freebsd-skq/share/man/man9/pwm.9
2019-02-06 03:57:51 +00:00

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.\" Copyright (c) 2018 Emmanuel Vadot <manu@freebsd.org>
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.Dd January 12, 2019
.Dt PWM 9
.Os
.Sh NAME
.Nm pwm ,
.Nm PWM_GET_BUS ,
.Nm PWM_CHANNEL_CONFIG ,
.Nm PWM_CHANNEL_GET_CONFIG ,
.Nm PWM_CHANNEL_SET_FLAGS ,
.Nm PWM_CHANNEL_GET_FLAGS ,
.Nm PWM_CHANNEL_ENABLE ,
.Nm PWM_CHANNEL_IS_ENABLED ,
.Nm PWM_CHANNEL_MAX
.Nd PWM methods
.Sh SYNOPSIS
.Cd "device pwm"
.In "pwm_if.h"
.Ft device_t
.Fn PWM_GET_BUS "device_t dev"
.Ft int
.Fn PWM_CHANNEL_CONFIG "device_t dev" "int channel" "uint64_t period" "uint64_t duty"
.Ft int
.Fn PWM_CHANNEL_GET_CONFIG "device_t dev" "int channel" "uint64_t *period" "uint64_t *duty"
.Ft int
.Fn PWM_CHANNEL_SET_FLAGS "device_t dev" "int channel" "uint32_t flags"
.Ft int
.Fn PWM_CHANNEL_GET_FLAGS "device_t dev" "int channel" "uint32_t *flags"
.Ft int
.Fn PWM_CHANNEL_ENABLE "device_t dev" "int channel" "bool enable"
.Ft int
.Fn PWM_CHANNEL_IS_ENABLED "device_t dev" "int channel" "bool *enabled"
.Ft int
.Fn PWM_CHANNEL_MAX "device_t dev" "int channel" "int *nchannel"
.Sh DESCRIPTION
The PWM (Pulse-Width Modulation) interface allows the device driver to register to a global
bus so other devices in the kernel can use them in a generic way.
.Sh INTERFACE
.Bl -tag -width indent
.It Fn PWM_GET_BUS "device_t dev"
Return the bus device.
.It Fn PWM_CHANNEL_CONFIG "device_t dev" "int channel" "uint64_t period" "uint64_t duty"
Configure the period and duty (in nanoseconds) in the PWM controller for the specified channel.
Returns 0 on success or
.Er EINVAL
if the values are not supported by the controller or
.Er EBUSY
is the PWM controller is in use and does not support changing the value on the fly.
.It Fn PWM_CHANNEL_GET_CONFIG "device_t dev" "int channel" "uint64_t *period" "uint64_t *duty"
Get the current configuration of the period and duty for the specified channel.
.It Fn PWM_CHANNEL_SET_FLAGS "device_t dev" "int channel" "uint32_t flags"
Set the flags of the channel (like inverted polarity).
.It Fn PWM_CHANNEL_GET_FLAGS "device_t dev" "int channel" "uint32_t *flags"
Get the current flags for the channel.
.It Fn PWM_CHANNEL_ENABLE "device_t dev" "int channel" "bool enable"
Enable the PWM channel.
.It Fn PWM_CHANNEL_ISENABLED "device_t dev" "int channel" "bool *enable"
Test if the PWM channel is enabled.
.It Fn PWM_CHANNEL_MAX "device_t dev" "int channel" "int *nchannel"
Get the maximum number of channels supported by the controller.
.El
.Sh HISTORY
The
.Nm pwm
interface first appeared in
.Fx 13.0 .
The
.Nm pwm
interface and manual page was written by
.An Emmanuel Vadot Aq Mt manu@FreeBSD.org .