| commit | e73bd0a11e54b7d2a7037d0b1e8d49de1042f44a | [log] [tgz] |
|---|---|---|
| author | Andrew Jeffery <andrew@aj.id.au> | Wed Jan 25 10:39:57 2023 +1030 |
| committer | Andrew Jeffery <andrew@aj.id.au> | Wed Jan 25 10:45:23 2023 +1030 |
| tree | c2345d4da32f08c3f1bd9ea402de30bf4bb2bcbf | |
| parent | ea148ec6f913c1b1d4a145591097628b01384d96 [diff] |
sensors: Align source structure away from anti-patterns The anti-patterns document comments on source structure, specifically on placing internal headers in a parallel subtree[1]. dbus-sensors is an example of violating this anti-pattern, so fix it. [1]: https://github.com/openbmc/docs/blob/master/anti-patterns.md#placing-internal-headers-in-a-parallel-subtree Signed-off-by: Andrew Jeffery <andrew@aj.id.au> Change-Id: I50ecaddd53fa9c9b7a0441af9de5e60bd94e47c6
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.
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
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.
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.
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.