tree f60ee0481b1c41f26dd80b984a0c9a3658b7919f
parent 86433ae8e8866b8dae23a3a5a0c240c11ff196fd
author Matt Spinler <spinler@us.ibm.com> 1678475209 -0600
committer Matt Spinler <spinler@us.ibm.com> 1678803839 +0000

psu-ng: Put input voltage rating on D-Bus

IBM systems must tell the BIOS (called hostboot) the power supply input
voltage rating during a boot, where the rating is 110 or 220.  This is
done via PLDM BIOS attributes where the attribute is backed by a D-Bus
property.

This commit adds support for that by putting the input voltage rating
of each PS on D-Bus using the Value property of the
xyz.openbmc_project.Sensor.Value interface. The path is like
/xyz/openbmc_project/sensors/voltage/ps0_input_voltage_rating.

$ busctl get-property xyz.openbmc_project.Power.PSUMonitor \
  /xyz/openbmc_project/sensors/voltage/ps0_input_voltage_rating \
  xyz.openbmc_project.Sensor.Value Value
d 220

$ busctl get-property xyz.openbmc_project.Power.PSUMonitor \
  /xyz/openbmc_project/sensors/voltage/ps0_input_voltage_rating \
  xyz.openbmc_project.Sensor.Value Unit
s "xyz.openbmc_project.Sensor.Value.Unit.Volts"

These D-Bus objects won't have any associations, unlike normal sensors,
so they will not show up in any Redfish output as a sensor.

The interface is only created for present power supplies, and is only
updated when the application starts up and when the boot starts.

If a power supply is hot added or removed after that, the D-Bus property
doesn't need to be updated as hostboot has already consumed it.

Change-Id: I277516e8d86f1ba1a75b75fe76c67f192d911f88
Signed-off-by: Matt Spinler <spinler@us.ibm.com>