Regulator Configuration

Overview

The configuration of voltage regulators can be modified. Configuration changes usually override hardware default settings.

The most common configuration change is setting the output voltage for a regulator rail. Other examples include modifying pgood thresholds and overcurrent settings.

Regulator configuration occurs early in the system boot before regulators have been enabled (turned on).

How configuration is defined

Configuration is defined for a voltage regulator using the configuration object in the JSON config file.

This object specifies actions to run, such as pmbus_write_vout_command and i2c_write_byte.

How configuration is initiated

During the system boot, the systemd service file phosphor-regulators-config.service is started. This runs the regsctl utility. This utility invokes the D-Bus configure method on the phosphor-regulators application. phosphor-regulators will perform the configuration defined in the JSON config file.

Multiple chassis

In a multiple chassis system, phosphor-regulators will only configure regulators in chassis with the proper status:

  • Present property is true
  • Enabled property is true (if interface exists)
  • Available property is true (if interface exists)

See Chassis Status for more information on these properties.

Error handling

If an error occurs while executing actions to perform configuration:

  • The error will be logged.
  • Any remaining actions for the current voltage regulator/rail will be skipped.
  • Configuration changes will still be applied to all remaining voltage regulators in the system.
  • The system boot will continue.