Fan PWM monitoring and control

[Patrick Venture]

On Tue, Sep 17, 2019 at 8:32 AM Matthew Barth <msbarth at linux.ibm.com> wrote:
>
>
> On 9/17/19 5:40 AM, rgrs wrote:
> > Hi,
> >
> > I need some help with phosphor hwmon related to fan sensors.
> >
> > I'm trying to control Fans in a server motherboard using ADT7462
> > controller. Hw mon porting is done and the sysfs interfaces are working
> > as expected.
> >
> > While I am able to read RPM, i don't find pwm/target to control the fans
> > exposed as dbus objects.
> Do you have the hwmon config set similar to this to denote the fan
> targets are of PWM type?
>
> https://github.com/openbmc/openbmc/blob/master/meta-ibm/meta-romulus/recipes-phosphor/sensors/phosphor-hwmon/obmc/hwmon/ahb/apb/pwm-tacho-controller%401e786000.conf
> >
> > # busctl --no-page tree xyz.openbmc_project.FanSensor
> > Failed to introspect object / of service xyz.openbmc_project.FanSensor:
> > The name is not activatable
> > No objects discovered.
> That does not look like a hwmon service name. If you are using
> phosphor-objmgr, you can use `# mapper get-service
> /xyz/openbmc_project/sensors/fan_tach` otherwise you'll need to find the
> hwmon service name associated with your fan controller device.

running `busctl tree --no-pager` will just list everything, and you
should see your fans in there.  You can use the mapper too.  I was
curious, are you using entity-manager/dbus-sensors?  When you mention
FanSensor as the service, that's what it sounds like.

> >
> > I came across this post, I think it is similar to my issue.
> > (https://gerrit.openbmc-project.xyz/c/openbmc/phosphor-hwmon/+/8353)
> >
> > Please someone point to latest documentation or reference Fan porting
> > from openBMC repo?
> > What are the exact fields in YAML that are used create FanPWM objects.
> The Romulus machine should be a good reference for PWM based fan control
> using phosphor-hwmon. It uses the
> phosphor-fan-presence/[control|monitor] apps for controlling and
> monitoring fans
>
> https://github.com/openbmc/openbmc/tree/master/meta-ibm/meta-romulus
> >
> > (I'm using Feb release in my sandbox,
> > https://github.com/openbmc/docs/blob/master/release/release-notes.md#26-feb-4-2019)
> >
> > Thanks,
> > Raj
>
> Matt