phosphor-power-sequencer/docs/README.md

1 # phosphor-power-sequencer
5 The phosphor-power-sequencer application powers the chassis on/off and monitors
14 The application is a single-threaded C++ executable. It is a 'daemon' process
18 The application is driven by an optional, system-specific JSON configuration
30 - UCD90160
31 - UCD90320
33 Additional device types can be supported by creating a new sub-class within the
38 - A BMC application or script sets the `state` property to 1 on the
39   `org.openbmc.control.Power` D-Bus interface.
40 - The phosphor-power-sequencer application writes the value 1 to the named GPIO
41   `power-chassis-control`.
42   - This GPIO is defined in the device tree. The GPIO name is defined in the
43 …n OpenBMC document](https://github.com/openbmc/docs/blob/master/designs/device-tree-gpio-naming.md)
44 - The power sequencer device powers on all the voltage rails in the correct
46 - When all rails have been successfully powered on, the power sequencer device
47   sets the named `power-chassis-good` GPIO to the value 1.
48   - This GPIO is defined in the device tree. The GPIO name is defined in the
49 …n OpenBMC document](https://github.com/openbmc/docs/blob/master/designs/device-tree-gpio-naming.md)
50 - The phosphor-power-sequencer application sets the `pgood` property to 1 on the
51   `org.openbmc.control.Power` D-Bus interface.
52 - The rest of the boot continues
56 - A BMC application or script sets the `state` property to 0 on the
57   `org.openbmc.control.Power` D-Bus interface.
58 - The phosphor-power-sequencer application writes the value 0 to the named GPIO
59   `power-chassis-control`.
60 - The power sequencer device powers off all the voltage rails in the correct
62 - When all rails have been successfully powered off, the power sequencer device
63   sets the named `power-chassis-good` GPIO to the value 0.
64 - The phosphor-power-sequencer application sets the `pgood` property to 0 on the
65   `org.openbmc.control.Power` D-Bus interface.
71 - When attempting to power on the chassis:
72   - The power sequencer device is powering on all voltage rails in order, and
74 - After the chassis was successfully powered on:
75   - A voltage rail suddenly turns off or stops providing the expected level of
84 chassis power good status by reading the named GPIO `power-chassis-good`.
93 - The power sequencer device type is supported by this application
94 - A JSON config file is defined for the current system
108 JSON configuration files are system-specific and are stored in the
109 [config_files](../config_files/) sub-directory.
120 - PowerInterface
121   - Defines the `org.openbmc.control.Power` D-Bus interface.
122   - The `state` property is set to power the chassis on or off. This contains
124   - The `pgood` property contains the actual power state of the chassis.
125 - PowerControl
126   - Created in `main()`. Handles the event loop.
127   - Sub-class of PowerInterface that provides a concrete implementation of the
128     `org.openbmc.control.Power` D-Bus interface.
129   - Finds and loads the JSON configuration file.
130   - Finds power sequencer device information.
131   - Creates a sub-class of PowerSequencerDevice that matches power sequencer
133   - Powers the chassis on and off using the `power-chassis-control` named GPIO.
134   - Monitors the chassis pgood status every 3 seconds using the
135     `power-chassis-good` named GPIO.
136   - Enforces a minimum power off time of 15 seconds from cold start and 25
138 - DeviceFinder
139   - Finds power sequencer device information on D-Bus published by
141 - Rail
142   - A voltage rail that is enabled or monitored by the power sequencer device.
143 - PowerSequencerDevice
144   - Abstract base class for a power sequencer device.
145   - Defines virtual methods that must be implemented by all child classes.
146 - StandardDevice
147   - Sub-class of PowerSequencerDevice that implements the standard pgood fault
149 - PMBusDriverDevice
150   - Sub-class of StandardDevice for power sequencer devices that are bound to a
152 - UCD90xDevice
153   - Sub-class of PMBusDriverDevice for the UCD90X family of power sequencer
155 - UCD90160Device
156   - Sub-class of UCD90xDevice representing a UCD90160 power sequencer device.
157 - UCD90320Device
158   - Sub-class of UCD90xDevice representing a UCD90320 power sequencer device.
159 - Services
160   - Abstract base class that provides an interface to system services like error
162 - BMCServices
163   - Sub-class of Services with real implementation of methods.
164 - MockServices
165   - Sub-class of Services with mock implementation of methods for automated