xref: /openbmc/phosphor-power/phosphor-regulators/README.md (revision 0dbce5689e08edcd242ae33eee3500ffa4407a80)
191090e41SShawn McCarney## Overview
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391090e41SShawn McCarneyThe `phosphor-regulators` application configures and monitors voltage
491090e41SShawn McCarneyregulators. The application is controlled by a JSON configuration file.
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691090e41SShawn McCarneyThe application does not control how voltage regulators are enabled or how to
791090e41SShawn McCarneymonitor their Power Good (pgood) status. Those operations are typically
891090e41SShawn McCarneyperformed by power sequencer hardware and related firmware.
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1091090e41SShawn McCarney## Configuring Voltage Regulators
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1291090e41SShawn McCarneyThe configuration of voltage regulators can be modified. Configuration changes
1391090e41SShawn McCarneyusually override hardware default settings.
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1591090e41SShawn McCarneyThe most common configuration change is setting the output voltage for a
1691090e41SShawn McCarneyregulator rail. Other examples include modifying pgood thresholds and
1791090e41SShawn McCarneyovercurrent settings.
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1991090e41SShawn McCarneyThe configuration changes are applied early in the boot process before
2091090e41SShawn McCarneyregulators are enabled.
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2291090e41SShawn McCarney## Monitoring Voltage Regulators
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2491090e41SShawn McCarneyTwo types of regulator monitoring are supported:
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26*0dbce568SPatrick Williams- Sensor monitoring
27*0dbce568SPatrick Williams- Phase fault monitoring
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2991090e41SShawn McCarney### Sensor Monitoring
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3191090e41SShawn McCarneyThe sensor values for a voltage rail are read, such as voltage output, current
3291090e41SShawn McCarneyoutput, and temperature. Sensor values are measured, actual values rather than
3391090e41SShawn McCarneytarget values.
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3591090e41SShawn McCarneySensors are read once per second. The sensor values are stored on D-Bus on the
3691090e41SShawn McCarneyBMC, making them available to external interfaces like Redfish.
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3891090e41SShawn McCarney### Phase Fault Monitoring
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4091090e41SShawn McCarneySome voltage regulators contain redundant phases. If a redundant phase fails,
4191090e41SShawn McCarneythe regulator can continue functioning normally. However redundancy has been
4291090e41SShawn McCarneylost, and the regulator may fail if another phase fails.
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4491090e41SShawn McCarneyVoltage regulators can be monitored for redundant phase faults. If a fault is
4591090e41SShawn McCarneydetected, an error is logged on the BMC.
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4791090e41SShawn McCarney## JSON Configuration File
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4991090e41SShawn McCarneyThe JSON configuration file defines the following:
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51*0dbce568SPatrick Williams- Voltage regulators in the system.
52*0dbce568SPatrick Williams- Operations to perform on those regulators, such as configuration or sensor
5391090e41SShawn McCarney  monitoring.
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5591090e41SShawn McCarneyConfiguration files are stored in the `config_files` directory.
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5791090e41SShawn McCarneySee the [configuration file documentation](docs/config_file/README.md) for
5891090e41SShawn McCarneyinformation on the file format, validation tool, and installation directories.
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