xref: /freebsd/share/man/man9/pwmbus.9 (revision 7202a380991a7dfaeff259c6d6fb4a005205e41d)

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.Dd June 21, 2019
.Dt PWMBUS 9
.Os
.Sh NAME
.Nm pwmbus ,
.Nm PWMBUS_GET_BUS ,
.Nm PWMBUS_CHANNEL_CONFIG ,
.Nm PWMBUS_CHANNEL_GET_CONFIG ,
.Nm PWMBUS_CHANNEL_SET_FLAGS ,
.Nm PWMBUS_CHANNEL_GET_FLAGS ,
.Nm PWMBUS_CHANNEL_ENABLE ,
.Nm PWMBUS_CHANNEL_IS_ENABLED ,
.Nm PWMBUS_CHANNEL_MAX
.Nd PWMBUS methods
.Sh SYNOPSIS
.Cd "device pwm"
.In "pwmbus_if.h"
.Ft int
.Fn PWMBUS_CHANNEL_CONFIG "device_t bus" "int channel" "uint64_t period" "uint64_t duty"
.Ft int
.Fn PWMBUS_CHANNEL_GET_CONFIG "device_t bus" "int channel" "uint64_t *period" "uint64_t *duty"
.Ft int
.Fn PWMBUS_CHANNEL_SET_FLAGS "device_t bus" "int channel" "uint32_t flags"
.Ft int
.Fn PWMBUS_CHANNEL_GET_FLAGS "device_t bus" "int channel" "uint32_t *flags"
.Ft int
.Fn PWMBUS_CHANNEL_ENABLE "device_t bus" "int channel" "bool enable"
.Ft int
.Fn PWMBUS_CHANNEL_IS_ENABLED "device_t bus" "int channel" "bool *enabled"
.Ft int
.Fn PWMBUS_CHANNEL_COUNT "device_t bus" "int channel" "int *nchannel"
.Sh DESCRIPTION
The PWMBUS (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 PWMBUS_CHANNEL_CONFIG "device_t bus" "int channel" "uint64_t period" "uint64_t duty"
Configure the period and duty (in nanoseconds) in the PWM controller on the bus for the specified channel.
Returns 0 on success or
.Er EINVAL
if the values are not supported by the controller or
.Er EBUSY
if the PWMBUS controller is in use and doesn't support changing the value on the fly.
.It Fn PWMBUS_CHANNEL_GET_CONFIG "device_t bus" "int channel" "uint64_t *period" "uint64_t *duty"
Get the current configuration of the period and duty for the specified channel.
.It Fn PWMBUS_CHANNEL_SET_FLAGS "device_t bus" "int channel" "uint32_t flags"
Set the flags of the channel (such as inverted polarity), if the driver or controller
doesn't support this a do-nothing default method is used.
.It Fn PWMBUS_CHANNEL_GET_FLAGS "device_t bus" "int channel" "uint32_t *flags"
Get the current flags for the channel.
If the driver or controller
doesn't support this, a default method returns a flags value of zero.
.It Fn PWMBUS_CHANNEL_ENABLE "device_t bus" "int channel" "bool enable"
Enable the PWM channel.
.It Fn PWMBUS_CHANNEL_ISENABLED "device_t bus" "int channel" "bool *enable"
Test if the PWM channel is enabled.
.It PWMBUS_CHANNEL_COUNT "device_t bus" "int channel" "int *nchannel"
Get the number of channels supported by the controller.
Channel numbers count up from zero.
.El
.Sh HISTORY
The
.Nm pwmbus
interface first appear in
.Fx 13.0 .
The
.Nm pwmbus
interface and manual page was written by
.An Emmanuel Vadot Aq Mt manu@FreeBSD.org .