Generic Pulse-Width Modulation (PWM) support.

In Pulse-Width Modulation, a variation of the width of pulses
in a rectangular pulse signal is used as a means to alter the
average power of the signal. Applications include efficient
power delivery and voltage regulation. In computer systems,
PWMs are commonly used to control fans or the brightness of
display backlights.

This framework provides a generic interface to PWM devices
within the Linux kernel. On the driver side it provides an API
to register and unregister a PWM chip, an abstraction of a PWM
controller, that supports one or more PWM devices. Client
drivers can request PWM devices and use the generic framework
to configure as well as enable and disable them.

This generic framework replaces the legacy PWM framework which
allows only a single driver implementing the required API. Not
all legacy implementations have been ported to the framework
yet. The framework provides an API that is backward compatible
with the legacy framework so that existing client drivers
continue to work as expected.

If unsure, say no.

source code:

drivers/pwm/core.c