation/devicetree/bindings/hwmon/pmbus/max31785.txt
> index 96e705434a59..f2ab18f5f503 100644
> --- a/Documentation/devicetree/bindings/hwmon/pmbus/max31785.txt
> +++ b/Documentation/devicetree/bindings/hwmon/pmbus/max31785.txt
> @@ -31,6 +31,8 @@ Optional subnode properties:
>  - fan-mode               : "rpm" or "pwm". Default value is "pwm".
>  - tach-pulses            : Tachometer pulses per revolution. Valid values are
>                             1, 2, 3 or 4. The default is 1.
> +- mark-fan-installed     : Mark the fan as installed if the hardware doesn't
> +                           already report it so
>  - maxim,fan-no-fault-ramp: Do not ramp the fan to 100% PWM duty on detecting a
>                             fan fault
>  - maxim,fan-startup      : The number of rotations required before taking
> --
> 2.11.0
>