pseq: Document enhanced JSON config file format

The JSON config file format is being enhanced for the
phosphor-power-sequencer application.

The enhancements are intended to provide the following benefits:
* Generalize the format so it can be used for any power sequencer
  device.  The current format is intended only for UCD90XXX devices.
* Remove the "pins" array.  Move the GPIO pin information to an optional
  property of a rail object.  This will eliminate some duplication and
  make pgood isolation more flexible.
* Change the meaning of the rail order within the array of rails.
  * In the current format, the array index implies the PMBus PAGE.  This
    causes problems because it is impossible to ignore a PAGE that is
    not a valid voltage rail.  It also does not provide information
    on the power on sequence, which is often different than the PAGE
    order.
  * In the new format, the rails in the array will be in power on
    sequence order.  The PMBus page will be explicitly defined using
    a new property.
* Add rail property that specifies the PMBus PAGE.
* Add rail property that specifies the pgood status should be obtained
  using the PMBus STATUS_VOUT command.
* Add rail property that specifies the pgood status should be obtained
  by comparing the output voltage (READ_VOUT) to the undervoltage
  (VOUT_UV_FAULT_LIMIT) and overvoltage (VOUT_OV_FAULT_LIMIT) limits.
* Add rail property that specifies the pgood status should be obtained
  from a GPIO.

Note: This commit contains only the new JSON file format documentation.
Subsequent commits will contain the new C++ implementation and new
versions of the existing JSON files.  The current documentation, C++,
and JSON files will be retained and will remain active until all of the
new support has been merged.

Change-Id: I358a885f1675a9dd8f9ae0115e560abb3c0828fe
Signed-off-by: Shawn McCarney <shawnmm@us.ibm.com>
4 files changed
tree: 3fe50c810f8c15161918972b030a1636232b5d6e
  1. cold-redundancy/
  2. example/
  3. org/
  4. phosphor-power-sequencer/
  5. phosphor-power-supply/
  6. phosphor-regulators/
  7. power-sequencer/
  8. power-supply/
  9. services/
  10. subprojects/
  11. test/
  12. tools/
  13. .clang-format
  14. .gitignore
  15. .shellcheck
  16. device.hpp
  17. device_monitor.hpp
  18. elog-errors.hpp
  19. file_descriptor.hpp
  20. gpio.cpp
  21. gpio.hpp
  22. LICENSE
  23. meson.build
  24. meson.options
  25. names_values.hpp
  26. OWNERS
  27. pmbus.cpp
  28. pmbus.hpp
  29. README.md
  30. types.hpp
  31. utility.cpp
  32. utility.hpp
README.md

Overview

This repository contains applications for configuring and monitoring devices that deliver power to the system.

  • cold-redundancy: Application that makes power supplies work in Cold Redundancy mode and rotates them at intervals.
  • phosphor-power-sequencer: Applications for configuring and monitoring power sequencer and related devices that support JSON-driven configuration.
  • phosphor-power-supply: Next generation power supply monitoring application.
  • phosphor-regulators: JSON-driven application that configures and monitors voltage regulators.
  • power-sequencer: A power sequencer monitoring application.
  • power-supply: Original power supply monitoring application.
  • tools/power-utils: Power supply utilities.

Build

To build all applications in this repository:

  meson setup build
  ninja -C build

To clean the repository and remove all build output:

  rm -rf build

You can specify meson options to customize the build process. For example, you can specify:

  • Which applications to build and install.
  • Application-specific configuration data, such as power sequencer type.
  • Whether to build tests.

Power Supply Monitor and Util JSON config

Several applications in this repository require a PSU JSON config to run. The JSON config file provides information for:

  • Where to access the pmbus attributes
  • Which attribute file in pmbus maps to which property and interface in D-Bus
  • Which kernel device directory is used on which PSU

There is an example psu.json to describe the necessary configurations.

  • inventoryPMBusAccessType defines the pmbus access type, which tells the service which sysfs type to use to read the attributes. The possible values are:
    • Base: The base dir, e.g. /sys/bus/i2c/devices/3-0069/
    • Hwmon: The hwmon dir, e.g. /sys/bus/i2c/devices/3-0069/hwmon/hwmonX/
    • Debug: The pmbus debug dir, e.g. /sys/kernel/debug/pmbus/hwmonX/
    • DeviceDebug: The device debug dir, e.g. '/sys/kernel/debug/./`
    • HwmonDeviceDebug: The hwmon device debug dir, e.g. /sys/kernel/debug/pmbus/hwmonX/cffps1/
  • fruConfigs defines the mapping between the attribute file and the FRU inventory interface and property. The configuration example below indicates that the service will read part_number attribute file from a directory specified by the above pmbus access type, and assign to PartNumber property in xyz.openbmc_project.Inventory.Decorator.Asset interface.
      "fruConfigs": [
        {
          "propertyName": "PartNumber",
          "fileName": "part_number",
          "interface": "xyz.openbmc_project.Inventory.Decorator.Asset"
        }
      ]
    
  • psuDevices defines the kernel device dir for each PSU in inventory. The configuration example below indicates that powersupply0's device is located in /sys/bus/i2c/devices/3-0069.
      "psuDevices": {
        "/xyz/openbmc_project/inventory/system/chassis/motherboard/powersupply0" : "/sys/bus/i2c/devices/3-0069",
      }