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gerrit.openbmc.org / openbmc / phosphor-gpio-monitor / refs/heads/master
commit75ff16717de9a7b3beeda9f3cace9456cad98156[log] [tgz]
authorChristopher Meis <christopher.meis@9elements.com>Tue Sep 23 11:40:06 2025 +0200
committerPatrick Williams <patrick@stwcx.xyz>Tue Oct 14 15:25:34 2025 -0400
tree6234fc8ad7340f7b8cc159938d51697236f3bacc
parent90c6b7378e904948bc41ea1aa8eff05ec92a29cd [diff]
Copyright: Move to SPDX-Identifier

SPDX-Identifier cleans up the files and creates visibility on each file
while not using too much space.

Replacing all instances on the long apache-2.0 text and adding the
SPDX-Identifier where not present before.

Change-Id: I7566febfd29dac6c81df6ff4045a6663aa50fca4
Signed-off-by: Christopher Meis <christopher.meis@9elements.com>
Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
16 files changed
tree: 6234fc8ad7340f7b8cc159938d51697236f3bacc
  1. multi-presence/
  2. presence/
  3. subprojects/
  4. test/
  5. .clang-format
  6. .clang-tidy
  7. .gitignore
  8. 99-gpio-keys.rules
  9. evdev.cpp
  10. evdev.hpp
  11. file.hpp
  12. gpioMon.cpp
  13. gpioMon.hpp
  14. gpioMonMain.cpp
  15. LICENSE
  16. mainapp.cpp
  17. meson.build
  18. meson.options
  19. monitor.cpp
  20. monitor.hpp
  21. OWNERS
  22. phosphor-gpio-monitor@.service
  23. phosphor-gpio-presence@.service
  24. phosphor-multi-gpio-monitor.json
  25. phosphor-multi-gpio-monitor.service
  26. phosphor-multi-gpio-presence.json
  27. phosphor-multi-gpio-presence.service
  28. README.md
README.md

GPIO Monitoring

Implemented Daemons

phosphor-gpio-monitor

This daemon accepts a command line parameter for monitoring single gpio line and take action if requested. This implementation uses GPIO keys and only supports monitoring single GPIO line, for multiple lines, user has to run this daemon seperately for each gpio line.

phosphor-multi-gpio-monitor

This daemon accepts command line parameter as a well-defined GPIO configuration file in json format to monitor list of gpios from config file and take action defined in config based on gpio state change. It uses libgpiod library.

Difference

New implementation (phosphor-multi-gpio-monitor) provides multiple gpio line monitoring in single instance of phosphor-multi-gpio-monitor running. It is very easy to add list of gpios into JSON config file and it also supports of GPIO line by name defined in kernel.

Configuration

There is a phosphor-multi-gpio-monitor.json file that defines details of GPIOs which is required to be monitored. This file can be replaced with a platform specific configuration file via bbappend.

Following are fields in json file

  1. Name: Name of gpio for reference.
  2. LineName: this is the line name defined in device tree for specific gpio
  3. GpioNum: GPIO offset, this field is optional if LineName is defined.
  4. ChipId: This is device name either offset ("0") or complete gpio device ("gpiochip0"). This field is not required if LineName is defined.
  5. EventMon: Event of gpio to be monitored. This can be "FALLING", "RISING" OR "BOTH". Default value for this is "BOTH".
  6. Target: This is an optional systemd service which will get started after triggering event. A journal entry will be added for every event occurs irrespective of this definition.
  7. Targets: This is an optional systemd service which will get started after triggering corresponding event(RISING or FALLING). A journal entry will be added for every event occurs irrespective of this definition. Upon start up, depending on the current GPIO value, the systemd services for INIT_HIGH and INIT_LOW will be called (if defined).
  8. Continue: This is a optional flag and if it is defined as true then this gpio will be monitored continuously. If not defined then monitoring of this gpio will stop after first event.

Sample config file

[
  {
    "Name": "PowerButton",
    "LineName": "POWER_BUTTON",
    "GpioNum": 34,
    "ChipId": "gpiochip0",
    "EventMon": "FALLING",
    "Target": "PowerButtonDown.service",
    "Continue": true
  },
  {
    "Name": "PowerGood",
    "LineName": "PS_PWROK",
    "EventMon": "BOTH",
    "Targets": {
      "FALLING": ["PowerGoodFalling.service", "PowerOff.service"],
      "RISING": ["PowerGoodRising.service", "PowerOn.service"]
    },
    "Continue": false
  },
  { "Name": "SystemReset", "GpioNum": 46, "ChipId": "0" }
]

phosphor-multi-gpio-presence

This daemon accepts command line parameter as a well-defined GPIO configuration file in json format to monitor list of gpios from config file and sets inventory presence as defined in config based on gpio state change. It uses libgpiod library.

Difference

New implementation (phosphor-multi-gpio-presence) provides multiple gpio line monitoring in single instance of phosphor-multi-gpio-presence running. It is very easy to add list of gpios into JSON config file and it also supports of GPIO line by name defined in kernel.

Configuration

There is a phosphor-multi-gpio-presence.json file that defines details of GPIOs which is required to be monitored. This file can be replaced with a platform specific configuration file via bbappend.

Following are fields in json file

  1. Name: PrettyName of inventory item
  2. LineName: this is the line name defined in device tree for specific gpio
  3. GpioNum: GPIO offset, this field is optional if LineName is defined.
  4. ChipId: This is device name either offset ("0") or complete gpio device ("gpiochip0"). This field is not required if LineName is defined.
  5. Inventory: Object path under inventory that will be created
  6. ExtraInterfaces: [Optional] List of interfaces to associate to inventory item
  7. ActiveLow: [Optional] Object is present on LOW level
  8. Bias: [Optional] Configure a BIAS on the GPIO line, for example PULL_UP

Sample config file

[
  {
    "Name": "DIMM A0",
    "LineName": "POWER_BUTTON",
    "Inventory": "/system/chassis/motherboard/dimm_a0"
  },
  {
    "Name": "Powersupply 0",
    "ChipId": "0",
    "GpioNum": 14,
    "Inventory": "/system/chassis/motherboard/powersupply0",
    "ActiveLow": true,
    "Bias": "PULL_UP",
    "ExtraInterfaces": ["xyz.openbmc_project.Inventory.Item.PowerSupply"]
  }
]