Chargers
The charger subsystem exposes an API to uniformly access battery charger devices.
A charger device, or charger peripheral, is a device used to take external power provided to the system as an input and provide power as an output downstream to the battery pack(s) and system. The charger device can exist as a module, an integrated circuit, or as a functional block in a power management integrated circuit (PMIC).
The action of charging a battery pack is referred to as a charge cycle. When the charge cycle is executed the battery pack is charged according to the charge profile configured on the charger device. The charge profile is defined in the battery pack’s specification that is provided by the manufacturer. On charger devices with a control port, the charge profile can be configured by the host controller by setting the relevant properties, and can be adjusted at runtime to respond to environmental changes.
Basic Operation
Initiating a Charge Cycle
A charge cycle is initiated or terminated using charger_charge_enable().
Properties
Fundamentally, a property is a configurable setting, state, or quantity that a charger device can measure.
Chargers typically support multiple properties, such as temperature readings of the battery-pack or present-time current/voltage.
Properties are fetched by the client one at a time using charger_get_prop().
Properties are set by the client one at a time using charger_set_prop().