docs/designs/psu-monitoring.md

7 Created: 2019-06-17
22 The OpenBMC project currently has a [witherspoon-pfault-analysis][1] repository
28 a single power supply application that can communicate with one or more
30 in the existing application that has multiple instances talking to a single
47    moved from the `phosphor-dbus-monitor` to this application, depending on if
49    system.
55 7. The power supply application must allow power supply hot-plug and concurrent
60    are present in the system, what type of power supply is present (maximum
71     the sysfs file system files updated via a PMBus device driver (currently
72     only known to be created and updated by the [ibm-cffps][4] device driver).
83 The proposal is to create a single new power supply application in the OpenBMC
84 [phosphor-power][6] repository. The application would be written in C++17.
88 file. This file would contain information such as the D-Bus object name(s),
89 possible power supply types, possible system types that the various power
93 The power supply application would then detect which system type it is running
100 When the system is powered on, the power supplies should start outputting power
101 to the system. At that point the application will start to and continue to
112 considered, essentially similar to the [psu-monitor][5] from the
113 [witherspoon-pfault-analysis][1] repository. This design was avoided due to:
115 - Complexity of the various valid and invalid configuration combinations.
116 - Power line disturbance communication.
117 - Timing/serialization concerns with power supply communication.
136 - Configuration not listed as valid results in appropriate behavior.
137 - Application detects and logs faults for power supply faults including input
140 - Power supply VPD data reported for present power supplies.
141 - Power supply removal and insertion, on a system supporting concurrent
142   maintenance, does not result in power loss to powered on system.
143 - System operates through power supply faults and power line disturbances as
146 CI testing could be impacted if a system being used for testing is in an
149 [1]: https://github.com/openbmc/witherspoon-pfault-analysis
152 …https://github.com/openbmc/phosphor-dbus-interfaces/blob/master/yaml/xyz/openbmc_project/Control/R…
154   https://github.com/openbmc/linux/blob/dev-5.3/drivers/hwmon/pmbus/ibm-cffps.c
156   https://github.com/openbmc/witherspoon-pfault-analysis/tree/master/power-supply
157 [6]: https://github.com/openbmc/phosphor-power/