Chapter 1. Introduction

Table of Contents


This framework is designed to provide a standard kernel interface to control voltage and current regulators.

The intention is to allow systems to dynamically control regulator power output in order to save power and prolong battery life. This applies to both voltage regulators (where voltage output is controllable) and current sinks (where current limit is controllable).

Note that additional (and currently more complete) documentation is available in the Linux kernel source under Documentation/power/regulator.


The regulator API uses a number of terms which may not be familiar:



Electronic device that supplies power to other devices. Most regulators can enable and disable their output and some can also control their output voltage or current.


Electronic device which consumes power provided by a regulator. These may either be static, requiring only a fixed supply, or dynamic, requiring active management of the regulator at runtime.

Power Domain

The electronic circuit supplied by a given regulator, including the regulator and all consumer devices. The configuration of the regulator is shared between all the components in the circuit.

Power Management Integrated Circuit

An IC which contains numerous regulators and often also other subsystems. In an embedded system the primary PMIC is often equivalent to a combination of the PSU and southbridge in a desktop system.