The main (non-standby) voltage rails in a chassis are powered on or off by toggling a named GPIO to the power sequencer device in the chassis.
The GPIO name is defined in the Linux device tree. For single chassis systems, the standard GPIO name is power-chassis-control. See Device Tree GPIO Naming in OpenBMC for more information.
The GPIO name in each chassis is specified in the JSON configuration file. If no configuration file is found for the current system, the standard GPIO name is used.
The power sequencer device provides a chassis power good (pgood) signal, indicating whether all the main (non-standby) rails are powered on.
The phosphor-power-sequencer application reads the chassis power good signal from a named GPIO.
The GPIO name is defined in the Linux device tree. For single chassis systems, the standard GPIO name is power-chassis-good. See Device Tree GPIO Naming in OpenBMC for more information.
The GPIO name in each chassis is specified in the JSON configuration file. If no configuration file is found for the current system, the standard GPIO name is used.