fuchsia.hardware.power.source

PROTOCOLS

Source

Defined in fuchsia.hardware.power.source/source.fidl

GetSpec

Returns static hardware characteristics that do not change during operation.

Request

<EMPTY>

Response

Name	Type
payload	Source_GetSpec_Result

GetStatus

Returns dynamic status of the source immediately.

Request

<EMPTY>

Response

Name	Type
payload	Source_GetStatus_Result

SetRole

Set the role of this specific node.

Errors:

• INVALID_ARGS: If the provided role is invalid.
• NOT_SUPPORTED: If the requested role is not supported by the hardware.
• INTERNAL: If an unexpected error occurred.

Request

Name	Type
role	Role

Response

Name	Type
payload	Source_SetRole_Result

Watch

Change notification for power source state using a "hanging-get" pattern.

The first call to this method returns the current hardware state immediately. Subsequent calls block until a change occurs that matches the provided masks.

At most one Watch call may be outstanding at a time per connection. Completing a call acknowledges that the client has received the previous update.

Power Management and Suspend

To prevent lost wakeups, the server (driver) must ensure that the Watch call remains active (and hardware interrupts armed) while the system is suspended.

• Interest Triggers: If a change in the interest mask occurs while the system is suspended, the server MUST NOT complete the Watch call until the system wakes for another reason (e.g., a wake_on event or external trigger). This ensures the CPU remains asleep for non-critical updates.
• Wake-On Triggers: If a change in the wake_on mask occurs, the server MUST wake the system and complete the call immediately with a wake_lease.

As a result of this queuing behavior, if multiple changes occur while the system is suspended, they may be merged into a single returned status table, and intermediate state transitions may be lost.

• interest: The client wants to be notified if any of the fields present in this table change. If any field in interest changes, the method returns.
• wake_on: Similar to interest, but if a change occurs in these fields, the server will attempt to keep the system awake using the provided lease (or by returning a wake_lease) until the client acknowledges the update.
• lease: A power lease token used to coordinate handoff between the server and client, ensuring the system does not suspend before the client can process a critical power event.

Returns:

• status: The updated status table containing the fields that changed.
• wake_lease: An optional lease token provided if the change triggered a wake_on condition and the server is maintaining system state.

Request

Name	Type
interest	Status
wake_on	Status
lease	fuchsia.power.system/LeaseToken

Response

Name	Type
payload	Source_Watch_Result

STRUCTS

Source_GetSpec_Response

Defined in fuchsia.hardware.power.source/source.fidl

Field	Type	Description	Default
spec	Spec		No default

Source_GetStatus_Response

Defined in fuchsia.hardware.power.source/source.fidl

Field	Type	Description	Default
status	Status		No default

Source_SetRole_Response

Defined in fuchsia.hardware.power.source/source.fidl

<EMPTY>

Source_Watch_Response resource

Defined in fuchsia.hardware.power.source/source.fidl

Field	Type	Description	Default
status	Status		No default
wake_lease	fuchsia.power.system/LeaseToken		No default

ENUMS

Error flexible

Type: uint32

Defined in fuchsia.hardware.power.source/source.fidl

General errors returned by power source protocols.

Name	Value	Description
INTERNAL	1	An unexpected error occurred within the driver or service.
NOT_SUPPORTED	2	The requested operation or field is not supported by this hardware.
INVALID_ARGS	3	One or more arguments provided to the method were invalid.

SourceType flexible

Type: uint32

Defined in fuchsia.hardware.power.source/source.fidl

The type of power source connected to the device.

Name	Value	Description
AC	1	Standard wall-plug or DC barrel-jack power. Typically uses the base fuchsia.hardware.power.source/Source protocol.
BATTERY	2	Internal or external chemical battery. See fuchsia.hardware.power.battery/Battery.
USB	3	Power supplied over a USB connection. See fuchsia.hardware.power.usb/UsbSource.

TABLES

Auto

Defined in fuchsia.hardware.power.source/source.fidl

Ordinal	Field	Type	Description

Disconnected

Defined in fuchsia.hardware.power.source/source.fidl

Ordinal	Field	Type	Description

SinkRole

Defined in fuchsia.hardware.power.source/source.fidl

Ordinal	Field	Type	Description
1	name	string	Name of the source it's drawing from.
2	type	SourceType	What type of source it's drawing from.

SourceRole

Defined in fuchsia.hardware.power.source/source.fidl

Ordinal	Field	Type	Description

Spec

Defined in fuchsia.hardware.power.source/source.fidl

Static hardware characteristics of a power source.

Ordinal	Field	Type	Description
1	name	string	Unique name of the source (e.g., "USB-C", "Main Battery").
2	supported_roles	vector<Role>	The roles this source is capable of performing.
3	manufacturer	string	The name of the manufacturer of this hardware.
4	model_name	string	The model name or number assigned by the manufacturer.
5	type	SourceType	The category of this power entity.

Status

Defined in fuchsia.hardware.power.source/source.fidl

Dynamic status of a power source.

Ordinal	Field	Type	Description
1	present	bool	Whether the power entity is currently physically present.
2	voltage_uv	uint32	The voltage at the node, in microvolts.
3	current_ua	int32	The current flowing at the node, in microamps. Positive means flowing out (if Source) or in (if Sink).
4	current_role	Role	The role the node is currently performing.

UNIONS

Role flexible

Defined in fuchsia.hardware.power.source/source.fidl

The role a power node plays in the system.

Ordinal	Variant	Type	Description
1	disconnected	Disconnected	The node is disconnected or isolated from the power system.
2	source	SourceRole	The node provides energy to the common system bus.
3	sink	SinkRole	The node consumes or stores energy from the common bus.
4	auto	Auto	The hardware automatically decides the role based on physical detection.

Source_GetSpec_Result strict

Defined in fuchsia.hardware.power.source/source.fidl

Ordinal	Variant	Type	Description
1	response	Source_GetSpec_Response
2	err	Error
3	framework_err	internal

Source_GetStatus_Result strict

Defined in fuchsia.hardware.power.source/source.fidl

Ordinal	Variant	Type	Description
1	response	Source_GetStatus_Response
2	err	Error
3	framework_err	internal

Source_SetRole_Result strict

Defined in fuchsia.hardware.power.source/source.fidl

Ordinal	Variant	Type	Description
1	response	Source_SetRole_Response
2	err	Error
3	framework_err	internal

Source_Watch_Result strict resource

Defined in fuchsia.hardware.power.source/source.fidl

Ordinal	Variant	Type	Description
1	response	Source_Watch_Response
3	framework_err	internal

SERVICES

Service

Defined in fuchsia.hardware.power.source/source.fidl

Name	Type	Transport
source	fuchsia.hardware.power.source/Source	Channel