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Do some general cleanup and light wordsmithing.

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Sort methods alphabetically.  Wrap long lines.  Start sentences on a new
line.  Remove contractions (not because it's a good idea, just to silence
igor).  Add some explanation of the units for the period and duty arguments
and the convention for channel numbers.
This commit is contained in:
ian 2019-06-21 15:12:17 +00:00
parent 2a1f073196
commit 679b7ef604
1 changed files with 46 additions and 26 deletions
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72
share/man/man9/pwmbus.9
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@ -27,14 +27,14 @@
.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_COUNT ,
.Nm PWMBUS_CHANNEL_ENABLE ,
.Nm PWMBUS_CHANNEL_GET_CONFIG ,
.Nm PWMBUS_CHANNEL_GET_FLAGS ,
.Nm PWMBUS_CHANNEL_IS_ENABLED ,
.Nm PWMBUS_CHANNEL_MAX
.Nm PWMBUS_CHANNEL_SET_FLAGS ,
.Nm PWMBUS_GET_BUS
.Nd PWMBUS methods
.Sh SYNOPSIS
.Cd "device pwm"
@ -42,45 +42,65 @@
.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"
.Fn PWMBUS_CHANNEL_COUNT "device_t bus" "int channel" "int *nchannel"
.Ft int
.Fn PWMBUS_CHANNEL_ENABLE "device_t bus" "int channel" "bool enable"
.Ft int
.Fn PWMBUS_CHANNEL_GET_CONFIG "device_t bus" "int channel" "uint64_t *period" "uint64_t *duty"
.Ft int
.Fn PWMBUS_CHANNEL_GET_FLAGS "device_t bus" "int channel" "uint32_t *flags"
.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"
.Fn PWMBUS_CHANNEL_SET_FLAGS "device_t bus" "int channel" "uint32_t flags"
.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.
The PWMBUS (Pulse-Width Modulation) interface allows a device driver to
register to a global bus so other devices in the kernel can use them in a
generic way.
.Pp
For all
.Nm
methods, the
.Va period
argument is the duration in nanoseconds of one complete on-off cycle, and the
.Va duty
argument is the duration in nanoseconds of the on portion of that cycle.
.Pp
Some PWM hardware is organized as a single controller with multiple channels.
Channel numbers count up from zero.
When multiple channels are present, they sometimes share a common clock or
other resources.
In such cases, changing the period or duty cycle of any one channel may affect
other channels within the hardware which share the same resources.
Consult the documentation for the underlying PWM hardware device driver for
details on channels that share resources.
.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.
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.
if the PWMBUS controller is in use and does not support changing the value on
the fly.
.It Fn PWMBUS_CHANNEL_COUNT "device_t bus" "int *nchannel"
Get the number of channels supported by the controller.
.It Fn PWMBUS_CHANNEL_ENABLE "device_t bus" "int channel" "bool enable"
Enable the PWM channel.
.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.
does not support this, a default method returns a flags value of zero.
.It Fn PWMBUS_CHANNEL_IS_ENABLED "device_t bus" "int channel" "bool *enable"
Test whether the PWM channel is enabled.
.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 does not support this a do-nothing default method
is used.
.El
.Sh HISTORY
The