Parallel Port Devices

16x50 UART Driver

Pulse-Width Modulation (PWM)

Pulse-width modulation is a modulation technique primarily used to control power supplied to electrical devices.

The PWM framework provides an abstraction for providers and consumers of PWM signals. A controller that provides one or more PWM signals is registered as :c:type:`struct pwm_chip <pwm_chip>`. Providers are expected to embed this structure in a driver-specific structure. This structure contains fields that describe a particular chip.

A chip exposes one or more PWM signal sources, each of which exposed as a :c:type:`struct pwm_device <pwm_device>`. Operations can be performed on PWM devices to control the period, duty cycle, polarity and active state of the signal.

Note that PWM devices are exclusive resources: they can always only be used by one consumer at a time.