dbus-sensors: utils: Utility to get device bus & addr from dev name.

This is applicable to all the services which rely on "bus-addr" fmt.
1. FanSensor
2. HwmonTempSensor
3. IntelCPUSensor
4. PSUSensor

In addition this would also fix Fansensor Daemon crashes due to
stoi() exceptions weren't caught earlier.

For example: In a FanSensor Daemon -
Device of f0103000.pwm-fan-controller would be classified as i2cfan
based on new way of defining fan type.
Hence when we parse string for bus-addr, bus=f0103000.pwm and
addr=fan-controller for which stoi() would crash.
This would be true for all non I2c devices defaulting to I2cFan type.

Solution is to use 'std::from_chars' which handles under/overflow
properly. Centralizing this now in Utils would also allow us to manage
this appropriatelty across various services.

Tested:
Tested sanity of all daemons in the system and they work as expected.

Change-Id: I546e967abae7c0fb9fca645867e3037046037647
Signed-off-by: Akshit Shah <shahakshit@google.com>
7 files changed
tree: 698602c66b641c29c93d512243722a5b7dfb705d
  1. include/
  2. service_files/
  3. src/
  4. subprojects/
  5. tests/
  6. .clang-format
  7. .clang-tidy
  8. .gitignore
  9. LICENSE
  10. meson.build
  11. meson_options.txt
  12. OWNERS
  13. README.md
README.md

dbus-sensors

dbus-sensors is a collection of sensor applications that provide the xyz.openbmc_project.Sensor collection of interfaces. They read sensor values from hwmon, d-bus, or direct driver access to provide readings. Some advance non-sensor features such as fan presence, pwm control, and automatic cpu detection (x86) are also supported.

key features

  • runtime re-configurable from d-bus (entity-manager or the like)

  • isolated: each sensor type is isolated into its own daemon, so a bug in one sensor is unlikely to affect another, and single sensor modifications are possible

  • async single-threaded: uses sdbusplus/asio bindings

  • multiple data inputs: hwmon, d-bus, direct driver access

dbus interfaces

A typical dbus-sensors object support the following dbus interfaces:

Path        /xyz/openbmc_project/sensors/<type>/<sensor_name>

Interfaces  xyz.openbmc_project.Sensor.Value
            xyz.openbmc_project.Sensor.Threshold.Critical
            xyz.openbmc_project.Sensor.Threshold.Warning
            xyz.openbmc_project.State.Decorator.Availability
            xyz.openbmc_project.State.Decorator.OperationalStatus
            xyz.openbmc_project.Association.Definitions

Sensor interfaces collection are described here.

Consumer examples of these interfaces are Redfish, Phosphor-Pid-Control, IPMI SDR.

Reactor

dbus-sensor daemons are reactors that dynamically create and update sensors configuration when system configuration gets updated.

Using asio timers and async calls, dbus-sensor daemons read sensor values and check thresholds periodically. PropertiesChanged signals will be broadcasted for other services to consume when value or threshold status change. OperationStatus is set to false if the sensor is determined to be faulty.

A simple sensor example can be found here.

configuration

Sensor devices are described using Exposes records in configuration file. Name and Type fields are required. Different sensor types have different fields. Refer to entity manager schema for complete list.

sensor documentation