Add phosphor-fan configuration for the fan which added by dbus-sensor

[Matthew Barth]

On 5/6/21 4:22 AM, Thu Nguyen OS wrote:
> Hi,
>
> I’m supporting the fan control algorithms using phosphor-fan. Phosphor-fan monitoring and controlling require interface xyz.openbmc_project.Control.FanPwm in the fan inventory object.
That is a sensor interface, not an interface that's added to inventory objects
> https://github.com/openbmc/phosphor-fan-presence/blob/master/docs/monitor/inventory.md
What you linked to here refers to where the fan inventory object is located and nothing to do with with the fan sensors that fan monitor is to be monitoring.
>
> But FanSensor daemon of dbus-sensor only adds /xyz/openbmc_project/sensors/fan_tach to inventory list, and this path don’t support xyz.openbmc_project.Control.FanPwm interface.
I cant speak to the support of dbus-sensors and the use of the FanPwm interface, but phosphor-fan-monitor can support either the use of RPM or PWM fan sensors for monitoring and updating the corresponding OperationalStatus of a fan in inventory.
https://github.com/openbmc/phosphor-fan-presence/blob/master/docs/monitor/sensors.md

Supplying the ` "target_interface": "xyz.openbmc_project.Control.FanPwm" ` directs fan monitor to monitor the fan sensor using the Target property from that interface. When the "target_interface" is not provided on a fan sensor, the default is to use the "xyz.openbmc_project.Control.FanSpeed" (RPM) interface.
>
> Do you have any solution to make phosphor-fan work with dbus-sensor?
>
> I’m currently update FanSensor in dbus-sensor to add xyz.openbmc_project.Control.FanPwm to /xyz/openbmc_project/sensors/fan_tach.
Refer to the doc link I provided above on how to utilize monitoring fans that use a PWM target on that interface. Then phosphor-fan-monitor will update the fan inventory object's (as configured with https://github.com/openbmc/phosphor-fan-presence/blob/master/docs/monitor/inventory.md) xyz.openbmc_project.State.Decorator.OperationalStatus Functional property based on how you configure fan monitor to monitor the fan sensors.
>
> Regards.
> Thu Nguyen.