1*27ae70b8SShawn McCarney# Powering Off 2*27ae70b8SShawn McCarney 3*27ae70b8SShawn McCarney## Initiating a power off 4*27ae70b8SShawn McCarney 5*27ae70b8SShawn McCarneyThe system can be powered off by several methods, such as the `obmcutil` tool, a 6*27ae70b8SShawn McCarneyRedfish command, or a power button on the system enclosure. 7*27ae70b8SShawn McCarney 8*27ae70b8SShawn McCarneyWhichever method is used, it sets the `state` property to 0 on the 9*27ae70b8SShawn McCarney`org.openbmc.control.Power` D-Bus interface. The D-Bus object path is 10*27ae70b8SShawn McCarney`/org/openbmc/control/power0`, which represents the entire system. See 11*27ae70b8SShawn McCarney[Chassis Status](chassis_status.md) for more information. 12*27ae70b8SShawn McCarney 13*27ae70b8SShawn McCarneyThe `phosphor-power-sequencer` application only supports powering off the entire 14*27ae70b8SShawn McCarneysystem. In a multiple chassis system, `phosphor-power-sequencer` does not 15*27ae70b8SShawn McCarneysupport powering off individual chassis independent of the rest of the system. 16*27ae70b8SShawn McCarney 17*27ae70b8SShawn McCarney## Determining which chassis to power off 18*27ae70b8SShawn McCarney 19*27ae70b8SShawn McCarneyIn a single chassis system, `phosphor-power-sequencer` will always attempt to 20*27ae70b8SShawn McCarneypower off the chassis. 21*27ae70b8SShawn McCarney 22*27ae70b8SShawn McCarneyIn a multiple chassis system, `phosphor-power-sequencer` will only attempt to 23*27ae70b8SShawn McCarneypower off chassis with the proper status: 24*27ae70b8SShawn McCarney 25*27ae70b8SShawn McCarney- `Present` property is true 26*27ae70b8SShawn McCarney- `Available` property is true (if interface exists) 27*27ae70b8SShawn McCarney 28*27ae70b8SShawn McCarney`phosphor-power-sequencer` will set the `state` property to 0 for all chassis. 29*27ae70b8SShawn McCarney 30*27ae70b8SShawn McCarney`phosphor-power-sequencer` will set the `pgood` property to 0 for all chassis 31*27ae70b8SShawn McCarneywhere `Present` or `Available` are false. 32*27ae70b8SShawn McCarney 33*27ae70b8SShawn McCarneySee [Chassis Status](chassis_status.md) for more information on these 34*27ae70b8SShawn McCarneyproperties. 35*27ae70b8SShawn McCarney 36*27ae70b8SShawn McCarney## Powering off the voltage rails 37*27ae70b8SShawn McCarney 38*27ae70b8SShawn McCarney`phosphor-power-sequencer` powers off the main (non-standby) voltage rails in a 39*27ae70b8SShawn McCarneychassis by toggling a named GPIO to the power sequencer device in the chassis. 40*27ae70b8SShawn McCarneyFor more information, see [Named GPIOs](named_gpios.md). 41*27ae70b8SShawn McCarney 42*27ae70b8SShawn McCarneyIn each chassis being powered off, the power sequencer device powers off the 43*27ae70b8SShawn McCarneyindividual voltage rails in the correct order. 44*27ae70b8SShawn McCarney 45*27ae70b8SShawn McCarney## Determining when power off is complete 46*27ae70b8SShawn McCarney 47*27ae70b8SShawn McCarneyWhen the voltage rails have been powered off in a chassis, the power sequencer 48*27ae70b8SShawn McCarneydevice will set the chassis power good (pgood) signal to false. 49*27ae70b8SShawn McCarney 50*27ae70b8SShawn McCarney`phosphor-power-sequencer` reads the chassis pgood signal from a named GPIO. For 51*27ae70b8SShawn McCarneymore information, see 52*27ae70b8SShawn McCarney[Monitoring Chassis Power Good](monitoring_chassis_pgood.md). 53*27ae70b8SShawn McCarney 54*27ae70b8SShawn McCarneyWhen the chassis power good signal changes to false, `phosphor-power-sequencer` 55*27ae70b8SShawn McCarneywill set the `pgood` property to 0 on the `org.openbmc.control.Power` interface 56*27ae70b8SShawn McCarneyfor the **chassis** object path. The power off has finished for that chassis. 57*27ae70b8SShawn McCarney 58*27ae70b8SShawn McCarneyWhen all chassis that were being powered off have finished, 59*27ae70b8SShawn McCarney`phosphor-power-sequencer` will set the `pgood` property to 0 on the 60*27ae70b8SShawn McCarney`org.openbmc.control.Power` interface for the **system** object path. 61*27ae70b8SShawn McCarney 62*27ae70b8SShawn McCarneySee [Chassis Status](chassis_status.md) for more information on the `pgood` 63*27ae70b8SShawn McCarneyproperty. 64